by the ,posner ,memorial ,collection 7http3_/_/posner4library4cmu4edu_/,posne r_/77 ,,vvilliam ,,gilbert ,,of ,,colchester1 ,,physician ,,of ,,london4 ,,on ,,the ,,magnet1 ,,magnetick ,,bodies ,,also1 ,,and ,,on the great magnet the earth2 a new ,physiology1 demonstrated by many arguments experiments4 ,illustration ,,london 99 99 99 99 99 ,,imprinted ,,at ,,the ,,chiswick ,,press ,,anno ,,mcm4 99 99 99 99 99 ,illustration 99 99 99 99 99 ij ,illustration ,,preface ,,to ,,the ,,candid ,,reader1 ,,studious ,,of ,,the ,,magnetick ,,philosophy4 ,clearer proofs1 in the discovery of secrets1 and in the investigation of the hidden causes of things1 being afforded by trustworthy experiments and by demonstrated arguments1 than by the probable guesses and opinions of the ordinary professors of philosophy3 so1 therefore1 that the noble substance of that great magnet1 our common mother 7the earth71 hitherto quite unknown1 and the conspicuous and exalted powers of this our globe1 may be the better understood1 we have proposed to begin with the common magnetick1 stony1 and iron material1 and with magnetical bodies1 and with the nearer parts of the earth which we can reach with our hands and perceive with our senses2 then to proceed with demonstrable magnetick experiments2 and so penetrate1 for the first time1 into the innermost parts of the earth4 ,for after we had1 in order finally to learn the true substance of the globe1 seen and thoroughly examined many of those things which have been obtained from mountain heights or ocean depths1 or from the profoundest caverns and from hidden mines3 we applied much prolonged labour on investigating the magnetical forces2 so wonderful indeed are they1 compared with the forces of all other minerals1 surpassing even the virtues of all other bodies about us4 ,nor have we found this our labour idle or unfruitful2 since daily during our experimenting1 new and unexpected properties came to light2 and our ,philosophy hath grown so much from the things diligently observed1 that we have attempted to expound the interior parts of the terrene globe1 and its native substance1 upon magnetick principles2 and to reveal to men the earth 7our common mother71 and to point it out as if with the finger1 by real demonstrations and by experiments manifestly apparent to the senses4 ,and as geometry ascends from sundry very small and very easy principles to the greatest and most difficult2 by which the wit of man climbs above the firmament3 so our magnetical doctrine and science first sets forth in convenient order the things which are less obscure2 from these there come to light others that are more remarkable2 and at length in due order there are opened the concealed and most secret things of the globe of the earth1 and the causes are made known of those things which1 either through the ignorance of the ancients or the neglect of moderns1 have remained unrecognized and overlooked4 ,but why should ,i1 in so vast an ,ocean of ,books by which the minds of studious men are troubled and fatigued1 through which very foolish productions the world and unreasoning men are intoxicated1 and puffed up1 rave and create literary broils1 and while professing to be philosophers1 physicians1 mathematicians and astrologers1 neglect and despise men of learning3 why should ,i1 ,i say1 add aught further to this so-perturbed republick of letters1 and expose this noble philosophy1 which seems new and incredible by reason of so many things hitherto unrevealed1 to be damned and torn to pieces by the maledictions of those who are either already sworn to the opinions of other men1 or are foolish corruptors of good arts1 learned idiots1 grammatists1 sophists1 wranglers1 and perverse little folk8 ,but to you alone1 true philosophizers1 honest men1 who seek knowledge not from books only but from things themselves1 have ,i addressed these magnetical principles in this new sort of ,philosophizing4 ,but if any see not fit to assent to these self-same opinions and paradoxes1 let them nevertheless mark the great array of experiments and discoveries 7by which notably every philosophy flourisheth71 which have been wrought out and demonstrated by us with many pains and vigils and expenses4 ,in these rejoice1 and employ them to better uses1 if ye shall be able4 ,i know how arduous it is to give freshness to old things1 lustre to the antiquated1 light to the dark1 grace to the despised1 credibility to the doubtful2 so much the more by far is it difficult to win and establish some authority for things new and unheard-of1 in the face of all the opinions of all men4 ,nor for that do we care1 since philosophizing1 as we deemed1 is for the few4 ,to our own discoveries and experiments we have affixed asterisks1 larger and smaller1 according to the importance and subtlety of the matter4 ,whoso desireth to make trial of the same experiments1 let him handle the substances1 not negligently and carelessly1 but prudently1 deftly1 and in the proper way2 nor let him 7when a thing doth not succeed7 ignorantly denounce our discoveries3 for nothing hath been set down in these books which hath not been explored and many times performed and repeated amongst us4 ,many things in our reasonings and hypotheses will1 perchance1 at first sight1 seem rather hard1 when they are foreign to the iij commonly received opinion2 yet ,i doubt not but that hereafter they will yet obtain authority from the demonstrations themselves4 ,wherefore in magnetical science1 they who have made most progress1 trust most in and profit most by the hypotheses2 nor will anything readily become certain to any one in a magnetical philosophy in which all or at least most points are not ascertained4 ,this nature-knowledge is almost entirely new and unheard-of1 save what few matters a very few writers have handed down concerning certain common magnetical powers4 ,wherefore we but seldom quote antient ,greek authors in our support1 because neither by using greek arguments nor greek words can the truth be demonstrated or elucidated either more precisely or more significantly4 ,for our doctrine magnetical is at variance with most of their principles and dogmas4 ,nor have we brought to this work any pretence of eloquence or adornments of words2 but this only have we done1 that things difficult and unknown might be so handled by us1 in such a form of speech1 and in such words as are needed to be clearly understood3 ,sometimes therefore we use new and unusual words1 not that by means of foolish veils of vocabularies we should cover over the facts with shades and mists 7as ,alchemists are wont to do7 but that hidden things which have no name1 never having been hitherto perceived1 may be plainly and correctly enunciated4 ,after describing our magnetical experiments and our information of the homogenick parts of the earth1 we proceed to the general nature of the whole globe2 wherein it is permitted us to philosophize freely and with the same liberty which the ,egyptians1 ,greeks1 and ,latins formerly used in publishing their dogmas3 whereof very many errors have been handed down in turn to later authors3 and in which smatterers still persist1 and wander as though in perpetual darkness4 ,to those early forefathers of philosophy1 ,aristotle1 ,theophrastus1 ,ptolemy1 ,hippocrates1 and ,galen1 let due honour be ever paid3 for by them wisdom hath been diffused to posterity2 but our age hath detected and brought to light very many facts which they1 were they now alive1 would gladly have accepted4 ,wherefore we also have not hesitated to expound in demonstrable hypotheses those things which we have discovered by long experience4 ,farewell4 99 99 99 99 99 ,,to ,,the ,,most ,,eminent ,,and ,,learned ,,man ,,dr4 ,,william ,,gilbert1 a distinguished ,doctor of ,medicine amongst the ,londoners1 and ,father of ,magnetick ,philosophy1 an ,encomiastic ,preface of ,edward ,wright on the subject of these books ,magnetical4 ,should there by chance be any one1 most eminent ,sir1 who reckons as of small account these magnetical books and labours of yours1 and thinks these studies of yours of too little moment1 and by no means worthy enough of the attention of an eminent man devoted to the weightier study of ,medicine3 truly he must deservedly be judged to be in no common degree void of understanding4 ,for that the use of the magnet is very important and wholly admirable is better known for the most part to men of even the lowest class than to need from me at this time any long address or commendation4 ,nor truly in my judgment could you have chosen any topick either more noble or more useful to the human race1 upon which to exercise the strength of your philosophic intellect2 since indeed it has been brought about by the divine agency of this stone1 that continents of such vast circuit1 such an infinite number of lands1 islands1 peoples1 and tribes1 which have remained unknown for so many ages1 have now only a short time ago1 almost within our own memory1 been quite easily discovered and quite frequently explored1 and that the circuit of the whole terrestrial globe also has been more than once circumnavigated by our own countrymen1 ,drake and ,cavendish2 a fact which ,i wish to mention to the lasting memory of these men4 ,for by the pointing of the iron touched by a loadstone1 the points of ,south1 ,north1 ,east1 and ,west1 and the other quarters of the world are made known to navigators even under an overcast sky and in the darkest night2 so that thus they always very easily understand to which point of the world they ought to direct their ship's course2 which before the discovery of this wonderful virtue of the magnetick ,greek3 boreodeixis was clearly impossible4 ,hence in old times 7as is established in histories71 an incredible anxiety and immense danger was continually threatening sailors2 for at the coming on of a tempest and the obscuring of the view of sun and stars1 they were left entirely in ignorance whither they were making2 nor could they find out this by any reasoning or skill4 ,with what joy then may we suppose them to have been filled1 to what feelings of delight must all shipmasters have given utterance1 when that index magnetical first offered itself to them as a most sure guide1 and as it were a ,mercury1 for their journey8 ,but neither was this sufficient for this magnetical ,mercury2 to indicate1 namely1 the right way1 and to point1 as it were1 a finger in the direction toward which the course must be iiij directed2 it began also long ago to show distinctly the distance of the place toward which it points4 ,for since the index magnetical does not always in every place look toward the same point of the ,north1 but deviates from it often1 either toward the ,east or toward the ,west1 yet always has the same deviation in the same place1 whatever the place is1 and steadily preserves it2 it has come about that from that deviation1 which they call variation1 carefully noticed and observed in any maritime places1 the same places could afterwards also be found by navigators from the drawing near and approach to the same variation as that of these same places1 taken in conjunction with the observation of the latitude4 ,thus the ,portuguese in their voyages to the ,east ,indies had the most certain indications of their approach to the ,cape of ,good ,hope2 as appears from the narrations of ,hugo van ,lynschoten and of the very learned ,richard ,hakluyt1 our countryman4 ,hence also the experienced skippers of our own country1 not a few of them1 in making the voyage from the ,gulf of ,mexico to the islands of the ,azores1 recognized that they had come as near as possible to these same islands2 although from their sea-charts they seemed to be about six hundred ,british miles from them4 ,and so1 by the help of this magnetick index1 it would seem as though that geographical problem of finding the longitude1 which for so many centuries has exercised the intellects of the most learned ,mathematicians1 were going to be in some way satisfied2 because if the variation for any maritime place whatever were known1 the same place could very readily be found afterward1 as often as was required1 from the same variation1 the latitude of the same place being not unknown4 ,it seems1 however1 that there has been some inconvenience and hindrance connected with the observation of this variation2 because it cannot be observed excepting when the sun or the stars are shining4 ,accordingly this magnetick ,mercury of the sea goes on still further to bless all shipmasters1 being much to be preferred to ,neptune himself1 and to all the sea-gods and goddesses2 not only does it show the direction in a dark night and in thick weather1 but it also seems to exhibit the most certain indications of the latitude4 ,for an iron index1 suspended on its axis 7like a pair of scales71 with the most delicate workmanship so as to balance in quilibrio1 and then touched and excited by a loadstone1 dips to some fixed and definite point beneath the horizon 7in our latitude in ,london1 for example1 to about the seventy-second degree71 at which it at length comes to rest4 ,but under the quator itself1 from that admirable agreement and congruency which1 in almost all and singular magnetical experiments1 exists between the earth itself and a terrella 7that is1 a globular loadstone71 it seems exceedingly likely 7to say the very least71 and indeed more than probable1 that the same index 7again stroked with a loadstone7 will remain in quilibrio in an horizontal position4 ,whence it is evident that this also is very probable1 that in an exceedingly small progress from the ,south toward the ,north 7or contrariwise7 there will be at least a sufficiently perceptible change in that declination2 so that from that declination in any place being once carefully observed along with the latitude1 the same place and the same latitude may be very easily recognized afterward1 even in the darkest night and in the thickest mist by a declination instrument4 ,wherefore to bring our oration at length back to you1 most eminent and learned ,dr4 ,gilbert 7whom ,i gladly recognize as my teacher in this magnetick philosophy71 if these books of yours on the ,magnet had contained nothing else1 excepting only this finding of latitude from magnetick declination1 by you now first brought to light1 our shipmasters1 ,britains1 ,french1 ,belgians1 and ,danes1 trying to enter the ,british ,channel or the ,straits of ,gibraltar from the ,atlantick ,ocean in dark weather1 would still most deservedly judge them to be valued at no small sum of gold4 ,but that discovery of yours about the whole globe of the earth being magnetical1 although perchance it will seem to many most paradoxical1 producing even a feeling of astonishment1 has yet been so firmly defended by you at all points and confirmed by so many experiments so apposite and appropriate to the matter in hand1 in ,bk4 #b1 chap4 #cd2 ,bk4 #c1 chap4 #d and #ab2 and in almost the whole of the fifth book1 that no room is left for doubt or contradiction4 ,i come therefore to the cause of the magnetick variation1 which hitherto has distracted the minds of all the learned2 for which no mortal has ever adduced a more probable reason than that which has now been set forth by you for the first time in these books of yours on the ,magnet4 ,the ,greek3 orthoboreodeixis of the index magnetical in the middle of the ocean1 and in the middle of continents 7or at least in the middle of their stronger and more lofty parts71 its inclining near the shore toward those same parts1 even by sea and by land1 agreeing with the experiments ,bk4 #d1 chap4 #b1 on an actual terrella 7made after the likeness of the terrestrial globe1 uneven1 and rising up in certain parts1 either weak or wanting in firmness1 or imperfect in some other way71--this inclination having been proved1 very certainly demonstrates the probability that that variation is nought else than a certain deviation of the magnetick needle toward those parts of the earth that are more vigorous and more prominent4 ,whence the reason is readily established of that irregularity which is often perceived in the magnetick variations1 arising from the inquality and irregularity of those eminences and of the terrestrial forces4 ,nor of a surety have ,i any doubt1 that all those even who have either imagined or admitted points attractive or points respective in the sky or the earth1 and those who have imagined magnetick mountains1 or rocks1 or poles1 will immediately begin to waver as soon as they have perused these books of yours on the ,magnet1 and willingly will march with your opinion4 ,finally1 as to the views which you discuss in regard to the circular motion of the earth and of the terrestrial poles1 although to some perhaps they will seem most supposititious1 yet ,i do not see why they should not gain some favour1 even among the very men who do not recognize a sphrical motion of the earth2 since not even they can easily clear themselves from many difficulties1 which necessarily follow from the daily motion of the v whole sky4 ,for in the first place it is against reason that that should be effected by many causes1 which can be effected by fewer2 and it is against reason that the whole sky and all the sphres 7if there be any7 of the stars1 both of the planets and the fixed stars1 should be turned round for the sake of a daily motion which can be explained by the mere daily rotation of the earth4 ,then whether will it seem more probable1 that the quator of the terrestrial globe in a single second 7that is1 in about the time in which any one walking quickly will be able to advance only a single pace7 can accomplish a quarter of a ,british mile 7of which sixty equal one degree of a great circle on the earth71 or that the quator of the primum mobile in the same time should traverse five thousand miles with celerity ineffable2 and in the twinkling of an eye should fly through about five hundred ,british miles1 swifter than the wings of lightning1 if indeed they maintain the truth who especially assail the motion of the earth74 ,finally1 will it be more likely to allow some motion to this very tiny terrestrial globe2 or to build up with mad endeavour above the eighth of the fixed sphres those three huge sphres1 the ninth 7,i mean71 the tenth1 and the eleventh1 marked by not a single star1 especially since it is plain from these books on the magnet1 from a comparison of the earth and the terrella1 that a circular motion is not so alien to the nature of the earth as is commonly supposed4 ,nor do those things which are adduced from the sacred ,scriptures seem to be specially adverse to the doctrine of the mobility of the earth2 nor does it seem to have been the intention of ,moses or of the ,prophets to promulgate any mathematical or physical niceties1 but to adapt themselves to the understanding of the common people and their manner of speech1 just as nurses are accustomed to adapt themselves to infants1 and not to go into every unnecessary detail4 ,thus in ,gen4 i4 v4 #af1 and ,psal4 #acf1 the moon is called a great light1 because it appears so to us1 though it it is agreed nevertheless by those skilled in astronomy that many of the stars1 both of the fixed and wandering stars1 are much greater4 ,therefore neither do ,i think that any solid conclusion can be drawn against the earth's mobility from ,psal4 #ajd1 v4 #e2 although ,god is said to have laid the foundations of the earth that it should not be removed for ever2 for the earth will be able to remain evermore in its own and self-same place1 so as not to be moved by any wandering motion1 nor carried away from its seat 7wherein it was first placed by the ,divine artificer74 ,we1 therefore1 with devout mind acknowledging and adoring the inscrutable wisdom of the triune ,divinity 7having more diligently investigated and observed his admirable work in the magnetical motions71 induced by philosophical experiments and reasonings not a few1 do deem it to be probable enough that the earth1 though resting on its centre as on an immovable base and foundation1 nevertheless is borne around circularly4 ,but passing over these matters 7concerning which ,i believe no one has ever demonstrated anything with greater certainty71 without any doubt those matters which you have discussed concerning the causes of the variation and of the magnetick dip below the horizon1 not to mention many other matters1 which it would take too long to speak of here1 will gain very great favour amongst all intelligent men1 and especially 7to speak after the manner of the ,chemists7 amongst the sons of the magnetick doctrine4 ,nor indeed do ,i doubt that when you have published these books of yours on the ,magnet1 you will excite all the diligent and industrious shipmasters to take no less care in observing the magnetick declination beneath the horizon than the variation4 ,since 7if not certain7 it is at least probable1 that the latitude itself1 or rather the effect of the latitude1 can be found 7even in very dark weather7 much more accurately from that declination alone1 than can either the longitude or the effect of the longitude from the variation1 though the sun itself is shining brightly or all the stars are visible1 with the most skilful employment likewise of all the most exact instruments4 ,nor is there any doubt but that those most learned men1 ,peter ,plancius 7not more deeply versed in ,geography than in observations magnetical71 and ,simon ,stevinus1 the most distinguished mathematician1 will rejoice in no moderate degree1 when they first see these magnetical books of yours1 and observe their ,greek3 limeneuretik1 or ,haven-finding ,art1 enlarged and enriched by so great and unexpected an addition2 and without doubt they will urge all their own shipmasters 7as far as they can7 to observe also everywhere the magnetick declination below the horizon no less than the variation4 ,may your ,magnetical ,philosophy1 therefore1 most learned ,dr4 ,gilbert1 come forth into the light under the best auspices1 after being kept back not till the ninth year only 7as ,horace prescribes71 but already unto almost a second nine1 a philosophy rescued at last by so many toils1 studyings1 watchings1 with so much ingenuity and at no moderate expense maintained continuously through so many years1 out of darkness and dense mist of the idle and feeble philosophizers1 by means of endless experiments skilfully applied to it2 yet without neglecting anything which has been handed down in the writings of any of the ancients or of the moderns1 all which you did diligently peruse and perpend4 ,do not fear the boldness or the prejudice of any supercilious and base philosophaster1 who by either enviously calumniating or stealthily arrogating to himself the investigations of others seeks to snatch a most empty glory4 ,verily ,envy detracts from great ,homer's genius2 but ,whoever thou art1 ,zoilus1 thou hast thy name from him4 ,may your new physiology of the ,magnet1 ,i say 7kept back for so many years71 come forth now at length into the view of all1 and your ,philosophy1 never to be enough admired1 concerning the great ,magnet 7that is1 the earth72 for1 believe me 7,if there is any truth in the forebodings of seers71 these books of yours on the ,magnet will avail more for perpetuating the memory of your name than the monument of any great ,magnate placed upon your tomb4 vj 99 99 99 99 99 ,interpretation of certain words4#a ,terrella1 a globular loadstone4 ,verticity1 polar vigour1 not ,greek3 peridinsis but ,greek3 peridineisios dunamis3 not a vertex or ,greek3 polos but a turning tendency4 ,electricks1 things which attract in the same manner as amber4 ,excited ,magnetick1 that which has acquired powers from the loadstone4 ,magnetick ,versorium1 a piece of iron upon a pin1 excited by a loadstone4 ,non-magnetick ,versorium1 a versorium of any metal1 serving for electrical experiments4 ,capped loadstone1 which is furnished with an iron cap1 or snout4 ,meridionally1 that is1 along the projection of the meridian4 ,paralleletically1 that is1 along the projection of a parallel4 ,cusp1 tip of a versorium excited by the loadstone4 ,cross1 sometimes used of the end that has not been touched and excited by a loadstone1 though in many instruments both ends are excited by the appropriate termini of the stone4 ,cork1 that is1 bark of the cork-oak4 ,radius of the ,orbe of the ,loadstone1 is a straight line drawn from the summit of the orbe of the loadstone1 by the shortest way1 to the surface of the body1 which1 continued1 will pass through the centre of the loadstone4 ,orbe of ,virtue1 is all that space through which the ,virtue of any loadstone extends4 ,orbe of ,coition1 is all that space through which the smallest magnetick is moved by the loadstone4 ,proof1 for a demonstration shown by means of a body4 ,magnetick ,coition3 since in magnetick bodies1 motion does not occur by an attractive faculty1 but by a concourse or concordance of both1 not as if there were an ,greek3 helktik dunamis of one only1 but a ,greek3 sundrom of both2 there is always a coition of the vigour3 and even of the body if its mass should not obstruct4 ,declinatorium1 a piece of ,iron capable of turning about an axis1 excited by a loadstone1 in a declination instrument4 99 99 99 99 99 ,,index ,,of ,,chapters4 ,book #a4 ,chap4 #a4 ,ancient and modern writings on the ,loadstone1 with certain matters of mention only1 various opinions1 vanities4 ,chap4 #b4 ,magnet ,stone1 of what kind it is1 and its discovery4 ,chap4 #c4 ,the loadstone has parts distinct in their natural power1 poles conspicuous for their property4 ,chap4 #d4 ,which pole of the stone is the ,boreal3 and how it is distinguished from the austral4 ,chap4 #e4 ,loadstone seems to attract loadstone when in natural position3 but repels it when in a contrary one1 and brings it back to order4 ,chap4 #f4 ,loadstone attracts the ore of iron1 as well as iron proper1 smelted wrought4 ,chap4 #g4 ,what iron is1 and of what substance1 and its uses4 ,chap4 #h4 ,in what countries and districts iron originates4 ,chap4 #i4 ,iron ore attracts iron ore4 ,chap4 #aj4 ,iron ore has poles1 and acquires them1 and settles itself toward the poles of the universe4 ,chap4 #aa4 ,wrought iron1 not excited by a loadstone1 draws iron4 ,chap4 #ab4 ,a long piece of ,iron 7even though not excited by a loadstone7 settles itself toward ,north ,south4 ,chap4 #ac4 ,wrought iron has in itself certain parts ,boreal ,austral3 a magnetick vigour1 verticity1 and determinate vertices or poles4 ,chap4 #ad4 ,concerning other powers of loadstone1 its medicinal properties4 ,chap4 #ae4 ,the medicinal virtue of iron4 ,chap4 #af4 ,that loadstone iron ore are the same1 but iron an extract from both1 as other metals are from their own ores2 that all magnetick virtues1 though weaker1 exist in the ore itself in smelted iron4 ,chap4 #ag4 ,that the globe of the earth is magnetick1 a magnet2 how in our hands the magnet stone has all the primary forces of the earth1 while the earth by the same powers remains constant in a fixed direction in the universe4 ,book #b4 ,chap4 #a4 ,on ,magnetick ,motions4 ,chap4 #b4 ,on the ,magnetick ,coition1 and first on the attraction of ,amber1 or more truly1 on the attaching of bodies to ,amber4 ,chap4 #c4 ,opinions of others on ,magnetick ,coition1 which they call ,attraction4 ,chap4 #d4 ,on ,magnetick ,force ,form1 what it is2 and on the cause of the ,coition4 ,chap4 #e4 ,how the ,power dwells in the ,loadstone4 ,chap4 #f4 ,how magnetick pieces of ,iron and smaller loadstones conform themselves to a terrella to the earth itself1 and by them are disposed4 ,chap4 #g4 ,on the ,potency of the ,magnetick ,virtue1 and on its nature capable of spreading out into an orbe4 ,chap4 #h4 ,on the geography of the ,earth1 and of the ,terrella4 ,chap4 #i4 ,on the quinoctial ,circle of the ,earth and of a ,terrella4 ,chap4 #aj4 ,magnetick ,meridians of the ,earth4 ,chap4 #aa4 ,parallels4 vij ,chap4 #ab4 ,the ,magnetick ,horizon4 ,chap4 #ac4 ,on the ,axis and ,magnetick ,poles4 ,chap4 #ad4 ,why at the ,pole itself the ,coition is stronger than in the other parts intermediate between the quator and the pole2 and on the proportion of forces of the coition in various parts of the earth and of the terrella4 ,chap4 #ae4 ,the ,magnetick ,virtue which is conceived in ,iron is more apparent in an iron rod than in a piece of ,iron that is round1 square1 or of other figure4 ,chap4 #af4 ,showing that ,movements take place by the ,magnetical ,vigour though solid bodies lie between2 and on the interposition of iron plates4 ,chap4 #ag4 ,on the ,iron ,cap of a ,loadstone1 with which it is armed at the pole 7for the sake of the virtue71 and on the efficacy of the same4 ,chap4 #ah4 ,an armed ,loadstone does not indue an excited piece of ,iron with greater vigour than an unarmed4 ,chap4 #ai4 ,union with an armed ,loadstone is stronger2 hence greater weights are raised2 but the coition is not stronger1 but generally weaker4 ,chap4 #bj4 ,an armed ,loadstone raises an armed ,loadstone1 which also attracts a third2 which likewise happens1 though the virtue in the first be somewhat small4 ,chap4 #ba4 ,if ,paper or any other ,medium be interposed1 an armed loadstone raises no more than an unarmed one4 ,chap4 #bb4 ,that an armed ,loadstone draws ,iron no more than an unarmed one3 and that an armed one is more strongly united to iron is shown by means of an armed loadstone and a polished ,cylinder of iron4 ,chap4 #bc4 ,the ,magnetick ,force causes motion toward unity1 and binds firmly together bodies which are united4 ,chap4 #bd4 ,a piece of ,iron placed within the ,orbe of a ,loadstone hangs suspended in the air1 if on account of some impediment it cannot approach it4 ,chap4 #be4 ,exaltation of the power of the magnet4 ,chap4 #bf4 ,why there should appear to be a greater love between iron loadstone1 than between loadstone loadstone1 or between iron iron1 when close to the loadstone1 within its orbe of virtue4 ,chap4 #bg4 ,the ,centre of the ,magnetick ,virtues in the earth is the centre of the earth2 and in a terrella is the centre of the stone4 ,chap4 #bh4 ,a ,loadstone attracts magneticks not only to a fixed point or pole1 but to every part of a terrella save the quinoctial zone4 ,chap4 #bi4 ,on ,variety of ,strength due to ,quantity or ,mass4 ,chap4 #cj4 ,the ,shape and ,mass of the ,iron are of most importance in cases of coition4 ,chap4 #ca4 ,on long and round stones4 ,chap4 #cb4 ,certain ,problems and ,magnetick ,experiments about the ,coition1 and ,separation1 and regular ,motion of ,bodies magnetical4 ,chap4 #cc4 ,on the ,varying ,ratio of ,strength1 and of the ,motion of coition1 within the orbe of virtue4 ,chap4 #cd4 ,why a ,loadstone should be stronger in its poles in a different ratio2 as well in the ,northern regions as in the ,southern4 ,chap4 #ce4 ,on a ,perpetual ,motion ,machine1 mentioned by authors1 by means of the attraction of a loadstone4 ,chap4 #cf4 ,how a more robust ,loadstone may be recognized4 ,chap4 #cg4 ,use of a ,loadstone as it affects iron4 ,chap4 #ch4 ,on ,cases of ,attraction in other ,bodies4 ,chap4 #ci4 ,on ,bodies which mutually repel one another4 ,book #c4 ,chap4 #a4 ,on ,direction4 ,chap4 #b4 ,the ,directive or ,versorial ,virtue 7which we call verticity73 what it is1 how it exists in the loadstone2 and in what way it is acquired when innate4 ,chap4 #c4 ,how ,iron acquires ,verticity through a loadstone1 and how that verticity is lost and changed4 ,chap4 #d4 ,why ,iron touched by a ,loadstone acquires an opposite verticity1 and why iron touched by the true ,northern side of a stone turns to the ,north of the earth1 by the true ,southern side to the ,south2 and does not turn to the ,south when rubbed by the ,northern point of the stone1 and when by the ,southern to the ,north1 as all who have written on the ,loadstone have falsely supposed4 ,chap4 #e4 ,on the ,touching of pieces of ,iron of divers shapes4 ,chap4 #f4 ,what seems an ,opposing ,motion in ,magneticks is a proper motion toward unity4 ,chap4 #g4 ,a determined ,verticity and a disponent ,faculty are what arrange magneticks1 not a force1 attracting them or pulling them together1 nor merely a strongish coition or unition4 ,chap4 #h4 ,of ,discords between pieces of ,iron upon the same pole of a ,loadstone1 and how they can agree and stand joined together4 ,chap4 #i4 ,figures illustrating direction and showing varieties of rotations4 ,chap4 #aj4 ,on ,mutation of ,verticity and of ,magnetick ,properties1 or on alteration in the power excited by a loadstone4 ,chap4 #aa4 ,on the ,rubbing of a piece of ,iron on a ,loadstone in places midway between the poles1 and upon the quinoctial of a terrella4 ,chap4 #ab4 ,in what way ,verticity exists in any ,iron that has been smelted though not excited by a loadstone4 ,chap4 #ac4 ,why no other ,body1 excepting a magnetick1 is imbued with verticity by being rubbed on a loadstone1 and why no body is able to instil and excite that virtue1 unless it be a magnetick4 ,chap4 #ad4 ,the ,placing of a ,loadstone above or below a magnetick body suspended in quilibrio changes neither the power nor the verticity of the magnetick body4 ,chap4 #ae4 ,the ,poles1 quator1 ,centre in an entire ,loadstone remain and continue steady2 by diminution and separation of some part they vary and acquire other positions4 ,chap4 #af4 ,if the ,southern ,portion of a ,stone be lessened1 something is also taken away from the power of the ,northern ,portion4 ,chap4 #ag4 ,on the ,use and ,excellence of ,versoria3 and how iron versoria used as pointers in sun-dials1 and the fine needles of the mariners' compass1 are to be rubbed1 that they may acquire stronger verticity4 viij ,book #d4 ,chap4 #a4 ,on ,variation4 ,chap4 #b4 ,that the variation is caused by the inquality of the projecting parts of the earth4 ,chap4 #c4 ,the variation in any one place is constant4 ,chap4 #d4 ,the arc of variation is not changed equally in proportion to the distance of places4 ,chap4 #e4 ,an island in ,ocean does not change the variation1 as neither do mines of loadstone4 ,chap4 #f4 ,the variation and direction arise from the disponent power of the earth1 and from the natural magnetick tendency to rotation1 not from attraction1 or from coition1 or from other occult cause4 ,chap4 #g4 ,why the variation from that lateral cause is not greater than has hitherto been observed1 having been rarely seen to reach two points of the mariners' compass1 except near the pole4 ,chap4 #h4 ,on the construction of the common mariners' compass1 and on the diversity of the compasses of different nations4 ,chap4 #i4 ,whether the terrestrial longitude can be found from the variation4 ,chap4 #aj4 ,why in various places near the pole the variations are much more ample than in a lower latitude4 ,chap4 #aa4 ,cardan's error when he seeks the distance of the centre of the earth from the centre of the cosmos by the motion of the stone of ,hercules2 in his book #e1 ,on ,proportions4 ,chap4 #ab4 ,on the finding of the amount of variation3 how great is the arc of the ,horizon from its arctick to its antarctick intersection of the meridian1 to the point respective of the magnetick needle4 ,chap4 #ac4 ,the observations of variation by seamen vary1 for the most part1 and are uncertain3 partly from error and inexperience1 and the imperfections of the instruments3 and partly from the sea being seldom so calm that the shadows or lights can remain quite steady on the instruments4 ,chap4 #ad4 ,on the variation under the quinoctial line1 and near it4 ,chap4 #ae4 ,the variation of the magnetick needle in the great thiopick and ,american sea1 beyond the quator4 ,chap4 #af4 ,on the variation in ,nova ,zembla4 ,chap4 #ag4 ,variation in the ,pacifick ,ocean4 ,chap4 #ah4 ,on the variation in the ,mediterranean ,sea4 ,chap4 #ai4 ,the variation in the interior of large ,continents4 ,chap4 #bj4 ,variation in the ,eastern ,ocean4 ,chap4 #ba4 ,how the deviation of the versorium is augmented and diminished by reason of the distance of places4 ,book #e4 ,chap4 #a4 ,on ,declination4 ,chap4 #b4 ,diagram of declinations of the magnetick needle1 when excited1 in the various positions of the sphere1 and horizons of the earth1 in which there is no variation of the declination4 ,chap4 #c4 ,an indicatory instrument1 showing by the virtue of a stone the degrees of declination from the horizon of each several latitude4 ,chap4 #d4 ,concerning the length of a versorium convenient for declination on a terrella4 ,chap4 #e4 ,that declination does not arise from the attraction of the loadstone1 but from a disposing and rotating influence4 ,chap4 #f4 ,on the proportion of declination to latitude1 and the cause of it4 ,chap4 #g4 ,explanation of the diagram of the rotation of a magnetick needle4 ,chap4 #h4 ,diagram of the rotation of a magnetick needle1 indicating magnetical declination in all latitudes1 and from the rotation and declination1 the latitude itself4 ,chap4 #i4 ,demonstration of direction1 or of variation from the true direction1 at the same time with declination1 by means of only a single motion in water1 due to the disposing and rotating virtue4 ,chap4 #aj4 ,on the variation of the declination4 ,chap4 #aa4 ,on the essential magnetick activity sphrically effused4 ,chap4 #ab4 ,magnetick force is animate1 or imitates life2 and in many things surpasses human life1 while this is bound up in the organick body4 ,book #f4 ,chap4 #a4 ,on the globe of the earth1 the great magnet4 ,chap4 #b4 ,the ,magnetick axis of the ,earth persists invariable4 ,chap4 #c4 ,on the magnetick diurnal revolution of the ,earth's globe1 as a probable assertion against the time-honoured opinion of a ,primum ,mobile4 ,chap4 #d4 ,that the ,earth moves circularly4 ,chap4 #e4 ,arguments of those denying the ,earth's motion1 and their confutation4 ,chap4 #f4 ,on the cause of the definite time of an entire rotation of the ,earth4 ,chap4 #g4 ,on the primary magnetick nature of the ,earth1 whereby its poles are parted from the poles of the ,ecliptick4 ,chap4 #h4 ,on the ,prcession of the quinoxes1 from the magnetick motion of the poles of the ,earth1 in the ,arctick ,antarctick circle of the ,zodiack4 ,chap4 #i4 ,on the anomaly of the ,prcession of the quinoxes1 of the obliquity of the ,zodiack4 ,illustration 99 99 99 99 99 #a ,illustration ,,william ,,gilbert ,,on ,,the ,,loadstone1 ,,bk4 ,i4 ,,chap4 ,i4 ,,ancient ,,and ,,modern ,,writings on the ,loadstone1 with certain matters of mention only1 various opinions1 vanities4 ,at an early period1 while philosophy lay as yet rude and uncultivated in the mists of error and ignorance1 few were the virtues and properties of things that were known and clearly perceived3 there was a bristling forest of plants and herbs1 things metallick were hidden1 and the knowledge of stones was unheeded4 ,but no sooner had the talents and toils of many brought to light certain commodities necessary for the use and safety of men1 and handed them on to others 7while at the same time reason and experience had added a larger hope71 than a thorough examination began to be made of forests and fields1 hills and heights2 of seas too1 and the depths of the waters1 of the bowels of the earth's body2 and all things began to be looked into4 ,and at length by good luck the magnet-stone was discovered in iron lodes1 probably by smelters of iron or diggers of metals4 ,this1 on being handled by metal folk1 quickly displayed that powerful and strong attraction for iron1 a virtue not latent and obscure1 but easily proved by all1 and highly praised and commended4 ,and in after time when it had emerged1 as it were out of darkness and deep dungeons1 and had become dignified of men on account of its strong and amazing attraction for iron1 many philosophers as well as physicians of ancient days discoursed of it1 in short celebrated1 as it were1 its memory only2 as for instance ,plato in the ,io#b1 ,aristotle in the ,de ,anima#c1 in ,book ,i4 only1 ,theophrastus the ,lesbian1 ,dioscorides1 ,c4 ,plinius ,secundus1 and ,julius ,solinus#d4 ,as handed down by them the loadstone merely attracted iron1 the rest of its virtues were all undiscovered4 ,but that the story of the #b loadstone might not appear too bare and too brief1 to this singular and sole known quality there were added certain figments and falsehoods1 which in the earliest times1 no less than nowadays1 used to be put forth by raw smatterers and copyists to be swallowed of men4 ,as for instance1 that if a loadstone be anointed with garlick1 or if a diamond be near1 it does not attract iron#e4 ,tales of this sort occur in ,pliny1 and in ,ptolemy's ,quadripartitum2 and the errors have been sedulously propagated1 and have gained ground 7like ill weeds that grow apace7 coming down even to our own day1 through the writings of a host of men1 who1 to fill put their volumes to a proper bulk1 write and copy out pages upon pages on this1 that1 and the other subject1 of which they knew almost nothing for certain of their own experience4 ,such fables of the loadstone even ,georgius ,agricola himself1 most distinguished in letters1 relying on the writings of others1 has embodied as actual history in his books ,de ,natura ,fossilium4 ,galen noted its medicinal power in the ninth book of his ,de ,simplicium ,medicamentorum ,facultatibus1 and its natural property of attracting iron in the first book of ,de ,naturalibus ,facultatibus2 but he failed to recognize the cause1 as ,dioscorides before him1 nor made further inquiry4 ,but his commentator ,matthiolus repeats the story of the garlick and the diamond1 and moreover introduces ,mahomet's shrine vaulted with loadstones#f1 and writes that1 by the exhibition of this 7with the iron coffin hanging in the air7 as a divine miracle1 the public were imposed upon4 ,but this is known by travellers to be false4 ,yet ,pliny relates that ,chinocrates the architect had commenced to roof over the temple of ,arsinoe at ,alexandria with magnet-stone#g1 that her statue of iron placed therein might appear to hang in space4 ,his own death1 however1 intervened1 and also that of ,ptolemy1 who had ordered it to be made in honour of his sister4 ,very little was written by the ancients as to the causes of attraction of iron2 by ,lucretius and others there are some short notices2 others only make slight and meagre mention of the attraction of iron3 all of these are censured by ,cardan for being so careless and negligent in a matter of such importance and in so wide a field of philosophizing2 and for not supplying an ampler notion of it and a more perfect philosophy3 and yet1 beyond certain received opinions and ideas borrowed from others and ill-founded conjectures1 he has not himself any more than they delivered to posterity in all his bulky works any contribution to the subject worthy of a philosopher4 ,of modern writers some set forth its virtue in medicine only1 as #h;,antonius ,musa ,brasavolus1 ,baptista ,montanus1 ,amatus ,lusitanus1 as before them ,oribasius in his thirteenth chapter ,de ,facultate ,metallicorum1 ,aetius ,amidenus1 ,avicenna1 ,serapio ,mauritanus1 ,hali ,abbas1 ,santes de ,ardoynis1 ,petrus ,apponensis1 ,marcellus#i1 ,arnaldus4 ,bare mention is made of certain points relating to the loadstone in very few words by ,marbodeus ,callus1 ,albertus1 #c ,matthus ,silvaticus1 ,hermolaus ,barbarus1 ,camillus ,leonhardus1 ,cornelius ,agrippa1 ,fallopius1 ,johannes ,langius1 ,cardinal ,cusan1 ,hannibal ,rosetius ,calaber2 by all of whom the subject is treated very negligently1 while they merely repeat other people's fictions and ravings4 ,matthiolus compares the alluring powers of the loadstone which pass through iron materials1 with the mischief of the torpedo1 whose venom passes through bodies and spreads imperceptibly2 ,guilielmus ,pateanus in his ,ratio ,purgantium ,medicamentorum discusses the loadstone briefly and learnedly4 ,thomas ,erastus#aj1 knowing little of magnetical nature1 finds in the loadstone weak arguments against ,paracelsus2 ,georgius ,agricola1 like ,encelius#aa and other metallurgists1 merely states the facts2 ,alexander ,aphrodiseus in his ,problemata considers the question of the loadstone inexplicable2 ,lucretius ,carus1 the poet of the ,epicurean school1 considers that an attraction is brought about in this way3 that as from all things there is an efflux of very minute bodies1 so from the iron atoms flow into the space emptied by the elements of the loadstone1 between the iron and the loadstone1 and that as soon as they have begun to stream towards the loadstone1 the iron follows1 its corpuscles being entangled4 ,to much the same effect ,johannes ,costus adduces a passage from ,plutarch2 ,thomas ,aquinas#ab1 writing briefly on the loadstone in ,chapter ,,vii4 of his ,physica1 touches not amiss on its nature1 and with his divine and clear intellect would have published much more1 had he been conversant with magnetick experiments4 ,plato thinks the virtue divine4 ,but when three or four hundred years afterwards1 the magnetick movement to ,north and ,south was discovered or again recognized by men1 many learned men attempted1 each according to the bent of his own mind1 either by wonder and praise1 or by some sort of reasonings1 to throw light upon a virtue so notable1 and so needful for the use of mankind4 ,of more modern authors a great number have striven to show what is the cause of this direction and movement to ,north and ,south1 and to understand this great miracle of nature1 and to disclose it to others3 but they have lost both their oil and their pains2 for1 not being practised in the subjects of nature1 and being misled by certain false physical systems1 they adopted as theirs1 from books only1 without magnetical experiments1 certain inferences based on vain opinions1 and many things that are not1 dreaming old wives' tales4 ,marsilius ,ficinus ruminates over the ancient opinions1 and in order to show the reason of the direction seeks the cause in the heavenly constellation of the ,bear1 supposing the virtue of the ,bear to prevail in the stone and to be transferred to the iron4 ,paracelsus asserted that there are stars1 endowed with the power of the loadstone1 which attract to themselves iron4 ,levinus ,lemnius describes and praises the compass#ac1 and infers its antiquity on certain grounds2 he does not divulge the hidden miracle which he propounds4 ,in the kingdom #d of ,naples the ,amalfians were the first 7so it is said7 to construct the mariners' compass3 and as ,flavius ,blondus says the ,amalfians#ad boast1 not without reason1 that they were taught by a certain citizen1 ,johannes ,goia1 in the year thirteen hundred after the birth of ,christ4 ,that town is situated in the kingdom of ,naples not far from ,salerno1 near the promontory of ,minerva2 and ,charles ,v4 bestowed that principality on ,andrea ,doria1 that great ,admiral1 on account of his signal naval services4 ,indeed it is plain that no invention of man's device has ever done more for mankind than the compass3 some notwithstanding consider that it was discovered by others previously and used in navigation1 judging from ancient writings and certain arguments and conjectures4 ,the knowledge of the little mariners' compass seems to have been brought into ,italy by ,paolo1 the ,venetian#ae1 who learned the art of the compass in the ,chinas about the year ,,mcclx42 yet ,i do not wish the ,amalfians to be deprived of an honour so great as that of having first made the construction common in the ,mediterranean ,sea4 ,goropius#af attributes the discovery to the ,cimbri or ,teutons1 forsooth because the names of the thirty-two winds inscribed on the compass are pronounced in the ,german tongue by all ship-masters1 whether they be ,french1 ,british1 or ,spaniards2 but the ,italians describe them in their own vernacular4 ,some think that ,solomon1 king of ,juda1 was acquaint with the use of the mariners' compass1 and made it known to his ship-masters in the long voyages when they brought back such a power of gold from the ,west ,indies3 whence also1 from the ,hebrew word ,parvaim#ag1 ,arias ,montanus maintains that the gold-abounding regions of ,peru are named ,but it is more likely to have come from the coast of lower thiopia1 from the region of ,cephala1 as others relate4 ,yet that account seems to be less true1 inasmuch as the ,phoenicians1 on the frontier of ,juda1 who were most skilled in navigation in former ages 7a people whose talents1 work1 and counsel ,solomon made use of in constructing ships and in the actual expeditions1 as well as in other operations71 were ignorant of magnetick aid1 the art of the mariners' compass3 ,for had it been in use amongst them1 without doubt the ,greeks and also ,italians and all barbarians would have understood a thing so necessary and made famous by common use2 nor could matters of much repute1 very easily known1 and so highly requisite ever have perished in oblivion2 but either the learning would have been handed down to posterity1 or some memorial of it would be extant in writing4 ,sebastian ,cabot was the first to discover that the magnetick iron varied#ah4 ,gonzalus ,oviedus#ai is the first to write1 as he does in the ,historia1 that in the south of the ,azores it does not vary4 ,fernelius in his book ,de ,abditis ,rerum ,causis says that in the loadstone there is a hidden and abstruse cause1 elsewhere calling it celestial2 and he brings forth nothing but the unknown by means of what is still more unknown4 #e ,for clumsy1 and meagre1 and pointless is his inquiry into hidden causes4 ,the ingenious ,fracastorio1 a distinguished philosopher1 in seeking the reason for the direction of the loadstone1 feigns ,hyperborean magnetick mountains attracting magnetical things of iron3 this view1 which has found acceptance in part by others1 is followed by many authors and finds a place not in their writings only1 but in geographical tables1 marine charts1 and maps of the globe3 dreaming1 as they do1 of magnetick poles and huge rocks1 different from the poles of the earth4 ,more than two hundred years earlier than ,fracastorio there exists a little work1 fairly learned for the time1 going under the name of one ,peter ,peregrinus#bj1 which some consider to have originated from the views of ,roger ,bacon1 the ,englishman of ,oxford3 ,in which book causes for magnetick direction are sought from the poles of the heaven and from the heaven itself4 ,from this ,peter ,peregrinus1 ,johannes ,taisnier of ,hainault#ba extracted materials for a little book1 and published it as new4 ,cardan talks much of the rising of the star in the tail of the ,greater ,bear1 and has attributed to its rising the cause of the variation3 supposing that the variation is always the same1 from the rising of the star4 ,but the difference of the variation according to the change of position1 and the changes which occur in many places1 and are even irregular in southern regions1 preclude the influence of one particular star at its northern rising4 ,the ,college of ,coimbra#bb seeks the cause in some part of the heaven near the pole3 ,scaliger in section ,,cxxxi4 of his ,exercitationes on ,cardan suggests a heavenly cause unknown to himself1 and terrestrial loadstones nowhere yet discovered4 ,a cause not due to those sideritic mountains named above1 but to that power which fashioned them1 namely that portion of the heaven which overhangs that northern point4 ,this view is garnished with a wealth of words by that erudite man1 and crowned with many marginal subtilities2 but with reasonings not so subtile4 ,martin ,cortes#bc considers that there is a place of attraction beyond the poles1 which he judges to be the moving heavens4 ,one ,bessardus#bd1 a ,frenchman1 with no less folly notes the pole of the zodiack4 ,jacobus ,severtius#be1 of ,paris1 while quoting a few points1 fashions new errors as to loadstones of different parts of the earth being different in direction3 and also as to there being eastern and western parts of the loadstone4 ,robert ,norman#bf1 an ,englishman1 fixes a point and region respective1 not attractive2 to which the magnetical iron is collimated1 but is not itself attracted4 ,franciscus ,maurolycus#bg treats of a few problems on the loadstone1 taking the trite views of others1 and avers that the variation is due to a certain magnetical island mentioned by ,olaus ,magnus#bh4 ,josephus ,acosta#bi1 though quite ignorant about the loadstone1 nevertheless pours forth vapid talk upon the loadstone4 ,livio ,sanuto#cj in his ,italian ,geographia1 discusses at length the question whether the prime magnetick #f meridian and the magnetick poles are in the heavens or in the earth2 also about an instrument for finding the longitude3 but through not understanding magnetical nature1 he raises nothing but errors and mists in that so important notion4 ,fortunius ,affaytatus#ca philosophizes foolishly enough on the attraction of iron1 and its turning to the poles4 ,most recently1 ,baptista ,porta#cb1 no ordinary philosopher1 in his ,magia ,naturalis1 has made the seventh book a custodian and distributor of the marvels of the loadstone2 but little did he know or ever see of magnetick motions2 and some things that he noted of the powers which it manifested1 either learned by him from the ,reverend ,maestro ,paolo1 the ,venetian#cc1 or evolved from his own vigils1 were not so well discovered or observed2 but abound in utterly false experiments1 as will be clear in due place3 still ,i deem him worthy of high praise for having attempted so great a subject 7as he has done with sufficient success and no mean result in many other instances71 and for having given occasion for further research4 ,all these philosophizers of a previous age1 philosophizing about attraction from a few vague and untrustworthy experiments1 drawing their arguments from the hidden causes of things2 and then1 seeking for the causes of magnetick directions in a quarter of the heavens1 in the poles1 the stars1 constellations1 or in mountains1 or rocks1 space1 atoms1 attractive or respective points beyond the heavens1 and other such unproven paradoxes1 are whole horizons wrong1 and wander about blindly4 ,and as yet we have not set ourselves to overthrow by argument those errors and impotent reasonings of theirs1 nor many other fables told about the loadstone1 nor the superstitions of impostors and fabulists3 for instance1 ,franciscus ,rueus'#cd doubt whether the loadstone were not an imposture of evil spirits3 or that1 placed underneath the head of an unconscious woman while asleep1 it drives her away from the bed if an adulteress3 or that the loadstone is of use to thieves by its fume and sheen1 being a stone born1 as it were1 to aid theft3 or that it opens bars and locks1 as ,serapio#ce crazily writes3 or that iron held up by a loadstone1 when placed in the scales1 added nothing to the weight of the loadstone1 as though the gravity of the iron were absorbed by the force of the stone3 or that1 as ,serapio and the ,moors relate1 in ,india there exist certain rocks of the sea abounding in loadstone1 which draw out all the nails of the ships which are driven toward them1 and so stop their sailing2 which fable ,olaus ,magnus#cf does not omit1 saying that there are mountains in the north of such great powers of attraction1 that ships are built with wooden pegs1 lest the iron nails should be drawn from the timber as they passed by amongst the magnetick crags4 ,nor this3 that a white loadstone may be procured as a love potion3 or as ,hali ,abbas#cg thoughtlessly reports1 that if held in the hand it will cure gout and spasms3 ,or that it makes one acceptable and in favour with princes1 or eloquent1 as ,pictorio#ch has #g sung2 ,or as ,albertus ,magnus#ci teaches1 that there are two kinds of loadstones1 one which points to the ,north1 the other to the ,south3 ,or that iron is directed toward the ,northern stars by an influence imparted by the polar stars1 even as plants follow the sun1 as ,heliotrope does3 ,or that there is a magnet-stone situated under the tail of the ,greater ,bear1 as ,lucas ,gauricus the ,astrologer stated3 ,he would even assign the loadstone1 like the ,sardonyx and onyx1 to the planet ,saturn1 yet at the same time he assigns it with the adamant1 ,jasper1 and ,ruby1 to ,mars2 so that it is ruled by two planets4 ,the loadstone moreover is said by him to pertain to the sign ,virgo2 and he covers many such shameful pieces of folly with a veil of mathematical erudition4 ,such as that an image of a bear is engraved on a loadstone when the ,moon faces towards the north1 so that when hung by an iron wire it may conciliate the influence of the celestial ,bear1 as ,gaudentius ,merula#dj relates3 ,or that the loadstone drew iron and directed it to the north1 because it is superior in rank to iron1 at the ,bear1 as ,ficinus writes1 and ,merula repeats3 ,or that by day it has a certain power of attracting iron1 but by night the power is feeble1 or rather null3 ,or that when weak and dulled the virtue is renewed by goats' blood1 as ,ruellius#da writes3 ,or that ,goats' blood sets a loadstone free from the venom of a diamond1 so that the lost power is revived when bathed in goats' blood by reason of the discord between that blood and the diamond3 ,or that it removed sorcery from women1 and put to flight demons1 as ,arnaldus de ,villanova dreams3 ,or that it has the power to reconcile husbands to their wives1 or to recall brides to their husbands1 as ,marbodeus ,gallus#db1 chorus-leader of vanities1 teaches3 ,or that in a loadstone pickled in the salt of a sucking fish#dc there is power to pick up gold which has fallen into the deepest wells1 according to the narratives of ,clius ,calcagninus4 ,with such idle tales and trumpery do plebeian philosophers delight themselves and satiate readers greedy for hidden things1 and unlearned devourers of absurdities3 ,but after the magnetick nature shall have been disclosed by the discourse that is to follow1 and perfected by our labours and experiments1 then will the hidden and abstruse causes of so great an effect stand out1 sure1 proven1 displayed and demonstrated2 and at the same time all darkness will disappear1 and all error will be torn up by the roots and will lie unheeded2 and the foundations of a grand magnetick philosophy which have been laid will appear anew1 so that high intellects may be no further mocked by idle opinions4 ,some learned men there are who in the course of long voyages have observed the differences of magnetick variation3 the most scholarly ,thomas ,hariot#dd1 ,robert ,hues1 ,edward ,wright1 ,abraham ,kendall1 all ,englishmen2 ,others there are who have invented and produced magnetical instruments1 and ready methods of observation1 indispensable for sailors and to those travelling afar3 #h as ,william ,borough#de in his little book on the ,variation of the ,compass or ,magneticall ,needle1 ,william ,barlowe#df in his ,supply1 ,robert ,norman in his ,newe ,attractive4 ,and this is that ,robert ,norman#dg 7a skilful seaman and ingenious artificer7 who first discovered the declination of the magnetick needle4 ,many others ,i omit wittingly2 modern ,frenchmen1 ,germans1 and ,spaniards1 who in books written for the most part in their native tongues either misuse the placets of others1 and send them forth furbished with new titles and phrases as tricky traders do old wares with meretricious ornaments2 or offer something not worthy of mention even3 and these lay hands on some work filched from other authors and solicit some one as their patron1 or go hunting after renown for themselves among the inexperienced and the young2 who in all branches of learning are seen to hand on errors and occasionally add something false of their own4 99 99 99 99 99 ,,chap4 ,,ii4 ,magnet ,stone1 of what kind it is1 and its discovery4 ,loadstone1 the stone which is commonly called the ,magnet1 derives its name either from the discoverer 7though he was not ,pliny's fabulous herdsman#dh1 quoted from ,nicander1 the nails of whose shoes and the tip of whose staff stuck fast in a magnetick field while he pastured his flocks71 or from the region of ,magnesia in ,macedonia1 rich in loadstones3 ,or else from the city ,magnesia in ,ionia in ,afia ,minor1 near the river ,mander4 ,hence ,lucretius says1 ,the ,magnet's name the observing ,grecians drew ,from the ,magnetick region where it grew4 ,it is called ,heraclean from the city ,heraclea1 or from the invincible ,hercules1 on account of the great strength and domination and power which there is in iron of subduing all things3 it is also called siderite1 as being of iron2 being not unknown to the most ancient writers1 to the ,greeks1 ,hippocrates1 and others1 as also 7,i believe7 to ,jewish and ,egyptian writers2 ,for in the oldest mines of iron1 the most famous in ,asia1 the loadstone was often dug out with its uterine brother1 iron4 ,and if the tales be true which are told of the people of the ,chinas1 they were not unacquainted in primitive times with magnetical experiments1 for even amongst #i them the finest magnets of all are still found4 ,the ,egyptians1 as ,manetho relates1 gave it the name ,os ,ori3 calling the power which governs the turning of the sun ,orus1 as the ,greeks call it ,apollo4 ,but later by ,euripides1 as narrated by ,plato1 it was designated under the name of ,magnet4 ,by ,plato in the ,io1 ,nicander of ,colophon1 ,theophrastus1 ,dioscorides1 ,pliny1 ,solinus1 ,ptolemy1 ,galen1 and other investigators of nature it was recognized and commended2 such1 however1 is the variety of magnets and their points of unlikeness in hardness1 softness1 heaviness1 lightness1 density1 firmness1 and friability of substance3 so great and manifold are the differences in colour and other qualities1 that they have not handed down any adequate account of it1 which therefore was laid aside or left imperfect by reason of the unfavourable character of the time2 for in those times varieties of specimens and foreign products never before seen were not brought from such distant regions by traders and mariners as they have been lately1 and now that all over the globe all kinds of merchandise1 stones1 woods1 spices1 herbs1 metals1 and ore in abundance are greedily sought after3 neither was metallurgy so generally cultivated in a former age4 ,there is a difference in vigour2 as whether it is male or female3 for it was thus that the ancients used often to distinguish many individuals of the same species4 ,pliny quotes from ,sotacus five kinds2 those from thiopia1 ,macedonia1 ,boeotia1 the ,troad1 and ,asia1 which were especially known to the ancients3 but we have posited as many kinds of loadstones as there are in the whole of nature regions of different kinds of soil4 ,for in all climates1 in every province1 on every soil1 the loadstone is either found1 or else lies unknown on account of its rather deep site and inaccesible position2 or by reason of its weaker and less obvious strength it is not recognized by us while we see and handle it4 ,to the ancients the differences were those of colour#di1 how they are red and black in ,magnesia and ,macedonia1 in ,boeotia red rather than black1 in the ,troad black1 without strength3 ,while in ,magnesia in ,asia they are white1 not attracting iron1 and resemble pumice-stone4 ,a strong loadstone of the kind celebrated so often nowadays in experiments presents the appearance of unpolished iron1 and is mostly found in iron mines3 it is even wont to be discovered in an unbroken lode by itself3 ,loadstones of this sort are brought from ,east ,india1 ,china1 and ,bengal1 of the colour of iron1 or of a dark blood or liver colour2 and these are the finest1 and are sometimes of great size1 as though broken off a great rock1 and of considerable weight2 sometimes single stones1 as it were1 and entire3 some of these1 though of only one pound weight1 can lift on high four ounces of iron or a half-pound or even a whole pound4 ,red ones are found in ,arabia1 as broad as a tile1 not equal in weight to those brought from ,china1 but strong and good3 they are a little darker in the island of ,elba in the ,tuscan sea1 and together with #aj these also grow white ones1 like some in ,spain in the mines of ,caravaca3 but these are of lesser power4 ,black ones also are found1 of lower strength1 such as those of the iron mines in ,norway and in sea-coast places near the strait of ,denmark4 ,amongst the blue-black or dusky blue also some are strong and highly commended4 ,other loadstones are of a leaden colour1 fissile and not-fissile1 capable of being split like slates in layers4 ,i have also some like gray marble of an ashen colour1 and some speckled like gray marble1 and these take the finest polish4 ,in ,germany there are some perforated like honeycombs1 lighter than any others1 and yet strong4 ,those are metallick which smelt into the best iron2 others are not easily smelted1 but are burned up4 ,there are loadstones that are very heavy1 as also others very light2 some are very powerful in catching up pieces of iron1 while others are weaker and of less capacity1 others so feeble and barren that they with difficulty attract ever so tiny a piece of iron and cannot repel an opposite magnetick4 ,others are firm and tough1 and do not readily yield to the artificer4 ,others are friable4 ,again1 there are some dense and hard as emery1 or loose-textured and soft as pumice2 porous or solid2 entire and uniform1 or varied and corroded2 now like iron for hardness1 yea1 sometimes harder than iron to cut or to file2 others are as soft as clay4 ,not all magnets can be properly called stones2 some rather represent rocks2 while others exist rather as metallick lodes2 others as clods and lumps of earth4 ,thus varied and unlike each other1 they are all endowed1 some more1 some less1 with the peculiar virtue4 ,for they vary according to the nature of the soil1 the different admixture of clods and humours1 having respect to the nature of the region and to their subsidence in this last-formed crust of the earth1 resulting from the confluence of many causes1 and the perpetual alternations of growth and decline1 and the mutations of bodies4 ,nor is this stone of such potency rare2 and there is no region wherein it is not to be found in some sort4 ,but if men were to search for it more diligently and at greater outlay1 or were able1 where difficulties are present1 to mine it1 it would come to hand everywhere1 as we shall hereafter prove4 ,in many countries have been found and opened mines of efficacious loadstones unknown to the ancient writers1 as for instance in ,germany1 where none of them has ever asserted that loadstones were mined4 ,yet since the time when1 within the memory of our fathers1 metallurgy began to flourish there1 loadstones strong and efficacious in power have been dug out in numerous places2 as in the ,black ,forest beyond ,helceburg2 in ,mount ,misena not far from ,schwartzenberg#ej2 a fairly strong kind between ,schneeberg and ,annaberg in ,joachimsthal1 as was noticed by ,cordus3 also near the village of ,pela in ,franconia4 ,in ,bohemia it occurs in iron mines in the ,lessa district and other places1 as ,georgious ,agricola and several other men learned in metallurgy #aa witness4 ,in like manner in other countries in our time it is brought to light2 for as the stone remarkable for its virtues is now famous throughout the whole world1 so also everywhere every land produces it1 and it is1 so to speak1 indigenous in all lands4 ,in ,east ,india1 in ,china1 in ,bengal near the river ,indus it is common1 and in certain maritime rocks3 in ,persia1 ,arabia1 and the islands of the ,red ,sea2 in many places in thiopia1 as was formerly ,zimiri1 of which ,pliny makes mention4 ,in ,asia ,minor around ,alexandria and the ,troad2 in ,macedonia1 ,boeotia1 in ,italy1 the island of ,elba1 ,barbary2 in ,spain still in many mines as aforetime4 ,in ,england quite lately a huge power of it was discovered in a mine belonging to ,adrian ,gilbert1 gentleman#ea2 also in ,devonshire and the ,forest of ,dean2 in ,ireland1 too1 ,norway1 ,denmark1 ,sweden1 ,lapland1 ,livonia1 ,prussia1 ,poland1 ,hungary4 ,for although the terrestrial globe1 owing to the varied humours and natures of the soil arising from the continual succession of growth and decay1 is in the lapse of time efflorescing through all its ambit deeper into its surface1 and is girt about with a varied and perishable covering1 as it were with a veil2 yet out of her womb ariseth in many places an offspring nigher to the more perfect body and makes its way to the light of day4 ,but the weak and less vigorous loadstones1 enfeebled by the flow of humours1 are visible in every region1 in every strath4 ,it is easy to discover a vast quantity of them everywhere without penetrating mountains or great depths1 or encountering the difficulties and hardships of miners2 as we shall prove in the sequel4 ,and these we shall take pains so to prepare by an easy operation that their languid and dormant virtue shall be made manifest4 ,it is called by the ,greeks#eb ,greek3 heraklios1 as by ,theophrastus1 and ,greek3 magntis2 and ,greek3 magns1 as by ,euripides1 as quoted by ,plato in the ,io3 by ,orpheus#ec too ,greek3 magnosa1 and ,greek3 siderits as though of iron3 by the ,latins magnes1 ,herculeus2 by the ,french aimant#ed1 corruptly from adamant2 by the ,spaniards piedramant3 by the ,italians calamita#ee2 by the ,english ,,loadstone and ,,adamant ,,stone#ef1 by the ,germans magness#eg and siegelstein3 ,among ,english1 ,french1 and ,spaniards it has its common name from adamant2 perhaps because they were at one time misled by the name sideritis being common to both3 the magnet is called ,greek3 siderits from its virtue of attracting iron3 the adamant is called ,greek3 siderits from the brilliancy of polished iron4 ,aristotle designates it merely by the name of the stone3#eh ,greek3 ,eoike de kai thals ex hn apomnmoneuousi1 kintikon ti tn psuchn hupolabein1 eiper ton lithon eph psuchn echein1 hoti ton sidron kinei3 ,de ,anima1 ,lib4 ,i4 ,the name of magnet is also applied to another stone differing from siderite1 having the appearance of silver2 it is like ,amianth in its nature2 and since it consists of lamin 7like specular stone7#ei1 it differs in form3 in ,german ,katzensilber and ,talke#fj4 99 99 99 99 99 #ab ,,chap4 ,,iii4 ,the ,loadstone has parts distinct in their natural power1 poles conspicuous for their property4 ,the stone itself manifests many qualities which1 though known afore this1 yet1 not having been well investigated1 are to be briefly indicated in the first place so that students may understand the powers of loadstone and iron1 and not be troubled at the outset through ignorance of reasonings and proofs4 ,in the heaven astronomers assign a pair of poles for each moving sphere3 so also do we find in the terrestrial globe natural poles preeminent in virtue1 being the points that remain constant in their position in respect to the diurnal rotation1 one tending to the ,bears and the seven stars2 the other to the opposite quarter of the heaven4 ,in like manner the loadstone has its poles1 by nature northern and southern1 being definite and determined points set in the stone1 the primary boundaries of motions and effects1 the limits and governors of the many actions and virtues4 ,however1 it must be understood that the strength of the stone does not emanate from a mathematical point1 but from the parts themselves1 and that while all those parts in the whole belong to the whole1 the nearer they are to the poles of the stone the stronger are the forces they acquire and shed into other bodies3 these poles are observant of the earth's poles1 move toward them1 and wait upon them4 ,magnetick poles can be found in every magnet1 in the powerful and mighty 7which ,antiquity used to call the masculine7 as well as in the weak1 feeble and feminine2 whether its figure is due to art or to chance1 whether long1 flat1 square1 three-cornered1 polished2 whether rough1 broken1 or unpolished2 always the loadstone contains and shows its poles4 99 ,but since the spherical form1 which is also the most perfect1 agrees best with the earth1 being a globe1 and is most suitable for use and experiment1 we accordingly wish our principal demonstrations by the stone to be made with a globe-shaped magnet as being more perfect and adapted for the purpose4 ,take1 then1 a powerful loadstone1 solid1 of a just size1 uniform1 hard1 without flaw#fa2 make of it a globe upon the turning tool used for rounding crystals and some other stones1 or with other tools as the material and firmness of the stone requires1 for sometimes it is difficult to be worked4 ,the stone thus perpared is a true1 homogeneous offspring of the earth and of the same shape with it3 artificially possessed of the orbicular form which nature granted from the beginning to the common mother earth3 and it is a physical corpuscle imbued with many virtues1 by #ac means of which many abstruse and neglected truths in philosophy buried in piteous darkness may more readily become known to men4 ,this round stone is called by us a ,greek3 mikrog or ,terrella#fb4 ,to find1 then1 the poles conformable to the earth's1 take the round stone in hand1 and place upon the stone a needle or wire of iron3 the ends of the iron move upon their own centre and suddenly stand still4 ,mark the stone with ochre or with chalk where the wire lies and sticks3 move the middle or centre of the wire to another place1 and so on to a third and a fourth1 always marking on the stone along the length of the iron where it remains at rest3 those lines show the meridian circles1 or the circles like meridians on the stone1 or terrella1 all of which meet as will be manifest at the poles of the stone4 ,by the circles thus continued the poles are made out1 the ,boreal as well as the southern1 and in the middle space betwixt these a great circle may be drawn for an quator1 just as ,astronomers describe them in the heavens and on their own globes1 or as ,geographers do on the terrestrial globe3 for that line so drawn on this our terrella is of various uses in our demonstrations and experiments magnetical4 ,poles are also found in a round stone by a versorium1 a piece of iron touched with a loadstone1 and placed upon a needle or point firmly fixed on a foot so as to turn freely about in the following way3#fc ,illustration ,on the stone ,a ,b the versorium is placed in such a way that the versorium may remain in equilibrium3 you will mark with chalk the course of the iron when at rest3 ,move the instrument to another spot1 and again make note of the direction and aspect3 do the same thing in several places1 and from the concurrence of the lines of direction you will find one pole at the point ,a1 the other at ,b4 ,a versorium placed near the stone also indicates the true pole2 when at right angles it eagerly beholds the stone and seeks the pole itself directly1 and is turned in a straight line through the axis to the #ad centre of the stone4 ,for instance1 the versorium ,d faces toward ,a and ,f1 the pole and centre1 whereas ,e does not exactly respect 99 either the pole ,a or the centre ,f#fd4 ,a bit of rather fine iron wire1 of the length of a barley-corn1 is placed on the stone1 and is moved over the regions and surface of the stone1 until it rises to the perpendicular#fe3 for it stands erect at the actual pole1 whether ,boreal or austral2 the further from the pole1 the more it inclines from the vertical4 ,the poles thus found you shall mark with a sharp file or gimlet4 99 99 99 99 99 ,,chap4 ,,iiii4 ,which pole of the stone is the ,boreal3 how it is distinguished from the austral4 ,one pole of the earth turns toward the constellation of the ,cynosure1 and constantly regards a fixed point in the heaven 7except so far as it changes by the fixed stars being shifted in longitude1 which motion we recognize as existing in the earth1 as we shall hereafter prove73 ,while the other pole turns to the opposite face of heaven1 unknown to the ancients1 now visible on long voyages1 and adorned with multitudinous stars3 ,in the same way the loadstone has the property and power of directing itself ,north and ,south 7the earth herself consenting and contributing force thereto7 according to the conformation of nature1 which arranges the movements of the stone towards its native situation4 ,which thing is proved thus3 ,place a magnetick stone 7after finding the poles7 in a round wooden vessel1 a ,bowl or dish1 at the same time place it together with the vessel 7like a sailor in a skiff7 upon water in some large vessel or cistern1 so that it may be able to float freely in the middle1 nor touch the edge of it1 and where the air is not disturbed by winds1 which would thwart the natural movement of the stone4 ,hereupon the stone placed as it were in a ship1 in the middle of the surface of the still and unruffled water1 will at once put itself in motion along with the vessel that carries it1 and revolve circularly1 until its austral pole points to the north1 and its boreal pole to the south4 ,for it reverts from the contrary position to the poles3 and although by the first too-vehement impulse it over-passes the poles2 yet after returning again and again1 it rests at length at the poles1 or at the meridian 7unless because of local reasons it is diverted some little from those points1 or from the meridional line1 by some sort of variation#ff1 the cause of which we will hereafter state74 ,however often you move it away from its place1 so often by virtue of nature's noble dower does it seek again those sure and #ae determined goals2 and this is so1 not only if the poles have been disposed in the vessel evenly with the plane of the horizon1 but also in the case of one pole1 whether austral or boreal1 being raised in the vessel ten1 or twenty1 or thirty1 or fifty or eighty degrees1 above 99 the plane of the horizon1 or lowered beneath it3 ,still you shall see the boreal part of the stone seek the south1 and the austral part seek the north2 ,so much so that if the pole of the stone shall be only one degree distant from the ,zenith and highest point of the heaven1 in the case of a spherical stone1 the whole stone revolves until the pole occupies its own site2 though not in the absolutely direct line1 it will yet tend toward those parts1 and come to rest in the meridian of the directive action4 ,with a like impulse too it is borne if the austral pole have been raised toward the upper quarters1 the same as if the ,boreal had been exalted above the ,horizon4 ,but it is always to be noted that1 though there are various kinds of unlikeness in the stones1 and one loadstone may far surpass another in virtue and efficiency2 yet all hold to the same limits1 and are borne toward the same points4 ,further it is to be remembered 99 that all who before our time wrote of the poles of the stone1 and all the craftsmen and navigators1 have been very greatly in error in considering the part of the stone which tended to the north as the north pole of the stone1 and that which verged toward the south1 the south pole1 which we shall hereafter prove to be false4 ,so badly hitherto hath the whole magnetick philosophy been cultivated1 even as to its foundation principles4 99 99 99 99 99 ,,chap4 ,v4 ,loadstone seems to attract ,loadstone when in natural position3 but repels it when in a contrary one1 and brings it back to order4 ,first of all we must declare1 in familiar language1 what are the apparent and common virtues of the stone2 afterward numerous subtilities1 hitherto abstruse and unknown1 hidden in obscurity1 are to be laid open1 and the causes of all these 7by the unlocking of nature's secrets7 made evident1 in their place1 by fitting terms and devices4 ,it is trite and commonplace that loadstone draws iron2 in the same way too does loadstone attract loadstone4 ,place the stone which you have seen to have poles clearly distinguished1 and marked austral and boreal1 in its vessel so as to float2 and let the poles be rightly arranged with respect to the plane of the horizon1 or1 at any rate not much raised or awry3 hold in your hand another stone the poles of which are also known2 in #af such a way that its austral pole may be toward the boreal pole of the one that is swimming1 and near it1 sideways3 for the floating stone forthwith follows the other stone 7provided it be within its force and dominion7 and does not leave off nor forsake it until it adhres2 unless by withdrawing your hand1 you cautiously avoid contact4 ,in like manner if you set the boreal pole of the one you hold in your hand opposite the austral pole of the swimming stone1 they rush together and follow each other in turn4 ,for contrary poles allure contrary4 ,if1 however1 you apply in the same way the northern to the northern1 and the austral to the austral pole1 the one stone puts the other to flight1 and it turns aside as though a pilot were pulling at the helm and it makes sail in the opposite ward as one that ploughs the sea1 and neither stands anywhere1 nor halts1 if the other is in pursuit4 ,for stone disposeth stone2 the one turns the other around1 reduces it to range1 and brings it back to harmony with itself4 ,when1 however1 they come together and are conjoined according to the order of nature1 they cohre firmly mutually4 ,for instance1 if you were to set the boreal pole of that stone which is in your hand before the tropic of ,capricorn of a round floating loadstone 7for it will be well to mark out on the round stone1 that is the terrella1 the mathematical circles as we do on a globe itself71 or before any point between the quator and the austral pole2 at once the swimming stone revolves1 and so arranges itself that its austral pole touches the other's boreal pole1 and forms a close union with it4 ,in the same way1 again1 at the other side of the quator1 with the opposite poles1 you may produce similar results2 and thus by this art and subtilty we exhibit attraction1 repulsion1 and circular motion for attaining a position of agreement and for declining hostile encounters4 ,moreover 'tis in one and the same stone that we are thus able to demonstrate all these things and also how the same part of one stone may on division become either boreal or austral4 ,let ,a ,d be an oblong stone1 in which ,a is the northern1 ,d the southern pole2 cut this into two equal parts1 then set part ,a in its vessel on the water#fg1 so as to float4 ,illustration #ag ,and you will then see#fh that ,a the northern point will turn to the south1 as before2 in like manner also the point ,d will move to the north1 in the divided stone1 as in the whole one4 ,whereas1 of the parts ,b and ,c1 which were before continuous1 and are now divided1 the one is southern ,b1 the other northern ,c4 ,b draws ,c1 desirous to be united1 and to be brought back into its pristine continuity3 for these which are now two stones were formed out of one3 and for this cause ,c of the one turning itself to ,b of the other1 they mutually attract each other1 and when freed from obstacles and relieved of their own weight1 as upon the surface of water1 they run together and are conjoined4 ,but if you direct the part or point ,a to ,c in the other stone1 the one repels or turns away from the other3 for so were nature perverted1 and the form of the stone perturbed1 a form that strictly keeps the laws which it imposed upon bodies3 hence1 when all is not rightly ordered according to nature1 comes the flight of one from the other's perverse position and from the discord1 for nature does not allow of an unjust and inequitable peace1 or compromise3 but wages war and exerts force to make bodies acquiesce well and justly4 ,rightly arranged1 therefore1 these mutually attract each other2 that is1 both stones1 the stronger as well as the weaker1 run together1 and with their whole forces tend to unity1 a fact that is evident in all magnets1 not in the thiopian only1 as ,pliny supposed4 ,the thiopian magnets if they be powerful1 like those brought from ,china1 because all strong ones show the effect more quickly and more plainly1 attract more strongly in the parts nearest the pole1 and turn about until pole looks directly at pole4 ,the pole of a stone more persistently attracts and more rapidly seizes the corresponding part 7which they term the adverse part7 of another stone2 for instance1 ,north pulls ,south2 just so it also summons iron with more vehemence1 and the iron cleaves to it more firmly whether it have been previously excited by the magnet1 or is untouched4 ,for thus1 not without reason hath it been ordained by nature1 that the parts nearer to the pole should more firmly attract3 but that at the pole itself should be the seat1 the throne1 as it were1 of a consummate and splendid virtue1 to which magnetical bodies on being brought are more vehemently attracted1 and from which they are with utmost difficulty dislodged4 ,so the poles are the parts which more particularly spurn and thrust away things strange and alien perversely set beside them4 99 99 99 99 99 #ah ,,chap4 ,,vi4 ,loadstone attracts the ore of iron1 as well as iron proper1 smelted and wrought4 ,principal and manifest among the virtues of the 99 magnet1 so much and so anciently commended1 is the attraction of iron2 for ,plato states that the magnet1 so named by ,euripides1 allures iron1 and that it not only draws iron rings but also indues the rings with power to do the same as the stone2 to wit1 draw other rings1 so that sometimes a long chain of iron objects1 nails or rings is formed1 some hanging from others4 ,the best iron 7like that which is called acies from its use1 or chalybs from the country of the ,chalybes7 is best and strongly drawn by a powerful loadstone2 whereas the less good sort1 which is impure1 rusty1 and not thoroughly purged from dross1 and not wrought in second furnaces1 is more feebly drawn2 and yet more weakly when covered and defiled with thick1 greasy1 and sluggish humours4 ,it also draws ores of iron1 those that are rich and of iron colour2 the poorer and not so productive ores it does not attract1 except they be prepared with some art4 ,a loadstone loses some attractive virtue1 and1 as it were1 pines away with age1 if exposed too long to the open air instead of being laid in a case with filings or scales of iron4 ,whence it should be buried in such materials2 for there is nothing that plainly resists this exhaustless virtue which does not destroy the form of the body1 or corrode it2 not even if a thousand adamants were conjoined4 ,nor do ,i consider that there is any such thing as the ,theamedes#fi1 or that it has a power opposite to that of the loadstone4 ,although ,pliny1 that eminent man and prince of compilers 7for it is what others had seen and discovered1 not always or mainly his own observations1 that he has handed down to posterity7 has copied from others the fable now made familiar by repetition3 ,that in ,india there are two mountains near the river ,indus2 the nature of one being to hold fast all that is iron1 for it consists of loadstone2 the other's nature being to repel it1 for it consists of the ,theamedes4 ,thus if one had iron nails in one's boots1 one could not tear away one's foot on the one mountain1 nor stand still on the other4 ,albertus ,magnus writes that a loadstone had been found in his day which with one part drew to itself iron1 and repelled it with its other end2 but ,albertus observed the facts badly2 for every loadstone attracts with one end iron that has been touched with a loadstone1 and drives it away with the other2 and draws iron that been touched with a loadstone more powerfully than iron that has not been so touched4 99 99 99 99 99 #ai ,,chap4 ,,vii4 ,what ,iron is1 and of what substance1 and its uses4 ,for that now we have declared the origin and nature of the loadstone1 we think it necessary first to add a history of iron and to indicate the hitherto unknown forces of iron1 before this our discourse goes on to the explanation of magnetick difficulties and demonstrations1 and to deal with the coitions and harmonies of loadstone with iron4 ,iron is by all reckoned in the class of metals1 and is a metal livid in colour1 very hard1 glows red-hot before it melts1 being most difficult of fusion1 is beaten out under the hammer1 and is very resonant4 ,chemists say that if a bed of fixed earthy sulphur be combined with fixed earthy quicksilver1 and the two together are neither pure white but of a livid whiteness1 if the sulphur prevail1 iron is formed4 ,for these stern masters of metals who by many inventions twisting them about1 pound1 calcine1 dissolve1 sublime1 and precipitate1 decide that this metal1 both on account of the earthy sulphur and of the earthy mercury1 is more truly a son of the earth than any other2 they do not even think gold or silver1 lead1 tin1 or copper itself so earthy2 for that reason it is not smelted except in the hottest furnaces1 with bellows2 and when thus fused1 on having again grown hard it is not melted again without heavy labour2 but its slag with the utmost difficulty4 ,it is the hardest of metals1 subduing and breaking all things1 by reason of the strong concretion of the more earthy matter4 ,wherefore we shall better understand what iron is1 when we shall declare what are the causes and substance of metals1 in a different way from those who before our time have considered them4 ,aristotle takes the material of the metals to be vapour4 ,the chemists in chorus pronounce their actual elements to be sulphur and quicksilver4 ,gilgil ,mauritanus gives it as ashes moistened with water4 ,georgius ,agricola makes it out to be water and earth mixed2 nor1 to be sure1 is there any difference between his opinion and the position taken by ,mauritanus4 ,but ours is that metals arise and effloresce at the summits of the earth's globe1 being distinguished each by its own form1 like some of the other substances dug out of it1 and all bodies around us4 ,the earth's globe does not consist of ashes or inert dust4 ,nor is fresh water an element1 but a more simple consistency of evaporated fluids of the earth4 ,unctuous bodies1 fresh water devoid of properties1 quicksilver and sulphur1 none of these are principia of metals3 these latter1 #bj things are the results of a different nature1 they are neither constant nor antecedent in the course of the generation of metals4 ,the earth emits various humours1 not begotten of water nor of dry earth1 nor from mixtures of these1 but from the substance of the earth itself3 these humours are not distinguished by contrary qualities or substance1 nor is the earth a simple substance1 as the ,peripateticks dream4 ,the humours proceed from vapours sublimated from great depths2 all waters are extracts and1 as it were1 exudations from the earth4 ,rightly then in some measure does ,aristotle make out the matter of metals to be that exhalation which in continuance thickens in the lodes of certain soils3 for the vapours are condensed in places which are less hot than the spot whence they issued1 and by help of the nature of the soils and mountains1 as in a womb1 they are at fitting seasons congealed and changed into metals3 but it is not they alone which form ores1 but they flow into and enter a more solid material1 and so form metals4 ,so when this concreted matter has settled down in more temperate beds1 it begins to take shape in those tepid places1 just as seed in the warm womb1 or as the embryo acquires growth3 sometimes the vapour conjoins with suitable matter alone3 hence some metals are occasionally though rarely dug up native1 and come into existence perfect without smelting3 but other vapours which are mixed with alien soils require smelting in the way that the ores of all metals are treated1 which are rid of all their dross by the force of fires1 and being fused flow out metallick1 and are separated from earthy impurities but not from the true substance of the earth4 ,but in so far as that it becomes gold1 or silver1 or copper1 or any other of the existing metals1 this does not happen from the quantity or proportion of material1 nor from any forces of matter1 as the ,chemists fondly imagine2 but when the beds and region concur fitly with the material1 the metals assume forms from the universal nature by which they are perfected2 in the same manner as all the other minerals1 plants1 and animals whatever3 otherwise the species of metals would be vague and undefined1 which are even now turned up in such scanty numbers that scarce ten kinds are known4 ,why1 however1 nature has been so stingy as regards the number of metals1 or why there should be as many as are known to man1 it is not easy to explain2 though the simple-minded and raving ,astrologers refer the metals each to its own planet4 ,but there is no agreement of the metals with the planets1 nor of the planets with the metals1 either in numbers or in properties4 ,for what connexion is there of iron with ,mars8 unless it be that from the former numerous instruments1 particularly swords and engines of war1 are fashioned4 ,what has copper to do with ,venus8 or how does tin1 or how does spelter correspond with ,jupiter8 ,they should rather be dedicated to ,venus4 ,but this is old wives' talk4 ,vapour is then a remote cause in the generation of the metals2 the fluid condensed from #ba vapours is a more proximate one1 like the blood and semen in the generation of animals4 ,but those vapours and juices from vapours pass for the most part into bodies and change them into marcasites and are carried into lodes 7for we have numerous cases of wood so transmuted71 the fitting matrices of bodies1 where they are formed as metals4 ,they enter most often into the truer and more homogeneal substance of the globe1 and in the process of time a vein of iron results2 loadstone is also produced1 which is nought else than a noble kind of iron ore3 and for this reason1 and on account of its substance being singular1 alien from all other metals1 nature very rarely1 if ever1 mixes with iron any other metal1 while the other metals are very often minutely mixed1 and are produced together4 ,now when that vapour or those juices happen to meet1 in fitting matrices1 with efflorescences deformed from the earth's homogenic substance1 and with divers precipitates 7the forms working thereto71 the remainder of the metals are generated 7a specifick nature affecting the properties in that place74 ,for the hidden primordial elements of metals and stones lie concealed in the earth1 as those of herbs and plants do in its outer crust4 ,for the soil dug out of a deep well1 where would seem to be no suspicion of a conception of seed1 when placed on a very high tower1 produces1 by the incubation of sun and sky1 green herbage and unbidden weeds2 and those of the kind which grow spontaneously in that region1 for each region produces its own herbs and plants1 also its own metals4 #gj;,here corn exults1 and there the grape is glad1 ,here trees and grass unbidden verdure add4 ,so mark how ,tmolus yields his saffrone store1 ,but ivory is the gift of ,indian shore2 ,with incense soft the softer ,shebans deal2 ,the stark ,chalybeans' element is steel3 ,with acrid castor reek the ,pontic wares1 ,epirus wins the palm of ,elian mares4 ,but what the ,chemists 7as ,geber1 and others7 call fixed earthy sulphur in iron is nothing else than the homogenic earth-substance concreted by its own humour1 amalgamated with a double fluid3 a metallick humour is inserted along with a small quantity of the substance of the earth not devoid of humour4 ,wherefore the common saying that in gold there is pure earth1 but in iron mostly impure1 is wrong2 as though there were indeed such a thing as natural earth1 and that the globe itself were 7by some unknown process of refining7 depurate4 ,in iron1 especially in the best iron1 there is earth in its own nature true and genuine2 in the other metals there is not so much earth as that in place of earth and precipitates there are consolidated and 7so to speak7 fixed salts1 which are efflorescences of the globe1 and which differ also greatly #bb in firmness and consistency3 ,in the mines their force rises up along with a twofold humour from the exhalations1 they solidify in the underground spaces into metallic veins3 so too they are also connate by virtue of their place and of the surrounding bodies1 in natural matrices1 and take on their specific forms4 ,of the various constitutions of loadstones and their diverse substances1 colours1 and virtues1 mention has been made before3 but1 now having stated the cause and origin of metals1 we have to examine ferruginous matter not as it is in the smelted metal1 but as that from which the metal is refined4 ,quasi-pure iron is found of its proper colour and in its own lodes2 still1 not as it will presently be1 nor as adapted for its various uses4 ,it is sometimes dug up covered with white silex or with other stones4 ,it is often the same in river sand1 as in ,noricum4 ,a nearly pure ore of iron is now often dug up in ,ireland1 which the smiths1 without the labours of furnaces1 hammer out in the smithy into iron implements4 ,in ,france iron is very commonly smelted out of a liver-coloured stone1 in which are glittering scales2 the same kind#ga without the scales is found in ,england1 which also they use for craftsmen's ruddle#gb4 ,in ,sussex in ,england#gc is a rich dusky ore and also one of a pale ashen hue1 both of which on being dried for a time1 or kept in moderate fires1 presently acquire a liver-colour2 here also is found a dusky ore square-shaped with a black rind of greater hardness4 ,an ore having the appearance of liver is often variously intermingled with other stones3 as also with the perfect loadstone which yields the best of iron4 ,there is also a rusty ore of iron1 one of a leaden hue tending to black1 one quite black1 or black mixed with true cobalt3 there is another sort mixed either with pyrites1 or with sterile plumbago4 ,one kind is also like jet1 another like bloodstone4 ,the emery used by armourers1 and by glaziers for glass-cutting1 called amongst the ,english ,emerelstone1 by the ,germans ,smeargel1 is ferruginous2 albeit iron is extracted from it with difficulty1 yet it attracts the versorium4 ,it is now and then found in deep iron and silver diggings4 ,thomas ,erastus says he had heard from a certain learned man of iron ores1 of the colour of iron1 but quite soft and fatty1 which can be smoothed with the fingers like butter1 out of which excellent iron can be smelted3 somewhat the same we have seen found in ,england1 having the aspect of ,spanish soap4 ,besides the numberless kinds of stony ores1 iron is extracted from clay1 from clayey earth1 from ochre1 from a rusty matter deposited from chalybeate waters2 ,in ,england iron is copiously extracted in furnaces often from sandy and clayey stones which appear to contain iron not more than sand1 marl1 or any other clay soils contain it4 ,thus in ,aristotle's book ,de ,mirabilibus ,auscultationibus#gd1 ,there is said 7he states7 to be a peculiar formation of ,chalybean and ,misenian iron1 for instance the sort collected from river gravel2 some say #bc that after being simply washed it is smelted in the furnace2 others declare that it and the sediment which subsides after several washings are cast in and purified together by the fire2 with the addition of the stone pyrimachus which is found there in abundance4 ,thus do numerous sorts of things contain in their various substances notably and abundantly this element of iron and earth4 ,however1 there are many stones1 and very common ones1 found in every soil1 also earths1 and various and mixed materials1 which do not hold rich substances1 but yet have their own iron elements1 and yield them to skilfully-made fires1 yet which are left aside by metallick men because they are less profitable2 while other soils give some show of a ferruginous nature1 yet 7being very barren7 are hardly ever smelted down into iron2 and being neglected are not generally known4 ,manufactured irons differ very greatly amongst themselves4 ,for one kind is tenacious in its nature1 and this is the best2 one is of medium quality3 another is brittle1 and this is the worst4 ,sometimes the iron1 by reason of the excellency of the ore1 is wrought into steel1 as to-day in ,noricum4 ,from the finest iron1 too1 well wrought and purged from all dross1 or by being plunged in water after heating1 there issues what the ,greeks call ,greek3 stomma2 the ,latins acies2 others aciarium1 such as was at times called ,syrian1 ,parthian1 ,noric1 ,comese1 ,spanish2 elsewhere it is named from the water in which it is so often plunged1 as at ,como in ,italy#ge1 ,bambola and ,tarazona in ,spain4 ,acies fetches a much larger price than mere iron4 ,and owing to its superiority it better accords with the loadstone1 from which more powerful quality it is often smelted1 and it acquires the virtues from it more quickly1 retains them longer at their full1 and in the best condition for magnetical experiments4 ,after iron has been smelted in the first furnaces1 it is afterward wrought by various arts in large worksteads or mills1 the metal acquiring consistency when hammered with ponderous blows1 and throwing off the dross4 ,after the first smelting it is rather brittle and by no means perfect4 ,wherefore with us 7,english7 when the larger military guns are cast1 they purify the metal from dross more fully1 so that they may be stronger to withstand the force of the firing2 and they do this by making it pass again 7in a fluid state7 through a chink1 by which process it sheds its recremental matter4 ,smiths render iron sheets tougher with certain liquids1 and by blows of the hammer1 and from them make shields and breastplates that defy the blows of battle-axes4 ,iron becomes harder through skill and proper tempering1 but also by skill turns out in a softer condition and as pliable as lead4 ,it is made hard by the action of certain waters into which while glowing it is plunged1 as at ,bambola and ,tarazona in ,spain3 ,it grows soft again1 either by the effect of fire alone1 when without hammering and without water1 it is left to cool by itself2 or by that of grease into which it is plunged2 or #bd 7that it may the better serve for various trades7 it is tempered variously by being skilfully besmeared4 ,baptista ,porta expounds this art in book #ac of his ,magia ,naturalis4 ,thus this ferric and telluric nature is included and taken up in various bodies of stones1 ores1 and earths2 so too it differs in aspect1 in form1 and in efficiency4 ,art smelts it by various processes1 improves it1 and turns it1 above all material substances1 to the service of man in trades and appliances without end4 ,one kind of iron is adapted for breastplates1 another serves as a defence against shot1 another protects against swords and curved blades 7commonly called scimitars71 another is used for making swords1 another for horseshoes4 ,from iron are made nails1 hinges1 bolts1 saws1 keys1 grids1 doors1 folding-doors1 spades1 rods1 pitchforks1 hooks1 barbs1 tridents1 pots1 tripods1 anvils1 hammers1 wedges1 chains1 hand-cuffs1 fetters1 hoes1 mattocks1 sickles1 baskets1 shovels1 harrows1 planes1 rakes1 ploughshares1 forks1 pans1 dishes1 ladles1 spoons1 spits1 knives1 daggers1 swords1 axes1 darts1 javelins1 lances1 spears1 anchors1 and much ship's gear4 ,besides these1 balls1 darts1 pikes1 breastplates1 helmets1 cuirasses1 horseshoes1 greaves1 wire1 strings of musical instruments1 chairs1 portcullises1 bows1 catapults1 and 7pests of human kind7 cannon1 muskets1 and cannon-balls1 with endless instruments unknown to the ,latins3 which things ,i have rehearsed in order that it may be understood how great is the use of iron1 which surpasses a hundred times that of all the other metals2 and is day by day being wrought by metal-workers whose stithies are found in almost every village4 ,for this is the foremost of metals1 subserving many and the greatest needs of man1 and abounds in the earth above all other metals1 and is predominant4 ,wherefore those ,chemists are fools#gf who think that nature's will is to perfect all metals into gold2 she might as well be making ready to change all stones to diamonds1 since diamond surpasses all in splendour and hardness1 because gold excels in splendour1 gravity1 and density1 being invincible against all deterioration4 ,iron as dug up is therefore1 like iron that has been smelted1 a metal1 differing a little indeed from the primary homogenic terrestrial body1 owing to the metallick humour it has imbibed2 yet not so alien as that it will not1 after the manner of refined matter1 admit largely of the magnetick forces1 and may be associated with that prepotent form belonging to the earth1 and yield to it a due submission4 99 99 99 99 99 #be ,,chap4 ,,viii4 ,in what countries and districts iron originates4 ,plenty of iron mines exist everywhere1 both those of old time recorded in early ages by the most ancient writers1 and the new and modern ones4 ,the earliest and most important seem to me to be those of ,asia4 ,for in those countries which abound naturally in iron1 governments and the arts flourished exceedingly1 and things needful for the use of man were discovered and sought after4 ,it is recorded to have been found about ,andria1 in the region of the ,chalybes near the river ,thermodon in ,pontus2 in the mountains of ,palestine which face ,arabia2 in ,carmania3 in ,africa there was a mine of iron in the ,isle of ,meroe2 in ,europe in the hills of ,britain1 as ,strabo writes2 in ,hither ,spain1 in ,cantabria4 ,among the ,petrocorii and ,cubi ,biturges#gg 7peoples of ,gaul71 there were worksteads in which iron used to be wrought4 ,in greater ,germany near ,luna1 as recorded by ,ptolemy2 ,gothinian iron is mentioned by ,cornelius ,tacitus2 ,noric iron is celebrated in the verses of poets2 and ,cretan1 and that of ,euboea2 many other iron mines were passed over by these writers or unknown to them2 and yet they were neither poor nor scanty1 but most extensive4 ,pliny#gh says that ,hither ,spain and all the district from the ,pyrenees is ferruginous1 and on the part of maritime ,cantabria washed by the ,ocean 7says the same writer7 there is 7incredible to relate7 a precipitously high mountain wholly composed of this material4 ,the most ancient mines were of iron rather than of gold1 silver1 copper or lead2 since mainly this was sought because of the demand2 and also because in every district and soil they were easy to find1 not so deep-lying1 and less beset by difficulties4 ,if1 however1 ,i were to enumerate modern iron workings1 and those of this age and over ,europe only1 ,i should have to write a large and bulky volume1 and sheets of paper would run short quicker than the iron1 and yet for one sheet they could furnish a thousand worksteads4 ,for amongst minerals1 no material is so ample2 all metals1 and all stones distinct from iron1 are outdone by ferric and ferruginous matter4 ,for you will not readily find any region1 and scarcely any country district over the whole of ,europe 7if you search at all deeply71 that does not either produce a rich and abundant vein of iron or some soil containing or slightly charged with ferruginous stuff2 and that this is #bf true any expert in the arts of metals and chemistry will easily find4 ,beside that which has ferruginous nature1 and the metallick lode1 there is another ferric substance which does not yield the metal in this way because its thin humour is burnt out by fierce fires1 and it is changed into an iron slag like that which is separated from the metal in the first furnaces4 ,and of this kind is all clay and argillaceous earth1 such as that which apparently forms a large part of the whole of our island of ,britain3 all of which1 if subjected very vehemently to intense heat1 exhibits a ferric and metallick body1 or passes into ferric vitreous matter1 as can be easily seen in buildings in bricks baked from clay1 which1 when placed next the fires in the open kilns 7which our folk call clamps7#gi and burned1 present an iron vitrification1 black at the other end4 ,moreover all those earths as prepared are drawn by the magnet1 and like iron are attracted by it4 ,so perpetual and ample is the iron offspring of the terrestrial globe4 ,georgius ,agricola says that almost all mountainous regions are full of its ores1 while as we know a rich iron lode is frequently dug in the open country and plains over nearly the whole of ,england and ,ireland2 in no other wise than as1 says he1 iron is dug out of the meadows at the town of ,saga in pits driven to a two-foot depth4 ,nor are the ,west ,indies without their iron lodes1 as writers tell us2 but the ,spaniards1 intent upon gold1 neglect the toilsome work of iron-founding1 and do not search for lodes and mines abounding in iron4 ,it is probable that nature and the globe of the earth are not able to hide1 and are evermore bringing to the light of day1 a great mass of inborn matter1 and are not invariably obstructed by the settling of mixtures and efflorescences at the earth's surface4 ,it is not only in the common mother 7the terrestrial globe7 that iron is produced1 but sometimes also in the air from the earth's exhalations1 in the highest clouds4 ,it rained iron in ,lucania1 the year in which ,m4 ,crassus was slain4 ,the tale is told1 too1 that a mass of iron1 like slag1 fell from the air in the ,nethorian forest1 near ,grina1 and they narrate that the mass was many pounds in weight2 so that it could neither be conveyed to that place1 on account of its weight1 nor be brought away by cart1 the place being without roads4 ,this happened before the civil war waged between the rival dukes in ,saxony4 ,a similar story1 too1 comes to us from ,avicenna4 ,it once rained iron in the ,torinese#hj1 in various places 7,julius ,scaliger telling us that he had a piece of it in his house71 about three years before that province was taken over by the king4 ,in the year #aeaj in the country bordering on the river ,abdua 7as ,cardan writes#ha in his book ,de ,rerum ,varietate7 there fell from the sky #abjj stones1 one weighing #abj pounds1 another #cj or #dj pounds1 of a rusty iron colour and remarkably hard4 ,these occurrences being rare are regarded as portents1 like the showers of earth and stones mentioned in ,roman history4 ,but that it ever rained other metals is not #bg recorded2 for it has never been known to rain from the sky gold1 silver1 lead1 tin1 or spelter#hb4 ,copper1 however1 has been at some time noticed to fall from the sky1 and this is not very unlike iron2 and in fact cloud-born iron of this sort1 or copper1 are seen to be imperfectly metallick1 incapable of being cast in any way1 or wrought with facility4 ,for the earth hath of her store plenty of iron in her highlands1 and the globe contains the ferric and magnetick element in rich abundance4 ,the exhalations forcibly derived from such material may well become concreted in the upper air by the help of more powerful causes1 and hence some monstrous progeny of iron be begotten4 99 99 99 99 99 ,,chap4 ,,ix4 ,iron ore attracts iron ore4 ,from various substances iron 7like all the rest of the 99 metals7 is extracted3 such substances being stones1 earth1 and similar concretions which miners call veins because it is in veins#hc1 as it were1 that they are generated4 ,we have spoken above of the variety of these veins4 ,if a properly coloured ore of iron and a rich one 7as miners call it7 is placed1 as soon as mined1 upon water in a bowl or any small vessel 7as we have shown before in the case of a loadstone71 it is attracted by a similar piece of ore brought near by hand1 yet not so powerfully and quickly as one loadstone is drawn by another loadstone1 but slowly and feebly4 ,ores of iron that are stony1 cindery1 dusky1 red1 and several more of other colours1 do not attract one another mutually1 nor are they attracted by the loadstone itself1 even by a strong one1 no more than wood1 or lead1 silver1 or gold4 ,take those ores and burn1 or rather roast them1 in a moderate fire1 so that they are not suddenly split up1 or fly asunder1 keeping up the fire ten or twelve hours1 and gently increasing it1 then let them grow cold1 skill being shown in the direction in which they are placed3 ,these ores thus prepared a loadstone will now draw1 and they now show a mutual sympathy1 and when skilfully arranged run together by their own forces4 99 99 99 99 99 #bh ,,chap4 ,x4 99 ,iron ore has poles1 and acquires them1 and settles itself toward the poles of the universe4 ,deplorable is man's ignorance in natural science1 and modern philosophers1 like those who dream in darkness1 need to be aroused1 and taught the uses of things and how to deal with them1 and to be induced to leave the learning sought at leisure from books alone1 and that is supported only by unrealities of arguments and by conjectures4 ,for the knowledge of iron 7than which nothing is in more common use71 and that of many more substances around us1 remains unlearned2 iron1 a rich ore of which1 placed in a vessel upon water1 by an innate property of its own directs itself1 just like the loadstone1 ,north and ,south1 at which points it rests1 and to which1 if it be turned aside1 it reverts by its own inherent vigour4 ,but many ores1 less perfect in their nature1 which yet contain amid stone or earthy substances plenty of iron1 have no such motion2 but when prepared by skilful treatment in the fires1 as shown in the foregoing chapter1 they acquire a polar vigour 7which we call verticity#hd72 and not only the iron ores in request by miners1 but even earth merely charged with ferruginous matter1 and many rocks1 do in like manner tend and lean toward those portions of the heavens1 or more truly of the earth1 if they be skilfully placed1 until they reach the desired location1 in which they eagerly repose4 99 99 99 99 99 #bi ,,chap4 ,,xi4 99 ,wrought ,iron1 not excited by a loadstone1 draws iron4 ,from the ore1 which is converted1 or separated1 partly into metal1 partly into slag1 by the intense heat of fires1 iron is smelted in the first furnaces in a space of eight1 ten1 or twelve hours1 and the metal flows away from the dross and useless matter1 forming a large and long mass1 which being subjected to a sharp hammering is cut into parts1 out of which when reheated in the second hearth of the forge1 and again placed on the anvil1 the smiths fashion quadrangular lumps1 or more specially bars which are bought by merchants and blacksmiths1 from which in smithies usually it is the custom to fashion the various implements4 ,this iron we term wrought1 and its attraction by the loadstone is manifest to all4 ,but we1 by more carefully trying everything#he1 have found out that iron merely1 by itself alone1 not excited by any loadstone1 not charged by any alien forces1 attracts other iron2 though it does not so eagerly snatch and suddenly pluck at it as would a fairly strong loadstone2 this you may know thus3 ,a small piece of cork1 the size of a hazel-nut1 rounded1 is traversed by an iron wire up to the middle of the wire3 when set swimming on still water apply to one end of it1 close 7yet so as not to touch71 the end of another iron wire2 and wire draws wire1 and one follows the other when slowly drawn back1 and this goes on up to the proper boundaries4 ,let ,a be the cork with the iron wire1 ,b one end of it raised a little above the surface of the water1 ,c the end of the second wire1 showing the way in which ,b is drawn by ,c4 ,you may prove it in another way in a larger body4 ,let a long bright iron rod 7such as is made for hangings and window curtains7 be hung in balance by a slender silken cord3 to one end of this as it rests in the air bring a small oblong mass of polished iron1 with its proper #cj end at the distance of half a digit4 ,the balanced iron turns itself to the mass2 do you with the same quickness draw back the mass in your hand in a circular path about the point of equilibrium of the suspension2 the end of the balanced iron follows after it1 and turns in an orbit4 ,illustration 99 99 99 99 99 ,,chap4 ,,xii4 99 ,a long piece of ,iron1 even though not excited by a loadstone1 settles itself toward ,north and ,south4 ,every good and perfect piece of iron1 if drawn out in length1 points ,north and ,south1 just as the loadstone or iron rubbed with a magnetical body does2 a thing that our famous philosophers have little understood1 who have sweated in vain to set forth the magnetick virtues and the causes of the friendship of iron for the stone4 ,you may experiment with either large or small iron works1 and either in air or in water4 ,a straight piece of iron six feet long of the thickness of your finger is suspended 7in the way described in the foregoing chapter7 in exact quipoise by a strong and slender silken cord4 ,but the cord should be cross-woven of several silk filaments1 not twisted simply in one way2 and it should be in a small chamber with all doors and windows closed1 that the wind may not enter1 nor the air of the room be in any way disturbed2 for which reason it is not expedient that the trial should be made on windy days1 or while a storm is brewing4 ,for thus it freely follows its bent1 and slowly moves until at length1 as it rests1 it points with its ends ,north and ,south1 just as iron touched with a loadstone does in shadow-clocks1 and in compasses1 and in the mariners' compass4 ,you will be able1 if curious enough1 to balance all at the same time by fine threads a number of small rods1 or iron wires1 or long pins with which women knit stockings2 you will see that all of them at the same time are in accord1 unless there be some error in this delicate operation3 for unless you prepare everything fitly and skilfully1 the labour will be void4 ,make trial of this thing in water also1 which is done both more certainly and more easily4 ,let an iron wire two or three digits long1 more or less1 be passed through a round cork1 so that it may just float upon water2 and as soon as you have committed it to the waves1 it turns upon its own centre1 and one end tends to the ,north1 the other to the ,south2 the causes #ca of which you will afterwards find in the laws of the direction4 ,this too you should understand1 and hold firmly in memory1 that 99 as a strong loadstone1 and iron touched with the same1 do not invariably point exactly to the true pole but to the point of the variation2 so does a weaker loadstone1 and so does the iron1 which directs itself by its own forces only1 not by those impressed by the stone2 and so every ore of iron1 and all bodies naturally endowed with something of the iron nature1 and prepared1 turn to the same point of the horizon1 according to the place of the variation in that particular region 7if there be any variation therein71 and there abide and rest4 99 99 99 99 99 ,,chap4 ,,xiii4 99 ,wrought iron has in itself certain parts ,boreal and ,austral3 ,a magnetick vigour1 verticity1 and determinate vertices1 or poles4 ,iron settles itself toward the ,north and ,south2 not with one and the same point toward this pole or that3 for one end of the piece of ore itself and one extremity also of a wrought-iron wire have a sure and constant destination to the ,north1 the other to the ,south1 whether the iron hang in the air1 or float on water1 be the iron large rods or thinner wires4 ,even if it be a little rod1 or a wire ten or twenty or more ells in length2 one end as a rule is ,boreal1 the other ,austral4 ,if you cut off part of that wire1 and if the end of that divided part were ,boreal1 the other end 7which was joined to it7 will be ,austral4 ,thus if you divide it into several parts1 before making an experiment on the surface of water1 you can recognize the vertex#hf4 ,in all of them a ,boreal end draws an ,austral and repels a ,boreal1 and contrariwise1 according to the laws magnetical4 ,yet herein wrought iron differs from the loadstone and from its own ore1 inasmuch as in an iron ball of any size1 such as those used for artillery or cannon1 or bullets used for carbines or fowling-pieces1 verticity is harder to acquire and is less apparent than in a piece of loadstone1 or of ore itself1 or than in a round loadstone4 ,but in long and extended pieces of iron a power is at once discerned2 the causes of which fact1 and the methods by which it acquires its verticity and its poles without use of a loadstone1 as well as the reasons for all the other obscure features of verticity1 we shall set forth in describing the motion of direction4 99 99 99 99 99 #cb ,,chap4 ,,xiiii4 ,concerning other powers of loadstone1 and its medicinal properties4 ,dioscorides prescribes loadstone to be given with sweetened water1 three scruples' weight1 to expel gross humours4 ,galen writes that a like quantity of bloodstone avails4 ,others relate that loadstone perturbs the mind and makes folk melancholick1 and mostly kills4 ,gartias ab ,horto#hg thinks it not deleterious or injurious to health4 ,the natives of ,east ,india tell us1 he says1 that loadstone taken in small doses preserves youth4 ,on which account the aged king1 ,zeilam1 is said to have ordered the pans in which his victuals were cooked to be made of loadstone4 ,the person 7says he7 to whom this order was given told me so himself4 ,there are many varieties of loadstone produced by differences in the mingling of earths1 metals1 and juices2 hence they are altogether unlike in their virtues and effects1 due to propinquities of places and of agnate bodies1 and arising from the pits themselves as it were from the matrices being soul4 ,one loadstone is therefore able to purge the stomach1 and another to check purging1 to cause by its fumes a serious shock to the mind1 to produce a gnawing at the vitals1 or to bring on a grave relapse2 in case of which ills they exhibit gold and emerald1 using an abominable imposture for lucre4 ,pure loadstone may1 indeed1 be not only harmless1 but even able to correct an over-fluid and putrescent state of the bowels and bring them back to a better temperament2 of this sort usually are the oriental magnets from ,china1 and the denser ones from ,bengal1 which are neither misliking nor unpleasant to the actual senses4 ,plutarch and ,claudius ,ptolemy#hh1 and all the copyists since their time1 think that a loadstone smeared with garlick does not allure iron4 ,hence some suspect that garlick is of avail against any deleterious power of the magnet3 thus in philosophy many false and idle conjectures arise from fables and falsehoods4 ,some physicians#hi have that a loadstone has power to extract the iron of an arrow from the human body4 ,but it is when whole that the loadstone draws1 not when pulverized and formless1 buried in plasters2 for it does not attract by reason of its material1 but is rather adapted for the healing of open wounds1 by reason of exsiccation1 closing up and drying the sore1 an effect by which the arrow-heads would rather be retained in the wounds4 ,thus vainly and preposterously do the sciolists #cc look for remedies while ignorant of the true causes of things4 ,the application of a loadstone for all sorts of headaches no more cures them 7as some make out7 than would an iron helmet or a steel cap4 ,to give it in a draught to dropsical persons is an error of the ancients1 or an impudent tale of the copyists1 though one kind of ore may be found which1 like many more minerals1 purges the stomach2 but this is due to some defect of that ore and not to any magnetick property4 ,nicolaus puts a large quantity of loadstone into his divine plaster#ij1 just as the ,augsburgers do into a black plaster#ia for fresh wounds and stabs2 the virtue of which dries them up without smart1 so that it proves an efficacious medicament4 ,in like manner also ,paracelsus to the same end mingles it in his plaster for stab wounds#ib4 99 99 99 99 99 ,,chap4 ,,xv4 ,the ,medicinal ,virtue of ,iron4#ic ,not foreign to our present purpose will it be to treat briefly also of the medicinal virtue of iron3 for it is a prime remedial for some diseases of the human body1 and by its virtues1 both those that are natural and those acquired by suitable preparation1 it works marvellous changes in the human body1 so that we may the more surely recognize its nature through its medicinal virtue and through certain manifest experiments4 ,so that even those tyros in medicine who abuse this most famous medicament may learn to prescribe it with better judgment for the healing of the sick1 and not1 as too often they use it1 to their harm4 ,the best iron1 ,stomoma1 or ,chalybs1 ,acies1 or ,aciarium1 is reduced to a fine powder by a file2 the powder is steeped in the sharpest vinegar1 and dried in the sun1 and again soused in vinegar1 and dried2 afterwards it is washed in spring water or other suitable water1 and dried2 then for the second time it is pulverized and reduced on porphyry1 passed through a very fine sieve1 and put back for use4 ,it is given chiefly in cases of laxity and over-humidity of the liver1 in enlargement of the spleen1 after due evacuations2 for which reason it restores young girls when pallid1 sickly1 and lacking colour1 to health and beauty2 since it is very siccative1 and is astringent without harm4 ,but some who in every internal malady always talk of obstruction #cd of the liver and spleen1 think it beneficial in those cases because it removes obstructions1 mainly trusting to the opinions of certain ,arabians#id3 wherefore they administer it to the dropsical and to those suffering from tumour of the liver or from chronic jaundice1 and to persons troubled with hypochondrical melancholia or any stomachic disorder1 or add it to electuaries1 without doubt to the grievous injury of many of their patients4 ,fallopius commends it prepared in his own way for tumours of the spleen1 but is much mistaken2 for loadstone is pre-eminently good for spleens relaxed with humour1 and swollen2 but it is so far from curing spleens thickened into a tumour that it mightily confirms the malady4 ,for those drugs which are strong siccatives and absorb humour force the viscera when hardened into a tumour more completely into a quasi-stony body4 ,there are some who roast iron in a closed oven with fierce firing1 and burn it strongly1 until it turns red1 and they call this ,saffron of ,mars2 which is a powerful siccative1 and more quickly penetrates the intestines4 ,moreover they order violent exercise1 that the drug may enter the viscera while heated and so reach the place affected2 wherefore also it is reduced to a very fine flour2 otherwise it only sticks in the stomach and in the chyle and does not penetrate to the intestines4 ,as a dry and earthy medicament1 then1 it is shown by the most certain experiments to be1 after proper evacuations1 a remedy for diseases arising from humour 7when the viscera are charged and overflowing with watery rheum74 ,prepared steel is a medicament proper for enlarged spleen4 ,iron waters too are effectual in reducing the spleen1 although as a rule iron is of a frigid and astringent efficiency1 not a laxative2 but it effects this neither by heat nor by cold1 but from its own dryness when mixed with a penetrative fluid3 it thus disperses the humour1 thickens the villi1 hardens the tissues1 and contracts them when lax2 while the inherent heat in the member thus strengthened1 being increased in power1 dissipates what is left4 ,whereas if the liver be hardened and weakened by old age or a chronic obstruction1 or the spleen be shrivelled and contracted to a schirrus1 by which troubles the fleshy parts of the limbs grow flaccid1 and water under the skin invades the body1 in the case of these conditions the introduction of iron accelerates the fatal end1 and considerably increases the malady4 ,amongst recent writers there are some who in cases of drought of the liver prescribe1 as a much lauded and famous remedy1 the electuary of iron slag1 described by ,rhazes#ie in his ninth book ad ,almansorem1 ,chap4 #fc1 or prepared filings of steel2 an evil and deadly advice3 which if they do not some time understand from our philosophy1 at least everyday experience1 and the decline and death of their patients1 will convince them1 even the sluggish and lazy4 ,whether iron be warm or cold is variously contended by #ce many4 ,by ,manardus1 ,curtius1 ,fallopius and others1 many reasons are adduced on both sides2 each settles it according to his own sentiment4 ,some make it to be cold1 saying that iron has the property of refrigerating1 because ,aristotle in his ,meteorologica would put iron in the class of things which grow concreted in cold by emission of the whole of their ,heat3 ,galen1 too1 says that iron has its consistency from cold2 also that it is an earthy and dense body4 ,further that iron is astringent1 also that ,chalybeate water quenches thirst3 and they adduce the cooling effect of thermal iron waters4 ,others1 however1 maintain that it is ,warm1 because of ,hippocrates making out that waters are warm which burst forth from places where iron exists4 ,galen says that in all metals there is considerable substance1 or essence1 of fire4 ,paolo#if affirms that iron waters are warm4 ,rhazes will have it that iron is warm and dry in the third degree4 ,the ,arabians think that it opens the spleen and liver2 wherefore also that iron is warm4 ,montagnana recommends it in cold affections of the uterus and stomach4 ,thus do the smatterers cross swords together1 and puzzle inquiring minds by their vague conjectures1 and wrangle for trifles as for goats' wool1 when they philosophize1 wrongly allowing and accepting properties3 but these matters will appear more plainly by and by when we begin to discuss the causes of things2 the clouds being dispersed that have so darkened all ,philosophy4 ,filings1 scales1 and slag of iron are1 as ,avicenna makes out1 not wanting in deleterious power 7haply when they are not well prepared or are taken in larger quantity than is fit71 hence they cause violent pain in the bowels1 roughness of the mouth and tongue1 marasmus1 and shrivelling of the limbs4 ,but ,avicenna wrongly#ig and old-womanishly makes out that the proper antidote to this iron poison is loadstone to the weight of a drachm taken as a draught in the juice of mercurialis or of ,beet2 for loadstone is of a twofold nature1 usually malefiant and pernicious1 nor does it resist iron1 since it attracts it2 nor when drunk in a draught in the form of powder does it avail to attract or repel1 but rather inflicts the same evils4 99 99 99 99 99 #cf ,,chap4 ,,xvi4 ,that loadstone iron ore are the same1 but iron an extract from both1 as other metals are from their own ores2 that all magnetick virtues1 though weaker1 exist in the ore itself in smelted iron4 ,hitherto we have declared the nature powers of the loadstone1 also the properties essence of iron2 it now remains to show their mutual affinities1 kinship1 so to speak1 how very closely conjoined these substances are4 ,at the highest part of the terrestrial globe1 or at its perishable surface rind1 as it were1 these two bodies usually originate are produced in one and the same matrix1 as twins in one mine4 ,strong loadstones are dug up by themselves1 weaker ones too have their own proper vein4 ,both are found in iron mines4 ,iron ore most often occurs alone1 without strong loadstone 7for the more perfect are rarely met with74 ,strong loadstone is a stone resembling iron2 out of it is usually smelted the finest iron1 which the ,greeks call stomoma1 the ,latins acies1 the ,barbarians 7not amiss7 aciare1 or aciarium4 ,this same stone draws1 repels1 controls other loadstones1 directs itself to the poles of the world1 picks up smelted iron1 and works many other wonders1 some already set forth by us1 but many more which we must demonstrate more fully4 ,a weaker loadstone1 however1 will exhibit all these powers1 but in a lesser degree2 while iron ore1 also wrought iron 7if they have been prepared7 show their strength in all magnetick experiments not less than do feeble and weak 99 loadstones2 an inert piece of ore1 one possessed of no magnetick properties1 just thrown out#ih of the pit1 when roasted in the fire prepared with due art 7by the elimination of humours foreign excretions7 awakes1 and becomes in power potency a magnet1 99 occasionally a stone or iron ore is mined1 which attracts forthwith without being prepared3 for native iron of the right colour attracts and governs iron magnetically4 ,one form then belongs to the one mineral1 one species1 one self-same essence4 ,for to me there seems to be a greater difference1 unlikeness1 between the strongest #cg loadstone1 a weak one which scarce can attract a single chip of iron2 between one that is stout1 strong1 metallick1 one that is soft1 friable1 clayey2 amidst such variety of colour1 substance1 quality1 weight2 than there is on the one hand between the best ore1 rich in iron1 or iron that is metallick from the beginning1 and on the other the most excellent loadstone4 ,usually1 too1 there are no marks to distinguish them1 and even metallurgists cannot decide between them1 because they agree together in all respects4 ,moreover we see that the best loadstone and the ore of iron are both as it were distressed by the same maladies diseases1 both run to old age in the same way exhibit the same marks of it1 are preserved keep their properties by the same remedies safeguards2 yet again the one increases the potency of the other1 by artfully devised adjuncts marvellously intensifies1 exalts it4 ,for both are impaired by the more acrid juices as by poisons1 the aqua fortis of the ,chemists inflicts on both the same wounds1 and when exposed too long to harm from the atmosphere1 they both alike pine away1 so to speak1 grow old2 each is preserved by being kept in the dust scrapings of the other2 when a fit piece of steel or iron is adjoined above its pole1 the loadstone's vigour is augmented through the firm union4 ,the loadstone is laid up in iron filings1 not that iron is its food2 as though loadstone were alive and needed feeding1 as ,cardan philosophizes#ii2 nor yet that so it is delivered from the inclemency of the weather 7for which cause it as well as iron is laid up in bran by ,scaliger2 mistakenly1 however1 for they are not preserved well in this way1 and keep for years their own fixed forms73 nor yet1 since they remain perfect by the mutual action of their powders1 do their extremities waste away1 but are cherished preserved1 like by like4 ,for just as in their own places1 in the mines1 bodies like to each other endure for many ages entire and uncorrupt1 when surrounded by bodies of the same stuff1 as the lesser interior parts in a great mass3 so loadstone and ore of iron1 when inclosed in a mound of the same material1 do not exhale their native humour1 do not waste away1 but retain their soundness4 ,a loadstone lasts longer in filings of smelted iron1 a piece of iron ore excellently also in dust of loadstone2 as also smelted iron in filings of loadstone even in those of iron4 ,then both these allied bodies have a true just form of one the same species2 a form which until this day was considered by all1 owing to their outward unlikeness the inequality of the potency that is the same innate in both1 to be different unlike in kind2 the smatterers not understanding that the same powers1 though differing in strength1 exist in both alike4 ,and in fact they both are true intimate parts of the earth1 as such retain the prime natural properties of mutually attracting1 of moving1 of disposing themselves toward the position of the world1 #ch and of the terrestrial globe2 which properties they also impart to each other1 and increase1 confirm1 receive1 and retain each other's forces4 ,the stronger fortifies the weaker1 not as though aught were taken away from its own substance1 or its proper vigour1 nor because any corporeal substance is imparted1 but the dormant virtue of the one is aroused by the other1 without loss4 ,for if with a single small stone you touch a thousand bits of iron for the use of mariners#ajj1 that loadstone attracts iron no less strongly than before2 with the same stone weighing one pound1 any one will be able to suspend in the air a thousand pounds of iron4 ,for if any one were to fix high up on the walls so many iron nails of so great a weight1 were to apply to them the same number of nails touched1 according to the art1 by a loadstone1 they would all be seen to hang in the air through the force of one small stone4 ,so this is not solely the action1 labour1 or outlay of the loadstone2 but the iron1 which is in a sense an extract from loadstone1 and a fusion of loadstone into metal1 conceives vigour from it1 by proximity strengthens the magnetick faculties1 doth itself1 from whatever lode it may have come1 raise its own inborn forces through the presence contact of the stone1 even when solid bodies intervene4 ,iron that has been touched1 acts anew on another piece of iron by contact1 adapts it for magnetick movements1 this again a third4 ,but if you rub with a loadstone any other metal1 or wood1 or bones1 or glass1 as they will not be moved toward any particular and determinate quarter of heaven1 nor be attracted by any magnetick body1 so they are able not to impart any magnetick property to other bodies or to iron itself by attrition1 by infection4 ,loadstone differs from iron ore1 as also from some weaker magnets1 in that when molten in the furnace into a ferric metallick fused mass1 it does not so readily flow dissolve into metal2 but is sometimes burnt to ashes in large furnaces2 a result which it is reasonable to suppose arises from its having some kind of sulphureous matter mixed with it1 or from its own excellence simpler nature1 or from the likeness common form which it has with the common mother1 the ,great ,magnet4 ,for earths1 and iron stones1 magnets abounding in metal1 are the more imbued marred with excrementitious metallick humours1 and earthy corruptions of substance1 as numbers of loadstones are weaker from the mine2 hence they are a little further remote from the common mother1 are degenerate1 when smelted in the furnace undergo fusion more easily1 give out a more certain metallick product1 a metal that is softer1 not a tough steel4 ,the majority of loadstones 7if not unfairly burnt#aja7 yield in the furnace a very excellent iron4 ,but iron ore also agrees in all those primary qualities with loadstone2 for both1 being nearer and more closely akin to the earth above all bodies known to us1 have in themselves #ci a magnetick substance1 one that is more homogenic1 true cognate with the globe of the earth2 less infested spoiled by foreign blemish2 less confused with the outgrowths of earth's surface1 less debased by corrupt products4 ,and for this reason ,aristotle in the fourth book of his ,meteora seems not unfairly to separate iron from all the rest of the metals4 ,gold1 he says1 silver1 copper1 tin1 lead1 belong to water2 but iron is of the earth4 ,galen1 in the fourth chapter of ,de ,facultatibus ,simplicium ,medicamentorum1 says that iron is an earthy dense body4 ,accordingly a strong loadstone is on our showing especially of the earth3 the next place is occupied by iron ore or weaker loadstone2 so the loadstone is by nature and origin#ajb9999 of iron1 and it and magnetick iron are both one in kind4 ,iron ore yields iron in furnaces2 loadstone also pours forth iron in the furnaces1 but of a much more excellent sort1 that which is called steel or blade-edge2 and the better sort of iron ore is a weak loadstone1 the best loadstone being a most excellent ore of iron1 in which1 as is to be shown by us1 the primary properties are grand and conspicuous4 ,weaker loadstone or iron ore is that in which these properties are more obscure1 feeble1 and are scarce perceptible to the senses4 99 99 99 99 99 ,,chap4 ,,xvii4 ,that the globe of the earth is magnetick1 a magnet2 how in our hands the magnet stone has all the primary forces of the earth1 while the earth by the same powers remains constant in a fixed direction in the universe4 ,prior to bringing forward the causes of magnetical motions1 laying open the proofs of things hidden for so many ages1 our experiments 7the true foundations of terrestrial philosophy71 we have to establish present to the view of the learned our ,new unheard of doctrine about the earth2 and this1 when argued by us on the grounds of its probability1 with subsequent #dj experiments proofs1 will be as certainly assured as anything in philosophy ever has been considered confirmed by clever arguments or mathematical proofs4 ,the terrene mass1 which together with the vasty ocean produces the sphrick figure constitutes our globe1 being of a firm constant substance1 is not easily changed1 does not wander about1 fluctuate with uncertain motions1 like the seas1 flowing waves3 but holds all its volume of moisture in certain beds bounds1 as it were in oft-met veins1 that it may be the less diffused dissipated at random4 ,yet the solid magnitude of the earth prevails reigns supreme in the nature of our globe4 ,water1 however1 is attached to it1 as an appendage only1 a flux emanating from it2 whose force from the beginning is conjoined with the earth through its smallest parts1 and is innate in its substance4 ,this moisture the earth as it grows hot throws off freely when it is of the greatest possible service in the generation of things4 ,but the thews and dominant stuff of the globe is that terrene body which far exceeds in quantity all the volume of flowing streams and open waters 7whatever vulgar philosophers may dream of the magnitudes and proportions of their elements71 and which takes up most of the whole globe and almost fills it internally1 and by itself almost suffices to endow it with sphrick shape4 ,for the seas only fill certain not very deep or profound hollows1 since they rarely go down to a depth of a mile and generally do not exceed a hundred or #ej fathoms4 ,for so it is ascertained by the observations of seamen when by the plumb-line and sinker its abysms are explored with the nautical sounder2 which depths relatively to the dimensions of the globe1 do not much deform its globular shape4 ,small then appears to be that portion of the real earth that ever emerges to be seen by man1 or is turned up2 since we cannot penetrate deeper into its bowels1 further than the wreckage of its outer efflorescence1 either by reason of the waters which gush up in deep workings1 as through veins1 or for want of a wholesome air to support life in the miners1 or on account of the vast cost that would be incurred in pumping out such huge workings#ajc1 and many other difficulties2 so that to have gone down to a depth of four hundred1 or 7which is of rarest occurrence7 of five hundred fathoms#ajd as in a few mines1 appears to all a stupendous undertaking4 ,but it is easy to understand how minute1 how almost negligibly small a portion that #ejj fathoms is of the earth's diameter1 which is #f1hgb miles4 ,it is then parts only of the earth's circumference and of its prominences that are perceived by us with our senses2 and these in all regions appear to us to be either loamy1 or clayey1 or sandy1 or full of various soils1 or marls3 or lots of stones or gravel meet us1 or beds of salt1 or a metallick lode1 and metals in abundance4 ,in the sea and in deep waters1 however1 either reefs1 and huge boulders1 or smaller stones1 or sands1 or mud #da are found by mariners as they sound the depths4 ,nowhere does the ,aristotelian element of earth come to light2 and the ,peripateticks are the sport of their own vain dreams about elements4 ,yet the lower bulk of the earth and the inward parts of the globe consist of such bodies2 for they could not have existed1 unless they had been related to and exposed to the air and water1 and to the light and influences of the heavenly bodies1 in like manner as they are generated1 and pass into many dissimilar forms of things1 and are changed by a perpetual law of succession4 ,yet the interior parts imitate them1 and betake themselves to their own source1 on the principle of terrene matter1 albeit they have lost the first qualities and the natural terrene form1 and are borne towards the earth's centre1 and cohre with the globe of the earth1 from which they cannot be wrenched asunder except by force4 ,but the loadstone and all magneticks1 not the stone only1 but every magnetick homogenic substance1 would seem to contain the virtue of the earth's core and of its inmost bowels1 and to hold within itself and to have conceived that which is the secret and inward principle of its substance2 and it possesses the actions peculiar to the globe of attracting1 directing1 disposing1 rotating1 stationing itself in the universe1 according to the rule of the whole1 and it contains and regulates the dominant powers of the globe2 which are the chief tokens and proofs of a certain distinguishing combination1 and of a nature most thoroughly conjoint4 ,for if among actual bodies one sees something move and breathe1 and experience sensations1 and be inclined and impelled by reason1 will one not1 knowing and seeing this1 conclude that it is a man or something rather like a man1 than that it is a stone or a stick8 ,the loadstone far excels all other bodies known to us in virtues and properties pertaining to the common mother3 but those properties have been far too little understood or realized by philosophers3 for to its body bodies magnetical rush in from all sides and cleave to it1 as we see them do in the case of the earth4 ,it has poles1 not mathematical points1 but natural termini of force excelling in primary efficiency by the co-operation of the whole3 and there are poles in like manner in the earth which our forefathers sought ever in the sky3 it has an quator1 a natural dividing line between the two poles1 just as the earth has3 for of all lines drawn by the mathematicians on the terrestrial globe1 the quator is the natural boundary1 and is not1 as will hereafter appear1 merely a mathematical circle4 ,it1 like the earth1 acquires ,direction and stability toward ,north and ,south1 as the earth does2 also it has a circular motion toward the position of the earth1 wherein it adjusts itself to its rule3 it follows the ascensions and declinations of the earth's poles1 and conforms exactly to the same1 and by itself raises its own poles above the #db horizon naturally according to the law of the particular country and region1 or sinks below it4 ,the loadstone derives temporary properties1 and acquires its verticity from the earth1 and iron is affected by the verticity of the globe even as iron is by a loadstone3 ,magneticks are conformable to and are regulated by the earth1 and are subject to the earth in all their motions4 ,all its movements harmonize with1 and strictly wait upon1 the geometry and form of the earth1 as we shall afterwards prove by most conclusive experiments and diagrams2 and the chief part of the visible earth is also magnetical1 and has magnetick motions1 although it be disfigured by corruptions and mutations without end4 ,why then do we not recognize this the chief homogenic substance of the earth1 likest of substances to its inner nature and closest allied to its very marrow8 ,for none of the other mixed earths suitable for agriculture1 no other metalliferous veins1 nor stones1 nor sand1 nor other fragments of the earth which have come to our view possess such constant and peculiar powers4 ,and yet we do not assume that the whole interior of this globe of ours is composed of stones or iron 7although ,franciscus ,maurolycus1 that learned man1 deems the whole of the earth's interior to consist of solid stone74 ,for not every loadstone that we have is a stone1 it being sometimes like a clod1 or like clay and iron either firmly compacted together out of various materials1 or of a softer composition1 or by heat reduced to the metallick state2 and the magnetick substance by reason of its location and of its surroundings1 and of the metallick matrix itself1 is distinguished1 at the surface of the terrene mass1 by many qualities and adventitious natures1 just as in clay it is marked by certain stones and iron lodes4 ,but we maintain that the true earth is a solid substance1 homogeneous with the globe1 closely coherent1 endowed with a primordial and 7as in the other globes of the universe7 with a prepotent form2 in which position it persists with a fixed verticity1 and revolves with a necessary motion and an inherent tendency to turn1 and it is this constitution1 when true and native1 and not injured or disfigured by outward defects1 that the loadstone possesses above all bodies apparent to us1 as if it were a more truly homogenic part taken from the earth4 ,accordingly native iron which sui generis 7as metallurgists term it71 is formed when homogenic parts of the earth grow together into a metallick lode2 ,loadstone being formed when they are changed into metallick stone1 or a lode of the finest iron1 or steel3 so in other iron lodes the homogenic matter that goes together is somewhat more imperfect2 just as many parts of the earth1 even the high ground1 is homogenic but so much more deformate4 ,smelted iron is fused and smelted out of homogenic stuffs1 and cleaves to the earth more tenaciously than the ores themselves4 ,such then is our earth in its #dc inward parts1 possessed of a magnetick homogeneal nature1 and upon such more perfect foundations as these rests the whole nature of things terrestrial1 manifesting itself to us1 in our more diligent scrutiny1 everywhere in all magnetick minerals1 and iron ores1 in all clay1 and in numerous earths and stones2 while ,aristotle's simple element1 that most empty terrestrial phantom of the ,peripateticks1 a rude1 inert1 cold1 dry1 simple matter1 the universal substratum1 is dead1 devoid of vigour1 and has never presented itself to any one1 not even in sleep1 and would be of no potency in nature4 ,our philosophers were only dreaming when they spoke of a kind of simple and inert matter4 ,cardan does not consider the loadstone to be any kind of stone1 but a sort of perfected portion of some kind of earth that is absolute2 a token of which is its abundance1 there being no place where it is not found4 ,and there is 7he says7 a power of iron in the wedded ,earth which is perfect in its own kind when it has received fertilizing force from the male1 that is to say1 the stone of ,hercules 7in his book ,de ,proportionibus74 ,and later3 ,because 7he says7 in the previous proposition ,i have taught that iron is true earth4 ,a strong loadstone shows itself to be of the inward earth1 and upon innumerable tests claims to rank with the earth in the possession of a primary form1 that by which ,earth herself abides in her own station and is directed in her courses4 ,thus a weaker loadstone and every ore of iron1 and nearly all clay1 or clayey earth1 and numerous other sorts 7yet more1 or less1 owing to the different labefaction of fluids and slimes71 keep their magnetick and genuine earth-properties open to view1 falling short of the characteristic form1 and deformate4 ,for it is not iron alone 7the smelted metal7 that points to the poles1 nor is it the loadstone alone that is attracted by another and made to revolve magnetically2 but all iron ores1 and other stones1 as ,rhenish slates and the black ones from ,avignon 7the ,french call them ,ardoises7 which they use for tiles1 and many more of other colours and substances1 provided they have been prepared2 as well as all clay1 grit#aje1 and some sorts of rocks1 and1 to speak more clearly1 all the more solid earth that is everywhere apparent2 given that that earth be not fouled with fatty and fluid corruptions2 as mud1 as mire1 as accumulations of putrid matter2 nor deformate by the imperfections of sundry admixtures2 nor dripping with ooze1 as marls2 all are attracted by the loadstone1 when simply prepared by fire1 and freed from their refuse humour2 and as by the loadstone so also by the earth herself they are drawn and controlled magnetically1 in a way different from all other bodies2 and by that inherent force settle themselves according to the orderly arrangement and fabric of the universe and of the ,earth1 as will appear #dd later4 ,thus every part of the earth which is removed from it exhibits by sure experiments every impulse of the magnetick nature2 by its various motions it observes the globe of the earth and the principle common to both4 ,illustration 99 99 99 99 99 #de ,illustration ,,book ,,second4 ,,chap4 ,i4 ,,on ,,magnetick ,motions4 ,divers things concerning opinions about the magnet-stone1 and its variety1 concerning its poles and its known faculties1 concerning iron1 concerning the properties of iron1 concerning a magnetick substance common to both of these and to the earth itself1 have been spoken briefly by us in the former book4 ,there remain the magnetical motions1 and their fuller philosophy1 shown and demonstrated4 ,these motions are incitements of homogeneal parts either among themselves or toward the primary conformation of the whole earth4 ,aristotle admits only two simple motions of his elements1 from the centre and toward the centre2 of light ones upward1 heavy ones downward2 so that in the earth there exists one motion only of all its parts towards the centre of the world1--a rude and inert precipitation4 ,but what of it is light1 and how wrongly it is inferred by the ,peripateticks from the simple motion of the elements1 and also what is its heavy part1 we will discuss elsewhere4 ,but now our inquiry must be into the causes of other motions1 depending on its true form1 which we have plainly seen in our magnetick bodies2 and these we have seen to be present in the earth and in all its homogenic parts also4 ,we have noticed that they harmonize with the earth1 and are bound up with its forces4 ,five movements#ajf or differences of motions are then observed by us3 ,coition 7commonly called attraction71 the #df incitement to magnetick union2 ,direction towards the poles of the earth1 and the verticity and continuance of the earth towards the determinate poles of the world2 ,variation1 a deflexion from the meridian1 which we call a perverted movement2 ,declination1 a descent of the magnetick pole below the horizon2 and circular motion1 or ,revolution4 ,concerning all these we shall discuss separately1 and how they all proceed from a nature tending to aggregation1 either by verticity or by volubility4 ,jofrancus ,offusius#ajg makes out different magnetick motions2 a first toward a centre2 a second toward a pole at seventy-seven degrees2 a third toward iron2 a fourth toward loadstone4 ,the first is not always to a centre1 but exists only at the poles in a straight course toward the centre1 if the motion is magnetick2 otherwise it is only motion of matter toward its own mass and toward the globe4 ,the second toward a pole at seventy-seven degrees is no motion1 but is direction with respect to the pole of the earth1 or variation4 ,the third and fourth are magnetick and are the same4 ,so he truly recognizes no magnetick motion except the ,coition toward iron or loadstone1 commonly called attraction4 ,there is another motion in the whole earth1 which does not exist towards the terrella or towards its parts2 videlicet1 a motion of aggregation1 and that movement of matter1 which is called by philosophers a right motion1 of which elsewhere4 99 99 99 99 99 ,,chap4 ,,ii4 ,on the ,magnetick ,coition1 and first on the ,attraction of ,amber1 or more truly1 on the ,attaching of ,bodies to ,amber4 ,celebrated has the fame of the loadstone and of amber ever been in the memoirs of the learned4 ,loadstone and also amber do some philosophers invoke when in explaining many secrets their senses become dim and reasoning cannot go further4 ,inquisitive theologians also would throw light on the divine mysteries set beyond the range of human sense1 by means of loadstone and amber2 just as idle ,metaphysicians1 when they are setting up and teaching useless phantasms1 have recourse to the loadstone as if it were a ,delphick sword1 an illustration always applicable to everything4 ,but physicians even 7with the authority of #dg ,galen71 desiring to confirm the belief in the attraction of purgative medicines by means of the likeness of substance and the familiarities of the juices--truly a vain and useless error--bring in the loadstone as witness as being a nature of great authority and of conspicuous efficacy and a remarkable body4 ,so in very many cases there are some who1 when they are pleading a cause and cannot give a reason for it1 bring in loadstone and amber as though they were personified witnesses4 ,but these men 7apart from that common error7 being ignorant that the causes of magnetical motions are widely different from the forces of amber1 easily fall into error1 and are themselves the more deceived by their own cogitations4 ,for in other bodies a conspicuous force of attraction manifests itself otherwise than in loadstone2 like as in amber1 concerning which some things must first be said1 that it may appear what is that attaching of bodies1 and how it is different from and foreign to the magnetical actions2 those mortals being still ignorant1 who think that inclination to be an attraction1 and compare it with the magnetick coitions4 ,the ,greeks call it ,greek3 lektron#ajh because it attracts straws to itself1 when it is warmed by rubbing2 then it is called ,greek3 harpax#aji2 and ,greek3 chrusophoron from its golden colour4 ,but the ,moors call it ,carabe#aaj1 because they are accustomed to offer the same in sacrifices and in the worship of the ,gods4 ,for ,carab signifies to offer in ,arabic2 so ,carabe1 an offering3 or seizing chaff1 as ,scaliger quotes from ,abohalis1 out of the ,arabic or ,persian language4 ,some also call it ,amber1 especially the ,indian and ,ethiopian amber1 called in ,latin ,succinum1 as if it were a juice#aaa4 ,the ,sudavienses or ,sudini#aab call it geniter1 as though it were generated terrestrially4 ,the errors of the ancients concerning its nature and origin having been exploded1 it is certain that amber comes for the most part from the sea1 and the rustics collect it on the coast after the more violent storms1 with nets and other tackle2 as among the ,sudini of ,prussia2 and it is also found sometimes on the coast of our own ,britain4 ,it seems1 however1 to be produced also in the soil and at spots of some depth1 like other bitumens2 to be washed out by the waves of the sea2 and to become concreted more firmly from the nature and saltness of the sea-water4 ,for it was at first a soft and viscous material2 wherefore also it contains enclosed and entombed in pieces of it1 shining in eternal sepulchres1 flies1 grubs1 gnats1 ants2 which have all flown or crept or fallen into it when it first flowed forth in a liquid state#aac4 ,the ancients and also more recent writers recall 7experience proving the same thing71 that amber attracts straws and chaff#aad4 ,the same is also done by jet#aae1 which is dug out of the earth in ,britain1 in ,germany1 and in very many lands1 and is a rather hard concretion from black bitumen1 and as it were a transformation into stone4 ,there are many modern authors#aaf who have written and copied from others about amber and jet#aag attracting chaff1 and about other #dh substances generally unknown2 with whose labours the shops of booksellers are crammed4 ,our own age has produced many books about hidden1 abstruse1 and occult causes and wonders1 in all of which amber and jet are set forth as enticing chaff2 but they treat the subject in words alone1 without finding any reasons or proofs from experiments1 their very statements obscuring the thing in a greater fog1 forsooth in a cryptic1 marvellous1 abstruse1 secret1 occult1 way4 ,wherefore also such philosophy produces no fruit1 because very many philosophers1 making no investigation themselves1 unsupported by any practical experience1 idle and inert1 make no progress by their records1 and do not see what light they can bring to their theories2 but their philosophy rests simply on the use of certain ,greek words1 or uncommon ones2 after the manner of our gossips and barbers nowadays1 who make show of certain ,latin words to an ignorant populace as the insignia of their craft1 and snatch at the popular favour4 ,for it is not only amber and 99 jet 7as they suppose7 which entice small bodies#aah2 but ,diamond1 ,sapphire1 ,carbuncle1 ,iris gem#aai1 ,opal1 ,amethyst1 ,vincentina1 and ,bristolla 7an ,english gem or spar7#abj1 ,beryl1 and ,crystal#aba do the same4 ,similar powers of attraction are seen also to be possessed by glass 7especially when clear and lucid71 as also by false gems made of glass or ,crystal1 by glass of antimony1 and by many kinds of spars from the mines1 and by ,belemnites4 ,sulphur also attracts1 and mastick1 and hard sealing-wax#abb compounded of lac tinctured of various colours4 ,rather hard resin entices1 as does orpiment#abc1 but less strongly2 with difficulty also and indistinctly under a suitable dry sky#abd1 ,rock salt1 muscovy stone1 and rock alum4 ,this one may see when the air is sharp and clear and rare in mid-winter1 when the emanations from the earth hinder electricks less1 and the electrick bodies become 99 more firmly indurated2 about which hereafter4 ,these substances draw everything1 not straws and chaff only#abe1 but all metals1 woods1 leaves1 stones1 earths1 even water and oil1 and everything which is subject to our senses1 or is solid2 although some write that amber does not attract anything but chaff and certain twigs2 7wherefore ,alexander ,aphrodiseus falsely declares the question of amber to be inexplicable1 because it attracts dry chaff only1 and not basil leaves#abf71 but these are the utterly false and disgraceful tales of the writers4 ,but in order that you may be able clearly to test how such attraction occurs#abg1 and what those materials#abh are which thus entice other bodies 7for even if bodies incline towards some of these1 yet on account of weakness they seem not to be raised by them1 but are more easily turned71 make yourself a versorium of any metal you like1 three or four digits in length1 resting rather lightly on its point of support after the manner of a magnetick needle1 to one end of which bring up a piece of amber or a smooth #di ,illustration and polished gem which has been gently rubbed2 for the versorium turns forthwith4 ,many things are thereby seen to attract1 both those which are formed by nature alone1 and those which are by art prepared1 fused1 and mixed2 nor is this so much a singular property of one or two things 7as is commonly supposed71 but the manifest nature of very many1 both of simple substances1 remaining merely in their own form1 and of compositions1 as of hard sealing-wax1 of certain other mixtures besides1 made of unctuous stuffs4 ,we must1 however1 investigate more fully whence that tendency arises1 and what those forces be1 concerning which a few men have brought forward very little1 the crowd of philosophizers nothing at all4 ,by ,galen three kinds of attractives in general were recognized in nature3 a ,first class of those substances which attract by their elemental quality1 namely1 heat2 the ,second is the class of those which attract by the succession of a vacuum2 the ,third is the class of those which attract by a property of their whole substance1 which are also quoted by ,avicenna and others4 ,these classes1 however1 cannot in any way satisfy us2 they neither embrace the causes of amber1 jet1 and diamond1 and of other similar substances 7which derive their forces on account of the same virtue72 nor of the loadstone1 and of all magnetick substances1 which obtain their virtue by a very dissimilar and alien influence from them1 derived from other sources4 ,wherefore also it is fitting that we find other causes of the motions1 or else we must wander 7as in darkness71 with these men1 and in no way reach the goal4 ,amber truly does99 not allure by heat1 since if warmed by fire and brought near straws1 it does not attract them1 whether it be tepid1 or hot1 or glowing1 or even when forced into the flame4 ,cardan 7as also ,pictorio7 reckons that this happens in no different way#abi than with the cupping-glass1 by the force of fire4 ,yet the attracting force of the cupping-glass does not really come from the force of fire4 ,but he had previously said that the dry substance wished to imbibe fatty humour1 and therefore it was borne towards it4 ,but these statements are at variance with one another1 and also foreign to reason4 ,for if amber had moved towards its food1 or if other bodies had inclined towards amber as towards provender1 there would have been a diminution of the one which was devoured1 just as there would have been a growth of the other which was sated4 ,then why should an attractive force of fire be looked for in amber8 ,if the attraction existed from heat1 why should not very many other bodies also attract1 if warmed by fire1 by the sun1 or by friction8 ,neither can the attraction be on account of the dissipating of the air1 when it takes place in open air 7yet ,lucretius the poet adduces this as the reason for magnetical motions74 ,nor in the cupping-glass can heat or fire attract by feeding on air3 in the cupping-glass air1 having been exhausted into flame1 #ej when it condenses again and is forced into a narrow space1 makes the skin and flesh rise in avoiding a vacuum4 ,in the open air warm things cannot attract1 not metals even or stones1 if they should 99 be strongly incandescent by fire4 ,for a rod of glowing iron1 or a flame1 or a candle1 or a blazing torch1 or a live coal1 when they are brought near to straws1 or to a versorium1 do not attract2 yet at the same time they manifestly call in the air in succession2 because they consume it1 as lamps do oil4 ,but concerning heat1 how it is reckoned by the crowd of philosophizers1 in natural philosophy and in materia medica to exert an attraction otherwise than nature allows1 to which true attractions are falsely imputed1 we will discuss more at length elsewhere1 when we shall determine what are the properties of heat and cold4 ,they are very general qualities or kinships of a substance1 and yet are not to be assigned as true causes1 and1 if ,i may say so1 those philosophizers utter some resounding words2 but about the thing itself prove nothing in particular4 ,nor does this attraction accredited to amber arise from any singular quality of the substance or kinship1 since by more thorough research we find the same effect in very many other bodies2 and all bodies1 moreover1 of whatever quality1 are allured by all those bodies4 ,similarity also is not the cause2 because all things around us placed on this globe of the earth1 similar and dissimilar1 are allured by amber and bodies of this kind2 and on that account no cogent analogy is to be drawn either from similarity or identity of substance4 ,but neither do similars mutually attract one another1 as stone stone1 flesh flesh1 nor aught else outside the class of magneticks and electricks4 ,fracastorio would have it that things which mutually attract one another are similars1 as being of the same species1 either in action or in right subjection4 ,right subjection is that from which is emitted the emanation which attracts and which in mixtures often lies hidden on account of their lack of form1 by reason of which they are often different in act from what they are in potency4 ,hence it may be that hairs and twigs move towards amber and towards diamond1 not because they are hairs1 but because either there is shut up in them air or some other principle1 which is attracted in the first place1 and which bears some relation and analogy to that which attracts of itself2 in which diamond and amber agree through a principle common to each4 ,thus far ,fracastorio4 ,who if he had observed by a large number of experiments that all bodies are drawn to electricks except those which are aglow and aflame1 and highly rarefied1 would never have given a thought to such things4 ,it is easy for men of acute intellect1 apart from experiments and practice1 to slip and err4 ,in greater error do they remain sunk who maintain these same substances to be not similar1 but to be substances near akin2 and hold that on that account a thing moves towards another1 its like1 by which it is brought to more perfection4 ,but these are #ea ill-considered views2 for towards all electricks all things move#acj except such as are aflame or are too highly rarefied1 as air1 which is the universal effluvium of this globe and of the world4 ,vegetable substances draw moisture by which their shoots are rejoiced and grow2 from analogy with that1 however1 ,hippocrates1 in his ,de ,natura ,hominis1 ,book ,i41 wrongly concluded that the purging of morbid humour took place by the specifick force of the drug4 ,concerning the action and potency of purgatives we shall speak elsewhere4 ,wrongly also is attraction inferred in other effects2 as in the case of a flagon full of water1 when buried in a heap of wheat1 although well stoppered1 the moisture is drawn out2 since this moisture is rather resolved into vapour by the emanation of the fermenting wheat1 and the wheat imbibes the freed vapour4 ,nor do elephants' tusks attract moisture1 but drive it into vapour or absorb it4 ,thus then very many things are said to attract1 the reasons for whose energy must be sought from other causes4 ,amber in a fairly large mass allures1 if99 it is polished2 in a smaller mass or less pure it seems not to attract without friction4 ,but very many electricks 7as precious stones and some other substances7 do not attract at all unless rubbed4 ,on the other hand many gems1 as well as other bodies1 are polished1 yet do99 not allure1 and by no amount of friction are they aroused2 thus the emerald1 agate1 carnelian1 pearls1 jasper1 chalcedony1 alabaster1 porphyry1 coral1 the marbles1 touchstone1 flint1 bloodstone1 emery#aca1 do not acquire any power2 nor do bones1 or ivory1 or the hardest woods1 as ebony1 nor do cedar1 juniper1 or cypress2 nor do metals1 silver1 gold1 brass1 iron1 nor any loadstone1 though many of them are finely polished and shine4 ,but on the other hand there are some other polished substances of which we have spoken before1 toward which1 when they have been rubbed1 bodies incline4 ,this we shall understand only when we have more closely looked into the prime origin of bodies4 ,it is plain to all1 and all admit1 that the mass of the earth1 or rather the structure and crust of the earth1 consists of a twofold material1 namely1 of fluid and humid matter1 and of material of more consistency and dry4 ,from this twofold nature or the more simple compacting of one1 various substances take their rise among us1 which originate in greater proportion now from the earthy1 now from the aqueous nature4 ,those substances which have received their chief growth from moisture1 whether aqueous or fatty1 or have taken on their form by a simpler compacting from them1 or have been compacted from these same materials in long ages1 if they have a sufficiently firm hardness1 if rubbed after they have been polished and when they remain bright with the friction--towards those substances everything1 if presented to them in the air1 turns1 if its too heavy weight does not prevent it4 ,for amber has been compacted of moisture1 and jet also4 ,lucid gems are made of water2 just as ,crystal#acb1 which has been concreted from clear water1 not #eb always by a very great cold1 as some used to judge1 and by very hard frost1 but sometimes by a less severe one1 the nature of the soil fashioning it1 the humour or juices being shut up in definite cavities1 in the way in which spars are produced in mines4 ,so clear glass is fused out of sand1 and from other substances1 which have their origin in humid juices4 ,but the dross of metals1 as also metals1 stones1 rocks1 woods1 contain earth rather1 or are mixed with a good deal of earth2 99 and therefore they do not attract4 ,crystal1 mica1 glass1 and all electricks do not attract if they are burnt or roasted2 for their primordial supplies of moisture perish by heat1 and are changed and exhaled4 ,all things therefore which have sprung from a predominant moisture and are firmly concreted1 and retain the appearance of spar and its resplendent nature in a firm and compact body1 allure all bodies1 whether humid or dry4 ,those1 however1 which partake of the true earth-substance or are very little different from it1 are seen to attract also1 but from a far different reason1 and 7so to say7 magnetically2 concerning these we intend to speak afterwards4 ,but those substances which are more mixed of water and earth1 and are produced by the equal degradation of each element 7in which the magnetick force of the earth is deformed and remains buried2 while the watery humour1 being fouled by joining with a more plentiful supply of earth1 has not concreted in itself but is mingled with earthy matter71 can in no way of themselves attract or move from its place anything which they do not touch4 ,on this account metals1 marbles1 flints1 woods1 herbs1 flesh1 and very many other things can neither allure nor solicit any body either magnetically or electrically4 7,for it pleases us to call that an electrick force1 which hath 99 its origin from the humour47 ,but substances consisting mostly of humour1 and which are not very firmly compacted by nature 7whereby do they neither bear rubbing1 but either melt down and become soft1 or are not levigable1 such as pitch1 the softer kinds of resin1 camphor1 galbanum1 ammoniack#acc1 storax1 asafoetida1 benzoin1 asphaltum1 especially in rather warm weather7 towards them small bodies are not borne2 for without rubbing most electricks do not 99 emit their peculiar and native exhalation and effluvium4 ,the resin turpentine when liquid does not attract2 for it cannot be rubbed2 but if it has hardened into a mastick it does attract4 ,but now at length we must understand why small bodies turn towards those substances which have drawn their origin from water2 by what force and with what hands 7so to speak7 electricks seize upon kindred natures4 ,in all bodies in the world two causes or principles have been laid down1 from which the bodies themselves were produced1 matter and form#acd4 ,electrical motions become strong from matter1 but magnetick from form chiefly2 and they differ widely from one another and turn out unlike1 since the one is ennobled by numerous virtues and is prepotent2 the other is ignoble and of less potency1 and #ec mostly restrained1 as it were1 within certain barriers2 and therefore that force must at times be aroused by attrition or friction1 until it is at a dull heat and gives off an effluvium and a polish is induced on the body4 ,for spent air1 either blown out of the mouth or given99 off from moister air1 chokes the virtue4 ,if indeed either a sheet of paper or a piece of linen be interposed1 there will be no movement4 ,but a loadstone1 without friction or heat1 whether dry or suffused with moisture1 as well in air as in water1 invites magneticks1 even with the most solid bodies interposed1 even planks of wood or pretty thick slabs of stone or sheets of metal4 ,a loadstone appeals to magneticks99 only2 towards electricks all things move4 ,a loadstone#ace raises great weights2 so that if there is a loadstone weighing two ounces and strong1 it attracts half an ounce or a whole ounce4 ,an electrical substance only attracts very small weights2 as1 for instance1 a piece of amber of three ounces weight1 when rubbed1 scarce raises a fourth part of a grain of barley4 ,but this attraction of amber and of electrical substances must be further investigated2 and since there is this particular affection of matter1 it may be asked why is amber rubbed1 and what affection is produced by the rubbing1 and what causes arise which make it lay hold on everything8 ,as a result of friction it grows slightly warm and becomes smooth2 two results which must often occur together4 ,a large polished fragment of amber or jet attracts indeed1 even without friction1 but less strongly2 but if it be brought gently near a flame or a live coal1 so that it equally becomes warm1 it does not attract small bodies because99 it is enveloped in a cloud from the body of the flaming substance1 which emits a hot breath1 and then impinges upon it vapour from a foreign body which for the most part is at variance with the nature of amber4 ,moreover the spirit of the amber which is called forth is enfeebled by alien heat2 wherefore it ought not to have heat excepting that produced by motion only and friction1 and1 as it were1 its own1 not sent into it by other bodies4 ,for as the igneous heat emitted from any burning substance cannot be so used that electricks may acquire their force from it2 so also heat from the solar rays does not fit an electrick by the loosening of its99 right material1 because it dissipates rather and consumes it 7albeit a body which has been rubbed retains its virtue longer exposed to the rays of the sun than in the shade2 because in the shade the effluvia are condensed to a greater degree and more quickly74 ,then again the fervour from the light of the ,sun aroused by means of a99 burning mirror confers no vigour on the heated amber#acf2 indeed it dissipates and corrupts all the electrick effluvia4 ,again1 burning99 sulphur and hard wax1 made from shell-lac1 when aflame do not allure2 for heat from friction resolves bodies into effluvia1 which flame consumes away4 ,for it is impossible for solid electricks to be resolved into their own true effluvia otherwise than by attrition1 save #ed in the case of certain substances which by reason of innate vigour emit effluvia constantly4 ,they are rubbed with bodies which do not befoul their surface1 and which produce a polish1 as pretty stiff silk or a rough wool rag which is as little soiled as possible1 or the dry palm4 ,amber also is rubbed with amber1 with diamond1 and with glass1 and numerous other substances4 ,thus are electricks manipulated4 ,these things being so1 what is it which moves8 ,is it the body itself1 inclosed within its own circumference8 ,or is it something imperceptible to us1 which flows out from the substance into the ambient air8 ,somewhat as ,plutarch opines1 saying in his ,qustiones ,platonic#acg3 ,that there is in amber something flammable or something having the nature of breath1 and this by the attrition of the surface being emitted from its relaxed pores attracts bodies4 ,and if it be an effusion does it seize upon the air whose motion the bodies follow1 or upon the bodies themselves8 ,but if amber allured the body itself1 then what need were there of friction1 if it is bare and smooth8 ,nor does the force arise from the light which is reflected from a smooth and polished body2 for a ,gem of ,vincent's rock#ach1 ,diamond1 and clear glass1 attract when they are rough2 but not so powerfully and quickly1 because they are not so readily cleansed from extraneous moisture on the surface1 and are not rubbed equally so as to be copiously resolved at that part4 ,nor does the sun by its own beams of light and its rays1 which are of capital importance in nature1 attract bodies in this way2 and yet the herd of philosophizers considers that humours are attracted by the sun1 when it is only denser humours that are being turned into thinner1 into spirit and air2 and so by the motion of effusion they ascend into the upper regions1 or the attenuated exhalations are raised up from the denser air4 ,nor does it seem to take place from the effluvia attenuating the air1 so that bodies impelled by the denser air penetrate towards the source of the rarefaction2 in this case both hot and flaming bodies would also allure other bodies2 but not even the lightest chaff1 or any versorium moves towards a flame4 ,if there is a flow and rush of air towards the body1 how can a small diamond of the size of a pea#aci summon towards itself so much air1 that it seizes hold of a biggish long body placed in equilibrio 7the air about one or other very small part of an end being attracted78 ,it ought also to have slopped or moved more slowly1 before it came into contact with the body1 especially if the piece of amber was rather broad and flat1 from the accumulation of air on the surface of the amber and its flowing back again4 ,if it is because the effluvia are thinner1 and denser vapours come in return1 as in breathing1 then the body would rather have had a motion toward the electrick a little while after the beginning of the application2 but when electricks which have been rubbed are applied quickly to 99 a versorium then especially at once they act on the versorium1 and it is attracted more when near them4 ,but if it is because the rarefied #ee effluvia produce a rarefied medium1 and on that account bodies are more prone to slip down from a denser to a more attenuated medium2 they might have been carried from the side in this way or downwards1 but not to bodies above them2 or the attraction and apprehension of contiguous bodies would have been momentary only4 ,but with a single friction jet and amber draw and attract bodies to them strongly and for a long time1 sometimes for the twelfth part of an hour1 especially in clear weather4 ,but if the mass of amber be rather large1 and the surface polished1 it attracts without friction4 ,flint is rubbed and emits by attrition an inflammable matter that turns into sparks and heat4 ,therefore the denser effluvia of flint producing fire are very far different from electrical effluvia1 which on account of their extreme attenuation do not take fire1 nor are fit material for flame4 ,those effluvia are not of the nature of breath1 for when emitted they do not propel anything1 but are exhaled without sensible resistance and touch bodies4 ,they are highly attenuated humours much more subtile than the ambient air2 and in order that they may occur1 bodies are required produced from humour and concreted with a considerable degree of hardness4 ,non-electrick bodies are not resolved into humid effluvia1 and those effluvia mix with the common and general effluvia of the earth1 and are not peculiar4 ,also besides the attraction of bodies1 they retain them longer4 ,it is probable therefore that amber does exhale something peculiar to 99 itself1 which allures bodies themselves1 not the intermediate air4 ,indeed it plainly does draw the body itself in the case of a spherical drop of water standing on a dry surface2 for a piece of amber applied to it at a suitable distance pulls the nearest parts out of their position and draws it up into a cone2 otherwise1 if it were 99 drawn by means of the air rushing along1 the whole drop would have moved4 ,that it does not attract the air is thus demonstrated3 take a very thin wax candle1 which makes a very small and clear flame2 bring up to this1 within two digits or any convenient distance1 a piece of amber or jet1 a broad flat piece1 well prepared 99 and skilfully rubbed1 such a piece of amber as would attract bodies far and wide1 yet it does not disturb the flame2 which of necessity would have occurred1 if the air was disturbed1 for the flame would have followed the current of air4 ,as far as the effluvia are sent out1 so far it allures2 but as a body approaches1 its motion is accelerated1 stronger forces drawing it2 as also in the case of magneticks and in all natural motion2 not by attenuating or by expelling the air1 so that the body moves down into the place of the air which has gone out#adj2 for thus it would have allured only and would not have retained2 since it would at first also have repelled approaching bodies just as it drives the air itself2 but indeed a particle1 be it ever so small1 does not avoid the first application made very quickly after rubbing4 ,an effluvium exhales from amber and is emitted by rubbing3 pearls1 carnelian1 agate1 jasper1 chalcedony1 coral1 metals1 #ef and other substances of that kind1 when they are rubbed1 produce no effect4 ,is there not also something which is exhaled from them by heat and attrition8 ,most truly2 but from grosser bodies more blended with the earthy nature1 that which is exhaled is gross and spent2 for even towards very many electricks1 if they are rubbed 99 too hard1 there is produced but a weak attraction of bodies1 or none at all2 the attraction is best when the rubbing has been gentle and very quick2 for so the finest effluvia are evoked4 ,the effluvia arise from the subtile diffusion of humour1 not from excessive and turbulent violence2 especially in the case of those substances which have been compacted from unctuous matter1 which when the atmosphere is very thin1 when the ,north winds1 and amongst us 7,english7 the ,east winds1 are blowing1 have a surer and firmer effect1 but during ,south winds and in damp weather1 only a weak one2 so that those 99 substances which attract with difficulty in clear weather1 in thick weather produce no motion at all2 both because in grosser air lighter substances move with greater difficulty2 and especially because the effluvia are stifled1 and the surface of the body that has been rubbed is affected by the spent humour of the air1 and the effluvia are stopped at their very starting4 ,on that account in the case of amber1 jet1 and sulphur1 because they do not so easily take up moist air on their surface and are much more plenteously set free1 that force is not so quickly suppressed as in gems1 crystal1 glass1 and substances of that kind which collect on their surface the moister breath which has grown heavy4 ,but it may be asked why does amber allure water1 when water placed on its surface removes its action8 ,evidently because it is one thing to suppress it at its very start1 and quite another to extinguish it when it has been 99 emitted4 ,so also thin and very fine silk1 in common language ,sarcenet1 placed quickly on the amber1 after it has been rubbed1 99 hinders the attraction of the body2 but if it is interposed in the intervening space1 it does not entirely obstruct it4 ,moisture also from spent air1 and any breath blown from the mouth1 as well as water put on the amber1 immediately extinguishes its force4 ,but oil1 which is light and pure1 does not hinder it2 for although amber 99 be rubbed with a warm finger dipped in oil1 still it attracts4 ,but 99 if that amber1 after the rubbing1 is moistened with aqua vit or spirits of wine1 it does not attract2 for it is heavier than oil1 denser1 and when added to oil sinks beneath it4 ,for oil is light and rare1 and does not resist the most delicate effluvia4 ,a breath therefore1 proceeding from a body which had been compacted from humour or from a watery liquid1 reaches the body to be attracted2 the body that is reached is united with the attracting body1 and the one body lying near the other within the peculiar radius of its effluvia makes one out of two2 united1 they come together into the closest accord1 and this is commonly called attraction4 ,this unity1 according to #eg the opinion of ,pythagoras1 is the principle of all things1 and through participation in it each several thing is said to be one4 ,for since no action can take place by means of matter unless by contact1 these electricks are not seen to touch1 but1 as was necessary1 something is sent from the one to the other1 something which may touch closely and be the beginning of that incitement4 ,all bodies are united and1 as it were1 cemented together in some way by moisture2 so that a wet body1 when it touches another body1 attracts it1 if it is small4 ,so wet bodies on the surface of water attract wet bodies4 ,but the peculiar electrical effluvia1 which are the most subtile material of diffuse humour1 entice corpuscles4 ,air 7the common effluvium of the earth7 not only unites the disjointed parts1 but the earth calls bodies back to itself by means of the intervening air2 otherwise bodies which are in higher places would not so eagerly make for the earth4 ,electrical effluvia differ greatly from air2 and as air is the effluvium of the earth1 so electricks have their own effluvia and properties1 each of them having by reason of its peculiar effluvia a singular tendency toward unity1 a motion toward its origin and fount1 and toward the body emitting the effluvia4 ,but those substances which by attrition emit a gross or vapourous or aeriform effluvium produce no effect2 for either such effluvia are alien to the humour 7the uniter of all things71 or being very like common air are blended with the air and intermingle with the air1 wherefore they produce no effect in the air1 and do not cause motions different from those so universal and common in nature4 ,in like manner 99 bodies strive to be united and move on the surface of water1 just ,illustration as the rod ,c1 which is put a little way under water4 ,it is plain that the rod ,e ,f1 which floats on the water by reason of the cork ,h1 and only has its wet end ,f above the surface of the water1 is attracted by the rod ,c1 if the rod ,c is wet a little above the surface of the water2 they are suddenly united1 just as a drop adjoining a drop is attracted4 ,so a wet thing on the surface of water seeks union with a wet thing1 since the surface of the water is raised on both2 and they immediately flow together1 just like drops or bubbles4 ,but they are in much greater proximity than electricks1 and are united by their clammy natures4 ,if1 however1 the whole rod be dry 99 above the water1 it no longer attracts1 but drives away the stick ,e ,f4 ,the same is seen in those bubbles also which are made on #eh water4 ,for we see one drive towards another1 and the quicker the nearer they are4 ,solids are impelled towards solids by the medium of liquid3 for example1 touch the end of a versorium with the end of a rod on which a drop of water is projecting2 as soon as the versorium touches the top of the droplet1 immediately it is joined 99 strongly by a swift motion to the body of the rod4 ,so concreted humid things attract when a little resolved into air 7the effluvia in the intermediate space tending to produce unity72 for water has on wet bodies1 or on bodies wet with abundant moisture on the top of water1 the force of an effluvium4 ,clear air is a convenient medium for an electrical effluvium excited from concreted humour4 ,wet bodies projecting above the surface of water 7if they are near7 run together so that they may unite2 for the surface of the water is raised around wet substances4 ,but a dry thing is not impelled to a wet one1 nor a wet to a dry1 but seems to run away4 ,for if all is dry above the water1 the surface of the water close to it does not rise1 but shuns it1 the wave sinking around a dry thing4 ,so neither does a wet thing move towards the dry rim of a vessel2 but it seeks ,illustration a wet rim4 ,a ,b is the surface of the water2 ,c ,d two rods1 which stand up wet above the water2 it is manifest that the surface of the water is raised at ,c and ,d along with the rods2 and therefore the rod ,c1 by reason of the water standing up 7which seeks its level and unity71 moves with the water to ,d4 ,on ,e1 on the other hand1 a wet rod1 the water also rises2 but on the dry rod ,f the surface is depressed2 and as it drives to depress also the wave rising on ,e in its neighbourhood1 the higher wave at ,e turns away from ,f#ada2 for it does not suffer itself to be depressed4 ,all electrical attraction occurs through an intervening humour2 so it is by reason of humour that all things mutually come together2 fluids indeed and aqueous bodies on the surface of water1 but concreted things1 if they have been resolved into vapour1 in air2--in air indeed1 the effluvium of electricks being very rare1 that it may the better permeate the medium and not impel it by its motion2 for if that effluvium had been thick1 as that of air1 or of the winds1 or of saltpetre burnt by fire1 as the thick and foul effluvia given out with very great force1 from other bodies1 or air set free from humour by heat rushing out through a pipe 7in the instrument of ,hero of ,alexandria1 described in his #ei book ,spiritalia71 then the effluvium would drive everything away1 not allure it4 ,but those rarer effluvia take hold of bodies and embrace them as if with arms extended1 with the electricks to which they are united2 and they are drawn to the source1 the effluvia increasing in strength with the proximity4 ,but what is that effluvium from crystal1 glass1 and diamond1 since these are bodies of considerable hardness and firmly concreted8 ,in order that such an effluvium should be produced1 there is no need of any marked or perceptible flux#adb of the substance2 nor is it necessary that the electrick should be abraded1 or worn away1 or deformed4 ,some odoriferous substances are fragrant for many years1 exhaling continually1 yet are not quickly consumed4 ,cypress wood as long as it is sound1 and it lasts a very long time indeed1 is redolent2 as many learned men attest from experience4 ,such an electrick only for a moment1 when stimulated by friction1 emits powers far more subtile and more fine beyond all odours2 yet sometimes amber1 jet1 sulphur1 when they are somewhat easily let free into vapour1 also pour out at the same time an odour2 and on this account they allure with the very gentlest rubbing1 often even without rubbing2 they also excite more strongly1 and retain hold for a longer time1 because they have stronger effluvia and last longer4 ,but diamond1 glass1 rock-crystal1 99 and numerous others of the harder and firmly concreted gems first grow warm3 therefore at first they are rubbed longer1 and then they also attract strongly2 nor are they otherwise set free into vapour4 ,everything rushes towards electricks#adc excepting flame1 and flaming bodies1 and the thinnest air4 ,just as they do not draw flame1 in like manner they do not affect a versorium1 if on any side it is very near to a flame1 either the flame of a lamp or of any burning matter4 ,it is manifest indeed that the effluvia are destroyed by flame and igneous 99 heat2 and therefore they attract neither flame nor bodies very near a flame4 ,for electrical effluvia have the virtue of1 and are analogous with1 extenuated humour2 but they will produce their effect1 union and continuity1 not by the external impulse of vapours1 not by heat and attenuation of heated bodies1 but by their humidity itself attenuated into its own peculiar effluvia4 ,yet they entice 99 smoke sent out by an extinguished light2 and the more that smoke is attenuated in seeking the upper regions1 the less strongly is it turned aside2 for things that are too rarefied are not drawn to them2 and at length1 when it has now almost vanished1 it does not 99 incline towards them at all1 which is easily seen against the light4 ,when in fact the smoke has passed into air1 it is not moved1 as has been demonstrated before4 ,for air itself1 if somewhat thin1 is not attracted in any way1 unless on account of succeeding that which has vacated its place1 as in furnaces and such-like1 where the air is fed in by mechanical devices for drawing it in4 ,therefore an effluvium resulting from a non-fouling friction1 and one which #fj is not changed by heat1 but which is its own1 causes union and coherency1 a prehension and a congruence towards its source1 if only the body to be attracted is not unfitted for motion1 either by the surroundings of the bodies or by its own weight4 ,to the bodies therefore of the electricks themselves small bodies are borne4 ,the effluvia extend out their virtue--effluvia which are proper and peculiar to them1 and sui generis1 differing from common air1 being produced from humour1 excited by a calorifick motion from attrition and attenuation4 ,and as if they were material rays#add1 they hold and take up chaff1 straws1 and twigs1 until they become extinct or vanish away3 and then they 7the corpuscles7 being loosed again1 attracted by the earth itself1 fall down to the earth4 ,the difference between ,magneticks and ,electricks#ade is that all magneticks run together with mutual forces2 electricks only allure2 that which is allured is not changed by an implanted force1 but that which has moved up to 99 them voluntarily rests upon them by the law of matter4 ,bodies are borne towards electricks in a straight line towards the centre of the electrick2 a loadstone draws a loadstone directly at the poles only1 in other parts obliquely and transversely1 and in this way also they adhere and hang to one another4 ,electrical motion is a motion of aggregation of matter2 magnetical motion is one of disposition and conformation4 ,the globe of the earth is aggregated and cohres by itself electrically4 ,the globe of the earth is directed and turned magnetically2 at the same time also it both cohres1 and in order that it may be solid1 is in its inmost parts cemented together4 99 99 99 99 99 ,,chap4 ,,iii4 ,opinions of others on ,magnetick ,coition1 which they call ,attraction4 ,discussion having now been made concerning electricks1 the causes of magnetick coition must be set forth4 ,we say coition1 not attraction#adf4 ,the word attraction unfortunately crept into magnetick philosophy from the ignorance of the ancients2 for there seems to be force applied where there is attraction and an imperious violence dominates4 ,for1 if ever there is talk about magnetick attraction1 we understand thereby magnetick coition1 or a primary running together4 ,now in truth it will not be useless here first briefly to set forth the views given by others1 both the ancient #fa and the more modern writers4 ,orpheus in his hymns#adg narrates that iron is attracted by loadstone as the bride to the arms of her espoused4 ,epicurus holds that iron is attracted by a loadstone just as straws by amber2 and1 he adds1 the ,atoms and indivisible particles which are given off by the stone and by the iron fit one another in shape2 so that they easily cling to one another2 when therefore these solid particles of stone or of iron strike against one another1 then they rebound into space1 being brought against one another by the way1 and they draw the iron along with them4 ,but this cannot be the case in the least2 since solid and very dense substances interposed1 even squared blocks of marble1 do not obstruct this power1 though they can separate atoms from atoms2 and the stone and the iron would be speedily dissipated into such profuse and perpetual streams of atoms4 ,in the case of amber1 since there is another different method of attracting1 the ,epicurean atoms cannot fit one another in shape4 ,thales1 as ,aristotle writes1 ,de ,anima1 ,bk4 ,i41 deemed the loadstone to be endowed with a soul of some sort1 because it had the power of moving and drawing iron towards it4 ,anaxagoras also held the same view4 ,in the ,timus of ,plato there is an idle fancy#adh about the efficacy of the stone of ,hercules4 ,for he says that all flowings of water1 likewise the fallings of thunderbolts1 and the things which are held wonderful in the attraction of ,amber1 and of the ,herculean stone1 are such that in all these there is never any attraction2 but since there is no vacuum1 the particles drive one another mutually around1 and when they are dispersed and congregated together1 they all pass1 each to its proper seat1 but with changed places2 and it is forsooth1 on account of these intercomplicated affections that the effects seem to arouse the wonder in him who has rightly investigated them4 ,galen does not know why ,plato should have seen fit to select the theory of circumpulsion rather than that of attraction 7differing almost on this point alone from ,hippocrates71 though indeed it does not agree in reality with either reason or experiment4 ,nor indeed is either the air or anything else circumpelled2 and the bodies themselves which are attracted are carried towards the attracting substance not confusedly1 or in an orbe4 ,lucretius1 the poet of the ,epicurean sect1 sang his opinion of it thus3 #adi;,first1 then1 know1 ,ceaseless effluvia from the magnet flow1-- ,effluvia1 whose superior powers expel ,the air that lies between the stone and steel4 ,a vacuum formed1 the steely atoms fly ,in a link'd train1 and all the void supply2 ,while the whole ring to which the train is join'd ,the influence owns1 and follows close behind4 c4 #fb ,such a reason ,plutarch also alleges in the ,qustiones ,platonic3 ,that that stone gives off heavy exhalations1 whereby the adjacent air1 being impelled along1 condenses that which is in front of it2 and that air1 being driven round in an orbe and reverting to the place it had vacated1 drags the iron forcibly along with it4 ,the following explanation of the virtues of the loadstone and of amber is propounded by ,johannes ,costus of ,lodi#aej4 ,for he would have it that there is mutual work and mutual result1 and therefore the motion is partly due to the attraction of the loadstone and partly to a spontaneous movement on the part of the iron3 ,for as we say that vapours issuing from the loadstone hasten by their own nature to attract the iron1 so also the air repelled by the vapours1 whilst seeking a place for itself1 is turned back1 and when turned back1 it impels the iron1 lifts it up1 as it were1 and carries it along2 the iron being of itself also excited somehow4 ,so by being drawn out and by a spontaneous motion1 and by striking against another substance1 there is in some way produced a composite motion1 which motion would nevertheless be rightly referred to attraction1 because the terminus from which this motion invariably begins is the same terminus at which it ends1 which is the characteristic proper of an attraction4 ,there is certainly a mutual action1 not an operation1 nor does the loadstone attract in that way2 nor is there any impulsion4 ,but neither is there that origination of the motion by the vapours1 and the turning of them back1 which opinion of ,epicurus has so often been quoted by others4 ,galen errs in his ,de ,naturalibus ,facultatibus1 ,book ,i41 chap4 #ad1 when he expresses the view that whatever agents draw out either the venom of serpents or darts also exhibit the same power as the loadstone4 ,now of what sort may be the attraction of such medicaments 7if indeed it may be called attraction7 we shall consider elsewhere4 ,drugs against poisons or darts have no relation to1 no similitude with1 the action of magnetical bodies4 ,the followers of ,galen 7who hold that purgative medicaments attract because of similitude of substance7 say that bodies are attracted on account of similitude1 not identity1 of substance2 wherefore the loadstone draws iron1 but iron does not draw iron4 ,but we declare and prove that this happens in primary bodies1 and in those bodies that are pretty closely related to them and especially like in kind one to another1 on account of their identity2 wherefore also loadstone draws loadstone and likewise iron iron2 every really true earth draws earth2 and iron fortified by a loadstone within the orbe of whose virtue it is placed draws iron more strongly than it does the loadstone4 ,cardan asks why no other metal is attracted by any other stone2 because 7he replies7 no metal is so cold as iron2 as if indeed cold were the cause of the attraction1 or as if iron were much colder than lead1 which neither follows nor is deflected towards a loadstone4 #fc ,but that is a chilly story1 and worse than an old woman's tale4 ,so also is the notion that the loadstone is alive and that iron is its food4 ,but how does the loadstone feed on the iron1 when the filings in which it is kept are neither consumed nor become lighter8 ,cornelius ,gemma1 ,cosmographia1 ,bk4 ,x4#aea1 holds that the loadstone draws iron to it by insensible rays1 to which opinion he conjoins a story of a sucking fish and another about an antelope4 ,guilielmus ,puteanus#aeb derives it1 not from any property of the whole substance unknown to any one and which cannot be demonstrated in any way 7as ,galen1 and after him almost all the physicians1 have asserted71 but from the essential nature of the thing itself1 as if moving from the first by itself1 and1 as it were1 by its own most powerful nature and from that innate temperament1 as it were an instrument1 which its substance1 its effective nature uses in its operations1 or a secondary cause and deprived of its intermediary2 so the loadstone attracts the iron not without a physical cause and for the sake of some good4 ,but there is no such thing in other substances springing from some material form2 unless it were primary1 which he does not recognize4 ,but certes good is shown to the loadstone by the stroke of the iron 7as it were1 association with a friend72 yet it cannot either be discovered or conceived how that disposition may be the instrument of form4 ,for what can temperament do in magnetical motions1 which must be compared with the fixed1 definite1 constant motions of the stars1 at great distances in case of the interposition of very dense and thick bodies8 ,to ,baptista ,porta#aec the loadstone seems a sort of mixture of stone and iron1 in such a way that it is an iron stone or stony iron4 ,but ,i think 7he says7 the ,loadstone is a mixture of stone and iron1 as an iron stone1 or a stone of iron4 ,yet do not think the stone is so changed into iron1 as to lose its own ,nature1 nor that the iron is so drowned in the stone1 but it preserves itself2 and whilst one labours to get the victory of the other1 the attraction is made by the combat between them4 ,in that body there is more of the stone than of iron2 and therefore the iron1 that it may not be subdued by the stone1 desires the force and company of iron2 that being not able to resist alone1 it may be able by more help to defend itself4444 ,the ,loadstone draws not stones1 because it wants them not1 for there is stone enough in the body of it2 and if one ,loadstone draw another1 it is not for the stone1 but for the iron that is in it4 ,as if in the loadstone the iron were a distinct body and not mixed up as the other metals in their ores6 ,and that these1 being so mixed up1 should fight with one another1 and should extend their quarrel1 and that in consequence of the battle auxiliary forces should be called in1 is indeed absurd4 ,but iron itself1 when excited by a loadstone1 seizes iron no less strongly than the loadstone4 ,therefore those fights1 seditions1 and conspiracies in the stone1 as if it were nursing up perpetual quarrels1 #fd whence it might seek auxiliary forces1 are the ravings of a babbling old woman1 not the inventions of a distinguished mage4 ,others have lit upon sympathy as the cause4 ,there may be fellow-feeling1 and yet the cause is not fellow-feeling2 for no passion can rightly be said to be an efficient cause4 ,others hold likeness of substance1 many others insensible rays as the cause2 men who also in very many cases often wretchedly misuse rays1 which were first introduced in the natural sciences by the mathematicians4 ,more eruditely does ,scaliger#aed say that the iron moves toward the loadstone as if toward its parent1 by whose secret principles it may be perfected1 just as the earth toward its centre4 ,the ,divine ,thomas#aee does not differ much from him1 when in the #gth book of his ,physica he discusses the reasons of motions4 ,in another way1 he says1 it may be said to attract a thing1 because it moves it to itself by altering it in some way1 from which alteration it happens that when altered it moves according to its position1 and in this manner the loadstone is said to attract iron4 ,for as the parent moves things whether heavy or light1 in as far as it gives them a form1 by means of which they are moved to their place2 so also the loadstone gives a certain quality to the iron1 in accordance with which it moves towards it4 ,this by no means ill-conceived opinion this most learned man shortly afterwards endeavoured to confirm by things which had obtained little credence respecting the loadstone and the adverse forces of garlick4 ,cardinal ,cusan#aef also is not to be despised4 ,iron has1 he says1 in the loadstone a certain principle of its own effluence2 and whilst the loadstone by its own presence excites the heavy and ponderous iron1 the iron is borne by a wonderful yearning1 even above the motion of nature 7by which in accordance with its weight it ought to tend downwards7 and moves upwards1 in uniting itself with its own principle4 ,for if there were not in the iron a certain natural foretaste of the loadstone itself1 it would not move to the loadstone any more than to any other stone2 and unless there were in the stone a greater inclination for iron than for copper1 there would not be that attraction4 ,such are the opinions expressed about the loadstone attracting 7or the general sense of each71 all dubious and untrustworthy4 ,but those causes of the magnetical motions1 which in the schools of the ,philosophers are referred to the four elements and the prime qualities1 we relinquish to the moths and the worms4 99 99 99 99 99 #fe ,,chap4 ,,iiii4 ,on ,magnetick ,force ,form1 what it is2 and on the cause of the ,coition4 ,relinquishing the opinions of others on the attraction of loadstone1 we shall now show the reason of that coition and the translatory nature of that motion4 ,since there are really two kinds of bodies1 which seem to allure bodies with motions manifest to our senses1 ,electricks and ,magneticks1 the ,electricks produce the tendency by natural effluvia from humour2 the ,magneticks by agencies due to form1 or rather by the prime forces4 ,this form is unique1 and particular1 not the formal cause of the ,peripateticks1 or the specifick in mixtures1 or the secondary form2 not the propagator of generating bodies1 but the form of the primary and chief spheres and of those parts of them which are homogeneous and not corrupted1 a special entity and existence1 which we may call a primary and radical and astral form2 not the primary form of ,aristotle1 but that unique form1 which preserves and disposes its own proper sphere4 ,there is one such in each several globe1 in the ,sun1 the moon1 and the stars2 one also in the earth1 which is that true magnetick potency which we call the primary vigour4 ,wherefore there is a magnetick nature peculiar to the earth and implanted in all its truer parts in a primary and astonishing manner2 this is neither derived nor produced from the whole heaven by sympathy or influence or more occult qualities1 nor from any particular star2 for there is in the earth a magnetick vigour of its own1 just as in the sun and moon there are forms of their own1 and a small portion of the moon settles itself in moon-manner toward its termini and form2 and a piece of the sun to the sun1 just as a loadstone to the earth and to a second loadstone by inclining itself and alluring in accordance with its nature4 ,we must consider therefore about the earth what magnetical bodies are1 and what is a magnet2 then also about the truer parts of it1 which are magnetical1 and how they are affected as a result of the coition4 ,a body which is attracted by an electrick is not changed by it1 but remains unshaken and unchanged1 as it was before1 nor does it excel any the more in virtue4 ,a loadstone draws magnetical substances1 which eagerly acquire power from its strength1 not in their extremities only1 but in their inward parts and 99 their very marrow4 ,for when a rod of iron is laid hold of1 it is magnetically excited in the end by which it is laid hold of1 and that #ff force penetrates even to the other extremity1 not through its surface only1 but through the interior and all through the middle4 ,electrical bodies have material and corporeal effluvia4 ,is any such magnetical effluvium given off1 whether corporeal or incorporeal8 or is nothing at all given off that subsists8 ,if it really has a body1 that body must be thin and spiritual1 since it is necessary that it should be able to enter into iron4 ,or what sort of an exhalation is it that comes from lead1 when quicksilver which is bright and fluid is bound together by the odour merely and vapour of the lead1 and remains1 as it were1 a firm metal8 ,but even gold1 which is exceedingly solid and dense1 is reduced to a powder by the thin vapour of lead4 ,or1 seeing that1 as the quicksilver has entrance into gold1 so the magnetical odour has entrance into the substance of the iron1 how does it change it in its essential property1 although no change is perceptible to our senses in the bodies themselves8 ,for without ingression into the body1 the body is not changed1 as the ,chemists not incorrectly teach4 ,but if indeed these things resulted from a material ingression1 then if strong and dense and thick substances had been interposed between the bodies1 or if magnetical substances had been inclosed in the centres of the most solid and the densest bodies1 the iron particles would not have suffered anything from the loadstone4 ,but none the less they strive to come together and are changed4 ,therefore there is no such conception and origin of the magnetick powers2 nor do the very minute portions of the stone exist1 which have been wrongly imagined to exist by ,baptista ,porta1 aggregated1 as it were1 into hairs1 and arising from the rubbing of the stone which1 sticking to the iron1 constitute its strength4 ,electrick effluvia are not only impeded by any dense matter1 but also in like manner by flames1 or if a small flame is near1 they do not allure4 ,but as iron is not hindered by any obstacle from receiving force or motion from a loadstone1 so it will pass through the midst of flames to the body of the loadstone and adhre to the stone4 ,let there be a flame or a candle near the stone2 bring up a short piece of iron wire1 and when it has come near1 it will penetrate through the midst of the flames to the stone2 99 and a versorium turns towards the loadstone nor more slowly nor less eagerly through the midst of flames than through open air4 ,so flames interposed do not hinder the coition4 ,but if the iron itself became heated by a great heat1 it is demonstrable that it would not be attracted4 ,bring a strongly ignited rod of iron near a magnetized versorium2 the versorium remains steady and does not turn towards 99 such iron2 but it immediately turns towards it1 so soon as it has lost somewhat of its heat4 ,when a piece of iron has been touched by a loadstone1 if it be placed in a hot fire until it is perfectly red hot 99 and remain in the fire some considerable time1 it will lose that magnetick strength it had acquired4 ,even a loadstone itself through a #fg longish stay in the fire1 loses the powers of attracting implanted and innate in it1 and any other magnetick powers4 ,and although certain veins of loadstone exhale when burnt a dark vapour of a black colour1 or of a sulphurous foul odour1 yet that vapour was not the soul1 or the cause of its attraction of iron 7as ,porta thinks71 nor do all loadstones whilst they are being baked or burnt smell of or exhale sulphur4 ,it is acquired as a sort of inborn defect from a rather impure mine or matrix4 ,nor does anything analogous penetrate into the iron from that material corporeal cause1 since the iron conceives the power of attracting and verticity from the loadstone1 even if glass or gold or any other stone be interposed4 ,then also cast iron acquires the power of attracting iron1 and verticity1 from the verticity of the earth1 as we shall afterwards plainly demonstrate in ,direction4 ,but fire destroys the magnetick virtues in a stone1 not because it takes away any parts specially attractive1 but because the consuming force of the flame mars by the demolition of the material the form of the whole2 as in the human body the primary faculties of the soul are not burnt1 but the charred body remains without faculties4 ,the iron indeed may remain after the burning is completed and is not changed into ash or slag2 nevertheless 7as ,cardan not inaptly says7 burnt iron is not iron1 but something placed outside its nature until it is reduced4 ,for just as by the rigour of the surrounding air#aeg water is changed from its nature into ice2 so iron1 glowing in fire1 is destroyed by the violent heat1 and has its nature confused and perturbed2 wherefore also it is not attracted by a loadstone1 and even loses that power of attracting in whatever way acquired1 and acquires another verticity when1 being1 as it were1 born again1 it is impregnated by a loadstone or the earth1 or when its form is revived1 not having been dead but confused1 concerning which many things are manifest in the change of verticity4 ,wherefore ,fracastorio#aeh does not confirm his opinion1 that the iron is not altered2 for if it were altered1 he says1 by the form of the loadstone1 the form of the iron would have been spoiled4 ,this alteration is not generation1 but the restitution and reformation of a confused form4 ,there is not therefore anything corporeal which comes from the loadstone or which enters the iron1 or which is sent back from the iron when it is stimulated2 but loadstone disposes loadstone by its primary form2 iron1 however1 which is closely related to it1 loadstone at the same time recalls to its conformate strength1 and settles it2 on account of which it rushes to the loadstone and eagerly conforms itself to it 7the forces of each in harmony bringing them together74 ,the coition also is not vague or confused1 not a violent inclination of body to body1 no rash and mad congruency2 no violence is here applied to the bodies2 there are no strifes or discords2 but there is that concord 7without which the universe would go to pieces71 that analogy1 namely1 of the #fh perfect and homogeneous parts of the spheres of the universe to the whole1 and a mutual concurrency of the principal forces in them1 tending to soundness1 continuity1 position1 direction1 and to unity4 ,wherefore in the case of such wonderful action and such a stupendous implanted vigour 7diverse from other natures7 the opinion of ,thales of ,miletus#aei was not very absurd1 nor was it downright madness1 in the judgment of ,scaliger1 for him to grant the loadstone a soul2 for the loadstone is incited1 directed1 and orbitally moved by this force1 which is all in all1 and1 as will be made clear afterwards1 all in every part2 and it seems to be very like a soul4 ,for the power of moving itself seems to point to a soul2 and the supernal bodies1 which are also celestial1 divine1 as it were1 are thought by some to be animated1 because they move with admirable order4 ,if two loadstones be set one over against the other1 each in a boat1 on the surface of water1 they do not immediately run together1 but first they turn towards one another1 or the lesser conforms to the greater1 by moving itself in a somewhat circular manner1 and at length1 when they are disposed according to their nature1 they run together4 ,in smelted iron which has not been excited by a magnet there is no need for such an apparatus2 since it has no verticity1 excepting what is adventitious and acquired1 and that not stable and confirmed 7as is the case with loadstone1 even if the iron has been smelted from the best loadstone71 on account of the confusion of the parts by fire when it flowed as a liquid2 it suddenly acquires polarity and natural aptitude by the presence of the loadstone1 by a powerful mutation1 and by a conversion into a perfect magnet1 and by an absolute metamorphosis2 and it flies to the body of the magnet as if it were a real piece of loadstone4 ,for a loadstone has no power1 nor can a perfect loadstone do anything which iron when excited by loadstone cannot perform1 even when it has not been touched but only placed in its vicinity4 ,for when first it is within the orbe of virtue of the loadstone1 though it may be some distance away1 yet it is immediately changed1 and has a renovated form1 formerly indeed dormant and inert in body1 now lively and strong1 which will be clearly apparent in the demonstrations of ,direction4 ,so the magnetick coition is a motion of the loadstone and of the iron1 not an action of one#afj2 an ,greek3 entelecheia1 of each1 not ,greek3 ergon2 a ,greek3 sunentelecheia or conjoint action1 rather than a sympathy4 ,there is properly no such thing as magnetick antipathy4 ,for the flight and declination of the ends1 or an entire turning about1 is an action of each towards unity by the conjoint action and ,greek3 sunentelecheia of both4 ,it has therefore newly put on the form1 and on account of this being roused1 it then1 in order that it may more surely acquire it1 rushes headlong on the loadstone1 not with curves and turnings1 as a loadstone to a loadstone4 ,for since in a loadstone both verticity and the power disponent have existed through many ages1 or from the very beginnings1 #fi have been inborn and confirmed1 and also the special form of the terrestrial globe cannot easily be changed by another loadstone1 as iron is changed2 it happens from the constant nature of each1 that one has not the sudden power over another of changing its verticity1 but that they can only mutually come to agreement with each other4 ,again1 iron which has been excited by a loadstone1 99 if that iron on account of obstacles should not be able to turn round immediately in accordance with its nature1 as happens with a versorium1 is laid hold of1 when a loadstone approaches1 on either side or at either end4 ,because1 just as it can implant1 so it can suddenly change the polarity and turn about the formal energies to any part whatever4 ,so variously can iron be transformed when its form is adventitious and has not yet been long resident in the metal4 ,in the case of iron1 on account of the fusion of the substance when magnetick ore or iron is smelted1 the virtue of its primary form1 distinct before1 is now confused2 but an entire loadstone placed near it again sets up its primal activity2 its adjusted and arranged form joins its allied strength with the loadstone2 and both mutually agree and are leagued together magnetically in all their motions towards unity1 and whether joined by bodily contact or adjusted within the orbe1 they are one and the same4 ,for when iron is smelted out of its own ore1 or steel 7the more noble kind of iron7 out of its ore1 that is1 out of loadstone1 the material is loosed by the force of the fire1 and flows away1 and iron as well as steel flow out from their dross and are separated from it2 and the dross is either spoiled by the force of the fire and rendered useless1 or is a kind of dregs of a certain imperfection and of mixture in the prominent parts of the earth4 ,the material therefore is a purified one1 in which the metallick parts1 which are now mixed up by the melting1 since those special forces of its form are confused and uncertain1 by the approach of a loadstone are called back to life1 as if to a kind of disponent form and integrity4 ,the material is thus awakened and moves together into unity1 the bond of the universe and the essential for its conservation4 ,on this account and by the purging of the material into a cleaner body1 the loadstone gives to the iron a greater force of attracting than there is in itself4 ,for if iron dust 99 or an iron nail be placed over a large loadstone1 a piece of iron joined to it takes away the filings and nail from the loadstone and retains them so long as it is near the loadstone2 wherefore iron attracts iron more than loadstone does1 if it have been conformed by a loadstone and remains within the orbe of its communicated form4 ,a piece of iron even1 skilfully placed near the pole of a loadstone1 lifts up more than the loadstone4 ,therefore the material of its own ore is better1 and by the force of fire steel and iron are re-purged2 and they are again impregnated by the loadstone with its own forms2 therefore they move towards it by a spontaneous #gj approach as soon as they have entered within the orbe of the magnetick forces1 because they were possessed by it before1 connected and united with it in a perfect union2 they have immediately an absolute continuity within that orbe1 have been joined on account of their harmony1 though their bodies may have been disjoined4 ,for the iron is not taken possession of and allured by material effluvia1 after the manner of electricks1 but only by the immaterial action of its form or an incorporeal progression1 which in a piece of iron as its subject acts and is conceived1 as it were1 in a continuous homogeneous body1 and does not need more open ways4 ,therefore 7though the most solid substances be interposed7 the iron is still moved and attracted1 and by the presence of loadstone the iron moves and attracts the loadstone itself1 and by mutual forces a concurrency is made towards unity1 which is commonly called attraction of the iron4 ,but those formal forces pass out and are united to one another by meeting together2 a force also1 when conceived in the iron1 begins to flow out without delay4 ,but ,julius ,scaliger1 who by other examples contends that this theory is absurd1 makes in his #cddth ,exercise a great mistake4 ,for the virtues of primary bodies are not to be compared with bodies formed from and mixed with them4 ,he would now have been able 7had he been still alive7 to discern the nature of effused forms in the chapter on forms effused by spherical magneticks4 ,but if iron is injured somewhat by rust1 it is affected either only slightly or not at all by the stone4 ,for the metal is spoiled when eaten away and deformed by external injuries or by lapse of time 7just as has been said about the loadstone71 and it loses its prime qualities which are conjoined to its form2 or1 being worn out by age1 retains them in a languid and weak condition2 indeed it cannot be properly re-formed1 when it has been corrupted4 ,but a powerful and fresh loadstone attracts sound and clean pieces of iron1 and those pieces of iron 7when they have conceived strength7 have a powerful attraction for other iron wires and iron nails1 not only one at a time1 but even successively one behind another1 three1 four or five1 end to end1 sticking and hanging in order like a chain4 ,the loadstone1 however1 would not attract the last one following in such a row1 if there were no nails between4 ,illustration ,a loadstone placed as at ,a draws a nail or a bar ,b2 similarly behind ,b it draws ,c2 and after ,c1 ,d4 ,but the nails ,b and ,c being removed1 the loadstone ,a1 if it remain at the same distance1 does not raise the nail ,d into the air4 ,this occurs for this reason3 because in the case of a continuous row of nails the presence of the loadstone ,a1 besides its own powers1 raises the magnetick natures of the iron works ,b and ,c1 and makes them1 as it were1 forces auxiliary to itself4 ,but ,b and ,c1 like a continuous magnetical body1 extend as far as #ga ,d the forces by which ,d is taken and conformed1 though they are weaker than those which ,c receives from ,b4 ,and those iron nails indeed from that contact only1 and from the presence of the loadstone even without contact1 acquire powers which they retain in their own bodies1 as will be demonstrated most clearly in the passage on ,direction4 ,for not only whilst the stone is present does the iron assume these powers1 and take them1 as it were1 vicariously from the stone1 as ,themistius lays down in his #hth book on ,physicks#afa4 ,the best iron1 when it has been melted down 7such is steel71 is allured by a loadstone from a greater distance1 is raised though of greater weight1 is held more firmly1 assumes stronger powers than the common and less expensive1 because it is cast from a better ore or loadstone1 imbued with better powers4 ,but what is made from more impure ore turns out weaker and is moved more feebly4 ,as to ,fracastorio's#afb statement that he saw a piece of loadstone draw a loadstone by one of its faces1 but not iron2 by another face iron1 but not loadstone2 by another both2 which he says is an indication that in one part there is more of the loadstone1 in another more of the iron1 in another both equally1 whence arises that diversity of attraction2 it is most incorrect and badly observed on the part of ,fracastorio1 who did not know how to apply skilfully loadstone to loadstone4 ,a loadstone draws iron and also a loadstone1 if both are suitably arranged and free and unrestrained4 ,that is removed more quickly from its position and place which is lighter2 for the heavier bodies are in weight1 the more they resist2 but the lighter both moves itself to meet the heavier and is allured by the other4 99 99 99 99 99 ,,chap4 ,v4 ,how the ,power dwells in the ,loadstone4 ,that a loadstone attracts loadstone1 iron and other magnetical bodies1 has been shown above in the previous book1 and also with what strength the magnetick coition is ordered2 but now we must inquire how that vigour is disposed in a magnetick substance4 ,and indeed an analogy must be inferred from a large loadstone4 ,any magnetick substance joins itself with a loadstone strongly1 if the loadstone itself is strong2 but more weakly1 when it is somewhat imperfect or has been weakened by some flaw4 ,a loadstone does not draw iron equally well with every part2 or a magnetick substance does not approach every part of a loadstone alike2 because a loadstone has its points1 that is its true poles1 in which an exceptional virtue excels4 ,parts nearer the pole are #gb stronger1 those far away more weak1 and yet in all the power is in a certain way equal4 ,the poles of a terrella are ,a1 ,b2 the quinoctial is ,c1 ,d4 ,at ,a and ,b the alluring force seems greatest4 ,illustration ,at ,c and ,d there is no force alluring magnetick ends to the body1 for the forces tend toward both poles4 ,but direction is powerful on the quator4 ,at ,c1 ,d1 the distances are equal from both poles2 therefore iron which is at ,c1 ,d1 when it is allured in contrary ways1 does not adhre with constancy2 but it remains and is joined to the stone1 if only it incline to the one or other side4 ,at ,e there is a greater power of alluring than at ,f1 because ,e is nearer the pole4 ,this is not so because there is really greater virtue residing at the pole1 but since all the parts are united in the whole1 they direct their forces towards the pole4 ,from the forces flowing from the plane of the quinoctial towards the pole1 the power increases4 ,a fixed verticity exists at the pole1 so long as the loadstone remains whole2 if it is divided or broken1 the verticity obtains other 99 positions in the parts into which it is divided4 ,for the verticity always changes in consequence of any change in the mass1 and for this cause1 if the terrella be divided from ,a to ,b1 so that there are two stones1 the poles will not be ,a1 ,b1 in the divided parts1 but ,f1 ,g1 and ,h1 ,i4 ,illustration #gc ,although these stones now are in agreement with one another1 so that ,f would not seek ,h1 yet if ,a was previously the boreal pole#afc1 ,f is now boreal1 and ,h also boreal2 for the verticity is not changed 7as ,baptista ,porta incorrectly affirms in the fourth chapter of his seventh book72 since1 though ,f and ,h do not agree1 so that the one would incline to the other1 yet both turn to the same point of the horizon4 ,if the hemisphere ,h ,i be divided into two quadrants1 the one pole takes up its position in ,h1 the other in ,i4 ,the whole mass of the stone1 as ,i have said1 retains the site of its vertex constant2 and any part of the stone1 before it was cut out from the block#afd1 might have been the pole or vertex4 ,but concerning this more under ,direction4 ,it is important now to comprehend and to keep firmly in mind that the vertices are strong on account of the force of the whole1 so that 7the command being1 as it were1 divided by the quinoctial7 all the forces on one side tend towards the north2 but those of an opposite way towards the south1 so long as the parts are united1 as in the following demonstration4 ,illustration ,for so1 by an infinite number of curves from every point of the equator dividing the sphere into two equal parts1 and from every point of the surface from the quator towards the ,north1 and from the quator towards the ,southern pole1 the whole force tends asunder toward the poles4 ,so the verticity is from the quinoctial #gd circle towards the pole in each direction4 ,such is the power reposed in the undivided stone4 ,from ,a vigour is sent to ,b1 from ,a1 ,b1 to ,c1 from ,a1 ,b1 ,c1 to ,d1 and from them likewise to ,e4 ,in like manner from ,g to ,h1 and so forth1 as long as the whole is united4 ,but if a piece ,a ,b be cut out 7although it is near the quator71 yet it will be as strong in its magnetical actions as ,c ,d or ,d ,e1 if torn away from the whole in equal quantity4 ,for no part excels in special worth in the whole mass except by what is owing to the other adjoining parts by which an absolute and perfect whole is attained4 ,diagram of ,magnetic ,vigour transmitted from the plane of the quator to the peripherery of the terella or of the earth ,illustration #ge ,,heq is a terrella1 ,e a pole1 ,m the centre1 ,,hmq the quinoctial plane4 ,from every point of the quinoctial plane vigour extends to the periphery1 but by various methods2 for from ,a the formal force is transmitted towards ,c1 ,f1 ,n1 ,e1 and to every point from ,c up to ,e1 the pole2 but not towards ,b2 so neither from ,g towards ,c4 ,the power of alluring is not strengthened in the part ,,fhg from that which is in ,,gmfe1 but ,,fgh increases the force in the eminence ,,fe4 ,so no force rises from the internal parts1 from the lines parallel to the ,axis above those parallels1 but always inwards from the parallels to the pole4 ,from every point of the plane of the equator force proceeds to the pole ,e1 but the point ,f has its powers only from ,,gh1 and ,n from ,,oh2 but the pole ,e is strengthened from the whole plane ,,hq4 ,wherefore in it the mighty power excels 7just as in a palace72 but in the intermediate intervals 7as in ,f7 only so much force of alluring is exerted as the portion ,,hg of the plane can contribute4 99 99 99 99 99 ,,chap4 ,,vi4 ,how magnetick pieces of ,iron and smaller loadstones conform themselves to a terrella to the earth itself1 and by them are disposed4 ,coition of those bodies which are divided1 and do not naturally cohre1 if they are free1 occurs through another kind of motion4 ,a terrella sends out in an orbe its powers in proportion to its vigour and quality4 ,but when iron or any other magnetick of convenient magnitude comes within its orbe of virtue1 it is allured2 but the nearer it comes to the body1 the more quickly it runs up to it4 ,they move towards the magnet1 not as 99 to a centre1 nor towards its centre4 ,for they only do this in the case of the poles themselves1 when namely that which is being allured1 and the pole of the loadstone1 and its centre1 are in the same straight line4 ,but in the intervening spaces they tend obliquely1 just as is evident in the following figure1 in which it is shown how the influence is extended to the adjoining magneticks within the orbe2 in the case of the poles straight out4 #gf ,illustration ,the nearer the parts are to the quinoctial1 the more obliquely are magneticals allured2 but the parts nearer the poles appeal more directly1 at the poles quite straight4 ,the principle of the turning of all loadstones1 of those which are round and those which are long1 is the same1 but in the case of the long ones the experiment is easier4 ,for in whatever form they are the verticity exists1 and there are poles2 but on account of bad and unequal form1 they are often hindered by certain evils4 ,if the stone were long1 the vertex is at the ends1 not on the sides2 it allures more strongly at the vertex4 ,for the parts bring together stronger forces to the pole in right lines than oblique4 ,so the stone and the earth conform their magnetick motions by their nature4 99 99 99 99 99 ,,chap4 ,,vii4 ,on the ,potency of the ,magnetick ,virtue1 and on its nature capable of spreading out into an orbe4 ,from about a magnetical body the virtue magnetical is poured out on every side around in an orbe2 around a terrella2 in the case of other shapes of stones1 more confusedly and unevenly4 ,but yet there exists in nature no orbe or permanent or essential virtue spread through the air1 but a magnet #gg only excites magneticks at a convenient distance from it4 ,and as light comes in an instant 7as the opticians teach71 so much more#afe quickly is the magnetick vigour present within the limits of its strength2 and because its activity is much more subtile than light1 and does not consent with a non-magnetick substance1 it has no intercourse with air1 water1 or any non-magnetick2 nor does it move a magnetick with any motion by forces rushing upon it1 but being present in an instant1 it invites friendly bodies4 ,and as light strikes an object1 so a loadstone strikes a magnetick body and excites it4 ,and just as light does not remain in the air above vapours and effluvia1 and is not reflected from those spaces1 so neither is the magnetick ray held in air or water4 ,the appearances of things are apprehended in an instant in mirrors and in the eye by means of light2 so the magnetick virtue seizes upon magneticks4 ,without the more intangible and shining bodies1 the appearances of things are not seized or reflected2 so without magnetical objects the magnetick power is not perceived1 nor are the forces thus conceived sent back again to the magnetick substance4 ,in this1 however1 the magnetick power excels light1 in that it is not hindered by any opaque or solid substance1 but proceeds freely1 and extends its forces on every side4 ,in a terrella and globe-shaped loadstone the magnetick power is extended outside the body in an orbe2 in a longer one1 however1 not in an orbe1 but it is extended in an ambit conformably to the shape of the stone4 ,as in the somewhat long stone ,a1 the vigour is extended to the ambient limit ,f ,c ,d1 equidistant on every side from the stone ,a4 ,illustration 99 99 99 99 99 #gh ,,chap4 ,,viii4 ,on the geography of the ,earth1 and of the ,terrella4 ,desiring that what follows may be better understood1 we must now say something also about magnetick circles and limits4 ,astronomers1 in order to understand and observe methodically the motion of the planets and the revolution of the heavens1 and to describe with more accuracy the celestial attire of the fixed stars1 settled upon certain circles and definite limits in the sky 7which geographers also imitate71 so that the varied face of the earth and the beauty of its districts might be delineated4 ,but we1 in a way differing from them1 recognize those limits and circles1 and have found very many fixed by nature1 not merely conceived by the imagination1 both in the earth and in our terrella4 ,the earth they mark out#aff chiefly by means of the quator and the poles2 and those limits indeed have been arranged and marked out by nature4 ,the meridians also indicate straight paths from pole to pole through distinct points on the quator2 by which way the magnetick virtue directs its course and moves4 ,but the tropics and arctic circles1 as also the parallels1 are not natural limits placed on the earth2 but all parallel circles indicate a certain agreement of the lands situated in the same latitude1 or diametrically opposite4 ,all these the ,mathematicians use for convenience1 painting them on globes and maps4 ,in like manner also in a terrella all these are required2 not1 however1 in order that its exterior appearance may be geographically delineated1 since the loadstone may be perfect1 even1 and uniform on all sides4 ,and there are no upper and lower parts in the earth1 nor are there in a terrella2 unless perchance some one considers those parts superior which are in the periphery1 and those inferior which are situated more towards the centre4 99 99 99 99 99 #gi ,,chap4 ,,ix4 ,on the quinoctial ,circle of the ,earth and of a ,terrella4 ,as conceived by astronomers the quinoctial circle is equidistant from both poles1 cutting the world in the middle1 measures the motions of their primum mobile or tenth sphere1 and is named the zone of the primum mobile4 ,it is called quinoctial1 because when the sun stands in it 7which must happen twice in the year7 the days are equal to the nights4 ,that circle is also spoken of as quidialis1 wherefore it is called by the ,greeks ,greek3 ismerinos4 ,in like manner it is also properly called quator1 because it divides the whole frame of the earth between the poles into equal parts4 ,so also an quator may be rightly assigned to a terrella1 by which its power is naturally divided1 and by the plane of which permeating through its centre1 the whole globe is divided into equal parts both in quantity and strength 7as if by a transverse septum7 between verticities on both sides imbued with equal vigour4 99 99 99 99 99 ,,chap4 ,x4 ,magnetick ,meridians of the ,earth4 ,meridians have been thought out by the geographer1 by means of which he might both distinguish the longitude and measure the latitude of each region4 ,but the magnetick meridians are infinite1 running in the same direction also1 through fixed and opposite limits on the quator1 and through the poles themselves4 ,on them also the magnetick latitude is measured1 and declinations are reckoned from them2 and the fixed direction in them tends to the poles1 unless it varies from some defect and the magnetick is disturbed from the right way4 ,what is commonly called a magnetick meridian is not really magnetick1 nor is it really a meridian1 but it is understood to pass through the termini of the variation on the horizon4 ,the variation is a depraved deviation from a meridian1 nor is it fixed and constant in various places on any meridian4 99 99 99 99 99 #hj ,,chap4 ,,xi4 ,parallels4 ,in parallel circles the same strength and equal power are perceived everywhere1 when various magneticks are placed on one and the same parallel either on the earth or on a terrella4 ,for they are distant from the poles by equal intervals and have equal tendencies of declination1 and they are attracted and held1 and they come together with like forces2 just as those regions which are situated under the same parallel1 even if they differ in longitude1 yet we say possess the same quantity of daylight and a climate equally tempered4 99 99 99 99 99 ,,chap4 ,,xii4 ,the ,magnetick ,horizon4 ,horizon is the name given to the great circle1 separating the things which are seen from those which are not seen2 so that a half part of the heaven always is open and easily seen by us1 half is always hidden4 ,this seems so to us on account of the great distance of the star-bearing orbe3 yet the difference is as great as may arise from the ratio of the semi-diameter of the earth compared with the semi-diameter of the starry heaven1 which difference is in fact not perceived by our senses4 ,we maintain1 however1 that the magnetick horizon is a plane level throughout touching the earth or a terrella in the place of some one region1 with which plane the semi-diameter1 whether of the earth or of the terrella1 produced to the place of the region1 makes right angles on every side4 ,such a plane is to be considered in the earth itself and also in the terrella1 for magnetick proofs and demonstrations4 ,for we consider the bodies themselves only1 not the general appearances of the world4 ,therefore not with the idea of outlook 7which varies with the elevations of the lands71 but taking it as a plane which makes equal angles with the perpendicular1 we accept in magnetick demonstrations a sensible horizon or boundary1 not that which is called by ,astronomers the rational horizon4 99 99 99 99 99 #ha ,,chap4 ,,xiii4 ,on the ,axis and ,magnetick ,poles4 ,let the line be called the axis which is drawn in the earth 7as in a terrella7 through the centre to the poles4 ,they are called ,greek3 poloi by the ,greeks from ,greek3 polein1 to turn1 and by the ,latins they are also called ,cardines or ,vertices2 because the world rotates and is perpetually carried around them4 ,we are about to show1 indeed1 that the earth and a terrella are turned about them by a magnetick influence4 ,one of them in the earth1 which looks towards the ,cynosure1 is called ,boreal and ,arctic2 the other one1 opposite to this1 is called ,austral and ,antarctic4 ,nor do these also exist on the earth or on a terrella for the sake of the turning merely2 but they are also limits of direction and position1 both as respects destined districts of the world1 and also for correct turnings among themselves4 99 99 99 99 99 ,,chap4 ,,xiiii4 ,why at the ,pole itself the ,coition is stronger than in the other parts intermediate between the quator and the pole2 and on the proportion of forces of the coition in various parts of the earth and of the terrella4 ,observation has already been made that the highest power of alluring exists in the pole1 and that it is weaker and more languid in the parts adjacent to the quator4 ,and as this is apparent in the declination1 because that disponent and rotational virtue has an augmentation as one proceeds from the quator towards the poles3 so also the coition of magneticks grows increasingly fresh by the same steps1 and in the same proportion4 ,for in the parts more remote from the poles the loadstone does not draw magneticks straight down towards its own viscera2 but they tend obliquely and they allure obliquely4 ,for as the smallest chords in a circle differ from the diameter1 so much do the forces of attracting differ between themselves in different parts of the terrella4 #hb ,for since attraction is coition towards a body1 but magneticks run together by their versatory tendency1 it comes about that in the diameter drawn from pole to pole the body appeals directly1 but in other places less directly4 ,so the less the magnetick is turned toward the body1 the less1 and the more feebly1 does it approach and adhre4 ,illustration ,just as if ,a ,b were the poles and a bar of iron or a magnetick fragment ,c is allured at the part ,e2 yet the end laid hold of does not tend towards the centre of the loadstone1 but verges obliquely towards the pole2 and a chord drawn from that end obliquely as the attracted body tends is short2 therefore it has less vigour and likewise less inclination4 ,but as a greater chord proceeds from a body at ,f1 so its action is stronger2 at ,g still longer2 longest at ,a1 the pole 7for the diameter is the longest way7 to which all the parts from all sides bring assistance1 in which is constituted1 as it were1 the citadel and tribunal of the whole province1 not from any worth of its own1 but because a force resides in it contributed from all the other parts1 just as all the soldiers bring help to their own commander4 ,wherefore also a slightly longer stone attracts more than a spherical one1 since the length from pole to pole is extended1 even if the stones are both from the same mine and of the same weight and size4 ,the way from pole to pole is longer in a longer stone1 and the forces brought together from other parts are not so scattered as in a round magnet and terrella1 and in a narrow one they agree more and are better united1 and a united stronger force excels and is preeminent4 ,a much weaker office1 however1 does a plane or oblong stone perform1 when the length is extended according to the leading of the parallels1 and the pole stops neither on the apex nor in the circle and orbe1 but is spread over the flat4 ,wherefore also it invites a friend wretchedly1 and feebly retains him1 so that it is esteemed as one of an abject and contemptible class1 according to its less apt and less suitable figure4 99 99 99 99 99 #hc ,,chap4 ,,xv4 99 ,the ,magnetick ,virtue which is conceived in ,iron is more apparent in an iron rod than in a piece of iron that is round1 square1 or of other figure4 ,duly was it said before that the longer magnet attracts the greater weight of iron#afg2 so also in a longish piece of iron which has been touched the magnetick force conceived is stronger when the poles exist at the ends4 ,for the magnetick forces which are driven from the whole in every part into the poles are not scattered but united in the narrow ends4 ,in square and other angular figures the influence is dissipated1 and does not proceed in straight lines or in convenient arcs4 ,suppose also an iron globe have the shape of the earth1 yet for the same reasons it drags magnetick substances less2 wherefore a small iron sphere1 when excited1 draws another piece of iron more sluggishly than an excited rod of equal weight4 99 99 99 99 99 ,,chap4 ,,xvi4 ,showing that ,movements take place by the ,magnetical ,vigour though solid bodies lie between2 and on the interposition of iron plates4 ,float a piece of iron wire on the surface of water by transfixing it through a suitable cork2 or set a versatory piece of iron on a pin or in a seaman's compass 7a magnet being brought near or moved about underneath71 it is put into a state of motion2 neither the water1 nor the vessel1 nor the compass-box offering resistance in any way4 ,thick boards do not obstruct#afh1 nor earthen vessels nor marble vases1 nor the metals themselves2 nothing is so solid as to carry away or impede the forces excepting an iron plate4 ,everything which is interposed 7even though it is very dense7 does not carry away its influence or obstruct its path1 or indeed in any way hinder1 diminish1 or retard it4 ,but all the force is not suppressed by an iron plate1 but it is in some measure diverted aside4 ,for when the vigour passes into the middle of an iron plate within the orbe of the magnetick virtue or placed just #hd opposite the pole of the stone1 that virtue is scattered in very large measure towards its extremities2 so that the edges of a small round 99 plate of suitable size allure iron wires on every side4 ,this is also apparent in the case of a long iron wand1 which1 when it has been touched by a magnet in the middle1 has a like verticity at either end4 99 ,illustration ,b is a loadstone1 ,c ,d a long rod magnetized in the middle ,a2 ,e being the ,boreal pole2 ,c is an ,austral end or pole2 in like manner also the end ,d is another ,austral pole4 ,but observe here the exactness with which a versorium touched by a pole1 when a round plate is interposed1 turns towards the same pole in the same 99 way as before the interposition1 only weaker2 the plate not standing in the way1 because the vigour is diverted through the edges of the small plate1 and passes out of its straight course1 but yet the plate retains in the middle the same verticity1 when it is in the neighbourhood of that pole1 and close to it2 wherefore the versorium tends towards the plate1 having been touched by the same pole4 ,if a loadstone is rather weak1 a versorium hardly turns when a plate is put in between2 for the vigour of the rather weak loadstone1 being diffused through the extremities1 passes less through the 99 middle4 ,but if the plate has been touched in this way by a pole in the middle and has been removed from the stone outside its orbe of virtue1 then you will see the point of the same versorium tend in the contrary direction and desert the centre of the small plate1 which formerly it desired2 for outside the orbe of virtue it has an opposite verticity1 in the vicinity the same2 for in the vicinity it is1 as it were1 a part of the loadstone1 and has the same pole4 ,illustration ,a is an iron plate near the pole1 ,b a versorium which tends with its point towards the centre of the small plate1 which has been touched by the pole of the loadstone ,c4 ,but if the same small plate be #he placed outside the orbe of magnetick virtue1 the point will not turn towards its centre1 but the cross ,e of the same versorium does4 ,but an iron globe interposed 7if it is not too large7 attracts the 99 point of the iron on the other side of the stone4 ,for the verticity of that side is the same as that of the adjoining pole of the stone4 ,and this turning of the cusp 7that is1 of the end touched by that pole7 as well as of the cross-end1 at a greater distance1 takes place with an iron globe interposed1 which would not happen at all if 99 the space were empty1 because the magnetick virtue is passed on and continued through magnetick bodies4 ,illustration ,a is a terrella1 ,b an iron globe2 between the two bodies is ,f1 a versorium whose point has been excited by the pole ,c4 ,in the other figure ,a is a terrella1 ,c its pole1 ,b an iron globe2 where the versorium tends towards ,c1 the pole of the terrella1 through the iron globe4 ,so a versorium placed between a terrella and an iron globe vibrates more forcibly towards the pole of the terrella2 because the loadstone sends an instantaneous verticity into the opposite globe4 ,there is the same efficiency in the earth1 produced from the same cause4 ,for if a revolvable needle is shut up in a rather thick gold box 7this metal indeed excels all others in density7 or a glass or stone box1 nevertheless that magnetick needle has its forces connected and united with the influences of the earth1 and the iron will turn freely and readily 7unhindered by its prison7 to its desired points1 ,north and ,south4 99 ,it even does this when shut up in iron caverns1 if they are sufficiently spacious4 ,whatever bodies are produced among us1 or are artificially forged from things which are produced1 consist of matter of the terrestrial globe2 nor do those bodies hinder the prime forces of nature which are derived from their primary form1 nor can they resist them except by contrary forms4 ,but no forms of mixed bodies are inimical to the primary implanted earth-nature1 although some often do not agree#afi with one another4 ,but in the case of all those substances which have a material cause for their inclining 7as amber1 #hf jet1 sulphur71 their action is impeded by the interposition of a body 7as paper1 leaves1 glass1 or the like7 when that way is impeded and obstructed1 so that that which exhales#agj cannot reach the corpuscle to be allured4 ,terrestrial and magnetick coition and motion1 when corporeal impediments are interposed1 is demonstrated also by the efficiencies of other chief bodies due to their primary form4 ,the moon 7more than all the stars7 agrees with internal parts of the earth on account of its nearness and similarity in form4 ,the moon produces the movements of the waters and the tides of the sea2 twice it fills up the shores and empties them whilst it moves from a certain definite point in the sky back to the same point in a daily revolution4 ,this motion of the waters is incited and the seas rise and fall no less when the moon is below the horizon and in the lowest part of the heavens1 than if it had been raised at a height above the horizon4 ,so the whole mass of the earth interposed#aga does not resist the action of the moon1 when it is below the earth2 but the seas bordering on our shores1 in certain positions of the sky when it is below the horizon1 are kept in motion1 and likewise stirred by its power 7though they are not struck by its rays nor illuminated by its light71 rise1 come up with great force1 and recede4 ,but about the reason of the tides anon#agb2 here let it suffice to have merely touched the threshold of the question4 ,in like manner nothing on the earth can be hidden from the magnetick disposition of the earth or of the stone1 and all magnetical bodies are reduced to order by the dominant form of the earth1 and loadstone and iron show sympathy with a loadstone though solid bodies be interposed4 99 99 99 99 99 ,,chap4 ,,xvii4 ,on the ,iron ,cap of a ,loadstone1 with which it is armed at the pole 7for the sake of the virtue7 and on the efficacy of the same4 ,conceive a small round plate1 concave in shape1 of the breadth of a digit to be applied to the convex polar surface of a loadstone and skilfully attached2 or a piece of iron shaped like an acorn1 rising from the base into an obtuse cone1 hollowed out a little and fitted to the surface of the stone1 to be tied to the loadstone4 ,let the iron be the best steel1 smoothed1 shining1 and even4 ,a loadstone with such an appliance1 which before only bore four ounces of iron1 will now raise twelve4 ,but the greatest force of a combining or rather united nature is seen #hg when two loadstones1 armed with iron caps1 are so joined by their concurrent 7commonly called contrary7 ends1 that they mutually 99 attract and raise one another4 ,in this way a weight of twenty ounces is raised1 when either stone unarmed would only allure four ounces of iron4 ,iron unites to an armed loadstone more firmly than to a loadstone2 and on that account raises greater weights1 because the pieces of iron stick more pertinaciously to one that is armed4 ,for by the near presence of the magnet they are cemented together1 and since the armature#agc conceives a magnetick vigour from its presence and the other conjoined piece of iron is at the same time endued with vigour from the presence of the loadstone1 they are firmly bound together4 ,therefore by the mutual contact of strong pieces of iron1 the cohesion is strong4 ,which thing is also made clear and is exhibited by means of rods sticking together1 ,bk4 #c1 chap #dagd2 and also when the question of the concretion of iron dust into a united body was discussed4 ,for this reason a piece of iron set near a loadstone draws away any suitable piece of iron from the loadstone1 if only it touch the iron2 otherwise it does not snatch it away1 though in closest proximity4 ,for magnetick pieces of iron within the orbe of virtue1 or near a loadstone1 do not rush together with a greater endeavour#age than the iron and the magnet2 but joined they are united more strongly and1 as it were1 cemented together1 though the substance remain the same with the same forces acting4 99 99 99 99 99 ,,chap4 ,,xviii4 ,an armed ,loadstone does not endow an excited piece of ,iron with greater vigour than an unarmed4 ,suppose there are two pieces of iron1 one of 99 which has been excited by an armed loadstone1 the other by one unarmed2 and let there be applied to one of them another piece of iron of a weight just proportional to its strength1 it is manifest that the remaining one in like manner raises the same and no more4 ,magnetick versoria also touched by an armed loadstone turn with the same velocity and constancy towards the poles of the earth as those magnetized by the same loadstone unarmed4 99 99 99 99 99 #hh ,,chap4 ,,xix4 ,union with an armed ,loadstone is stronger2 hence greater weights are raised2 but the coition is not stronger#agf1 but generally weaker4 ,an armed magnet raises a greater weight1 as is manifest to all2 but a piece of iron moves towards a stone at an equal1 or rather greater1 distance when it 99 is bare1 without an iron cap4 ,this must be tried with two pieces of iron of the same weight and figure at an equal distance1 or with one and the same versorium1 the test being made first with an armed1 then with an unarmed loadstone1 at equal distances4 99 99 99 99 99 ,illustration ,,chap4 ,,xx4 99 ,an armed ,loadstone raises an armed ,loadstone1 which also attracts a third2 which likewise happens1 though the virtue in the first be somewhat small4 ,magnets armed cohre firmly when duly joined1 and accord into one2 and though the first be rather weak1 yet the second one adhres to it not only by the strength of the first1 but of the second1 which mutually give helping hands2 also to the second a third often adheres and in the case of robust stones1 a fourth to the third4 99 99 99 99 99 #hi ,,chap4 ,,xxi4 99 ,if ,paper or any other ,medium be interposed1 an armed loadstone raises no more than an unarmed one4 ,observation has shown above that an armed loadstone does not attract at a greater distance than an unarmed one2 yet raises iron in greater quantity1 if it is joined to and made continuous with the iron4 ,but if ,paper be placed between1 that intimate cohsion of the metal is hindered1 nor are the metals cemented together at the same time by the operation of the magnet4 99 99 99 99 99 ,illustration ,,chap4 ,,xxii4 99 ,that an armed ,loadstone draws ,iron no more than an unarmed one3 ,and that an armed one is more strongly united to iron is shown by means of an armed loadstone and a polished cylinder of iron4 ,if a cylinder be lying on a level surface1 of too great a weight for an unarmed loadstone to lift1 and 7a piece of paper being interposed7 if the pole of an armed loadstone be joined to the middle of it2 if the cylinder were drawn from there by the loadstone1 it would follow rolling2 but if no medium were interposed1 the cylinder would be drawn along firmly united with the armed loadstone1 and in no wise rolling4 ,but if the same loadstone be unarmed1 it will draw the cylinder rolling with the same speed as the armed loadstone with the paper between or when it was wrapped in paper4 ,armed loadstones of diverse weights1 of the same ore vigour 99 and form1 cling and hang to pieces of iron of a convenient size and proportionate figure with an equal proportion of strength4 ,the same is apparent in the case of unarmed stones4 ,a suitable piece 99 of iron being applied to the lower part of a loadstone1 which is 99 hanging from a magnetick body1 excites its vigour1 so that the loadstone hangs on more firmly4 ,for a pendent loadstone clings #ij more firmly to a magnetick body joined to it above with a hanging piece of iron added to it1 than when lead or any other non-magnetick body is hung on4 ,a loadstone1 whether armed or unarmed1 99 joined by its proper pole to the pole of another loadstone1 armed or unarmed1 makes the loadstone raise a greater weight by the opposite end#agg4 ,a piece of iron also applied to the pole of a magnet produces the same result1 namely1 that the other pole will carry a greater weight of iron2 just as a loadstone with a piece of iron superposed on it 7as in this figure7 holds up a piece of iron below1 which it cannot hold1 if the upper one be removed4 99 ,magneticks in conjunction make one magnetick4 ,wherefore as the mass increases1 the magnetick vigour is also augmented4 ,an armed loadstone1 as well as an unarmed 99 one1 runs more readily to a larger piece of iron and combines more firmly with a larger piece than with a lesser one4 99 99 99 99 99 ,,chap4 ,,xxiii4 ,magnetick ,force causes motion towards unity1 and binds firmly together bodies which are united4 ,magnetick fragments cohre within their strength well and harmoniously together4 ,pieces of iron in the presence of a loadstone 7even if they are not 99 touching the loadstone7 run together1 seek one another anxiously and embrace one another1 and when joined are as if they were cemented4 ,iron 99 filings or the same reduced to powder inserted in paper tubes1 placed upon a stone meridionally or merely brought rather close to it1 coalesce into one body1 and so many parts suddenly are concreted 99 and combine2 and the whole company of corpuscles thus conspiring together affects another piece of iron and attracts it1 as if it constituted one integral rod of iron2 and above the stone it is directed toward the ,north and ,south4 ,but when they are removed a long 99 #ia way from the stone1 the particles 7as if loosed again7 are separated and move apart singly4 ,in this way also the foundations of the world are connected and joined and cemented together magnetically4 ,so let ,ptolemy of ,alexandria1 and his followers1 and those philosophers of ours1 be the less terrified if the earth do move round in a circle1 nor threaten its dissolution4 ,iron filings1 after being heated for a long time1 are attracted by a loadstone1 yet not so strongly or from so great a distance as when not heated4 ,a loadstone loses some of its virtue by too great a heat2 for its humour is set free1 whence its peculiar nature is marred4 ,likewise also1 if iron filings are well burnt in a reverberatory furnace and converted into saffron of ,mars1 they are not attracted by a loadstone2 but if they are heated1 but not thoroughly burnt1 they do stick to a magnet1 but less strongly than the filings themselves not acted upon by fire4 ,for the saffron has become totally deformate1 but the heated metal acquires a defect from the fire1 and the forces in the enfeebled body are less excited by a loadstone2 and1 the nature of the iron being now ruined1 it is not attracted by a loadstone4 99 99 99 99 99 ,,chap4 ,,xxiiii4 ,a piece of ,iron placed within the ,orbe of a ,loadstone hangs suspended in the air1 if on account of some impediment it cannot approach it4 ,within the magnetick orbe a piece of iron moves towards the more powerful points of the stone1 if it be not hindered by force or by the material of a body placed between them2 either it falls down from above1 or tends sideways or obliquely1 or flies up above4 ,but if the iron cannot reach the stone on account of some obstacle1 it cleaves to it and remains there1 but with a less firm and constant connection1 since at greater intervals or distances the alliance is less amicable4 ,fracastorio1 in the eighth chapter of his ,de ,sympathia1 says that a piece of iron is suspended in the air1 so that it can be moved neither up nor down1 if a loadstone be placed above which is able to draw the iron up just as much as the iron itself inclines downwards with equal force2 for thus the iron would be supported in the air3 which thing is absurd2 because the force of a magnet is #ib always the stronger the nearer it is4 ,so that when a piece of iron is raised a very little from the earth by the force of the magnet1 it needs must be drawn steadily on towards the magnet 7if nothing else come in the way7 and cleave to it4 ,baptista ,porta suspends a piece of iron in the air#agh 7a magnet being fixed above71 and1 by no very subtile process1 the iron is detained by a slender thread from its lower part1 so that it cannot rise up to the stone4 ,the iron is raised upright by the magnet1 although the magnet does not 99 touch the iron1 but because it is in its vicinity2 but when the whole iron on account of its greater nearness is moved by that which erected it1 immediately it hurries with a swift motion to the magnet and cleaves to it4 ,for by approaching the iron is more and more excited1 and the coition grows stronger4 99 99 99 99 99 ,,chap4 ,,xxv4 ,exaltation of the power of the ,magnet4 ,one loadstone far surpasses another in power1 since one draws iron of almost its own weight1 another can hardly stir some shreds4 ,whatever things1 whether animals or plants1 are endowed with life need some sort of nourishment1 by which their strength not only persists but grows firmer and more vigorous4 ,but iron is not1 as it seemed to ,cardan and to ,alexander ,aphrodiseus1 attracted by the loadstone in order that it may feed on shreds of it1 nor does the loadstone take up vigour from iron filings as if by a repast on victuals4 ,since ,porta had doubts on this and resolved to test it1 he took a loadstone of ascertained weight1 and buried it in iron filings of not unknown weight2 and when he had left it there for many months1 he found the stone of greater weight1 the filings of less4 ,but the difference was so slender that he was even then doubtful as to the truth4 ,what was done by him does not convict the stone of voracity1 nor does it show any nutrition2 for minute portions of the filings are easily scattered in handling4 ,so also a very fine dust is insensibly born on a loadstone in some very slight quantity1 by which something might have been added to the weight of the loadstone but which is only a surface accretion and might even be wiped off with no great difficulty4 ,some think that a weak and sluggish stone can bring itself back into better condition1 and that a very powerful one also might present it with the highest powers4 ,do they acquire strength like animals when #ic they eat and are sated8 ,is the medicine prepared by addition or subtraction8 ,is there anything which can re-create this primary form or bestow it anew8 ,and1 certes1 nothing can do this which is not magnetical4 ,magneticks can restore a certain soundness to magneticks 7when not incurable72 some can even exalt them beyond their proper strength2 but when a body is at the height of perfection in its own nature1 it is not capable of being strengthened further4 ,so that that imposture of ,paracelsus1 who affirms that the force and virtue can be increased and transmuted tenfold1 turns out to be the more infamous4 ,the method of effecting this is as follows1 viz41 you make it semi-incandescent in a fire of charcoal 7that is1 you heat it very hot71 so that it does not become red-hot1 however1 and immediately slake it1 as much indeed as it can imbibe1 in oil of saffron of ,mars1 made from the best ,carynthian steel4 ,in this way you will be able so to strengthen a loadstone that it can draw a nail out of a wall and accomplish many other like wonderful things1 which are not possible for a common loadstone4 ,but a loadstone thus slaked in oil not only does not gain power1 but suffers also a certain loss of its inborn strength4 ,a loadstone is improved if polished and rubbed with steel4 ,buried in filings of the best iron or of pure steel1 not rusty1 it preserves its strength4 ,sometimes also a somewhat good and strong one gains ,illustration some strength when it is rubbed on the pole of another1 on the opposite part1 and receives virtue4 ,in all these experiments it is an advantage to observe the pole of the earth1 and to adjust according to magnetick laws the stone which we wish to strengthen2 which we shall set forth below4 ,a somewhat powerful and fairly large loadstone increases the strength of a loadstone as it does of iron4 ,a loadstone being placed over the boreal pole of a loadstone1 99 #id the boreal pole becomes stronger1 and an iron rod 7like an arrow7 sticks to the boreal pole ,a1 but not at all to the pole ,b4 ,the pole ,a also1 when it is at the top in a right line with the axis of both loadstones joined in accordance with magnetick laws1 raises the rod to the perpendicular1 which it cannot do if the large loadstone be removed1 on account of its own weaker strength4 ,but as a small iron globe1 when placed above the pole of a terrella1 raises the rod to the 99 perpendicular1 so1 when placed at the side1 the rod is not directed towards the centre of the globe1 but is raised obliquely and cleaves anywhere1 because the pole in a round piece of iron is always the point which is joined most closely to the pole of the terrella and is not constant as in a smaller terrella4 ,the parts of the earth1 as of all magneticks1 are in agreement and take delight in their mutual proximity2 if placed in the highest power1 they do not harm their inferiors1 nor slight them2 there is a mutual love among them all1 a perennial good feeling4 ,the weaker loadstones are re-created by the more powerful1 and the less powerful cause no harm to the stronger4 ,but a powerful one attracts and turns a somewhat strong one more than it does an impotent one4 ,because a strenuous one confers a stronger activity1 and itself hastens1 flies up to the other1 and solicits it more keenly2 therefore there is a more certain and a stronger co-action and cohrency4 99 99 99 99 99 ,,chap4 ,,xxvi4 ,why there should appear to be a greater love between iron and loadstone1 than between loadstone and loadstone1 or between iron and iron1 when close to the loadstone1 within its orbe of virtue4 ,magnet attracts magnet1 not in every part and on every side with equal conditions1 as iron1 but at one and a fixed point2 therefore the poles of both must be exactly disposed1 otherwise they do not cleave together duly and strongly4 ,but this disposition is not easy and expeditious2 wherefore a loadstone seems not to conform to a loadstone1 when nevertheless they agree very well together4 ,a piece of iron by the sudden impression of a loadstone is not only allured by the stone1 but is renewed1 its forces being drawn forth2 by which it follows and solicits the loadstone with no less impulse1 and even leads another piece of iron captive4 ,let there be a small iron spike above a loadstone clinging firmly to it2 if you apply an unmagnetized rod of iron to the spike1 not1 however1 #ie so that it touches the stone1 you will see the spike when it has touched the iron1 leaving the loadstone1 follow the rod1 try to grasp it by leaning toward it1 and 7if it should touch it7 cleave firmly to it3 for a piece of iron1 when united and joined to another piece of iron placed within the orbe of virtue of the loadstone1 draws it more strongly than does the loadstone itself4 ,the natural magnetick virtue1 confused and dormant in the iron1 is aroused by the loadstone1 is linked to the loadstone1 and rejoices with it in its primary form2 then smelted iron becomes a perfect magnetick1 as robust as the loadstone itself4 ,for as the one imparts and stirs1 so the other conceives1 and being stirred remains in virtue1 and pours back the forces also by its own activity4 ,but since iron is more like iron than loadstone1 and the virtue in both pieces of iron is exalted by the proximity of the loadstone1 so in the loadstone itself1 in case of equal strength1 likeness of substance prevails1 and iron gives itself up rather to iron1 and they are united by their very similar homogenic powers4 ,which thing happens not so much from a coition1 as from a firmer unition2 and a knob or snout of steel1 fixed skilfully on the pole of the stone1 raises greater weights of iron than the stone of itself could4 ,when steel or iron is smelted from loadstone or iron ore1 the slag and corrupt substances are separated from the better by the fusion of the material2 whence 7in very large measure7 that iron contains the nature of the earth1 purified from alien flaw and blemish1 and more homogenic and perfect1 though deformed by the fusion4 ,and when that material indeed is provoked by a loadstone1 it conceives the magnetick virtues1 and within their orbe is raised in strength more than the weaker loadstone1 which with us is often not free from some admixture of impurities4 99 99 99 99 99 ,,chap4 ,,xxvii4 99 ,the ,centre of the ,magnetick ,virtues in the earth is the centre of the earth2 and in a terrella is the centre of the stone4 ,rays of magnetick virtue spread out in every direction in an orbe2 the centre of this orbe is not at the pole 7as ,baptista ,porta reckons1 ,chap4 #bb71 but in the centre of the stone and of the terrella4 ,so also the centre of the earth is the centre of the magnetick motions of the earth2 though magneticks are not borne directly toward the centre by magnetical motion1 except when they are attracted by the true pole4 ,for since the formal #if power of the stone and of the earth does not promote anything but the unity and conformity of disjoined bodies1 it comes about that everywhere at an equal distance from the centre or from the circumference1 just as it seems to attract perpendicularly at one place1 so at another it is able even to dispose and to turn1 provided the stone is not uneven in virtue4 ,for if at the distance ,c from the pole ,d the stone is able to allure a versorium1 99 at an equally long interval above the quator at ,a that stone can also direct and turn the versorium4 ,so the very centre and middle of the terrella is the centre of its virtue1 and from this to the circumference of the orbe 7at equal intervals on every side7 its magnetick virtues are emitted4 ,illustration 99 99 99 99 99 ,,chap4 ,,xxviii4 ,a ,loadstone attracts magneticks not only to a fixed point or pole1 but to every part of a terrella save the quinoctial zone4 ,coitions are always more powerful when poles are near poles1 since in them by the concordancy of the whole there exists a stronger force2 wherefore the one embraces the other more strongly4 ,places declining from the poles have attractive forces1 but a little weaker and languid in the ratio of their distance2 so that at length on the quinoctial circle they are utterly enervated and evanescent4 ,neither do even the poles attract as mathematical points2 nor do magneticks come into conjunction by their own poles1 only on the poles of a loadstone4 ,but coition #ig is made on every part of the periphery1 both ,northern and ,southern1 by virtue emanating from the whole body2 magneticks nevertheless incline languidly towards magneticks in the parts bordering on the quator1 but quickly in places nearer the pole4 ,wherefore not the poles1 not the parts alone nearest to the pole allure and invite magneticks1 but magneticks are disposed and turned round and combine with magneticks in proportion as the parts facing and adjoined unite their forces together1 which are always of the same potency in the same parallel1 unless they are distributed otherwise from causes of variation4 99 99 99 99 99 ,,chap4 ,,xxix4 ,on ,variety of ,strength due to ,quantity or ,mass4 ,quite similar in potency are those stones which are of the same mine1 and not corrupted by adjacent ores or veins4 ,nevertheless that which excels in size shows greater powers1 since it seizes greater weights and has a wider orbe of virtue4 ,for a loadstone weighing one ounce does not lift a large nail as does one weighing a pound1 nor does it rule so widely1 nor extend its forces2 and if from a loadstone of a pound weight a portion is taken away1 something of its power will be seen to go also2 for when a portion is abstracted the virtue is lessened4 ,but if that part is properly applied and united to it1 though it is not fastened 99 to nor grown into it1 yet by the application it obtains its pristine power and its vigour returns4 ,sometimes1 however1 when a part is taken away1 the virtue turns out to be stronger on account of the 99 bad shape of the stone1 namely1 when the vigour is scattered through inconvenient angles4 ,in various species the ratio is various1 for one stone of a drachm weight draws more than another of twenty pounds4 ,since in very many the influence is so effete that it can hardly be perceived1 those weak stones are surpassed by prepared pieces of clay4 ,but1 it may be asked#agi1 if a stone of the same species and goodness weighing a drachm would seize upon a drachm of iron1 would a stone of an ounce weight seize on an ounce1 a pound on a pound1 and so on8 ,and this is indeed true2 for it both strains and remits its strength proportionately1 so that if a loadstone1 one drachm of which would attract one drachm of iron1 were in equal proportion applied either to a suitably large obelisk or to an immense pyramid of iron1 it would lift it directly in such #ih proportion and would draw it towards itself with no greater effort of its nature or trouble than a loadstone of a drachm weight embraces a drachm4 ,but in all such experiments as this let the vigour of the magnets be equal2 let there be also a just proportion in all of the shapes of the stones1 and let the shape of the iron to be attracted be the same1 and the goodness of the metal1 and let the position of the poles of the loadstones be most exact4 ,this is also no less true in the case of an armed loadstone than of an unarmed one4 ,for the sake of experiment1 let there be given a loadstone of eight ounces weight1 which when armed lifts twelve ounces of iron2 if you cut off from that loadstone a certain portion1 which when it has been 99 reduced to the shape of the former whole one is then only of two ounces1 such a loadstone armed lifts a piece of iron applied to it of three ounces1 in proportion to the mass4 ,in this experiment also the piece of iron of three ounces ought to have the same shape as the former one of twelve ounces2 if that rose up into a cone1 it is necessary that this also in the ratio of its mass should be given a pyramidal shape proportioned to the former4 99 99 99 99 99 ,,chap4 ,,xxx4 ,the ,shape and ,mass of the ,iron are of most importance in coition4 ,observation has shown above that the shape and mass of the loadstone have great influence in magnetick coitions2 likewise also the shape and mass of the iron bodies give back more powerful and steady forces4 ,oblong iron rods are both drawn more quickly to a loadstone and cleave to it with greater obstinacy than round or square pieces1 for the same reasons which we have proven in the case of the loadstone4 ,but1 moreover1 this is also worthy of observation1 that a smaller piece of iron1 to which is hung a weight of another material1 so that it is altogether in weight equal to another large whole piece of iron of a right weight 99 7as regards the strength of the loadstone71 is not lifted by the loadstone as the larger piece of iron would be4 ,for a smaller piece of iron does not join with a loadstone so firmly1 because it sends back less strength1 and only that which is magnetick conceives strength2 the foreign material hung on cannot acquire magnetick forces4 99 99 99 99 99 #ii ,,chap4 ,,xxxi4 ,on ,long and ,round ,stones4 ,pieces of iron join more firmly with a long stone than with a round one1 provided that the pole of the stone is at the extremity and end of its length2 because1 forsooth1 in the case of a long stone1 a magnetick is directed at the end straight towards the body in which the virtue proceeds in straighter lines and through the longer diameter4 ,but a somewhat long stone has but little power on the side1 much less indeed than a round one4 ,it is demonstrable#ahj1 indeed1 that at ,a and ,b the coition is 99 stronger in a round stone than at ,c and ,d1 at like distances from the pole4 ,illustration 99 99 99 99 99 ,,chap4 ,,xxxii4 ,certain ,problems and ,magnetick ,experiments about the ,coition1 and ,separation1 and regular ,motion of bodies magnetical4 ,equal loadstones come together with equal incitation4 99 ,also magnetick bodies of iron1 if alike in all respects1 99 come together when excited with similar incitation4 ,furthermore1 bodies of iron not excited by a 99 loadstone1 if they are alike and not weighed down by their bulk1 move towards one another with equal motion4 ,two loadstones1 disposed on the surface of some water in #ajj suitable skiffs1 if they are drawn up suitably within their orbes of virtue1 incite one another mutually to an embrace4 ,so a proportionate 99 piece of iron in one skiff hurries with the same speed towards the loadstone as the loadstone itself in its boat strives towards the iron4 ,from their own positions1 indeed1 they are so borne together1 that they are joined and come to rest at length in the middle of the space4 ,two iron wires magnetically excited1 floating in water by means of 99 suitable pieces of cork1 strive to touch and mutually strike one another with their corresponding ends1 and are conjoined4 ,coition is firmer and swifter than repulsion and separation in 99 equal magnetick substances4 ,that magnetick substances are more sluggishly repelled than they are attracted is manifest in all magnetical experiments in the case of stones floating on water in suitable skiffs2 also in the case of iron wires or rods swimming 7transfixed through corks7 and well excited by a loadstone1 and in the case of versoria4 ,this comes about because1 though there is one faculty of coition1 another of conformation or disposition1 repulsion and aversion is caused merely by something disposing2 on the other hand1 the coming together is by a mutual alluring to contact and a disposing1 that is1 by a double vigour4 ,a disponent vigour is often only the precursor of coition1 in order that the bodies may stand conveniently for one another before conjunction2 wherefore also they are turned round to the corresponding ends1 if they can not#aha reach them through the hindrances4 ,illustration ,if a loadstone be divided through a meridian into two equal parts1 the separate parts mutually repel one another1 the poles being 99 placed directly opposite one another at a convenient and equal distance4 ,they repel one another also with a greater velocity than when pole is put opposite pole incongruously4 ,just as the part ,b of the loadstone1 placed almost opposite the part ,a1 repels it floating in its skiff1 because ,d turns away from ,f1 and ,e from ,c2 but if ,b is exactly joined with ,a again1 they agree and become one body #aja magnetical2 but in proximity they raise enmities4 ,but if one part of the stone is turned round1 so that ,c faces ,d and ,f faces ,e1 then ,a pursues ,b within its orbe until they are united4 ,the ,southern parts of the stone avoid the ,southern parts1 and the ,northern parts the ,northern4 ,nevertheless1 if by force you move up the ,southern cusp of a piece of iron too near the ,southern part of the stone1 the cusp is seized and both are linked together in friendly embraces3 because it immediately reverses the implanted verticity of the iron1 and it is changed by the presence of the more powerful stone1 which is more constant in its forces than the iron4 ,for they come together according to their nature1 if by reversal and mutation true conformity is produced1 and just coition1 as also regular direction4 ,loadstones of the same shape1 size1 and vigour1 attract one another mutually with like efficacy1 and in the opposite position repel one another mutually with a like vigour4 ,iron rods not touched1 though alike and equal1 do yet often act 99 upon one another with different forces2 because as the reasons of their acquired verticity1 also of their stability and vigour1 are different1 so the more strongly they are excited1 the more vigorously do they incite4 ,pieces of iron excited by one and the same pole mutually repel 99 one another by those ends at which they were excited2 then also the opposite ends to those in these iron pieces raise enmities one to another4 ,in versoria whose cusps have been rubbed1 but not their cross-ends1 99 the crosses mutually repel one another1 but weakly and in proportion to their length4 ,in like versoria the cusps1 having been touched by the same 99 pole of the loadstone1 attract the cross-ends with equal strength4 ,in a somewhat long versorium the cross-end is attracted rather 99 weakly by the cusp of a shorter iron versorium2 the cross of the shorter more strongly by the cusp of the longer1 because the cross of the longer versorium has a weak verticity1 but the cusp has a stronger4 ,the cusp of a longer versorium drives away the cusp of a 99 shorter one more vehemently than the cusp of the shorter the cusp of the longer1 if the one is free upon a pin1 and the other is held in the hand2 for though both were equally excited by the same loadstone1 yet the longer one is stronger at its cusp on account of its greater mass4 ,the ,southern end of an iron rod which is not excited attracts 99 the ,northern1 and the ,northern the ,southern2 moreover1 also the ,southern parts repel the ,southern1 and the ,northern the ,northern4 ,if magnetick substances are divided or in any way broken in pieces1 each part has a ,northern and a ,southern end4 #ajb ,a versorium is moved as far off by a loadstone when an obstacle 99 is put in the way1 as through air and an open medium4 ,rods rubbed upon the pole of a stone strive after the same pole 99 and follow it4 ,therefore ,baptista ,porta errs when he says1 chapter #djahb1 ,if you put that part to it from which it received its force1 it will not endure it1 but drives it from it1 and draws to it the contrary and opposite part4 ,the principles of turning round and inclining are the same in the case of loadstone to loadstone1 of loadstone to iron1 of iron also to iron4 ,when magnetick substances which have been separated by force and dissected into parts flow together into a true union and are suitably connected1 the body becomes one1 and one united virtue1 nor have they diverse ends4 ,the separate parts assume two opposite poles1 if the division has 99 not been made along a parallel3 if the division has been made along a parallel1 they are able to retain one pole in the same site as before4 ,pieces of iron which have been rubbed and excited by a loadstone are more surely and swiftly seized by a loadstone at fitting ends than such as have not been rubbed4 ,if a spike is set up on the pole of a loadstone1 a spike or style 99 of iron placed on the upper end is strongly cemented to it1 and draws away the erect spike from the terrella when motion is made4 ,if to the lower end of the erect spike the end of another spike 99 is applied1 it does not cohre with it1 nor do they unite together4 ,as a rod of iron draws away a piece of iron from a terrella1 so is it also with a minute loadstone and a lesser terrella1 though weaker in strength4 ,illustration ,the piece of iron ,c comes into conjunction with the terrella ,a1 and the vigour in it is magnetically exalted and excited1 both in the adjoining end and in the other also which is turned away through #ajc its conjunction with the terrella4 ,the end that is turned away also conceives vigour from the loadstone ,b2 likewise the pole ,d of that loadstone is powerful on account of its suitable aspect and the nearness of the pole ,e of the terrella4 ,several causes therefore concur why the piece of iron ,c should cleave to the terrella ,b1 to which it is joined more firmly than to the terrella ,a2 the vigour excited in the rod1 the vigour also excited in the stone ,b1 and the strength implanted in ,b concur2 therefore ,d is more firmly cemented magnetically with ,c than ,e with ,c4 ,but if you were to turn the vertex ,f round to the iron ,c1 ,c would not adhre to ,f as formerly to ,d2 for stones so arranged being within the orbe of virtue are placed contrary to natural order2 wherefore ,f does not receive power from ,e4 ,two loadstones or excited pieces of iron1 duly cohring1 fly 99 asunder on the approach of another more powerful loadstone or magnetized piece of iron4 ,because the new-comer repels the other with its opposing face1 and dominates it1 and ends the relationship of the two which were formerly joined4 ,so the forces of the other are lessened and succumb2 but if it conveniently could1 being diverted of its association with the weaker1 and rolling round1 it would turn about to the stronger4 ,wherefore also magnetick bodies suspended in the air fall when a loadstone is brought near them with an opposing face1 not 7as ,baptista ,porta teaches7 because the faculty of both those which were joined before grows faint and torpid1 for no face can be hostile to both the ends which cohre1 but to one only2 and when the stronger loadstone1 coming fresh with opposing face1 impels this further from it1 it is put to flight by the friendly reception of the former4 99 99 99 99 99 ,,chap4 ,,xxxiii4 ,on the ,varying ,ratio of ,strength1 and of the ,motion of coition1 within the orbe of virtue4 ,should a very large weight1 which at a very small distance is drawn towards a loadstone1 be divided into ever so many equal parts1 and should the radius of the orbe of magnetick attraction be divided into the same number of parts1 the like named parts of the weight will correspond to the intermediate parts of the radius4 ,the orbe of virtue extends more widely than the orbe of motion of any magnetick2 for the magnetick is affected at its extremity1 even if it is not moved with local motion1 which effect is produced #ajd by the loadstone being brought nearer4 ,a small versorium also is turned when a good distance off1 even if at the same distance it would not flow towards the loadstone1 though free and disengaged from impediment4 ,the swiftness of the motion of a magnetick body to a loadstone is dependent on either the power of the loadstone1 on its mass1 on its shape1 on the medium1 or on its distance within the magnetick orbe4 ,a magnetick moves more quickly towards a more powerful 99 stone than towards a sluggish one in proportion to the strength1 and as appears by a comparison of the loadstones together4 ,a lesser mass of iron also is carried more quickly towards a loadstone1 just as also one that is a little longer in shape4 ,the swiftness of magnetick motion towards a loadstone is changed by reason of the medium2 for bodies are moved more quickly in air than in water1 and in clear air than in air that is thick and cloudy4 ,by reason of the distance1 the motion is quicker in the case of bodies near together than when they are far off4 ,at the limits of the orbe of virtue of a terrella a magnetick is moved feebly and slowly4 ,at very short distances close to the terrella the moving impetus is greatest4 ,a loadstone which in the outmost part of its orbe of virtue 99 hardly moves a versorium when one foot removed from it1 doth1 if a long piece of iron is joined to it1 attract and repel the versorium more strongly with its opposite poles when even three feet distant4 ,the result is the same whether the loadstone is armed or unarmed4 ,let the iron be a suitable piece of the thickness of the little finger4 ,for the vigour of the loadstone excites verticity in the iron and proceeds in the iron and through the iron much further than it extends through the air4 ,the vigour proceeds even through several pieces of iron 7joined 99 to one another end to end71 not so regularly1 however1 as through one continuous solid4 ,dust of steel placed upon paper rises up when a loadstone is moved near above it in a sort of steely hairiness2 but if the loadstone is placed below1 such a hairiness is likewise raised4 ,steel dust 7when the pole of a loadstone is placed near7 is cemented 99 into one body2 but when it desires coition with the loadstone1 the mass is split and it rises in conglomerated parts4 ,but if there is a loadstone beneath the paper1 the mass is split in the same way and many portions result1 each of which consists of very many parts1 and remains cemented together1 as individual bodies4 ,whilst the lower parts of these pursue greedily the pole of the loadstone placed directly beneath1 even they also are raised up as magnetick wholes1 just as a small iron wire of the length of a grain or two grains of barley is raised up1 both when the loadstone is moved near both beneath and above4 99 99 99 99 99 #aje ,,chap4 ,,xxxiiii4 ,why a ,loadstone should be stronger in its poles in a different ratio2 as well in the ,northern regions as in the ,southern4 ,the extraordinary magnetick virtue of the earth is 99 remarkably demonstrated by the subtility of the following magnetical experiment4 ,let there be given a terrella of no contemptible power1 or a long loadstone with equal cones as polar extremities2 but in any other shape which is not exactly round error is easy1 and the experiment difficult4 ,in the ,northern regions1 raise the true ,north pole of the terrella above the horizon straight toward the zenith2 it is demonstrable that it raises up a larger iron spike on its ,north pole1 than the ,south pole of the same terrella is able to raise1 when turned in the same way toward the highest point of the sky4 ,the same thing is shown by a small terrella placed in the same way above a larger4 ,illustration ,let a b be the earth or a somewhat large terrella1 also a b a smaller terrella4 ,there is set up above the ,northern pole of the smaller terrella a spike larger than the pole b of the smaller terrella can raise1 if it is turned round to the higher parts4 ,and the pole a of the #ajf smaller terrella has its strength from the larger1 declining from the ,zenith to the plane of the horizon or to the level4 ,but now1 if1 99 leaving the terrella disposed in the same way1 you bring a piece of iron to the lower and ,southern pole1 it will attract and retain a greater weight than the ,boreal pole could1 if it were turned round to the lower parts4 ,which thing is demonstrated thus3 let ,a be the earth or a terrella2 ,e the ,boreal pole or some place in some great latitude2 ,b a rather large terrella above the earth or a smaller terrella on the top of a larger2 ,d its ,southern pole4 ,it is manifest that ,d 7the ,southern pole7 attracts a larger piece of iron1 ,c1 than ,f 7the ,boreal pole7 will be able to1 if it is turned round downward to the position ,d1 toward the earth or the terrella in the ,northern regions4 ,illustration ,magneticks acquire strength through magneticks1 if they are properly placed according to their nature1 in near neighbourhood and within the orbe of virtue4 ,wherefore when a terrella is placed on the earth or on a terrella1 so that its ,southern pole is turned round toward the ,northern pole1 its ,northern pole1 however1 turned away from the ,northern pole1 the influence and strength of #ajg its poles are increased4 ,and so the ,northern pole of a terrella in such a position lifts up a larger spike than the ,southern pole1 if the ,southern pole is turned away4 ,similarly the ,southern pole in a proper and natural arrangement1 acquiring strength from the earth or from a larger terrella1 attracts and retains larger rods of iron4 ,in 99 the other part of the terrestrial globe toward the ,south1 as also in the ,austral portion of a terrella1 the reasoning is converse2 for the ,southern pole of the terrella being turned away is more robust1 as also the ,northern pole when turned round4 ,the more a region on the earth is distant from the quinoctial 7as also in a larger terrella71 the larger is the accession of strength perceived2 near the quator1 indeed1 the difference is small1 but on the quator itself null2 at the poles finally it is greatest4 99 99 99 99 99 ,,chap4 ,,xxxv4 ,on a ,perpetual ,motion ,machine1 mentioned by authors1 by means of the attraction of a loadstone4 ,cardan writes#ahc that out of iron and the ,herculean stone can be made a perpetual motion machine2 not that he himself had ever seen one1 but only conceived the idea from an account by ,antonius de ,fantis#ahd1 of ,treves4 ,such a machine he describes1 ,book #i1 ,de ,rerum ,varietate4 ,but they have been little practised in magnetick experiments who forge such things as that4 ,for no magnetick attraction can be greater 7by any skill or by any kind of instrument7 than the retention4 ,things which are joined and those which are approaching near are retained with a greater force than those which are enticed and set in motion1 and are moved2 and that coition is1 as we have shown above1 a motion of both1 not an attraction of one4 ,such a machine ,peter ,peregrinus feigned many centuries before or else depicted one which he had received from others1 and one which was much better fitted for the purpose4 ,johannes ,taysnier published it also1 spoiled by wretched figures1 and copied out the whole theory of it word for word4 ,o that the gods would at length bring to a miserable end such fictitious1 crazy1 deformed labours1 with which the minds of the studious are blinded6 99 99 99 99 99 #ajh ,,chap4 ,,xxxvi4 ,how a more robust ,loadstone may be recognized4 ,very powerful loadstones sometimes lift into the air a weight of iron equal to their own2 a weak one barely attracts a slender wire4 ,those therefore are more robust which appeal to and retain larger bodies1 if there is no defect in their form1 or the pole of the stone is not suitably moved up4 ,moreover1 when placed in a boat a keener influence turns its own poles round more quickly to the poles of the earth or the limits of variation on the horizon4 ,one which performs its function more feebly indicates a defect and an effete nature4 ,there must always be a similar preparation1 a similar figure1 and a like size2 for in such as are very dissimilar and unlike1 the experiment is doubtful4 ,the method of testing the strength is the same also with a versorium in a place somewhat remote from a loadstone2 for the one which is able to turn the versorium round at the greater distance1 that one conquers and is held the more potent4 ,rightly also is the force of a loadstone weighed in a balance by ,b4 ,porta2 a piece of loadstone is placed in one scale-pan1 in the other just as much weight of something else1 so that the scale-pans hang level4 ,soon a piece of iron lying on the table is adjusted so that it sticks to the loadstone placed in the scale1 and they cling together most perfectly1 according to their friendly points2 into the other scale-pan sand is gradually thrown1 and that until the scale in which the loadstone is placed is separated from the iron4 ,thus by weighing the weight of sand1 the magnetick force becomes known4 ,similarly also it will be pleasing to try with another stone1 in equilibrium1 the weight of the sand being observed1 and to find out the stronger by means of the weights of sand4 ,such is the experiment of ,cardinal ,cusan in his ,de ,staticis#ahe1 from whom it would seem that ,b4 ,porta learnt the experiment4 ,the better loadstones turn themselves round more quickly toward the poles or points of variation2 then they also lead along and turn round more quickly1 according to the greater quantity and mass of wood1 a boat and other stuff4 ,in a declination instrument1 the more powerful force of a loadstone is looked for and required4 ,those therefore are more lively when they get through their work readily1 and pass through and come back again with speed1 and swiftly at length settle at their own point4 ,languid and effete ones move more sluggishly#ahf1 settle more tardily1 adhre more uncertainly1 and are easily disturbed from their possession4 99 99 99 99 99 #aji ,,chap4 ,,xxxvii4 ,use of a ,loadstone as it affects iron4 ,by magnetick coition we test iron ore in a blacksmith's forge4 ,it is burnt1 broken in pieces1 washed and dried1 in which way it lays down its alien humours2 in the bits collected from the washing is placed a loadstone1 which attracts the iron dust to itself2 this1 being brushed off with feathers1 is received in a crucible1 and the loadstone is again placed in the bits collected from the washing1 and the dust wiped off1 as long as any remains which it will attract to itself4 ,this is then heated in the crucible along with sal nitri#ahg until it is liquid1 and from this a small mass of iron is cast4 ,but if the loadstone draws the dust to itself quickly and readily1 we conjecture that the iron ore is rich2 if slowly1 poor2 if it seems altogether to reject it1 there is very little iron in it or none at all4 ,in like manner iron dust can be separated from another metal4 ,many tricks there are also1 when iron is secretly applied to lighter bodies1 and1 being attracted by the motion of a loadstone which is kept out of sight1 causes movements which are amazing to those who do not know the cause4 ,very many such indeed every ingenious mechanician will perform by sleight of hand1 as if by incantations and jugglery#ahh4 99 99 99 99 99 ,,chap4 ,,xxxviii4 ,on ,cases of ,attraction in other ,bodies4 ,very often the herd of philosophizers and plagiarists repeat from the records of others in natural philosophy opinions and errors about the attractions of various bodies2 as that ,diamond attracts iron1 and snatches it away from a magnet2 that there are various kinds or magnets1 some which attract gold1 others silver1 brass1 lead2 even some which attract flesh1 water1 fishes4 ,the flame of sulphur is said to seek iron and stones2 so white naphtha is said to attract fire4 ,i have said above that #aaj inanimate natural bodies do not attract1 and are not attracted by1 others on the earth1 excepting magnetically or electrically4 ,wherefore it is not true that there are magnets which attract gold or other metals2 because a magnetick substance draws nothing but magnetick substances4 ,though ,fracastorio says that he has shown a magnet drawing silver2 if this were true1 it must have happened on account of iron skilfully mixed with that silver or concealed in it1 or else because nature 7as she does sometimes1 but rarely7 had mixed iron with the silver2 iron indeed is rarely mixed with silver by nature2 silver with iron very rarely or never4 ,iron is mixed with silver by forgers of false coin or from the avarice of princes in the coining of money1 as was the case with the denarius of ,antony#ahi1 provided that ,pliny is recording a true incident4 ,so ,cardan 7perhaps deceived by others7 says that there is a certain kind of loadstone which draws silver2 he adds a most foolish test of this3 ,if therefore 7he says7 a slender rod of silver be steeped in that in which a versatory needle has stood1 it will turn toward silver 7especially toward a large quantity7 although it be buried2 by this means anyone will be able easily to dig up concealed treasures4 ,he adds that it should be very good stone1 such as he has not yet seen4 ,nor indeed will either he or anyone else ever see such a stone or such an experiment4 ,cardan brings forward an attraction of flesh1 wrongly so named and very dissimilar from that of the loadstone2 for his magnes creagus or flesh-magnet1 from the experiment that it sticks to the lips1 must be hooted out from the assembly of loadstones1 or by all means from the family of things attractive4 ,lemnian earth1 ruddle1 and very many minerals do this1 and yet they are fatuously said to attract4 ,he will have it that there is another loadstone1 as it were1 a third species1 into which1 if a needle is driven and afterwards stuck into the body1 it is not felt4 ,but what has attraction to do with stupefaction1 or stupor with a ,philosopher's intellect1 when he is discoursing about attraction8 ,there are many stones1 both found in nature and made by art1 which have the power of stupefying4 ,sulphur flame is said by some to attract1 because it consumes certain metals by its power of penetration4 ,so white naphtha attracts flame1 because it gives off and exhales an inflammable vapour1 on which account it is kindled at some distance1 just as the smoke of a recently extinguished candle takes fire again from another flame2 for fire creeps to fire through an inflammable medium4 ,why the sucking fish ,echineis or the ,remora should stay ships has been variously treated by ,philosophers1 who are often accustomed to fit this fable 7as many others7 to their theories1 before they find out whether the thing is so in nature4 ,therefore1 in order that they may support and agree with the fatuities of the ancients1 they put forward even the most fatuous ratiocinations and ridiculous problems1 cliffs that attract1 where the #aaa sucking fish tarry1 and the necessity of some vacuum1 ,i know not what1 or how produced4 ,pliny and ,julius ,solinus make mention of a stone ,chatochitis#aij4 ,they say that it attracts flesh1 and keeps hold of the hands1 just as a loadstone does iron1 and amber chaff4 ,but that happens only from a stickiness and from glue contained in it1 since it sticks more easily to the hands when they are warm4 ,sagda or ,sagdo#aia1 of the colour of a sard1 is a precious stone mentioned by ,pliny1 ,solinus1 ,albertus1 and ,evax#aib2 they describe its nature and relate1 on the authority of others1 that it specially attracts wood to itself4 ,some even babble that woods cannot be wrenched away except they are cut off4 ,some also narrate that a stone is found which grows pertinaciously into ships1 in the same way as certain testacea on long voyages4 ,but a stone does not draw because it sticks2 and if it drew1 it would certainly draw shreds electrically1 ,encelius saw in the hands of a sailor such a stone of feeble virtue1 which would hardly attract even the smallest twigs2 and in truth1 not of the colour of the sard4 ,so ,diamond1 ,carbuncle1 ,crystal1 and others do attract4 ,i pass over other fabulous stones2 ,pantarbe1 about which ,philostratus writes that it draws other stones to itself2 ,amphitane also1 which attracts gold4 ,pliny in his origin of glass will have it that a loadstone is an attractor of glass1 as well as of iron4 ,for in his method of preparing glass1 when he has indicated its nature1 he subjoins this about loadstone4 ,soon 7such is the astute and resourceful craft7 it was not content to have mixed natron2 loadstone also began to be added1 since it was thought to attract to itself the liquor of glass 7as it does iron74 ,georgius ,agricola writes that to the material of glass 7sand and natron7 one part also of loadstone is added4 ,because that force is believed1 in our times just as in former times1 to attract the liquor of glass to itself1 as it attracts iron to itself1 purges it when drawn1 and makes clear glass from green or muddy2 but the fire afterwards burns up the loadstone4 ,it is true indeed that some sort of magnes 7as the magnesia of the glass-makers imbued with no magnetick virtues7 is sometimes put in and mixed with the material of the glass2 not1 however1 because it attracts glass4 ,but when a loadstone is burnt1 it does not lay hold of iron at all1 nor is iron when red-hot allured by any loadstone2 and loadstone also is burnt up by more powerful fires and loses its attractive potency4 ,nor is this a function of loadstone alone in the glass furnaces2 but also of certain pyrites and of some easily combustible iron ores1 which are the only ones used by our glass-makers1 who make clear1 bright glass4 ,they are mixed with the sand1 ashes1 and natron 7just as they are accustomed to make additions in the case of metallick ores whilst they are smelted71 so that when the material slows down into glass1 the green and muddy colour of the glass may be purged by the penetrating heat4 ,for no other material becomes so hot1 #aab or bears the fire for such a convenient time1 until the material of the glass is perfectly fluid1 and is at the same time burnt up by that ardent fire4 ,it happens1 however1 sometimes1 that on account of the magnetick stone1 the magnesia1 or the ore1 or the pyrites1 the glass has a dusky colour1 when they resist the fire too much and are not burnt up1 or are put in in too great quantity4 ,wherefore manufacturers are seeking for a stone suitable for them1 and are observing also more diligently the proportion of the mixture4 ,badly therefore did the unskilful philosophy of ,pliny impose upon ,georgius ,agricola and the more recent writers1 so that they thought the loadstone was wanted by glass-makers on account of its magnetick strength and attraction4 ,but ,scaliger in ,de ,subtilitate ad ,cardanum1 in making diamond attract iron1 when he is discussing magneticks1 wanders far from the truth1 unless it be that diamond attracts iron electrically1 as it attracts wood1 straws1 and all other minute bodies when it is rubbed4 ,fallopius reckons that quicksilver draws metals by reason of an occult property1 just as a loadstone iron1 amber chaff4 ,but when quicksilver enters metals1 it is wrongly called attraction4 ,for metals imbibe quicksilver1 just as clay water2 nor do they do this unless they are touching1 for quicksilver does not allure gold or lead to itself from afar1 but they remain motionless in their places4 99 99 99 99 99 ,,chap4 ,,xxxix4 ,on ,bodies which mutually repel one another4 ,writers who have discoursed on the forces of bodies which attract others have also spoken about the powers of bodies which repel1 but especially those who have instituted classes for natural objects on the basis of sympathy and antipathy4 ,wherefore it would seem necessary for us to speak also about the mutual strife of bodies1 so that published errors should not creep further1 and be received by all to the ruin of true philosophy4 ,they say that1 just as like things attract for the sake of preservation1 so unlike and contrary things for the same purpose mutually repel and put one another to flight4 ,this is evident in the reaction of many things1 but it is most manifest in the case of plants and animals1 which attract kindred and familiar things1 and in like manner reject foreign and unsuitable things4 ,but in other bodies there is not the same reason1 so that when they are separated1 they should come together by mutually #aac attracting one another4 ,animals take food 7as everything which grows71 and draw it into their interior2 they absorb the nourishment by certain parts and instruments 7through the action and operation of the anima74 ,they enjoy by natural instinct only the things set in front of them and near them1 not things placed afar off2 and this without any alien force or motion4 ,wherefore animals neither attract any bodies nor drive them away4 ,water does not repel oil 7as some think7 because the oil floats on water2 nor does water repel mud1 because the mud1 if mixed in water1 settles down in time4 ,this is a separation of unlike bodies or such as are not perfectly mixed as respects the material2 the separated bodies nevertheless remain joined without any natural strife4 ,wherefore a muddy sediment settles quietly on the bottom of vessels1 and oil remains on the top of the water and is not sent further away4 ,a drop of water remains intact on a dry surface1 and is not expelled from the dry substance4 ,wrongly therefore do those who discourse on these matters infer an antipathy 7that is1 the force of repelling by contrary passions72 for there is no repelling force in them2 and repulsion comes#aic from action1 not from passion4 ,but their greek vocables please them too much4 ,we1 however1 must inquire whether there is any body which drives anything else further off without material impetus1 as a loadstone attracts4 ,but a loadstone seems even to repel loadstone4 ,for the pole of one loadstone repels the pole of another1 which does not agree with it according to nature2 by repelling1 it turns it round in an orbit so that they may exactly agree according to their nature4 ,but if a somewhat weak loadstone1 floating freely on water1 cannot readily be turned round on account of impediments1 the whole loadstone is repelled and sent further away from the other4 ,all electricks attract all things3 they never repel or propel anything at all#aid4 ,as to what is related about certain plants 7as about the cucumber1 which turns aside when oil is applied to it71 there is a material change from the vicinity1 not a hidden antipathy4 ,but when they show a candle flame put against a cold solid substance 7as iron7 turn away to the side1 and allege antipathy as the cause1 they say nothing4 ,the reason of this they will see clearer than the day1 when we discourse on what heat is#aie4 ,but ,fracastorio's opinion that a loadstone can be found1 which would drive iron away1 on account of some opposing principle lurking in the iron1 is foolish4 99 99 99 99 99 #aae ,illustration ,,book ,,third4 ,,chap4 ,i4 ,,on ,,direction4 ,on referring to the earlier books it will be found shown that a loadstone has its poles1 and that a piece of iron has also poles1 and rotation1 and a certain verticity2 finally1 that the loadstone and the iron direct their poles toward the poles of the earth4 ,now1 however1 we must make clear the causes of these things and their admirable workings1 pointed out indeed before1 but not proven4 ,all those who have written before us about these rotations have left us their opinions so briefly1 so meagrely1 and with such hesitating judgment that they seem hardly likely ever to persuade anyone1 or even to be able to satisfy themselves2 and all their petty reasons are rejected by the more prudent as useless1 uncertain1 and absurd1 being supported by no proofs or arguments2 whence also magnetick science1 being all the more neglected and not understood1 has been in exile4 ,the true austral pole of a loadstone1 not the boreal 7as all before us used to think71 99 if the loadstone is placed in its boat on the surface of water1 turns to the ,north2 in the case of a piece of iron also1 whether it has been excited by a loadstone or not1 the southern end moves toward the ,north4 ,an oblong piece of iron of three or four digits' length#aif1 when skilfully rubbed with a loadstone1 quickly turns north and south4 ,wherefore mechanicians1 taking a piece of iron prepared in this way1 balance it on a pin in a box1 and fit it up with the requisites of a sun-dial2 or they prepare the versorium out of two curved pieces of iron with their ends touching one another1 so that the motion may be more constant4 ,in this way the mariners' versorium is arranged1 which is an instrument beneficial1 useful1 and auspicious to sailors for indicating1 like a good genius1 safety and the right way4 ,but it must be understood on the threshold of this argument 7before we proceed further7 that these pointings of the loadstone or of iron are not perpetually made #aaf toward the true poles of the world1 do not always seek those fixed and definite points1 or remain on the line of the true meridian2 but usually diverge some distance to the ,east or to the ,west4 ,sometimes also at certain places on land or sea they do indicate exactly the true poles4 ,this discrepancy is called the ,variation of the iron or of the loadstone2 and since this is brought about by other causes1 and is merely a certain disturbance and perversion of the true direction1 we are directing our attention in this place to the true direction of the compass and of the magnetick iron 7which would be equally toward the true poles and on the true meridian everywhere on the earth1 unless other obstacles and an untoward pervertency hindered it74 ,of its variation and the cause of the perversion we shall treat in the next book4 ,those who wrote about the world and about natural philosophy a century ago1 especially those remarkable elementary philosophers1 and all those who trace their knowledge and training to them down to our own times1 those men1 ,i say1 who represented the earth as always at rest and1 as it were1 a useless weight1 placed in the centre of the universe at an equal distance from the sky on every side1 and its nature to be simple1 imbued only with the qualities of dryness and cold1 sought diligently for the causes of all things and of all effects in the heavens1 the stars1 the planets1 in fire1 air1 waters and substances of mixed natures4 ,never indeed did they recognize that the terrestrial globe had1 besides dryness and cold1 some special1 effective1 and predominant properties1 strengthening1 directing1 and moving the globe itself through its whole mass and its very deepest vitals2 nor did they ever inquire whether there were any such4 ,for this reason the crowd of philosophizers1 in order to discover the reasons of the magnetical motions1 called up causes lying remote and far away4 ,and one man seems to me beyond all others worthy of censure1 ,martin ,cortes1 who1 since there was no cause which could satisfy him in the whole of nature1 dreamed that there was a point of magnetical attraction beyond the heavens1 which attracted iron4 ,peter ,peregrinus thinks that the direction arises from the poles of the sky4 ,cardan thought that the turning of iron was caused by a star in the tail of the ,great ,bear2 ,bessard1 the ,frenchman1 opines that a magnetick turns toward the pole of the zodiack4 ,marsilius ,ficinus will have it that the loadstone follows its own ,arctick pole2 but that iron follows the loadstone1 straws amber2 whilst this perhaps follows the ,antarctick pole--a most foolish dream4 ,others have recourse to ,i know not what magnetick rocks and mountains4 ,thus it is always customary with mortals1 that they despise things near home1 whilst foreign and distant things are dear and prized4 ,but we study the earth itself and observe in it the cause of so great an effect4 ,the earth1 as the common mother1 has these causes inclosed in her innermost parts2 in accordance with her rule1 #aag position1 condition1 verticity1 poles1 quator1 horizons1 meridians1 centre1 circumference1 diameter1 and the nature of the whole interior of her substance1 must all magnetical motions be discussed4 ,the earth has been ordered by the highest ,artificer and by nature in such a way that it should have parts dissimilar in position1 bounds of the whole and complete body1 ennobled by certain functions1 by which it might itself remain in a definite direction4 ,for just as a loadstone1 when it is floated on water in a suitable vessel1 or is hung by slender threads in the air1 by its implanted verticity conforms its poles to the poles of the common mother in accordance with magnetick laws2 so if the earth were to deviate from its natural direction and its true position in the universe1 or if its poles were to be drawn aside 7if this were possible7 toward the sun-rising or the sun-setting or toward any other points whatsoever in the visible firmament1 they would return again to the north and south by magnetical motion1 and would settle at the same points at which they are now fixed4 ,the reason why the terrestrial globe seems to remain more steadily with the one pole toward those parts and directed toward the ,cynosure1 and why its pole diverges by #bc degrees #bi minutes1 with a certain variation not sufficiently investigated as yet by ,astronomers1 from the poles of the ecliptick1 depends on its virtue magnetical4 ,the causes of the precession of the quinoxes and the progression of the fixed stars1 and of the change1 moreover1 in the declinations of the sun and of the tropicks1 must be sought from magnetick influences2 so that neither that absurd motion of trepidation of ,thebit ,bencora#aig1 which is at great variance with observations1 nor the monstrous superstructures of other heavens1 are any longer needed4 ,a versatory iron turns to the position of the earth1 and if disturbed ever so often returns always to the same points4 ,for in the far regions of the north1 in a latitude of #gj or #hj degrees 7to which at the milder seasons of the year our sailors are accustomed to penetrate without injury from the cold72 in the regions halfway between the poles2 on the quator in the torrid zone2 and again in all the maritime places and lands of the south1 in the highest latitude which has thus far been reached1 always the iron magnetick finds its way1 and points to the poles in the same manner 7excepting for the difference of variation72 on this side of the quator 7where we live71 and on the other side to the south1 less well known1 but yet in some measure explored by sailors3 and always the lily of the compass points toward the ,north4 ,this we have had confirmed by the most eminent captains1 and also by very many of the more intelligent sailors4 ,these facts have been pointed out to me and confirmed by our most illustrious ,sea-god1 ,francis ,drake1 and by another circumnavigator of the globe1 ,thomas ,candish2 our terrella also indicates the same thing4 ,this is demonstrated in the case of the #aah ,illustration orbicular stone1 whose poles are ,a and ,b2 an iron wire ,,cd1 which is placed upon the stone1 always points directly along the meridian toward the poles ,,ab1 whether the centre of the wire is on the central line or quator of the stone1 or on any other part situated between the quator and the poles1 as at ,h1 ,g1 ,f1 ,e4 ,so the cusp of a versorium on this side of the quator points toward the north2 99 on the other side the cross is always directed toward the south2 but the cusp or lily#aih does not1 as some one has thought1 turn toward the south beyond the quator4 ,some inexperienced people indeed1 who in distant parts beyond the quator have seen the versorium sometimes become more sluggish and less prompt1 thought that the distance from the arctick pole or from the magnetick rocks was the cause of this4 ,but they are very much mistaken2 for it is as powerful#aii1 and adjusts itself as quickly to the meridian or to the point of variation in the southern as in the northern parts of the earth4 ,yet sometimes the motion appears slower1 namely1 when the supporting pin by lapse of time and long voyaging has become somewhat blunt1 or the magnetick iron parts have lost1 by age or rust1 some of their acquired vigour4 ,this may also be shown experimentally by the versatory iron of a small sun-dial placed on a very short pin set perpendicular to the surface of the stone1 for the iron when touched by a loadstone points toward the poles of the stone and leaves the poles of the earth2 for the general and remoter cause is overcome by the particular and powerful cause which is so near at hand4 ,magnetick bodies have of themselves an inclination toward the position of the earth and are influenced by a terrella4 ,two equal stones of equal strength adjust themselves to a terrella in accordance with magnetick laws4 ,the iron conceives vigour from the loadstone and is influenced by the magnetical motions4 ,wherefore true direction is the motion of a magnetick body in regard to the verticity of the earth1 the natures of both agreeing and working together toward a natural position and unity4 ,for indeed we have found out at length1 by many experiments and in many ways1 that there is a disposing nature1 moving them together by reason of their various positions by one form that is common #aai to both1 and that in all magnetick substances there is attraction and repulsion4 ,for both the stone#bjj and the magnetick iron arrange themselves by inclination and declination1 according to the common position of their nature and the earth4 ,and the force of the earth by the virtue of the whole1 by attracting toward the poles1 and repelling1 arranges all magneticks which are unfixed and loose4 ,for in all cases all magneticks conform themselves to the globe of the earth in the same ways and by the same laws by which another loadstone or any magneticks do to a terrella4#bja 99 99 99 99 99 ,,chap4 ,,ii4 ,the ,directive or ,versorial ,virtue 7which we call verticity73 what it is1 how it exists in the loadstone2 and in what way it is acquired when innate4 ,directive force1 which is also called by us verticity1 is a virtue which spreads by an innate vigour from the quator in both directions toward the poles4 ,that power1 inclining in both directions towards the termini1 causes the motion of direction1 and produces a constant and permanent position in ,nature1 not only in the earth itself but also in all magneticks4 ,loadstone is found either in veins of its own or in iron mines1 when the homogeneous substance of the earth1 either having or assuming a primary form1 is changed or concreted into a stony substance1 which besides the primary qualities of its nature has various dissimilitudes and differences in different quarries and mines1 as if from different matrices1 and very many secondary qualities and varieties in its substance4 ,a loadstone which is dug out in this breaking up of the earth's surface and of protuberances upon it1 whether formed complete in itself 7as sometimes in ,china7 or in a larger vein1 is fashioned by the earth and follows the nature of the whole4 ,all the interior parts of the earth mutually conspire together in combination and produce direction toward north and south4 ,but those magnetical bodies which come together in the uppermost parts of the earth are not true united parts of the whole1 but appendages and parts joined on1 imitating the nature of the whole2 wherefore when floating free on water1 they dispose themselves just in the same way as they are placed in the terrestrial system of nature4 ,we had a large loadstone of twenty pounds 99 weight1 dug up and cut out of its vein1 after we had first observed and marked its ends2 then after it was dug out1 we placed it in a boat on water1 so that it could turn freely2 then immediately the face which had looked toward the north in the quarry began to #abj turn to the north on the waves and at length settled toward that point4 ,for that face which looked toward the north in the quarry is the southern1 and is attracted by the northern parts of the earth1 ,illustration in the same way as pieces of iron which acquire their verticity from the earth4 ,about this point we intend to speak afterwards#bjb under change of verticity4 ,but there is a different rotation of the internal parts of the earth1 which are perfectly united to the earth and which are not separated from the true substance of the earth by the interposition of bodies as are loadstones in the upper portion of the earth1 which is maimed1 corrupt1 and variable4 ,let ,a ,b be a piece of magnetick ore2 between which and the uniform globe of the earth lie various soils or mixtures which separate the ore to a certain extent from the globe of the true earth4 ,it is therefore influenced by the forces of the earth just in the same way as ,c ,d1 a piece of iron1 in the air4 ,so the face ,b of some ore or of that piece of it is moved toward the ,boreal pole ,g1 just as the extremity ,c of the iron1 not ,a or ,d4 ,but the condition of the piece ,e ,f is different1 which piece is produced in one connected mass with the whole1 and is not separated from it by any earthy mixture4 ,for if the part ,e ,f were taken out and floated freely in a boat by itself1 it is not ,e that would be directed toward the ,boreal pole1 but ,f4 ,so in those substances which acquire their verticity in the air1 ,c is the southern part and is seen to be attracted by the ,boreal pole ,g4 ,in the case of others which are found in the upper unstable portion of the earth1 ,b is the south1 and in like manner inclines toward the ,boreal pole4 ,but if those pieces deep down which are produced along with the earth are dug up1 they turn about on a different plan4 ,for ,f turns toward the ,boreal parts of the earth1 because 99 is the southern part2 ,e toward the south1 because it is the northern4 ,so of a magnetick body1 ,c ,d1 placed close to the earth1 the end ,c turns toward the ,boreal pole2 of one that is adnate to it ,b ,a1 ,b inclines to the ,north2 of one that is innate in it1 ,e ,f1 ,e turns toward the southern pole2 which is confirmed by the #aba ,illustration following demonstration1 and comes about of necessity according to all magnetick laws4 ,let there be a terrella with poles ,a ,b2 from its mass cut out a small part ,e ,f2 if this be suspended by a fine thread above the hole or over some other place1 ,e does not seek the pole ,a but the pole ,b1 and ,f turns to ,a2 very differently from a rod of iron ,c ,d2 because ,c1 touching some northern part of the terrella1 being magnetically carried away makes a turn round to ,a1 not to ,b4 ,and yet here it should be observed1 that if the pole ,a of 99 the terrella were moved toward the earth's south1 the end ,e of the piece cut out by itself1 if not brought too near to the stone1 would also move of itself toward the south4 ,but the end ,c of the piece of iron1 placed beyond its orbe of virtue1 will turn toward the north4 ,the part ,e ,f of the terrella1 whilst in the mass1 produced the same direction as the whole2 but when it is separated and suspended by a thread1 ,e turns to ,b1 and ,f to ,a4 ,illustration #abb ,so parts having the same verticity with the whole1 when separated1 are impelled in the contrary direction2 for contrary parts solicit contrary parts4 ,nor yet is this a true contrariety1 but the highest concordancy1 and the true and genuine conformation of bodies magnetical in the system of nature1 if they shall have been divided and separated3 for the parts thus divided should be raised some distance from the whole1 as will be made clear afterwards4 ,magnetick substances seek a unity as regards form2 they do not so much respect their own mass4 ,wherefore the part ,f ,e is not attracted into its former bed2 but when once it is unsettled and at a distance1 it is 99 solicited by the opposite pole4 ,but if the small piece ,f ,e is placed back again in its bed or brought close to1 without any substances intervening1 it acquires its former combination1 and1 as a part of the whole once more united1 accords with the whole and sticks readily in its former position2 and ,e remains toward ,a1 and ,f toward ,b1 and they settle steadily in their mother's lap4 ,the reasoning is the same when the stone is divided into equal parts through the poles4 ,illustration ,a spherical stone is divided into two equal parts along the axis ,a ,b2 99 whether therefore the surface ,a ,b is in the one part facing upward 7as in the former diagram7 or lying on its face in both parts 7as in 99 the latter71 the end ,a tends toward ,b4 ,but it must also be understood that the point ,a is not carried with a definite aim always toward the point ,b1 because in consequence of the division the verticity proceeds to other points1 as to ,f ,g1 as appears in the fourteenth chapter of this book4 ,and ,l ,m are now the axes in each1 and ,a ,b is no longer the axis2 for magnetick bodies1 as soon as they are divided1 become single magnetick wholes2 and they have #abc vertices in accordance with their mass1 new poles arising at each end in consequence of the division4 ,yet the axis and the poles always follow the leading of a meridian2 because that force passes along the meridians of the stone from the quator to the poles1 by an everlasting rule1 the inborn virtue of the substance agreeing thereto from the long and lasting position and the facing of a suitable substance toward the poles of the earth2 by whose strength continued through many centuries it has been fashioned2 toward fixed and determined parts of which it has remained since its origin firmly and constantly turned4 99 99 99 99 99 ,,chap4 ,,iii4 ,how ,iron acquires ,verticity through a ,loadstone1 and how that verticity is lost and changed4 ,friction between an oblong piece of iron and a loadstone imparts to the former magnetick virtues1 which are not corporeal nor inherent and persistent in any body1 as we showed in the discussion on coition4 ,it is plain that the iron1 when it has been rubbed hard with one end and applied to the stone for a pretty long time1 receives no stony nature1 acquires no weight2 for if1 before the iron is touched by the stone1 you weigh 99 it in a small and very exact goldsmith's balance1 you will see after the rubbing that it has exactly the same weight1 neither diminished nor increased4 ,but if you wipe the iron with cloths after it has been touched1 or wash it in water1 or scour it with sand or on a grindstone1 still it in nowise lays aside its acquired strength4 ,for the force is spread through the whole body and conceived in the inmost parts1 and cannot in any way be washed or wiped away4 ,let an experiment then be made in fire1 that untamed tyrant of nature4 ,take a piece of iron of the length of a palm and the thickness of a goosequill pen2 let this iron be passed through a suitable round cork and placed on the surface of water1 and observe the end which turns to the north2 rub this particular end with the true southern end of a loadstone2 the iron so rubbed turns toward the south4 ,remove the cork1 and place the end 99 which was excited in the fire until the iron is just red-hot2 when it is cooled1 it will retain the strength of the loadstone and the verticity1 though it will not be so prompt1 whether because the force of the fire had not yet continued long enough to overcome all its #abd strength1 or because the whole iron was not heated to redness1 for the virtue is diffused through the whole4 ,remove the cork a second time1 and putting the whole iron in the fire1 blow the fire with the bellows1 so that it may be all aglow1 and let it remain a little longer time red-hot2 when cooled 7so1 however1 that1 whilst it is cooling1 it does not rest in one position71 place it again on the water with the cork1 and you will see that it has lost the verticity 99 which it had acquired from the stone4 ,from these experiments it is clear how difficult it is for the property of polarity implanted by the loadstone to be destroyed4 ,but if a small loadstone had remained as long in the same fire1 it would have lost its strength4 ,iron1 because it does not so easily perish1 and is not so easily burnt up as very many loadstones1 retains its strength more stably1 and when it is lost can recover it again from a loadstone2 but a loadstone when burnt does not revive4 ,but now that iron1 which has 99 been deprived of its magnetick form1 moves in a different way from any other piece of iron1 for it has lost its polar nature2 and whereas before the touch of the loadstone it may have had a motion toward the north1 and after contact toward the south2 now it turns to no definite and particular point2 but afterwards1 very slowly and after 99 a long time1 it begins to turn in a doubtful fashion toward the poles of the earth 7having acquired some power from the earth74 ,i have said that the cause of direction was twofold1 one implanted in the stone and iron1 but the other in the earth1 implanted by the disponent virtue2 and for that reason 7the distinction of poles and the verticity in the iron having now been destroyed7 a slow and weak directive power is acquired anew from the verticity of the earth4 ,we may see1 therefore1 with what difficulty and only by the application of hot fires and by long ignition of the iron heated to softness1 the imparted magnetick virtue is eradicated4 ,when this ignition has overcome the acquired polarity1 and it has been now completely subdued and not awakened again1 that iron is left unsettled and utterly incapable of direction4 ,but we must further inquire how iron remains affected by verticity4 ,it is manifest that it strongly affects and changes the nature of the iron1 because the presence of a loadstone attracts the iron to itself with an altogether wonderful readiness4 ,nor is it only the part that is rubbed1 but on account of the rubbing 7on one end only7 the whole iron is affected together1 and gains by it a permanent though an unequal power4 ,this is demonstrated as follows4 ,rub an iron wire on the end so 99 that it is excited1 and it will turn towards the north2 afterward cut off some portion of it2 you will see that it still turns toward the north 7as before71 but more feebly4 ,for it must be understood that the loadstone excites a steady verticity in the whole iron 7if the rod be not too long7 more vigorous throughout the whole mass in a shorter bar1 and as long as the iron remains touching the loadstone a little #abe stronger4 ,but when the iron is separated from contact with it1 then it becomes much weaker1 especially in the end that was not touched4 ,just as a long rod1 one end of which is placed in the fire and heated1 grows exceedingly hot at that end1 less so in the parts adjoining and in the middle1 whilst at the other end it can be held in the hand1 and that end is only warm2 so the magnetical vigour diminishes from the excited end to the other end2 but it is present there instantly1 and does not enter after an interval of time nor successively1 as the heat in the iron2 for as soon as a piece of iron has been touched by a loadstone it is excited throughout its whole length4 ,for the sake of experiment1 let there be a rod of iron #d or 99 #e digits long1 untouched by a loadstone2 as soon as you touch one end only with a loadstone1 the opposite end immediately1 or in the twinkling of an eye1 by the power that it has conceived1 repels or attracts a versorium1 if it be applied to it ever so quickly4 99 99 99 99 99 ,,chap4 ,,iiii4 ,why ,iron touched by a ,loadstone acquires an opposite verticity1 and why iron touched by the true ,northern side of a stone turns to the ,north of the earth1 by the true ,southern side to the ,south2 and does not turn to the ,south when rubbed by the ,northern point of the stone1 and when by the ,southern to the ,north1 as all who have written on the loadstone have falsely supposed4 ,demonstration has already been given that the northern part of a loadstone does not attract the northern part of another stone1 but the southern1 and repels the northern part of another stone from its northern side when it is applied#bjc to it4 ,that general magnet1 the terrestrial globe1 disposes iron touched by a loadstone in the same way1 and likewise magnetick iron stirs this same iron by its implanted strength1 and excites motion and controls it4 ,for whether the comparison and experiment has been made between loadstone and loadstone1 or loadstone and iron1 or iron and iron1 or the earth and loadstone1 or the earth and iron conformed 99 by the earth or strengthened by the power of a loadstone1 the strength and inclinations of each must mutually harmonize and accord in the same way4 ,but the reason must be sought1 why a piece of iron when touched by a loadstone acquires a disposition to motion toward the opposite pole of the earth1 and not toward that #abf pole of the earth to which that pole of that loadstone turned by which it was excited4 ,it has been pointed out that iron and loadstone are of one primary nature2 when the iron is joined to the loadstone1 they become1 as it were1 one body1 and not only is the end of the iron changed1 but the remaining parts also are affected along with it4 ,a1 the north pole of a loadstone1 is placed against the cusp of a piece of iron2 the cusp of the iron has now become the southern part of the iron1 ,illustration because it is touching the northern part of the stone2 the cross-end of the iron has become the northern4 ,for if that contiguous magnetick substance be separated from the pole of the terrella1 or from the parts near the pole1 the one end 7or the end which1 whilst the connection was kept up1 was touching the northern part of the stone7 is the southern1 whilst the other is the northern4 ,so also if a versorium excited by a loadstone be divided into ever so many parts 7however small71 those parts when separated will1 it is clear1 arrange themselves in the same disposition as that in which they were disposed before1 when they were undivided4 ,wherefore whilst the cusp remains over the northern pole ,a1 it is not the southern end1 but is1 as it were1 part of a whole2 but when it is taken away from the stone1 it is the southern end1 because when rubbed it tended toward the northern parts of the stone1 and the cross 7the other end of the versorium7 is the northern end4 ,the loadstone and the iron make one body2 ,b is the south pole of the whole2 ,c 7that is1 the cross7 is the northern end of the whole2 divide the iron also at ,e1 and ,e will be the southern end with respect to the cross2 and ,e will likewise be the northern end in respect to ,b4 ,a is the true northern pole of the stone and is attracted by the southern pole of the earth4 ,the end of the iron which is touched by the true boreal part of the stone becomes the southern end1 and turns to ,a1 the north pole of the stone1 if it be near2 or if it be some distance from the stone it turns to the north pole of the earth4 ,so always iron which is touched 7if it is free and unrestrained7 tends to the opposite part of the earth from that part to which the loadstone that touched it tends4 ,nor does it 99 make any difference how it is rubbed1 whether straight up or slanting in some way4 ,for in any case the verticity flows into the iron1 #abg ,illustration provided it is touched by either end4 ,wherefore all the cusps at ,b acquire the same verticity1 after they are separated1 but opposite to that pole of the stone2 wherefore also they are united to the loadstone at the pole ,b2 and all the crosses in the present figure have the opposite verticity to the pole ,e1 and are moved and laid hold of by ,e when they are in a convenient position4 ,it is exactly the same in the case of the long stone ,f ,h divided at ,g2 ,f and ,h always move1 both in the whole and in the divided stone1 to opposite poles of the earth1 and ,o and ,p mutually attract one another1 the one of them being the northern1 the other the southern4 ,for1 supposing ,h to have been the southern in the whole stone and ,f the northern1 ,p will be the northern with respect to ,h in the divided stone1 and ,o the southern with respect to ,f4 ,so also ,f and ,h mutually incline to a connection1 if they are turned a very little toward one another1 and run together at length and join4 ,but supposing the division of the stone to have been meridional 7that is1 according to the line of a meridian1 not of any parallel circle71 then they turn ,illustration round1 and ,a attracts ,b1 and the end ,b is attracted to ,a and attracts ,a1 until1 being turned round1 they are connected and cemented together2 because magnetick attraction is not made along the parallels1 but meridionally4 ,for this reason pieces of iron placed on a terrella whose poles are ,a ,b1 near the quator along parallels1 99 do not combine or stick together firmly3 #abh ,illustration ,but if applied to one another along a meridian they are immediately 99 joined firmly together1 not only on and near the stone1 but even at some distance within the force of the controlling orbe4 ,thus they are joined and cemented together at ,e1 but not at ,c in the other figure4 ,for the opposite ends ,c and ,f meet and adhre together in the case of the iron just in the same way as ,a and ,b before in the case of the stone4 ,but they are opposite ends1 because the pieces of iron proceed from the opposite sides and poles of the terrella2 and ,c in reference to the northern pole ,a is southern1 and ,f is boreal in reference to the 99 southern pole ,b4 ,in like manner also they are cemented together1 if the rod ,c 7being not too long#bjd7 be moved further toward ,a1 and ,f toward ,b1 and they be joined together over the terrella1 like ,a and ,b of the divided stone above4 ,but now if the cusp ,a1 99 which has been touched by a loadstone1 be the southern end1 and you were to touch and rub with this the cusp of another iron needle ,b1 which has not been touched1 ,b will be northern1 and will point to the south4 ,but if you were to touch with the northern point ,b any other iron needle1 still new1 on its cusp1 this again will be southern1 and will turn to the north4 ,the iron not only receives the necessary strength from the loadstone1 if it be a good loadstone1 but also imparts its acquired strength to another piece of iron1 and the second to a third 7always in strict accordance with magnetick laws74 ,in all these demonstrations of ours it should always be borne in mind that the poles of a stone1 as well as those of iron1 whether touched or untouched1 are always in fact and by nature opposite to the pole toward which they point and are so designated by us1 as we have laid down above4 ,for in them all it is always the northern 99 which tends to the south1 either of the earth or of the stone1 and the southern which tends to the north of the stone4 ,northern parts are attracted by the southern of the earth2 so in the boat they #abi tend toward the south4 ,a piece of iron touched by the northern parts of a loadstone becomes south at the one end and tends always 7if it is near and within the orbe of the loadstone7 to the north of the stone1 and if it be free and left to itself at some distance from the stone1 it tends to the northern part of the earth4 ,the northern pole ,a of a loadstone turns to ,g1 the south of the earth2 a versorium touched at its cusp by the part ,a follows ,a1 because it has become southern4 ,but the versorium ,c1 placed farther away from the loadstone1 turns its cusp to ,f1 the north of the earth1 because 99 the cusp has become southern by contact with the boreal part of the stone4 ,so the ends touched by the northern part of the stone are made southern1 or are excited with a southern polarity1 and tend toward the north of the earth2 those touched by the southern pole are made northern1 or are excited with a northern force1 and turn to the south of the earth4 ,illustration 99 99 99 99 99 ,,chap4 ,v4 ,on the ,touching of pieces of ,iron of divers shapes4 ,bars of iron1 when touched by a loadstone1 have one end north1 the other south1 and in the middle is the limit of verticity1 like the quinoctial circle on the globe of a terrella or on an iron globe4 ,but when an iron ring is rubbed on one side on a 99 loadstone1 then the one pole is on the place that was in contact1 whilst the other is at the opposite point2 and the magnetick power divides the ring into two parts by a natural distinction which1 though not in shape1 yet in power and effect is like an quator4 ,but if a thin straight rod be bent into a ring without any welding or union of the ends1 and be touched in the middle by a loadstone1 both ends will be of the same verticity4 ,let a ring be taken which is whole and continuous1 and which has been 99 touched by a loadstone at one place1 and let it be divided afterward #acj at the opposite point and straightened out1 both ends will also be 99 of the same verticity1 no otherwise than a thin rod touched in the middle or a ring not cohrent at the joint4 99 99 99 99 99 ,,chap4 ,,vi4 ,what seems an ,opposing ,motion in ,magneticks is a proper motion toward unity4 ,illustration ,in things magnetical nature always tends to unity1 not merely to confluence and agglomeration1 but to harmony2 in such a way that the rotational and disponent faculty should not be disturbed1 as is variously shown in the following example4 ,let ,c ,d be an entire body of some magnetick substance1 in which ,c tends to ,b1 the north of the earth1 and ,d to the south1 ,a4 ,then#bje divide it in the middle in its quator1 and it will be ,e that is tending toward ,a1 and ,f tending toward ,b4 ,for just as in the undivided body1 so in the divided1 nature aims at these bodies being united2 the end ,e again joins with ,f harmoniously and 99 eagerly and they stick together1 but ,e is never joined to ,d1 nor ,f to ,c2 for then ,c must be turned contrary to nature toward ,a1 the south1 or ,d toward ,b1 the north1 which is foreign to them and incongruous4 ,separate the stone in the place where it is cut and turn ,d round to ,c2 they harmonize and combine excellently4 ,for ,d is tending to the south1 as before1 and ,c to the north2 ,e and ,f1 parts which were cognate in the ore1 are now widely separated1 for they do not move together on account of material affinity1 but they take their motion and inclination from their form4 ,so the ends1 whether joined or divided1 tend magnetically in the same way to the earth's poles in the first figure where there is one whole1 or divided as in the second figure2 and ,f ,e in the second figure is a perfect magnetick joined together into one body and ,c ,d1 just as it was primarily produced in its ore1 and ,f ,e in its boat1 turn in #aca this way to the poles of the earth and are conformed to them4 99 ,this harmony of the magnetick form is shown also in the forms of vegetables4 ,let ,a ,b be a twig from a branch of osier or other 99 tree which sprouts easily4 ,let ,a be the upper part1 ,b the lower part toward the root2 divide it at ,c ,d2 ,i say that the end ,d1 if grafted again to ,c by the primer's art1 grows to it2 just as also if ,b is grafted to ,a1 they grow together and germinate4 ,but ,d being grafted on ,a1 or ,c on ,b1 they are at variance1 and never grow into one another1 but one of them dies on account of the inverted and inharmonious arrangement1 since the vegetative force1 which moves in one way1 is now impelled in opposite directions4 ,illustration 99 99 99 99 99 ,,chap4 ,,vii4 ,a determined ,verticity and a disponent ,faculty are what arrange magneticks1 not a force1 attracting or pulling them together1 nor merely strongish coition or unition4 ,illustration #acb ,in the neighbourhood of the quinoctial ,a there is no coition of the ends of a piece of iron with the terrella2 at the poles there is the strongest4 ,the greater the distance from the quinoctial1 the stronger is the coition with the stone itself1 and with any part of it1 not with its pole alone4 ,yet pieces of iron are not raised up on account of some peculiar attracting force or a stronger combined force1 but on account of that common directing or conforming and rotating force2 nor indeed is a spike in the part about ,b1 even one that is very small and of no 99 weight#bjf1 raised up to the perpendicular by the strongest terrella1 but cleaves to it obliquely4 ,also just as a terrella attracts magnetick bodies variously with dissimilar forces1 so also an iron snout placed on the stone obtains a different potency in proportion to the latitude1 99 just as a snout at ,l by its firmer connection resists a greater weight more stoutly than one at ,m1 and at ,m than at ,n4 ,but neither does the snout raise the spike to the perpendicular except at the poles1 as is shown in the figure4 ,a snout at ,l may hold and lift from the earth two ounces of iron in one piece2 yet it is not strong enough to raise an iron wire of two grains weight to the perpendicular1 which would happen if the verticity arose on account of a 99 stronger attraction1 or rather coition or unition4 99 99 99 99 99 ,,chap4 ,,viii4 ,of ,discords between pieces of ,iron upon the same pole of a loadstone1 and how they can agree and stand joined together4 ,suppose two iron wires or a pair of needles stuck on the pole of a terrella2 though they ought to stand perpendicularly1 they mutually repel one another at the upper 99 end1 and produce the appearance of a fork2 and if one end be forcibly impelled toward the other1 the other declines and bends away from association with it1 as in the following figure4 ,illustration #acc ,a and ,b1 iron spikes1 adhre obliquely#bjg upon the pole on account of their nearness to one another2 either alone would otherwise stand erect and perpendicular4 ,for the extremities ,a ,b1 being of the same verticity1 mutually abhor and fly one another4 ,for if ,c be the northern pole of the terrella1 ,a and ,b are also northern ends2 but the ends which are joined to and held at the pole ,c are both 99 southern4 ,but if those spikes be a little longer 7as1 for example1 of two digits length7 and be joined by force1 they adhre together and unite in a friendly style1 and are not separated without force4 ,for they are magnetically welded1 and there are now no longer two distinct ends1 but one end and one body2 no less than a wire which is doubled and set up perpendicularly4 ,but here is seen also another subtile point1 that if those spikes were shorter1 not as much as the 99 breadth of one digit1 or even the length of a barleycorn1 they are in no way willing to harmonize or to stand straight up at the same time1 because naturally in shorter wires the verticity is stronger in the ends which are distant from the terrella and the magnetick discord more vehement than in long ones4 ,wherefore they in no way admit of an intimate association and connection4 ,illustration ,likewise if those lighter pieces of iron or iron wires be suspended1 hanging1 as ,a and ,b1 from a very fine silk thread1 not twisted 99 but braided1 distant from the stone the length of a single barleycorn1 then the opposing ends1 ,a and ,b1 being situated within the orbe of virtue above the pole1 keep a little away from one another for the same reason2 except when they are very near the pole of the stone ,c1 the stone then attracting them more strongly toward one end4 99 99 99 99 99 #acd ,,chap4 ,,ix4 ,figures illustrating direction and showing varieties of rotations4 ,illustration ,passing from the probable cause of motion toward fixed points 7according to magnetick laws and principles71 it remains for us to indicate those motions4 ,above a round loadstone 7whose poles are ,a1 ,b7 let a versatory needle be placed whose cusp has been excited by the pole ,a2 that cusp is certainly directed toward ,a1 and is strongly attracted by ,a2 because1 having been touched by ,a1 it is in true harmony with ,a1 and combines with it2 and yet it is called contrary1 because when the versorium is separated from the stone1 it is seen to be moved toward the opposite part of the earth to that toward which the pole ,a of the loadstone is moved4 ,for if ,a be the northern pole of the terrella1 the cusp is the southern end of the needle1 of which the other end 7namely1 the cross7 is pointed to ,b2 so ,b is the southern pole of the loadstone1 but the cross is the northern end of the versorium4 ,so also the cusp is attracted by ,e1 ,f1 ,g1 ,h1 and by every 99 part of a meridian1 from the quator toward the pole1 by the faculty disponent2 and when the versorium is on the same parts of the meridian1 the cusp is directed toward ,a4 ,for it is not the point ,a that turns the versorium toward it1 but the whole loadstone2 as also the whole earth does1 in the turning of loadstones to the earth4 ,illustration ,figures illustrating magnetick directions in a right sphere#bjh of stone1 and in the right sphere of the earth1 as well as the polar directions to the perpendicular of the poles4 ,all these cusps have been touched by the pole ,a2 all the cusps are turned toward ,a1 excepting that one which is repelled by ,b4 #ace ,illustration ,figures illustrating horizontal directions above the body of a loadstone4 ,all the cusps that have been made southern by rubbing on the boreal pole1 or some place round the northern pole ,a1 turn toward the pole ,a1 and turn away from the southern pole ,b1 toward which all the crosses look4 ,i call the direction horizontal1 because it is arranged along the plane of the horizon2 for nautical and 99 horological instruments are so constructed that the iron hangs or is supported in quilibrium on the point of a sharp pin1 which prevents the dipping of the versorium1 about which we intend to speak later4 ,and in this way it is of the greatest use to man1 indicating and distinguishing all the points of the horizon and the winds4 ,otherwise on every oblique sphere 7whether of stone or the earth7 versoria and all magnetick substances would have a dip by their own nature below the horizon2 and at the poles the directions would be perpendicular1 which appears in our discussion ,on ,declination4 ,illustration ,a round stone 7or terrella7 cut in two at the quator2 and all the cusps have been touched by the pole ,a4 ,the points at the centre of the earth1 and between the two parts of the terrella which has been cut in two through the plane of the quator1 #acf are directed as in the present#bji diagram4 ,this would also happen in the same way if the division of the stone were through the plane of a tropick1 and the mutual separation of the divided parts and the interval between them were the same as before1 when the loadstone was divided through the plane of the quator1 and the parts separated4 ,for the cusps are repelled by ,c1 are attracted by ,d2 and the versoria are parallel1 the poles or the verticity in both ends mutually requiring it4 ,illustration ,half a terrella by itself and its directions1 unlike the directions 99 of the two parts close to one another as shown in the figure above4 ,all the cusps have been touched by ,a2 all the crosses below except the middle one tend toward the loadstone1 not straight1 but obliquely2 because the pole is in the middle of the plane which before was the plane of the quator4 ,all cusps touched by places distant from the pole move toward the pole 7exactly the same as if they had been rubbed upon the pole itself71 not toward the place where they were rubbed1 wherever that may have been in the undivided stone in some latitude between the pole and the quator4 ,and for this reason there are only two distinctions of regions1 northern and southern1 in the terrella1 just #acg as in the general terrestrial globe1 and there is no eastern nor western place2 nor are there any eastern or western regions1 rightly speaking2 but they are names used in respect of one another toward the eastern or western part of the sky4 ,wherefore it does not appear that ,ptolemy did rightly in his ,quadripartitum1 making eastern and western districts and provinces1 with which he improperly connects the planets1 whom the common crowd of philosophizers and the superstitious soothsayers follow4 99 99 99 99 99 ,,chap4 ,x4 ,on ,mutation of ,verticity and of ,magnetick ,properties1 or on alteration in the power excited by a loadstone4 ,friction with a loadstone gives to a piece of iron a verticity strong enough2 not1 however1 so stable that the iron may not by being rubbed on the opposite part 7not only with a more powerful loadstone1 but with the same7 be changed and deprived of all its former verticity1 and indued with a new and opposite one4 ,take a piece of iron wire and rub each end of the wire equally with one and the same pole of a loadstone1 and let it be passed through a suitable cork and place it on water4 ,then truly one end of the wire will be directed toward that pole of the earth toward which that end of the stone will not turn4 ,but which end of the iron wire will it be8 ,that certainly which was rubbed last4 ,rub the other end of this again with the same pole1 and immediately 99 that end will turn itself in the opposite direction4 ,again touch the former end of the iron wire only with the same pole of the loadstone as before2 and that#baj end1 having gained the command1 immediately changes to the contrary side4 ,so you will be able to change the property of the iron frequently1 and that end of the wire rules which has been touched the last4 ,now then merely hold the boreal pole of the stone for some time near the boreal part of the wire which was last touched1 so that it does not touch1 but so that it is removed from it by one1 two1 or even three digits1 if the stone have been pretty 99 strong2 and again it will change its property and will turn round to the contrary side2 which will also happen 7albeit rather more feebly7 even if the loadstone be removed to a distance of four digits4 ,you will be able to do the same thing1 moreover1 with both the austral and the boreal part of the stone in all these experiments4 ,verticity may likewise be acquired and changed when thin plates of gold1 99 silver1 and glass are interposed between the stone and the end of the iron or iron wire1 if the stone were rather strong1 even if the #ach intermediate lamina is not touched either by the iron or the stone4 ,and these changes of verticity take place in smelted iron4 ,indeed what the one pole of the stone implants and excites1 the other disturbs and extinguishes1 and confers a new force4 ,for it does not require a stronger loadstone to take away the weaker and sluggish virtue and to implant the new one2 nor is iron inebriated by the equal strength of loadstones1 and made utterly uncertain and neutral1 as ,baptista ,porta teaches2 but by one and the same loadstone1 or by loadstones endowed with equal power and might1 its strength is1 in accordance with magnetick rules1 turned round and changed1 excited1 repaired1 or disturbed4 ,but a loadstone itself1 by being rubbed on another1 whether a larger or a more powerful stone1 is not disturbed from its own property and verticity1 nor does it turn round toward the opposite direction in its boat1 or to the other pole opposite to that to which it inclines by its own nature and implanted verticity4 ,for strength which is innate and has been implanted for a very long time abides more firmly1 nor does it easily yield from its ancient holding2 and that which has grown for a long time is not all of a sudden brought to nothing1 without the destruction of the substance containing it4 ,nevertheless in a long interval of time a change 99 does take place2 in one year1 that is to say1 or two1 or sometimes in a few months2 doubtless when a weaker loadstone remains lying by a stronger one contrary to the order of nature1 namely1 with the northern pole of one loadstone adjoined to the northern pole of another1 or the southern to the southern4 ,for so the weaker strength gradually declines with the lapse of time4 99 99 99 99 99 ,,chap4 ,,xi4 ,on the ,rubbing of a piece of ,iron on a ,loadstone in places midway between the poles1 and upon the quinoctial of a terrella4 ,select a piece of iron wire of three digits length1 not touched by a loadstone 7but it will be better if its acquired verticity be rather weak or have been damaged in some way72 touch it and rub it on the quator of a terrella1 exactly on the quinoctial line in the direction of its length1 on the one end1 or the ends only1 or in all its parts2 place the wire touched in this 99 way on water in a cork fitted for it2 it will swim about doubtfully on the waves without any acquired verticity1 and the verticity previously implanted will be disturbed4 ,if1 however1 it float by chance toward the poles1 it will be checked a little by the poles of the earth1 and will at length by the influence of the earth be indued with verticity4 99 99 99 99 99 #aci ,,chap4 ,,xii4 ,in what way ,verticity exists in any ,iron that has been smelted though not excited by a lodestone4 ,illustration ,having thus far#baa demonstrated natural and inborn causes and powers acquired by means of the stone1 we will now examine the causes of magnetick virtues in smelted iron that has not been excited by a stone4 ,loadstone and iron furnish and exhibit to us wonderful subtilities4 ,it has been repeatedly shown above that iron not excited by a stone turns north and south2 further that it has verticity1 that is1 special and peculiar polar distinctions1 just as a loadstone1 or iron which has been rubbed upon a loadstone4 ,this indeed seemed to us at first wonderful and incredible2 the metal of iron from the mine is smelted in the furnace2 it runs out of the furnace1 and hardens into a great mass2 this mass is divided in great worksteads1 and is drawn into iron bars1 from which smiths again construct many instruments and necessary pieces of iron-work4 ,thus the same mass is variously worked up and transformed into very many similitudes4 ,what is it1 then1 which #adj preserves its verticity1 and whence is it derived8 ,so take this first from the above#bab smithy4 ,let the blacksmith beat out upon his anvil a glowing mass of iron of two or three ounces weight into an iron spike of the length of a span of nine inches4 ,let the smith be standing with his face to the north1 his back to the south1 so that 99 the hot iron on being struck has a motion of extension to the north2 and let him so complete his work with one or two heatings of the iron 7if that be required72 let him always1 however1 whilst he is striking the iron1 direct and beat out the same point of it toward the north1 and let him lay down that end toward the north4 ,let him in this way complete two1 three1 or more pieces of iron1 nay1 a hundred or four hundred2 it is demonstrable that all those which are thus beaten out toward the north1 and so placed whilst they are cooling1 turn round on their centres2 and floating pieces of iron 7being transfixed1 of course1 through suitable corks7 make a motion in the water1 the determined end being toward the north4 ,in the same way also pieces of iron acquire verticity from their direction whilst they are being beaten out and hammered or drawn out1 99 as iron wires are accustomed to do toward some point of the horizon between east and south or between south and west1 or in the opposite direction4 ,those1 however1 which are pointed or drawn out rather toward the eastern or western point1 conceive 99 hardly any verticity or a very undecided one4 ,that verticity is especially acquired by being beaten out4 ,but a somewhat inferior iron ore1 in which no magnetick powers are apparent1 if put in a 99 fire 7its position being observed to be toward the poles of the world or of the earth7 and heated for eight or ten hours1 then cooled away from the fire1 in the same position towards the poles1 acquires a verticity in accordance with the position of its heating and cooling4 ,let a rod of cast iron be heated red-hot in a strong fire1 in which it lies 99 meridionally 7that is1 along the path of a meridian circle71 and let be removed from the fire and cooled1 and let it return to its former temperature1 remaining in the same position as before2 then from this it will turn out that1 if the same ends have been turned to the same poles of the earth1 it will acquire verticity1 and the end which looked toward the ,north on water with a cork before the heating1 if it have been placed during the heating and cooling toward the fourth1 now turns round to the south4 ,but if perchance sometimes the rotation have been doubtful and somewhat feeble1 let it be placed again in the fire1 and when it is taken out at a red heat1 let it be perfectly cooled toward the pole from which we desire the verticity1 and the verticity will be acquired4 ,let the same rod be heated 99 in the contrary position1 and let it be placed so at a red heat it is cool2 for it is from its position in cooling 7by the operation of the verticity of the earth7 that verticity is put into the iron1 and it turns round to parts contrary to its former verticity4 ,so #ada the end which formerly looked toward the north now turns to the south4 ,in accordance with these reasonings and in these ways the boreal pole of the earth gives to the end of a piece of iron turned toward it a southern verticity1 and that end is attracted by that pole4 99 ,and here it must be observed that this happens to iron not only when it is cooled in the plane of the horizon1 but also at any angle to it almost up to the perpendicular toward the centre of the earth4 ,so the heated iron conceives vigour and verticity from the earth more quickly in the course of its return to its normal state1 and in its recovery1 as it were 7in the course of which it is transformed71 than by its mere position alone4 ,this is effected better and more 99 perfectly in winter and in colder air1 when the metal returns more certainly to its natural temperature1 than in summer and in warm regions4 ,let us see also what position alone and a direction toward the poles of the earth can effect by itself without fire and heat4 ,iron rods which have been placed and fixed for a long time1 twenty 99 or more years1 from south to north 7as they not infrequently are fixed in buildings and across windows71 those rods1 ,i say1 by that long lapse of time acquire verticity and turn round1 whether hanging in the air1 or floating 7being placed on cork71 to the pole toward which they were pointing1 and magnetically attract and repel a balanced iron magnetick2 for the long continued position of the body toward the poles is of much avail4 ,this fact 7although conspicuous by manifest experiments7 is confirmed by an incident related in an ,italian letter#bac at the end of a book of ,maestro ,filippo ,costa1 of ,mantua1 ,sopra le ,compositioni degli ,antidoti written in ,italian1 which translated runs thus3 ,a druggist of ,mantua showed me a piece of iron entirely changed into a magnet1 drawing another piece of iron in such a way that it could be compared with a loadstone4 ,now this piece of iron1 when it had for a long time held up a brick ornament on the top of the tower of the church of ,st4 ,augustine at ,rimini1 had been at length bent by the force of the winds1 and remained so for a period of ten years4 ,when the monks wished to bend it back to its former shape1 and had handed it over to a blacksmith1 a surgeon named ,maestro ,giulio ,caesare discovered that it was like a magnet and attracted iron4 ,this was caused by the turning of its extremities toward the poles for so long a time4 ,and so what has been laid down before about change of verticity should be borne in mind2 how in fact the poles of iron spikes are altered1 when a loadstone is placed against them only with its pole and points toward them1 even at a rather long distance4 ,clearly it is in the same way that that large magnet also 7to wit1 the earth itself7 affects a piece of iron and changes its verticity4 ,for1 although the iron may not touch the pole of the earth1 nor any magnetick part of the earth1 yet verticity is acquired and changed2 not because the poles of the earth and the point itself which is #ci distant #adb from our city of ,london1 changes the verticity at a distance of so many miles2 but because the whole magnetick earth1 that which projects to a considerable height1 and to which the iron is near1 and that which is situated between us and the pole1 and the vigour existing within the orbe of its magnetick virtue 7the nature of the whole conspiring thereto71 produces the verticity4 ,for the magnetick effluence of the earth rules everywhere within the orbe of its virtue1 and transforms bodies2 but those things which are more similar to it1 and specially connected with it by nature1 it rules and controls2 as loadstone and iron4 ,wherefore in very many matters of business and actions it is clearly not superstitious and idle to observe the positions and conditions of lands1 the points of the horizon and the places of the stars4 ,for as when a babe is brought forth into the light from its mother's womb1 and acquires respiration and certain animal activities1 then the planets and celestial bodies#bad1 according to their position in the universe1 and according to that configuration which they have with regard to the horizon and the earth1 instil peculiar and individual qualities into the newly born2 so that piece of iron1 whilst it is being formed and lengthened out1 is affected by the common cause 7to wit1 the earth72 whilst it is returning also from its heated condition to its former temperature1 it is imbued with a special verticity in accord with its position4 ,rather long pieces of iron sometimes have the same verticity 99 at each end2 wherefore they have motions which are less certain and well ordered on account of their length and of the aforesaid processes1 exactly as when an iron wire four feet long is rubbed at each end upon the same pole of a loadstone4 99 99 99 99 99 ,,chap4 ,,xiii4 ,why no other ,body1 excepting a magnetick1 is imbued with verticity by being rubbed on a loadstone2 and why no body is able to instil and excite that virtue1 unless it be a magnetick4 ,ligneous substances floating on water never by their own strength turn round toward the poles of the earth1 save by chance4 ,so wires of gold1 silver1 brass1 tin1 lead1 or glass1 pushed through corks and floating1 have no sure direction2 and for this reason they do not show poles or points of variation when rubbed with a loadstone4 ,for those things which do not of themselves incline toward the poles and obey the earth are also not ruled by #adc the touch of a loadstone2 for the magnetick vigour has no entrance into their inward parts2 neither is the magnetick form received by them1 nor are their forms magnetically excited2 nor1 if it did enter1 would it effect anything1 because in those bodies 7mixed up with various kinds of efflorescent humours and forms1 corrupted from the original property of the earth7 there are no primary qualities4 ,but those prime qualities of iron are excited by the juxtaposition of a loadstone1 just as brute animals or men1 when they are awakened out of sleep1 move and put forth their strength4 ,here one must marvel at a demonstrable error of ,b4 ,porta1 who1 while rightly opposing a very old falsehood about the diamond1 in speaking of a power contrary to that of the loadstone1 introduces another still worse opinion2 that forsooth iron1 when touched by a diamond1 turns to the north4 ,if 7he says7 you rub a steel-,needle on a ,diamond1 and then put it in a ,boat1 or thrust it through a reed1 or hang it up by a ,thread1 it will presently turn to the ,north1 almost as well as if it had been touched with the ,loadstone2 but something more faintly4 ,and1 what is worth noting1 the contrary part will turn the iron to the ,south3 and when ,i had tried this in many steel-,needles1 and put them all into the ,water1 ,i found1 that they all stood equi-distant1 pointing to the ,north4 ,this indeed would 99 be contrary to our magnetick rules4 ,for this reason we made an experiment with seventy excellent diamonds1 in the presence of many witnesses1 on a large number of spikes and wires1 with the most careful precautions1 floating 7thrust1 of course1 through their corks7 on the surface of water2 never1 however1 could we observe this4 ,he was deceived by the verticity acquired from the earth 7as stated above7 in the spike or wire of iron itself1 and the iron itself turned aside to its own definite pole2 and he1 being ignorant of this1 thought it was done by the diamond4 ,but let the investigators of natural phenomena take heed that they are not the more deceived by their own badly observed experiments1 and disturb the commonwealth of letters with their errors and stupidities4 ,diamond is sometimes designated by the name of ,sideritis1 not because it is made of iron or because it draws iron1 but on account of its lustre1 resembling flashing steel2 with such a lustre do the choicest pieces of diamond shine2 hence by very many writers many qualities are imputed to diamond which really belong to siderite loadstone4 99 99 99 99 99 #add ,,chap4 ,,xiiii4 ,the ,placing of a ,loadstone above or below a magnetick body suspended in quilibrium changes neither the power nor the verticity of the magnetick body4 ,quietly to pass this over would be improper1 because a recent error arising from a defective observation of ,baptista ,porta must be overthrown2 on which he 7by an unfortunate repetition7 even writes three chapters1 namely1 the #ahth1 the #cast1 and the #dbnd4 ,for if a loadstone or a piece of magnetick iron1 hanging in quilibrium or floating on water1 is attracted and disposed toward certain definite points1 when you bring above it a piece of iron or another loadstone1 it will not1 if you afterward put the same#bae below it1 turn round to the contrary parts2 but the same ends of the iron or the loadstone will always be directed toward the same ends of the stone1 even if the loadstone or the iron is suspended in any way in quilibrium or is poised on a needle1 so that it can turn round freely4 ,he was deceived by the irregular shape of some stone1 or because he did not arrange the experiment suitably4 ,wherefore he is led astray by a vain opinion1 and thinks he may infer that1 just as a stone has an arctic and antarctic pole1 so also it has a western and an eastern1 and an upper and a lower pole4 ,so from foolish ideas conceived and admitted arise other fallacies4 99 99 99 99 99 ,,chap4 ,,xv4 ,the ,poles1 quator1 ,centre in an entire ,loadstone remain and continue steady2 by diminution and separation of some part they vary and acquire other positions4 ,illustration 99 ,suppose ,a ,b to be a terrella1 whose centre is ,e1 and whose diameter 7as also its quinoctial circle7 is ,d ,f4 ,if you cut off a portion 7through the arctic circle1 for example71 ,g ,h1 it is demonstrable that the pole which was at ,a now has a position at ,i4 ,but the centre and the quinoctial recede toward ,b #ade merely so that they are always in the middle of the mass that is left between the plane of the arctick circle ,g ,i ,h and the antarctick pole ,b4 ,therefore the segment of the terrella comprised between the plane of the former quinoctial 7that1 of course1 which was the quator before cutting that part away7 ,d ,e ,f and the newly acquired quator ,m ,l ,n will always be equal to the half of that part which was cut off1 ,g ,i ,h ,a4 ,illustration 99 ,but if the portions have been taken away from the side ,c ,d1 the poles and axis will not be in the line ,a ,b1 but in ,e ,f1 and the axis would be changed in the same proportion as the quator in the former figure4 ,for those positions of forces and virtues1 or rather limits of the virtues1 which are derived from the whole form1 are moved forward by change of quantity and shape2 since all these limits arise from the conspiring together of the whole and of all #adf the parts united2 and the verticity or the pole is not a virtue innate in one part1 or in some definite limit1 or fixed in the substance2 but it is an inclination of the virtue to that part4 ,and just as a terrella separated from the earth has no longer the earth's poles and quator1 but individual ones of its own2 so also if it again be divided1 those limits and distinctions of the qualities and virtues pass on to other parts4 ,but if a loadstone be divided in any way1 either along a parallel1 or meridionally1 so that by the change of shape either the poles or the quator move to other positions1 if the part cut off be merely applied in its natural position and joined to the whole1 even without any agglutination or cementing together1 the determining points of the virtues return again to their former sites1 as if no part of the body had been cut off4 ,when a body is entire1 its form remains entire2 but when the body is lessened1 a new whole is made1 and there arises a new entirety1 determined for every loadstone1 however small1 even for magnetick gravel1 and for the finest sand4 99 99 99 99 99 ,,chap4 ,,xvi4 ,if the ,southern ,portion of a ,stone be lessened1 something is also taken away from the power of the ,northern ,portion4 ,now although the southern end of a magnetick iron is attracted by a northern end1 and repelled by a southern1 yet the southern portion of a stone does not diminish1 but increases the potency of the boreal part4 ,wherefore if a stone be cut in two and divided through the arctick circle1 or through the tropick of ,cancer or the quator1 the southern portion does not attract magnetick substances so strongly with its pole as before2 because a new whole arises1 and the quator is removed from its old position and moves forward on account of that cutting of the stone4 ,in the former condition1 since the opposite portion of the stone increases the mass beyond the plane of the quator1 it strengthens also the verticity1 and the potency1 and the motion to unity4 99 99 99 99 99 #adg ,,chap4 ,,xvii4 ,on the ,use and ,excellence of ,versoria3 and how iron versoria used as pointers in sun-dials1 and the fine needles of the mariners' compass1 are to be rubbed1 that they may acquire stronger verticity4 ,versoria prepared by the loadstone subserve so many actions in human life that it will not be out of place to record a better method of touching them and exciting them magnetically1 and a suitable manner of operating4 ,rich ores of iron and such as yield a greater proportion of metal are recognized by means of an iron needle suspended in quilibrium and magnetically prepared2 and magnetick stones1 clays1 and earths are distinguished1 whether crude or prepared4 ,an iron needle 7the soul of the mariners' compass71 the marvellous director in voyages and finger of ,god1 one might almost say1 indicates the course1 and has pointed out the whole way around the earth 7unknown for so many ages74 ,the ,spaniards 7as also the ,english7 have frequently circumnavigated 7by an immense circuit7 the whole globe by aid of the mariners' compass4 ,those who travel about through the world or who sit at home have sun-dials4 ,a magnetick pointer follows and searches out the veins of ore in mines4 ,by its aid mines are driven in taking cities2 catapults and engines of war are aimed by night2 it has been of service for the topography of places1 for marking off the areas and position of buildings1 and for excavating aqueducts for water under ground4 ,on it depend instruments designed to investigate its own dip and variation4 ,when iron is to be quickened by the stone1 let it be clean and bright1 disfigured by no rust or dirt1 and of the best steel#baf4 ,let the stone itself be wiped dry1 and let it not be damp with any moisture1 but let it be filed gently with some smooth piece of iron4 ,but the hitting of the stone with a hammer is of no advantage4 ,by these means let their bare surfaces be joined1 and let them be rubbed1 so that they may come together more firmly2 not so that the material substance of the stone being joined to the iron may cleave to it1 but they are rubbed gently together with friction1 and 7useless parts being rubbed off7 they are intimately united2 whence a more notable ,illustration virtue arises in the iron that is excited4 ,a is the best way of touching a versorium when the cusp touches the pole and faces it2 ,b is a moderately good way1 when1 though facing it1 it is a little way #adh distant from the pole2 also in like manner ,c is only moderately good on account of the cusp being turned away from the pole2 ,d1 which is farther distant1 is hardly so good2 ,f1 which is prepared crosswise along a parallel1 is bad2 of no virtue and entirely irresponsive and feeble is the magnetick index ,l1 which is rubbed along the quator2 oblique and not pointing towards the pole as ,g1 and oblique1 not pointing toward but turned away from the pole as ,h1 are bad4 ,these have been placed so that they might indicate the distinct forces of a round stone4 ,but mechanicians very often have a stone tending more to a cone shape1 and more powerful on account of that shape since the pole1 on which they rub their wires1 is at the apex of the projecting part4 ,sometimes the stone has on the top and above its own pole an artificial acorn or snout made of steel for the sake of its power4 ,iron needles are rubbed on the top of this2 wherefore they turn toward the same pole as if they had been prepared on that part of the stone with the acorn removed4 ,let the stone be large enough and strong2 the needle1 even if it be rather long1 should be sufficiently thick1 not very slender2 with a moderate cusp1 not too sharp1 although the virtue is not in the cusp itself only1 but in the whole piece of iron4 ,a strong large stone is not unfit for rubbing all needles on1 excepting that sometimes by its strength it occasions some dip and disturbance in the iron in the case of longer needles2 so that one which1 having been touched before1 rested in equilibrium in the plane of the horizon1 now when touched and excited dips at one end1 as far as the upright pin on which it turns permits it4 ,wherefore in the case of longer versoria1 the end which is going to be the ,boreal1 before it is rubbed1 should be a little lighter1 so that it may remain exactly in quilibrio after it is touched4 ,but a needle in this way prepared does its 99 #adi work worse the farther it is beyond the quinoctial circle4 ,let the prepared needle be placed in its capsule1 and let it not be touched by any other magneticks1 nor remain in the near vicinity of them1 lest by their opposing forces1 whether powerful or sluggish1 it should become uncertain and dull4 ,if you also rub the other end of the needle on the other pole of the stone1 the needle will perform its functions more steadily1 especially if it be rather long4 ,a piece of iron touched by a loadstone retains the magnetick virtue1 excited in it even for ages#bag1 firm and strong1 if it is placed according to nature meridionally and not along a parallel1 and is not injured by rust or any external injury from the surrounding medium4 ,porta wrongly seeks for a proportion between the loadstone and the iron3 because1 he says1 a little piece of iron will not be capable of holding much virtue2 for it is consumed by the great force of the loadstone4 ,a piece of iron receives its own virtue fully1 even if it be only of the weight of one scruple1 whilst the mass of the loadstone is a thousand pounds4 ,it is also useless to make the needle rather flat at the end that is touched1 so that it may be better and more perfectly magnetick1 and that it may best receive and hold certain magnetick particles2 since hardly any part will stick on a sharp point2 because he thought that it was by the adhesion of parts of the loadstone 7as it were1 hairs7 that the influence is imparted and conserved1 though those particles are merely rubbed off by the rubbing of the iron over the softer stone1 and the iron none the less points toward the ,north and ,south1 if after it is touched it be scoured with sand or emery powder1 or with any other material1 even if by long rubbing of this kind the external parts of it are lessened and worn away4 ,when a needle is being rubbed1 one should always leave off at the end2 otherwise1 if it is rubbed on the loadstone from the point toward the middle1 less verticity is excited in the iron1 sometimes none at all1 or very little4 ,for where the last contact is1 there is the pole and goal of verticity4 ,in order that a stronger verticity may be produced in the iron by rubbing on the loadstone1 one 99 ought in northern lands to turn the true northern pole of the loadstone toward the highest part of the sky2 on this pole that end of the needle is going to be rubbed1 which shall afterwards turn toward the north of the earth2 whilst it will be an advantage for the other end of the needle to be rubbed on the southern pole of the terrella turned toward the earth1 and this being so excited will incline toward the south4 ,in southern regions beyond the quator the plan is just the contrary4 ,the reason of this dissimilarity is demonstrated1 ,book ,,ii41 chap1 xxxiv41 in which it is shown 7by a manifest combination of a terrella and the earth7 why the poles of a loadstone1 for different reasons1 are one stronger than the other4 ,if a needle be touched between the mutually accordant 99 poles of two loadstones1 equal in power1 shape1 and mass1 no strength #aej ,illustration is acquired by the needle4 ,a and ,b are two loadstones attracting one another1 according to nature1 at their dissimilar ends2 ,c1 the 99 point of a needle touched by both at once1 is not excited 7even if those loadstones be connected according to nature71 if they are equal2 but if they are not equal1 virtue is acquired from the stronger4 ,when a needle is being excited by a loadstone1 begin in the middle1 and draw the needle toward its end2 at the end let the application be continued with a very gentle rubbing around the end for some time2 that is to say1 for one or two minutes2 do not repeat the motion from the middle to the end 7as is frequently done7 for in this way the verticity is injured4 ,some delay is desirable1 for although the power is imparted instantly1 and the iron excited1 yet from the vicinity of the loadstone and a suitable delay1 a more steady verticity arises1 and one that is more firmly durable in the iron4 ,although an armed stone raises a greater weight of iron than an unarmed one1 yet a needle is not more strongly excited by an armed stone than by an unarmed one4 ,let there be two iron wires of the same length1 wrought from the same wire2 let one be excited by an armed end1 the other by an unarmed end2 it is manifest that the same needles have a beginning of motion or a sensible inclination at equal distances from the same armed and unarmed loadstone2 this is ascertained by measuring with a longish reed4 ,but objects which are more powerfully excited move more quickly2 those which are less powerfully excited1 more feebly1 and not unless brought rather close2 the experiment is made on water with equal corks4 99 99 99 99 99 #aea ,illustration ,,book ,,fourth4 ,,chap4 ,i4 ,,on ,,variation4 ,direction has hitherto been spoken of as if in nature there were no variation2 for in the preceding natural history we wished to omit and neglect this1 inasmuch as in a terrestrial globe1 perfect and in every sense complete1 there would be none4 ,since1 however1 in fact1 the earth's magnetick direction1 owing to some fault and slip1 deviates from its right course and from the meridian1 we must extract and demonstrate the obscure and hidden cause of that variance which has troubled and sore racked in vain the minds of many4 ,those who before us have written on the magnetick movements have made no distinction between direction and variation1 but consider the motion of magnetick iron to be uniform and simple4 ,now true direction is the motion of the magnetick body to the true meridian and its continuance therein with its appropriate ends towards the poles4 ,but it very often happens at sea and on land that the magnetick iron does not point to the true pole1 and that not only a versorium and magnetick pieces of iron1 and the needle of a compass1 or a mariners' compass1 but also a terrella in its boat1 as well as 99 iron ore1 iron stones1 and magnetick earths1 properly prepared1 are drawn aside and deviate towards some point of the ,horizon very near to the meridian4 ,for they with their poles frequently face termini away from the meridian4 ,this variation #aeb 7observed by means of instruments or a nautical variation compass7 is therefore the arc of the horizon between the common point of intersecion of it with the true meridian1 and the terminus of the deflecion on the horizon or projection of the deviating needle4 ,that arc varies and differs with change of locality4 ,to the terminus of the variation is commonly assigned a great circle1 called the circle of variation1 and also a magnetick meridian passing through the zenith and the point of variation on the horizon4 ,in the northern regions of the earth this variation is either from the north toward the east or from the north toward the west3 similarly in the southern regions it is from the south toward the east or toward the west4 ,wherefore one should observe in the northern regions of the earth 99 that end of the versorium or compass which turns toward the ,north2 but in the southern regions the other end looking to the south--which seamen and sciolists for the most part do not understand1 for in both regions they observe only the boreal lily of the compass 7that which faces ,north74 ,we have before said that all the motions of the magnet and iron1 all its turning1 its inclination1 and its settlement1 proceed from bodies themselves magnetical and from their common mother the earth1 which is the source1 the propagatrix1 and the origin of all these qualities and properties4 ,accordingly the earth is the cause of this variation and inclination toward a different point of the horizon3 but how and by what powers must be more fully investigated4 ,and here we must at the outset reject that common opinion of recent writers concerning magnetick mountains1 or any magnetick rock1 or any phantasmal pole distant from the pole of the earth1 by which the motion of the compass or versorium is controlled4 ,this opinion1 previously invented by others1 ,fracastorio himself adopted and developed2 but it is entirely at variance with experience4 ,for in that case in different places at sea and on land the point of variation would change toward the east or west in proportion and geometrical symmetry1 and the versorium would always respect the magnetick pole3 but experience teaches that there is no such definite pole or fixed terminus on the earth to account for the variation4 ,for the arcs of 99 variation are changed variously and erratically1 not only on different meridians but on the same meridian2 and when1 according to this opinion of the moderns1 the deviation should be more and more toward the east1 then suddenly1 with a small change of locality1 the deviation is from the north toward the west as in the northern regions near ,nova ,zembla4 ,moreover1 in the southern regions1 and at sea at a great distance from the quator towards the antarctick pole1 there are frequent and great variations1 and not only in the northern regions1 from the magnetick mountains4 ,but the cogitations of others are still more vain and trifling1 such as that of ,cortes about a moving influence beyond all the heavens2 that of #aec ,marsilius ,ficinus about a star in the ,bear2 that of ,peter ,peregrinus about the pole of the world2 that of ,cardan1 who derives it from the rising of a star in the tail of the ,bear#bah2 of ,bessardus1 the ,frenchman1 from the pole of the ,zodiack2 that of ,livio ,sanuto from some magnetick meridian2 that of ,franciscus ,maurolycus from a magnetical island2 that of ,scaliger from the heavens and mountains2 that of ,robert ,norman1 the ,englishman1 from a point respective4 ,leaving therefore these opinions1 which are at variance with common experience or by no means proved1 let us seek the true cause of the variation4 ,the great magnet or terrestrial globe directs iron 7as ,i have said7 toward the north and south2 and excited iron quickly settles itself toward those termini4 ,since1 however1 the globe of the earth is defective and uneven on its surface and marred by its diverse composition1 and since it has parts very high and convex 7to the height of some miles71 and those uniform neither in composition nor body1 but opposite and dissimilar3 it comes to pass that the whole of that force of the earth diverts magnetical bodies in its periphery toward the stronger and more prominent connected magnetick parts4 ,hence on the outermost surface of the earth magnetical bodies are slightly perverted from the true meridian4 ,moreover1 since the surface of the globe is divided into high lands and deep seas1 into great continental lands1 into ocean and vastest seas1 and since the force of all magnetical motions is derived from the constant and magnetick terrestrial nature which is more prevalent on the greater continent and not in the aquous or fluid or unstable part2 #bai;it follows that in certain parts there would be a magnetick inclination from the true pole east or west away from any meridian 7whether passing through seas or islands7 toward a great land or continent rising higher1 that is1 obviously toward a stronger and more elevated magnetick part of the terrestrial globe4 ,for since the diameter of the earth is more than #a1gjj ,german miles1 those large lands can rise from the centre of the earth more than four miles above the depth of the ocean bottom1 and yet the earth will retain the form of a globe although somewhat uneven at the top4 ,wherefore a magnetical body is turned aside1 so far as the true verticity1 when disturbed1 admits1 and departs from its right 7the whole earth moving it7 toward a vast prominent mass of land as though toward what is stronger4 ,but the variation does really take place1 not so much because of the more prominent and imperfect terrestrial parts and continent lands as because of the inquality of the magnetick globe1 and because of the real earth1 which stands out more under the continent lands than under the depths of the seas4 ,we must see1 therefore1 how the apodixis of this theory can be sustained by more definite observations4 ,since throughout all the course from the coast of ,guinea to ,cape ,verde1 the ,canary ,isles1 and the border of the kingdom of ,morocco1 and #aed thence along the coasts of ,spain1 ,france1 ,england1 ,belgium1 ,germany1 ,denmark1 and ,norway1 there lie on the right hand and toward the east a continent and extensive connected regions1 and on the left extensive seas and a vast ocean lie open far and wide1 it is consonant with the theory 7as has been carefully observed by many7 that magnetical bodies should turn slightly to the ,east from the true pole toward the stronger and more remarkable elevations of the earth4 ,but it is far otherwise on the eastern shores of northern ,america2 for from ,florida by ,virginia and ,norumbega to ,cape ,race and away to the north the versorium is turned toward the west4 ,but in the middle spaces1 so to speak1 as in the more westerly ,azores1 it looks toward the true pole4 ,that any magnetick body turns itself similarly to the same regions of the earth is not1 however1 because of that meridian or because of the concordancy of the meridian with any magnetick pole1 as the crowd of philosophizers reckon1 for it is not so throughout the whole of that meridian4 ,for on the same meridian 99 near ,brazil something very different occurs1 as we will show further on4 ,the variation 7cteris paribus7 is always less near the quator1 greater in higher latitudes1 with the limitation that it be not very near the pole itself4 ,hence the variation is greater on the coast of 99 ,norway and ,belgium than on the coast of ,morocco or ,guinea3 greater also near ,cape ,race than in the harbours of ,norumbega or of ,virginia4 ,on the coast of ,guinea magnetick implements deviate by a third part of one rumbe to the ,east3 in ,cape ,verde ,islands by a half3 on the coast of ,morocco by two thirds3 in ,england at the mouth of the ,thames by a whole rumbe3 and at ,london by nearly eleven degrees and one third4 ,for indeed the moving magnetick virtue is stronger in a higher latitude2 and the larger regions extending toward the poles dominate the more1 as is easily apparent anywhere on a terrella4 ,for as in the case of true ,direction magnetick bodies tend toward the pole 7namely1 toward the stronger end1 the whole earth causing the motion71 so also do they incline a little toward the stronger and higher parts by the action of the whole along with the conjoint action of iron bodies4 99 99 99 99 99 #aee ,,chap4 ,,ii4 ,that the variation is caused by the inquality of the projecting parts of the earth4 ,demonstration of this may manifestly be made ,illustration 99 by means of a terrella in the following way3 let there be a round loadstone somewhat imperfect in some part1 and impaired by decay 7such an one we had with a certain part corroded to resemble the ,atlantick or great ,ocean73 place upon it some fine iron wire of the length of two barleycorns1 as in the following figure4 ,a ,b1 a ,terrella in certain parts somewhat imperfect and of unqual virtue on the circumference4 ,the versoria ,e1 ,f1 do not vary1 but look directly to the pole ,a2 for they are placed in the middle of the firm and sound part of the terrella and somewhat distant from the imperfect part3 that part of the surface which is distinguished by dots and transverse lines is the weaker4 ,the versorium ,o also does not vary 7because it is placed in the middle of the imperfect part71 but is directed toward the pole1 #aef just as near the western ,azores on the earth4 ,the versoria ,h and ,l do vary1 for they incline toward the sounder parts very near them4 ,as this is manifest in a terrella whose surface is sensibly rather imperfect1 so also is it in others whole and perfect1 when often one part of the stone has stronger external parts1 which nevertheless do not disclose themselves manifestly to the senses4 ,in such a terrella the demonstration of the variation and the discovery of the stronger parts is on this wise4 ,illustration 99 ,let ,a be the pole1 ,b the place of the variation1 ,c the stronger regions2 then the horizontal versorium at ,b varies from the pole ,a toward ,c3 so that both the variation is shown and the stronger places of the loadstone recognized4 ,the stronger surface is also found by a fine iron wire of the length of two barleycorns3 for since at the pole of the terrella it rears up perpendicularly1 but in other places inclines toward the quator1 if in one and the same parallel circle it should be more erect in one place than in another2 where the wire is raised more upright1 there the part and surface of the terrella is stronger4 ,also when the iron wire placed over the pole inclines more to one part than to another4 ,illustration 99 #aeg ,let the experiment be made by means of a fine iron wire of three digits length placed over the pole ,a1 so that its middle lies over the pole4 ,then one end is turned away from ,b toward ,c1 and is not willing to lie quietly toward ,b2 but on a terrella which is perfect#bbj all round and even it rests on the pole directed toward any point of the quator you please4 ,otherwise1 let there be two 99 ,illustration meridians meeting in the poles ,a ,b1 let iron wires be reared just at the ends ,d and ,c of the equal arcs ,d ,a and ,c ,a2 then the wire at ,d 7the stronger region7 will be more raised up than that at ,c1 the weaker4 ,and thus the sounder and stronger part of the loadstone is recognized1 which otherwise would not be perceived by the touch4 ,in a terrella which is perfect1 and even1 and similar in all its parts1 there is1 at equal distances from the pole1 no variation#bba4 ,variation is shown by means of a terrella1 a considerable part of which1 forming a surface a little higher than the rest1 does1 although it be not decayed and broken1 allure the versorium from the true 99 direction 7the whole terrella co-operating74 ,a terrella uneven in surface4 ,illustration #aeh ,it is shown by a small spike placed over a terrella or by a small versorium2 for they are turned by the terrella toward the mass that stands out and toward the large eminences4 ,in the same way on the earth the verticity is perturbed by great continents1 which are mostly elevated above the depths of the seas and make the versorium deviate sometimes from the right tracks 7that is1 from the true meridians74 ,on a terrella it is thus demonstrated3 the end of the versorium ,a is not directed straight to the pole ,p1 if there be a large protuberance ,b on the terrella2 so also the cusp ,c deviates from the pole because of the eminence ,f4 ,in the middle between the two eminences the versorium ,g collimates to the true pole because1 being at equal distances from the two eminences ,b and ,f1 it turns aside to neither1 but observes the true meridian1 especially when the protuberances are of equal vigour4 ,but the versorium ,n on the other side varies from the pole ,m toward the eminences ,h1 and is not held back1 stopped1 or restrained by the small eminence ,o on the terrella 7as it were1 some island of land in the ocean74 ,l1 however1 being unimpeded1 is directed to the pole ,m4 ,the variation is demonstrated in another way on a terrella1 just as on the earth4 ,let ,a be the pole of the earth1 ,b the equator1 ,c the parallel circle of latitude of #cj degrees1 ,d a great eminence spread out toward the pole1 ,e another eminence spread out from the pole toward the quator4 ,it is manifest that in the middle of ,d the versorium ,f #aei does not vary2 while ,g is very greatly deflected3 but ,h very little1 because it is further removed from ,d4 ,similarly also the versorium ,i placed directly toward ,e does not deviate from the pole3 but ,l and ,m turn themselves away from the pole ,a toward the eminence ,e4 ,illustration 99 99 99 99 99 ,,chap4 ,,iii4 ,the variation in any one place is constant4 ,illustration ,vnless there should be a great dissolution of a continent and a subsidence of the land such as there was of the region ,atlantis of which ,plato and the ancients tell1 the variation will continue perpetually immutable2 the arc of the variation remains the same in the same place or region1 whether it be at sea or on land1 as in times past a magnetick body has declined toward the ,east or the ,west4 ,the constancy of the variation and the pointing of the versorium to a definite point on the horizon in individual regions is demonstrated by a small versorium placed over a terrella the surface of which is uneven3 for it always deviates from the meridian by an equal arc4 ,it is also shown by the inclination of a versorium toward a second magnet2 although in reality it is by the turning power of the whole1 whether in the earth or in a terrella4 ,place upon a plane a versorium whose cusp is directed toward the north ,a3 place beside it a loadstone1 ,b1 at such a distance that the versorium may turn aside toward ,b to the point ,c1 and not beyond4 ,then move the needle of the versorium as often as you will 7the box and the loadstone not being moved71 and it will certainly always return to the point ,c4 ,in the same manner1 if you #afj placed the stone so that it may be truly directed toward ,e1 the cusp always reverts to ,e1 and not to any other point of the compass4 ,accordingly1 from the position of the land and from the distinctive nature of the highest parts of the earth 7certain terrene and more magnetick eminences of the regions prevailing71 the variation indeed becomes definite in one and the same place1 but diverse and unqual from a change of place1 since the true and polar direction originating in the whole terrestrial globe is diverted somewhat toward certain stronger eminences on the broken surface4 99 99 99 99 99 ,,chap4 ,,iiii4 ,the arc of variation is not changed equally in proportion to the distance of places4 ,in the open sea1 when a vessel is borne by a favourable wind along the same parallel1 if the variation be changed by one degree in the course of one hundred miles1 the next hundred miles do not therefore lessen it by another degree2 for the magnetick needle varies erratically as respects position1 form1 and vigour of the land1 and also because of the distance4 ,as1 for example1 when a course from the ,scilly ,isles to ,newfoundland has proceeded so far that the compass is directed to the true pole1 then1 as the vessel proceeds1 in the first part of the course the variation increases toward the north-west#bbb1 but rather indistinctly and with small difference3 thence1 after an equal distance1 the arc is increased in a greater proportion until the vessel is not far from the continent3 for then it varies most of all4 ,but before it touches actual land or enters port1 then at a certain distance the arc is again slightly diminished4 ,but if the vessel in its course should decline greatly from that parallel either toward the south or the north1 the magnetick needle will vary more or less1 according to the position of the land and the latitude 99 of the region4 ,for 7cteris paribus7 the greater the latitude the greater the variation4 99 99 99 99 99 #afa ,,chap4 ,v4 ,an island in ,ocean does not change the variation#bbc1 as neither do mines of loadstone4 ,islands1 although they be more magnetick than the sea1 yet do not change the magnetick directions or variations4 ,for since direction is a motion derived from the power of the whole earth1 not from the attraction of any hill but from the disposing and turning power of the whole2 so variation 7which is a perturbation of the direction7 is an aberration of the real turning power arising from the great inequalities of the earth1 in consequence of which it1 of itself1 slightly diverts movable magneticks toward those which are the largest and the more powerful4 ,the cause now shown may suffice to explain that which some so wonder at about the ,island of ,elba 7and although this is productive of loadstone1 yet the versorium 7or mariners' compass7 makes no special inclination toward it whenever vessels approach it in the ,tyrrhenian sea72 and the following causes are also to be considered1 viz43 that the virtue of smaller magnetick bodies extends scarcely or not at all of itself beyond their own mines3 for variation does not occur because of attraction1 as they would have it who have imagined magnetick poles4 ,besides1 magnetick mines are only agnate to the true earth1 not innate3 hence the whole globe does not regard them1 and magneticks are not borne to them1 as is demonstrated by the diagram of eminences4 99 99 99 99 99 ,,chap4 ,,vi4 ,that variation and direction arise from the disponent power of the earth1 and from the natural magnetick tendency to rotation1 not from attraction1 or from coition1 or from other occult cause4 ,owing to the loadstone being supposed 7amongst the crowd of philosophizers7 to seize and drag1 as it were1 magnetick bodies2 and since1 in truth1 sciolists have remarked no other forces than those so oft besung of attractive ones1 they therefore deem every motion toward the north and south to be caused by some alluring and inviting quality4 ,but the ,englishman1 #afb ,robert ,norman1 first strove to show that it is not caused by attraction3 wherefore1 as if tending toward hidden principles1 he imagined a point respective#bbd1 toward which the iron touched by a loadstone would ever turn1 not a point attractive2 but in this he erred greatly1 although he effaced the former error about attraction4 ,he1 however1 demonstrates his opinion in this way3 ,illustration ,let there be a round vessel filled with water3 in the middle of the surface of the water place a slender iron wire on a perfectly round cork1 so that it may just float in quilibrium on the water2 let the wire be previously touched by a magnet1 so that it may more readily show the point of variation1 the point ,d as it were3 and let it remain on the surface for some time4 ,it is demonstrable that the wire together with the cork is not moved to the side ,d of the vessel3 which it would do if an attraction came to the iron wire by ,d3 and the cork would be moved out of its place4 ,this assertion of the ,englishman1 ,robert ,norman1 is plausible and appears to do away with attraction because the iron remains on the water not moving about1 as well in a direction toward the pole itself 7if the direction be true7 as in a variation or altered direction2 and it is moved about its own centre without any transference to the edge of the vessel4 ,but direction does not arise from attraction1 but from the disposing and turning power which exists in the whole earth1 not in the pole or in some other attracting part of the stone1 or in any mass rising above the periphery of the true circle so that a ,illustration variation should occur because of the attraction of that mass4 ,moreover1 it is the directing power of the loadstone and iron and its natural power of turning around the centre which cause the motion of direction1 and of conformation1 in which is included also the motion of the dip4 ,and the terrestrial pole does not attract as if the terrene force were implanted only in the pole1 for the magnetick force exists in the whole1 although it predominates and excels at the pole4 ,wherefore that the cork should rest quiescent in the middle and that the iron excited by a loadstone should not be moved toward the side of the vessel are agreeable to and in conformity #afc with the magnetick nature1 as is demonstrated by a terrella3 for an iron spike placed on the stone at ,c clings on at ,c1 and is not pulled 99 further away by the pole ,a1 or by the parts near the pole3 hence it persists at ,d1 and takes a direction toward the pole ,a2 nevertheless it clings on at ,d and dips also at ,d in virtue of that turning power by which it conforms itself to the terrella3 of which we will say more in the part ,on ,declination4 99 99 99 99 99 ,,chap4 ,,vii4 ,why the variation from that lateral cause is not greater than has hitherto been observed1 having been rarely seen to reach two points of the mariners' compass1 except near the pole4 ,the earth1 by reason of lateral eminences of the stronger globe1 diverts iron and loadstone by some degrees from the true pole1 or true meridian4 ,as1 for example1 with us ,english at ,london it varies eleven degrees and #a_/c3 in some other places the variation is a little greater1 but in no other region is the end of the iron ever moved aside very much more from the meridian4 ,for as the iron is always directed by the true verticity of the earth1 so the polar nature of the continent land 7just as of the whole terrene globe7 acts toward the poles3 and even if that mass divert magnetick bodies from the meridian1 yet the verticity of those lands 7as also of the whole earth7 controls and disposes them so that they do not turn toward the ,east by any greater arc4 ,but it is not easy to determine by any general method how great the arc of variation is in all places1 and how many degrees and minutes it subtends on the horizon1 since it becomes greater or less #afd from diverse causes4 ,for both the strength of true verticity of the place and of the elevated regions1 as well as their distances from the given place and from the poles of the world1 must be considered and compared2 which indeed cannot be done exactly3 nevertheless by our method the variation becomes so known that no grave error will perturb the course at sea4 ,if the positions of the lands were uniform and straight along meridians1 and not defective and rugged1 the variations near lands would be simple2 such as appear in the following figure4 ,illustration ,this is demonstrated by a long loadstone the poles of which are in the ends ,a ,b2 let ,c ,d be the middle line and the quinoctial1 and let ,g ,h and ,e ,f 7the lines7 be for meridians on which versoria are disposed1 the variations of which are greater at a greater distance from the quator4 ,but the inequalities of the maritime parts of the habitable earth1 the enormous promontories1 the very wide gulfs1 the mountainous and more elevated regions1 render the variations more unequal1 or sudden1 or more obscure2 and1 moreover1 less certain and more inconstant in the higher latitude4 99 99 99 99 99 #afe ,,chap4 ,,viii4 ,on the construction of the common mariners' compass#bbe1 and on the diversity of the compasses of different nations4 ,in a round#bbf hollow wooden bowl1 all the upper part of which is closed with glass1 a versorium is placed upon a rather long pin which is fixed in the middle4 ,the covering prevents the wind1 and the motion of air from any external cause4 ,through the glass everything within can be discerned4 ,the versorium is circular1 consisting of some light material 7as card71 to the under part of which the magnetick pieces of iron are attached4 ,on the upper part #cb spaces 7which are commonly called points7 are assigned to the same number of mathematical intervals in the horizon or winds which are distinguished by certain marks and by a lily indicating the north4 ,the bowl is suspended in the plane of the horizon in quilibrium in a brass ring which also is itself suspended transversely in another ring within a box sufficiently wide with a leaden weight attached2 hence it conforms to the plane of the horizon even though the ship be tossed to and fro by the waves4 ,the iron works are either a pair with their ends united1 or else a single one of a nearly oval shape with projecting ends1 which does its work more certainly and more quickly4 ,this is to be fitted to the cardboard circle so that the centre of the circle may be in the middle of the magnetick iron4 ,but inasmuch as variation arises horizontally from the point of the meridian which cuts the horizon at right angles1 therefore on account of the variation the makers in different regions and cities mark out the mariners' compass in different ways1 and also attach in different ways the magnetick needles to the cardboard circle on which are placed the #cb divisions or points4 ,hence there are commonly in ,europe #d different constructions and forms4 ,first that of the ,states on the ,mediterranean ,sea1 ,sicily1 ,genoa1 and the ,republick of ,venice4 ,in all these the needles are attached under the rose or lily on the cardboard versorium1 so that 7where there is no variation7 they are directed to the true north and south points4 ,wherefore the north part marked with the lily always shows exactly the point of variation when the apex itself of the lily on the movable circle1 together with the ends of the magnetick wires attached below1 rests at the point of variation4 ,yet another is that of ,dantzig1 and throughout the ,baltic ,sea1 and the ,belgian provinces2 #aff in which the iron works fixed below the circle diverge from the lily of a rumbe to the east4 ,for navigation to ,russia the divergency is #b_/c4 ,but the compasses which are made at ,seville1 ,lisbon1 ,rochelle1 ,bordeaux1 ,rouen1 and throughout all ,england have an interval of a rumbe4 ,from those differences most serious errors have arisen in navigation1 and in the marine science4 ,for as soon as the bearings of maritime places 7such as promontories1 havens1 islands7 have been first found by the aid of the mariners' compass1 and the times of sea-tide or high water determined from the position of the moon over this or that point 7as they say7 of the compass1 it must be further inquired in what region or according to the custom of what region that compass was made by which the bearings of those places and the times of the sea-tides were first observed and discovered4 ,for one who should use the ,british compass and should follow the directions of the marine charts of the ,mediterranean ,sea would necessarily wander very much out of the straight course4 ,so also he that should use the ,italian compass in the ,british1 ,german1 or ,baltic ,sea1 together with marine charts that are made use of in those parts1 will often stray from the right way4 ,these different constructions have been made on account of the dissimilar variations1 so that they might avoid somewhat serious errors in those parts of the world4 ,but ,pedro ,nuez seeks the meridian by the mariners' compass1 or versorium 7which the ,spanish call the needle71 without taking account of the variation3 and he adduces many geometrical demonstrations which 7because of his slight use and experience in matters magnetical7 rest on utterly vicious foundations4 ,in the same manner ,pedro de ,medina1 since he did not admit variation1 has disfigured his ,arte de ,navegar with many errors4 99 99 99 99 99 ,,chap4 ,,ix4 ,whether the terrestrial longitude can be found from the variation4 ,grateful would be this work to seamen1 and would bring the greatest advance to ,geography4 ,but ,b4 ,porta in chap4 #ch of book #g is mocked by a vain hope and fruitless opinion4 ,for when he supposes that the magnetick needle would follow order and proportion in moving along meridians1 so that the neerer it is to the east1 the more it will decline from the ,meridian line1 toward the east2 and the neerer it comes to the west1 the #afg point of the needle will decline the more to the west 7which is totally untrue71 he thinks that he has discovered a true index of longitude4 ,but he is mistaken4 ,nevertheless1 admitting and assuming these things 7as though they were perfectly true71 he makes a large compass indicating degrees and minutes1 by which these proportional changes of the versorium might be observed4 ,but those very principles are false1 and ill conceived1 and very ill considered2 for the versorium does not turn more to the east because a journey is made toward the east3 and although the variation in the more westerly parts of ,europe and the adjoining ocean is to the east and beyond the ,azores is changed a little to the west1 yet the variation is1 in various ways1 always uncertain1 both on account of longitude and of latitude1 and because of the approach toward extensive tracts of land1 and also because of the form of the dominant terrestrial eminences2 nor does it1 as we have before demonstrated1 follow the rule of any particular meridian4 ,it is with the same vanity also that ,livio ,sanuto so greatly torments himself and his readers4 ,as for the fact that the crowd of philosophizers and sailors suppose that the meridian passing through the ,azores marks the limits of variation1 so that on the other and opposite side of that meridian a magnetick body necessarily respects the poles exactly1 which is also the opinion of ,joannes ,baptista ,benedictus and of many other writers on navigation1 it is by no means true4 ,stevinus 7on the authority of ,hugo ,grotius7 in his ,havenfinding ,art distinguishes the variation according to the meridians3 ,it may be seene in the ,table of variations1 that in ,coruo the ,magneticall needle pointeth due ,north3 but after that1 the more a man shal goe towards the ,east1 so much the more also shall he see the needle varie towards the ,east ,greek3 anatolizein1 till he come one mile to the ,eastward from ,plimouth1 where the variation comming to the greatest is #ac degr4 #bd min4 ,from hence the ,northeasting ,anatolismus beginneth to decrease1 til you come to ,helmshude 7which place is ,westward from the ,north ,cape of ,finmark7 where againe the needle pointeth due ,north4 ,now the longitude from ,coruo to ,helmshude is #fj degr4 ,which things being well weighed1 it appeareth that the greatest variation ,chalyboclysis #ac degr4 #bd minutes at ,plimmouth 7the longitude whereof is #cj degr47 is in the midst betweene the places where the needle pointeth due ,north4 ,but although this is in some part true in these places1 yet it is by no means true that along the whole of the meridian of the island of ,corvo the versorium looks truly to the north2 nor on the meridian of ,plymouth is the variation in other places #ac deg4 #bd min4--nor again in other parts of the meridian of ,helmshuda does it point to the true pole4 ,for on the meridian passing through ,plymouth in ,latitude #fj degrees the ,north-easterly variation is greater3 in ,latitude #dj deg4 much less2 in ,latitude #bj deg4 very small indeed4 ,on the meridian of ,corvo1 although there is no variation near the #afh island1 yet in ,latitude #ee degrees the variation is about a rumbe to the ,north-west2 in ,latitude #bj deg4 the versorium inclines of a rumbe toward the ,east4 ,consequently the limits of variation are not conveniently determined by means of great circles and meridians1 and much less are the ratios of the increment or decrement toward any part of the heavens properly investigated by them4 ,wherefore the rules of the abatement or augmentation of ,northeasting or ,northwesting1 or of increasing or decreasing the magnetick deviation1 can by no means be discovered by such an artifice4 ,the rules which follow later for variation in southern parts of the earth investigated by the same method are altogether vain and absurd4 ,they were put forth by certain ,portuguese mariners1 but they do not agree with the observations1 and the observations themselves are admitted to be bad4 ,but the method of haven-finding in long and distant voyages by carefully observed variation 7such as was invented by ,stevinus1 and mentioned by ,grotius7 is of great moment1 if only proper instruments are in readiness1 by which the magnetick deviation can be ascertained with certainty at sea4 99 99 99 99 99 ,,chap4 ,x4 ,why in various places near the pole the variations are much more ample than in a lower latitude4 ,variations are often slight1 and generally null1 when the versorium is at or near the earth's quator4 ,in a higher ,latitude of #fj1 #gj or #hj deg4 there are not seldom very wide variations4 ,the cause of this is to be sought partly from the nature of the earth and partly from the disposition of the versorium4 ,the earth turns magnetick bodies and at the quator directs them strongly toward the pole3 #bbg;at the poles there is no direction1 but only a strong coition through the congruent poles4 ,direction is therefore weaker near the poles1 because by reason of its own natural tendency to turn1 the versorium dips very much1 and is not strongly directed4 ,but since the force of those elevated lands is more vigorous1 for the virtue flows from the whole globe1 and since also the causes of variation are nearer1 therefore the versorium deflects the more from its true direction toward those eminences4 ,it must also be known that the direction of the versorium on its pin along the plane of the ,horizon is much stronger at the quator than anywhere else by reason of the disposition of the #afi versorium2 and this direction falls off with an increase of latitude4 ,for on the quator the versorium is1 following its natural property1 directed along the plane of the horizon2 but in other places it is1 contrary to its natural property1 compelled into quilibrium1 and remains there1 compelled by some external force3 because it would1 according to its natural property1 dip below the horizon in proportion to the latitude1 as we shall demonstrate in the book ,on ,declination4 ,hence the direction falls off and at the pole is itself nothing3 and for that reason a feebler direction is easily vanquished by the stronger causes of variation1 and near the pole the versorium deflects the more from the meridian4 ,it is demonstrated by means of a terrella3 if an iron wire of two digits length be placed on its quator1 it will be strongly and rapidly directed toward the poles along the meridian1 but more weakly so in the mid-intervals2 while near the poles one may discern a precipitate variation4 99 99 99 99 99 ,,chap4 ,,xi4 ,cardan's error when he seeks the distance of the centre of the earth from the centre of the cosmos by the motion of the stone of ,hercules2 in his book #e1 ,on ,proportions4 ,one may very easily fall into mistakes and errors when one is searching into the hidden causes of things1 in the absence of real experiments1 and this is easily apparent from the crass error of ,cardan2 who deems himself to have discovered the distances of the centres of the cosmos and of the earth through a variation of the magnetick iron of #i degrees4 ,for he reckoned that everywhere on the earth the point of variation on the ,horizon is always distant nine degrees from the true north1 toward the east3 and from thence he forms1 by a most foolish error1 his demonstrative ratio of the separate centres4 99 99 99 99 99 #agj ,,chap4 ,,xii4 ,on the finding of the amount of variation3 how great is the arc of the ,horizon from its arctick or antarctick intersection of the meridian1 to the point respective of the magnetick needle4 ,virtually the true meridian is the chief foundation of the whole matter3 when that is accurately known1 it will be easy by a mariners' compass 7if its construction and the mode of attachment of the magnetick iron works are known7 or by some other larger horizontal versorium to exhibit the arc of variation on the ,horizon4 ,by means of a sufficiently large nautical variation compass 7two equal altitudes of the sun being observed before and after midday71 the variation becomes known from the shadow2 the altitude of the sun is observed either by a staff or by a rather large quadrant4 ,on land the variation is found in another way which is easier1 and because of the larger size of the instrument1 more accurate4 ,let a thick squared board be made of some suitable wood1 the surface of which is two feet in length and sixteen inches in width3 describe upon it some semicircles as in the following figure1 only more in number4 ,in the centre let a brass style be reared perpendicularly3 let there be also a movable pointer reaching from the centre to the outmost semicircle1 and a magnetick versorium in a cavity covered over with glass3 then let the board be exactly adjusted to the level of the ,horizon by the plane instrument with its perpendicular2 and turn the lily of the instrument toward the north1 so that the versorium may rest truly over the middle line of the cavity1 which looks toward the point of variation on on the ,horizon4 ,then at some convenient hour in the morning 7eight or nine for instance7 observe the apex of the shadow thrown by the style when it reaches the nearest semicircle and mark the place of the apex of this shadow with chalk or ink3 then bring round the movable index to that mark1 and observe the degree on the ,horizon numbered from the lily1 which the index shows4 ,in the afternoon see when the end of the shadow shall again reach the periphery of the same semicircle1 and1 bringing the index to the apex of the shadow1 seek for the degree on the other side of the lily4 ,from the difference of the degrees becomes known ,illustration #agb the variation2 the less being taken from the greater1 half the remainder is the arc of variation4 ,the variation is sought by many other instruments and methods in conjunction with a convenient mariners' compass2 also by a globe1 by numbers1 and by the ratios of triangles and sines1 when the latitude is known and one observation is made of the sun's altitude3 but those ways and methods are of less use1 for it is superfluous to try to find in winding and roundabout ways what can be more readily and as accurately found in a shorter one4 ,for the whole art is in the proper use of the instruments by which the sun's place is expeditiously and quickly taken 7since it does not remain stationary1 but moves on73 for either the hand trembles or the sight is dim1 or the instrument makes an error4 ,besides1 to observe the altitude on both sides of the meridian is just as expeditious as to observe on one side only and at the same time to find the elevation of the pole4 ,and he who can take one altitude by the instrument can also take another2 but if the one altitude be uncertain1 then all the labour with the globe1 numbers1 sines and triangles is lost2 nevertheless those exercises of ingenious mathematicians are to be commended4 ,it is easy for anyone1 if he stand on land1 to learn the variation by accurate observations and suitable instruments1 especially in a nearly upright sphere2 but on the sea1 on account of the motion and the restlessness of the waters1 exact experiments in degrees and minutes cannot be made3 and with the usual instruments scarcely within the third or even the halt of a rumbe1 especially in a higher latitude2 hence so many false and bad records of the observations of navigators4 ,we have1 however1 taken care for the finding of the deviation by a sufficiently convenient and ready instrument1 by means of the rising of certain stars1 by the rising or setting of the sun1 and in northern regions by the ,pole ,star3 for the variation is learned with greater certainty even by the skilful with an instrument which is at once simple and less sensitive to the waves of the sea4 ,its construction is as follows4 #bbh,let an instrument be made of the form of a true and meridional mariners' compass of at least one foot in diameter 7with a versorium which is either nude or provided with a cardboard circle73 let the limb be divided into four quadrants1 and each quadrant into #ij degrees4 ,the movable compass-box 7as is usual in the nautical instrument7 is to be balanced below by a heavy weight of sixteen pounds4 ,on the margin of the suspended compass-box1 where opposite quadrants begin1 let a half-ring rising in an angular frame in the middle be raised 7with the feet of the half-ring fixed on either side in holes in the margin7 so that the top of the frame may be perpendicular to the plane of the compass2 on its top let a rule sixteen digits in length be fastened at its middle on a joint like a balance beam1 so that it may move1 as it were1 about a central axis4 ,at the ends of the rule there are small plates with holes1 #agc ,illustration #agd through which we can observe the sun or stars4 ,the variation is best observed and expeditiously by this instrument at the equinoxes by the rising or setting sun4 ,but even when the sun is in other parts of the zodiack1 the deviation becomes known when we have the altitude of the pole3 that being known1 one can learn the amplitude on the ,horizon and the distance from the true east both of the sun and of the following fixed stars by means of a globe1 or tables1 or an instrument4 ,then the variation readily becomes known by counting from the true east the degrees and minutes of the amplitude at rising4 ,observe the preceding star of the three in the ,belt of ,orion as soon as it appears on the horizon2 direct the instrument toward it and observe the versorium1 for since the star has its rising in the true east about one degree toward the south1 it can be seen how much the versorium is distant from the meridian1 account being taken of that one degree4 ,you will also be able to observe the arctick pole star when it is on the meridian1 or at its greatest distance from the meridian of about three degrees 7the pole star is distant #b deg4 #ee min4 from the pole1 according to the observations of ,tycho ,brahe71 and by the instrument you will learn the variation 7if the star be not on the meridian7 by adding or subtracting1 secundum artem1 the proper reduction prostaphresis#bbi of the star's distance from the meridian4 ,you will find when the pole star is on the meridian by knowing the sun's place and the hour of the night3 for this a practised observer will easily perceive without great error by the visible inclination of the constellation3 for we do not take notice of a few minutes1 as do some who1 when they toil to track the minutes of degrees at sea1 are in error by a nearly whole rumbe4 ,a practised observer will1 in the rising of sun or stars1 allow something for refraction1 so that he may be able to use a more exact calculation4 ,bright and conspicuous stars#bcj which are not far distant from the equator which it will be useful to observe at their rising and setting3 the amplitude at the ,horizon on rising being known from the altitude of the pole and from the declination of the stars1 by means of a globe1 or tables1 or an instrument whence the variation is perceived by technical calculation4 #age ,right ,ascension ,declination ,oculus ,tauri #fb #ee' #ae #ec' ,n ,sinister humerus ,orionis #gb #bd' #d #e' ,n ,dexter humerus ,orionis #hc #cj' #f #ai' ,n ,prcedens in cingulo ,orionis #gg #df' #a #af' ,s ,canis major #ig #aj' #ae #ee' ,s ,canis minor #aji #da' #e #ee' ,n ,lucida ,hydr #acg #aj' #e #c' ,s ,caput ,geminorum australe #aaj #ba' #bh #cj' ,n ,caput boreale #ajg #d' #cb #aj' ,n ,cor ,leonis #adf #h' #ac #dg' ,n ,cauda ,leonis #aga #ch' #af #cj' ,n ,spica ,virginis #aie #dd' #h #cd' ,s ,arcturus #bi #ac' #ba #ed' ,n ,cor ,aquil #bia #ef' #g #ce' ,n ,an instrument for finding the amplitude at rising on the horizon4 ,describe the circumference of a circle and let it be divided into quadrants by two diameters intersecting each other at right angles at its centre4 ,one of these will represent the quinoctial circle1 the other the axis of the world4 ,let each of these quadrants be divided 7in the accustomed way7 into #ij degrees2 on every fifth or tenth of which at each end of each diameter and on each side let marks 7showing the numbers7 be inscribed on the two limbs or margins made for that purpose outside the circumference4 ,then from each degree straight lines are drawn parallel to the quator4 ,you will then prepare a rule or alhidade equal to the diameter of that circle and divided throughout into the same parts into which the diameter of the circle representing the axis of the world is divided4 ,let there be left a small appendage attached to the middle of the rule1 by which the middle of the fiducial line itself of the rule may be connected with the centre of the circle3 but to every fifth or tenth part of that rule let numbers be attached proceeding from the centre toward each side4 ,this circle represents the plane of the meridian2 its centre the actual point of east or west1 i4e41 the common intersection of the horizon and quator2 all those lines quidistant from the quator denote the parallels of the sun and stars2 the fiducial line of the rule or alhidade represents the horizon2 and its parts signify the degrees of the horizon1 beginning from the point of setting or of rising4 #agf ,illustration ,therefore if the fiducial line of the rule be applied to the given latitude of the place reckoned from either end of that diameter which represents the axis of the world2 and if further the given declination of the sun or of some star from the quator 7less than the complement of the latitude of the place7 be found on the limb of the instrument2 then the intersection of the parallel drawn from that point of the declination with the horizon1 or with the fiducial line of the rule or alhidade1 will indicate for the given latitude of the place the amplitude at rising of the given star or the sun4 99 99 99 99 99 #agg ,,chap4 ,,xiii4 ,the observations of variation by seamen vary1 for the most part1 and are uncertain3 partly from error and inexperience1 and the imperfections of the instruments2 and partly from the sea being seldom so calm that the shadows or lights can remain quite steady on the instruments4 ,after the variation of the compass had first been noticed1 some more diligent navigators took pains to investigate in various ways the difference of aspect of the mariners' compass4 ,yet1 to the great detriment of the nautical art1 this has not been done so exactly as it ought to have been4 ,for either being somewhat ignorant they have not understood any accurate method or they have used bad and absurd instruments1 or else they merely follow some conjecture arising from an ill-formed opinion as to some prime meridian or magnetick pole2 whilst others again transcribe from others1 and parade these observations as their own2 and they who1 very unskilful themselves1 first of all committed their observations to writing are1 as by the prerogative of time1 held in esteem by others1 and their posterity does not think it safe to differ from them4 ,hence in long navigations1 especially to the ,east ,indies1 the records by the ,portuguese of the deviating compass are seen to be unskilful3 for whoever reads their writings will easily understand that they are in error in very many things1 and do not rightly understand the construction of the ,portuguese compass 7the lily of which diverges by half a rumbe from the needles toward the west71 nor its use in taking the variation4 ,hence1 while they show the variation of the compass in different places1 it is uncertain whether they measure the deviation by a true meridional compass or by some other whose needles are displaced from the lily4 ,the ,portuguese 7as is patent in their writings7 make use of the ,portuguese compass1 whose magnetick needles are fixed aside from the lily by half of one rumbe toward the east4 ,moreover on the sea the observation of the variation is a matter of great difficulty1 on account of the motion of the ship and the uncertainty of the deviation1 even with the more skilful observers1 if they use the best made instruments hitherto known and used4 ,hence there arise different opinions concerning the magnetick deviation3 as1 for instance1 near the ,island of ,st4 ,helena the ,portuguese ,rodriguez de #agh ,lagos measures half a rumbe4 ,the ,dutch in their nautical log fix it at a whole rumbe4 ,kendall1 the expert ,englishman1 with a true meridional compass admits only a sixth part of a rumbe4 ,a little to the ,east of ,cape ,agullias ,diego ,alfonso makes no variation1 and shows by an ,astrolabe that the compass remains in the true meridian4 ,rodriguez shows that the compass at ,cape ,agulhas has no variation if it is of ,portuguese construction1 in which the needles are inclined half a rumbe to the ,east4 ,and there is the same confusion1 negligence1 and vanity in very many other instances4 99 99 99 99 99 ,,chap4 ,,xiiii4 ,on the variation under the quinoctial line1 and near it4 ,in the ,north the magnetick needle varies because of the ,boreal eminences of the continent2 in the ,south because of the ,austral2 at the quator1 if the regions on both sides were equal1 there would be no variation4 ,but because this rarely happens some variation is often observed under the quator2 and even at some distance from the quator of three or #d degrees toward the ,north1 there may be a variation arising from the south1 if those very wide and influential southern continents be somewhat near on one side4 99 99 99 99 99 ,,chap4 ,,xv4 ,the variation of the magnetick needle in the great thiopick and ,american sea1 beyond the quator4 ,discourse hath already been had of the mode and reason of the variation in the great ,atlantick ,ocean3 but when one has advanced beyond the quator off the east coast of ,brazil the magnetick needle turns aside toward the mainland1 namely1 with that end of it which points to the south2 so that with that end of the versorium it deviates from the true meridian toward the west2 which navigators observe at the other end and suppose a variation to occur toward the east4 ,but throughout the whole way from the first promontory on the east of ,brazil1 by #agi ,cape ,st4 ,augustine and thence to ,cape ,frio1 and further still to the mouth of the ,strait of ,magellan1 the variation is always from the south toward the west with that end of the versorium which tends toward the antarctick pole4 ,for it is always with the accordant end that it turns toward a continent4 ,the variation1 however1 occurs not only on the coast itself1 but at some distance from land1 such as a space of fifty or sixty ,german miles or even more4 ,but when at length one has progressed far from land1 then the arc begins to diminish3 for the magnetick needle turns aside the less toward what is too far off1 and is turned aside the less from what is present and at hand1 since it enjoys what is present4 ,in the ,island of ,st4 ,helena 7the longitude of which is less than is commonly marked on charts and globes7 the versorium varies by one degree or nearly two4 ,the ,portuguese and others taught by them1 who navigate beyond the ,cape of ,good ,hope to the ,indies1 set a course toward the ,islands of ,tristan d',acunha1 in order that they may enjoy more favourable winds2 in the former part of their course the change of variation is not great2 but after they have approached the islands the variation increases2 and close to the islands it is greater than anywhere else in the whole course4 ,for the end of the versorium tending to the south 7in which lies the greatest source of the variation7 is caught and allured toward the south-west by the great promontory of the southern land4 ,but when they proceed onward toward the ,cape of ,good ,hope the variation diminishes the more they approach it4 ,but on the prime meridian in the latitude of #de degrees1 the versorium tends to the south-east3 and one who navigates near the coast from ,manicongo to the tropick1 and a little beyond1 will perceive that the versorium tends from the south to the east1 although not much4 ,at the promontory of ,agulhas it preserves slightly the variation which it showed near the islands of d',acunha1 which nevertheless is very much diminished because of the greater remoteness from the cause of variation1 and consequently there the southern end of the versorium does not yet face exactly to the pole4 99 99 99 99 99 ,,chap4 ,,xvi4 ,on the variation in ,nova ,zembla4 ,variations in parts near the pole are greater 7as has been shown before7 and also have sudden changes1 as in former years the ,dutch explorers observed not badly1 even if those observations were not exact--which indeed is pardonable in them2 for with the usual instruments it is with difficulty #ahj that the truth becomes known in such a high latitude 7of about #hj degrees74 ,now1 however1 from the deviation of the compass the reason for there being an open course to the east by the ,arctick ,ocean appears manifest2 for since the versorium has so ample a variation toward the north-west1 it is demonstrable that a continent does not extend any great distance in the whole of that course toward the east4 ,therefore with the greater hope can the sea be attempted and explored toward the east for a passage to the ,moluccas by the north-east than by the north-west4 99 99 99 99 99 ,,chap4 ,,xvii4 ,variation in the ,pacifick ,ocean4 ,passing the ,strait of ,magellan the deviation on the shore of ,peru is toward the south-east1 i4e41 from the south toward the east4 ,and a similar deflection would be continued along the whole coast of ,peru as far as the quator4 ,in a higher latitude up to #de deg4 the variation is greater than near the quator2 and the deflection toward the south-east is in nearly the same proportion as was the deviation from the south toward the west on the eastern shore of ,south ,america4 ,from the quator toward the ,north there is little or no variation until one comes to ,new ,galicia2 and thence along the whole shore as far as ,quivira the inclination is from the north toward the east4 99 99 99 99 99 ,,chap4 ,,xviii4 ,on the variation in the ,mediterranean ,sea4 ,sicilian and ,italian sailors think that in the ,sicilian ,sea and toward the east up to the meridian of the ,peloponnesus 7as ,franciscus ,maurolycus relates7 the magnetick needle grcizes1 that is1 turns from the pole toward what is called the greek wind or ,boreas2 that on the shore of the ,peloponnesus it looks toward the true pole2 but that when they have proceeded further east1 then it mistralizes1 because it tends from the pole toward the mistral or north-west wind3 which agrees with our rule for the variation4 ,for as the ,mediterranean ,sea is extended toward the west from that meridian1 so on the side #aha toward the east the ,mediterranean ,sea lies open as far as ,palestine2 as toward ,north and ,east lie open the whole ,archipelago and the neighbouring ,black ,sea4 ,from the ,peloponnesus toward the north pole the meridian passes through the largest and most elevated regions of all ,europe2 through ,achaia1 ,macedonia1 ,hungary1 ,transylvania1 ,lithuania1 ,novogardia1 ,corelia and ,biarmia4 99 99 99 99 99 ,,chap4 ,,xix4 ,the variation in the interior of large ,continents4 ,most of the great seas have great variations2 in some parts1 however1 they have none1 but the true directions are toward the pole4 ,on continents1 also1 the magnetick needle often deviates from the meridian1 as on the edge of the land and near the borders2 but it is generally accustomed to deviate by a somewhat small arc4 ,in the middle1 however1 of great regions there are no variations4 ,hence in the middle lands of ,upper ,europe1 in the interior of ,asia1 and in the heart of ,africa1 of ,peru1 and in the regions of ,north or ,mexican ,america1 the versorium rests in the meridian4 99 99 99 99 99 ,,chap4 ,,xx4 ,variation in the ,eastern ,ocean4 ,variation in the ,eastern ,ocean throughout the whole voyage to ,goa and the ,moluccas is observed by the ,portuguese2 but they err greatly in many things1 following1 as they do1 the first observers who note down variations in certain places with ill-adapted instruments1 and by no means accurate observations1 or by some conjectures4 ,as1 for instance1 in ,brande ,island1 they make the versorium deviate by #bb degrees to the north-west4 ,for in no region or place in the whole world1 of not greater latitude1 is there so great a deviation2 and1 in reality1 there the deviation is slight4 ,also when they make out that at ,mosambique the compass deviates by one rumbe to the north-west1 it is false2 even though they use 7as they are accustomed to do7 the ,portuguese compass3 for beyond all doubt on the shore of #ahb ,mosambique the versorium inclines rumbe or even more to the south-west4 ,very wrongly also beyond the quator in the course to ,goa they make the little compass incline by #a rumbe to the west3 whereas they should rather have said that in the first part of the course the ,portuguese compass inclines by #a rumbe3 but that the true meridional compass inclines by rumbe only4 ,in order that the amount of variation in the ,eastern ,ocean may be accurately settled in most places by our rules1 there is needed a more exact and truer survey of the southern land1 which spreads out from the south to the quinoctial more than is commonly described on maps and globes4 99 99 99 99 99 ,,chap4 ,,xxi4 ,how the deviation of the versorium is augmented and diminished by reason of the distance of places4 ,in the middle of great and continent lands there is no variation4 ,nor1 generally1 in the middle of very great seas4 ,on the margin of those lands and seas the variation is often ample1 yet not so great as at a little further distance on the sea4 ,as1 for example1 near ,cape ,st4 ,augustine the compass varies2 but at #ej miles from land toward the ,east it varies more2 and #hj miles off it varies still more2 and yet still more at a distance of #ajj miles4 ,but from a distance of #ajj miles the diminutions of deviation are slower1 when they are navigating toward the mainland1 than at a distance of #hj miles1 and at a distance of #hj miles than at #ej3 for the deviations change and are diminished rather more swiftly the more they approach and draw near land than when at a great distance off4 ,as1 for instance1 navigating toward ,newfoundland the change of variation is more rapid 7that is1 it decreases a degree in a smaller arc of the course on the parallel7 when they are not far from land than when they are a hundred miles distant3 but when travelling on land toward the interiors of regions the changes are slower in the first parts of the journey than when they come more into the interior4 ,the ratio of the arcs on a parallel circle1 when a versorium is moved toward continents which extend to the pole1 corresponds with the degrees of variation4 ,let ,a be the pole2 ,b the eminences of the dominant lands2 at ,c there is no variation caused by ,b1 for it is too far away2 at ,d the variation is very great because the versorium is allured or turned by the whole earth toward the eminent #ahc land ,b2 and moreover it is not hindered1 or restrained or brought back to the pole by the verticity of the earth2 but1 tending of its own nature to the pole1 it is nevertheless deflected from it by reason of the site1 or position1 and convenient distance of the dominant and high lands4 ,illustration ,now from ,c toward ,d the variation increases2 the versorium1 however1 does not deviate so rapidly in the first spaces as near ,d3 for more miles are traversed on the parallel circle ,c ,d1 near ,c1 in order that the versorium may deviate by one degree from the pole ,a1 than near ,d4 ,so also in order that the variation may be diminished from ,d toward ,e more miles are required near ,d than near ,e4 ,thus the deviations become equal in unequal courses1 whether the variation be increasing or decreasing2 and yet the variation decreases by lesser intervals than it increases4 ,there intervene1 however1 many other causes which perturb this proportion4 99 99 99 99 99 #ahd ,illustration ,,book ,,fifth4 ,,chap4 ,i4 ,,on ,,declination4 ,in due course we have now come to that notable experiment1 and remarkable motion of magnetick bodies dipping below the horizon by their own rotatory nature2 by the knowledge of which is revealed a unity1 a concordancy1 and a mutual agreement between the terrestrial globe and the loadstone 7or the magnetick iron71 which is wonderful in itself1 and is made manifest by our teaching4 ,this motion we have made known in many striking experiments1 and have established its rules2 and in the following pages we shall demonstrate the causes of it1 in such a way that no sound1 logical mind can ever rightly set at nought or disprove our chief magnetick principles4 ,direction1 as also variation1 is demonstrated in a horizontal plane1 when a balanced magnetick needle comes to rest at some definite point2 but declination is seen to be the motion of a needle1 starting from that point of the horizon1 first balanced on its own axis1 then excited by a loadstone1 one end or pole of it tending toward the centre of the earth4 ,and we have found that it takes place in proportion to the latitude of each region4 ,but that motion arises in truth1 not from any motion from the horizon toward the centre of the earth1 but from the turning of the whole magnetick body toward the whole of the earth1 as we shall show hereafter4 ,nor does the iron dip from the horizontal in some oblique sphere1 according to the number of degrees of elevation of the pole in the given region1 or by an equal arc in the quadrant1 as will appear hereafter4 #ahe ,instrument of the ,declination ,illustration #ahf ,now how much it dips at every horizon may be ascertained in the first place by a contrivance1 which1 however1 is not so easily made as is that in dials for measuring time1 in which the needle turns to the points of the horizon1 or in the mariners' compass4 ,from a plank of wood let a smooth and circular instrument be prepared1 at least six digits in diameter1 and affix this to the side of a square pillar1 which stands upright on a wooden base4 ,divide the periphery of this instrument into #d quadrants3 then each quadrant into #ij degrees4 ,at the centre of the instrument let there be placed a brass peg1 at the centre of the end of which let there be a small hollow1 well polished4 ,to this wooden instrument let a brass circle or ring be fixed1 about two digits in width1 with a thin plate or flat rod of the same metal1 representing the horizon1 fixed across it1 through the middle of the circle4 ,in the middle of the horizontal rod let there be another hollow1 which shall be exactly opposite the centre of the instrument1 where the former hollow was made4 ,afterward let a needle be fashioned out of steel1 as versoria are accustomed to be made4 ,divide this at right angles by a thin iron axis 7like a cross7 through the very middle and centre of the wire and the cross-piece4 ,let this dipping-needle be hung 7with the ends of the cross resting in the aforesaid holes7 so that it can move freely and evenly on its axis in the most perfect quilibrium1 so accurately that it turns away from no one point or degree marked on the circumference more than from another1 but that it can rest quite easily at any4 ,let it be fixed upright to the front part of the pillar1 whilst at the edge of the base is a small versorium to show direction4 ,afterward touch the iron1 suspended by this ingenious method1 on both ends with the opposite ends of a loadstone1 according to the scientifick method1 but rather carefully1 lest the needle be twisted in any way2 for unless you prepare everything very skilfully and cleverly1 you will secure no result4 ,then let another brass ring be prepared1 a little larger1 so as to contain the former one2 and let a glass or a very thin plate of mica be fitted to one side of it4 ,when this is put over the former ring1 the whole space within remains inclosed1 and the versorium is not interfered with by dust or winds4 ,dispose the instrument1 thus completed1 perpendicularly on its base1 and with the small versorium horizontal1 in such a way that1 while standing perpendicularly1 it may be directed toward the exact magnetical point respective4 ,then the end of the needle which looks toward the north dips below the horizon in northern regions1 whilst in southern regions the end of the needle which looks toward the south tends toward the centre of the earth1 in a certain proportion 7to be explained afterward7 to the latitude of the district in question1 from the quator on either side4 ,the needle1 however1 must be rubbed on #ahg a powerful loadstone2 otherwise it does not dip to the true point1 or else it goes past it1 and does not always rest in it4 ,a larger instrument may also be used1 whose diameter may be #aj or #ab digits2 but in such an instrument more care is needed to balance the versorium truly4 ,care must be taken that the needle be of steel2 also that it be straight2 likewise that both ends of the cross-piece be sharp and fixed at right angles to the needle1 and that the cross-piece pass through the centre of the needle4 ,as in other magnetical motions there is an exact agreement between the earth and the stone1 and a correspondence manifestly apparent to our senses by means of our experiments2 so in this declination there is a clear and evident concordance of the terrestrial globe with the loadstone4 ,of this motion1 so important and so long unknown to all men1 the following is the sure and true cause4 ,a magnet-stone is moved and turned round until one of its poles being impelled toward the north comes to rest toward a definite point of the horizon4 #bca,this pole1 which settles toward the north 7as appears from the preceding rules and demonstrations71 is the southern1 not the boreal2 though all before us deemed it to be the boreal1 on account of its turning to that point of the horizon4 ,a wire or versorium touched on this pole of the stone turns to the south1 and is made into a boreal pole1 because it was touched by the southern terminal of the stone4 ,so if the cusp of a versorium be excited in a similar manner1 it will be directed toward the southern pole of the earth1 and will adjust itself also to it2 but the cross 7the other end7 will be southern1 and will turn to the north of the earth 7the earth itself being the cause of its motion72 for so direction is produced from the disposition of the stone or of the excited iron1 and from the verticity of the earth4 ,but declination takes place when a magnetick is turned round toward the body of the earth1 with its southern end toward the north1 at some latitude away from the quator4 ,for this is certain and constant1 that exactly under the coelestial quator1 or rather over the quator of the terrestrial globe1 there is no declination of a loadstone or of iron2 but in whatever way the iron has been excited or rubbed1 it settles in the declination instrument precisely along the plane of the horizon1 if it were properly balanced before4 ,now this occurs thus because1 when the magnetick body is at an equal distance from either pole1 it dips toward neither by its own versatory nature1 but remains evenly directed to the level of the horizon1 as if it were resting on a pin or floating free and unhindered on water4 ,but when the magnetick substance is at some latitude away from the quator1 or when either pole of the earth is raised 7,i do not say raised above the visible horizon1 as the commonly imagined pole of the revolving universe in the sky1 but above the horizon or its centre1 or its proper diameter1 quidistant from the plane of the visible horizon1 which is the true elevation of the terrestrial pole71 #ahh ,illustration then declination is apparent1 and the iron inclines toward the body of the earth in its own meridian4 ,let ,a ,b1 for example1 be the visible horizon of a place2 ,c ,d the horizontal through the earth1 dividing it into equal parts2 ,e ,f the axis of the earth2 ,g the position of the place4 ,it is manifest that the boreal pole ,e is elevated above the point ,c by as much as ,g is distant from the quator4 ,wherefore1 since at ,e the magnetick needle stands perpendicularly in its proper turning 7as we have often shown before71 so now at ,g there is a certain tendency to turn in proportion to the latitude 7the magnetick dipping below the plane of the horizon71 and the magnetick body intersects the horizon at unequal angles1 and exhibits a declination below the horizon4 ,for the same reason1 if the declinatory needle be placed at ,g1 its southern end1 the one namely which is directed toward the ,north1 dips below the plane of the visible horizon ,a ,b4 ,and so there is the greatest difference between a right sphere#bcb and a polar or parallel sphere1 in which the pole is at the very ,zenith4 ,for in a right sphere the needle is parallel to the plane of the horizon2 but when the coelestial pole is vertically overhead1 or when the pole of the earth is itself the place of the region1 then the needle is perpendicular to the horizon4 ,this is shown by a round stone4 ,let a small dipping-needle1 of two digits length 7rubbed with a magnet71 be hung in the air like a balance1 and let the stone be carefully placed under it2 and first let the terrella be at right angles1 as in a right sphere1 and as in the first figure2 for so the magnetick needle will remain in equilibrium4 ,but in an oblique position of the terrella1 as in an oblique sphere1 and in the second figure1 the needle dips obliquely at one end toward the near pole1 but does not rest on the pole1 nor is its dip ruled by the pole1 but by the body and mass of the whole2 for the #ahi dip in higher latitudes passes beyond the pole4 ,but in the third position of the terrella the needle is perpendicular2 because the pole of the stone is placed at the top1 and the needle tending straight toward the body reaches to the pole4 ,the cross in the preceding figures always turns toward the boreal pole of the terrella1 having been touched by the boreal pole of the terrella2 the cusp of the needle1 having been touched by the southern pole of the stone1 turns to the south4 ,thus one may see on a terrella the level1 oblique1 and perpendicular positions of a magnetick needle4 99 ,illustration 99 99 99 99 99 ,,chap4 ,,ii4 ,diagram of declinations of the magnetick needle1 when excited1 in the various portions of the sphere1 and horizons of the earth1 in which there is no variation of the declination4 ,illustration #aij ,as quator let ,a ,b be taken1 ,c the north pole1 ,d the south1 ,e ,g dipping-needles in the northern1 ,h ,f in the southern part of the earth or of a terrella4 ,in the diagram before us all the cusps have been touched by the true ,arctick pole of the terrella4 ,here we have the level position of the magnetick needle on the quator of the earth and the stone1 at ,a and ,b1 and its perpendicular position at ,c1 ,d1 the poles2 whilst at the places midway between1 at a distance of #de degrees1 the crosses of the needle dip toward the south1 but the cusps just as much toward the north4 ,of which thing the reason will become clear from the demonstrations that follow4 99 ,diagram of the rotation and declination of a terrella conforming to the globe of the earth1 for a latitude of #ej degrees north4 ,illustration ,a is the boreal pole of the earth or of a rather large terrella1 ,b the southern1 ,c a smaller terrella1 ,e the southern pole of the smaller terrella1 dipping in the northern regions#bcc4 ,the centre ,c is placed on the surface of the larger terrella1 because the smaller terrella shows some variation on account of the length of the axis2 inappreciable1 however1 on the earth4 ,just as a magnetick needle dips in a regional latitude of #ej degrees1 so also the axis of a stone 7of a spherical stone1 of course7 is depressed below the horizon1 and its natural austral pole falls1 and its boreal pole is raised on the #aia south toward the ,zenith4 ,in the same way also a circular disc of iron behaves1 which has been carefully touched at opposite parts on its circumference2 but the magnetical experiments are less clear on account of the feebler forces in round pieces of iron4 ,variety in the declinations of iron spikes at various latitudes of a terrella4 ,illustration ,the declination of a magnetick needle above a terrella is shown by means of several equal iron wires1 of the length of a barleycorn1 arranged along a meridian4 ,the wires on the quator are directed by the virtue of the stone toward the poles1 and lie down upon its body along the plane of its horizon4 ,the nearer they are brought to the poles1 the more they are raised up by their versatory nature4 ,at the poles themselves they point perpendicularly toward the very centre4 ,but iron spikes1 if they are of more than a due length1 are not raised straight up except on a vigorous stone4 99 99 99 99 99 ,,chap4 ,,iii4 99 ,an indicatory instrument1 showing by the virtue of a stone the degrees of declination from the horizon of each several latitude4 #aib ,illustration #aic ,description of the ,instrument1 and its use4 ,take a terrella of the best strong loadstone1 and homogeneous throughout1 not weakened by decay or by a flaw in any parts2 let it be of a fair size1 so that its diameter is six or seven digits2 and let it be made exactly spherical4 ,having found its poles according to the method already shown1 mark them with an iron tool2 then mark also the quinoctial circle4 ,afterwards in a thick squared block of wood1 one foot in size1 make a hemispherical hollow1 which shall hold half of the terrella1 and such that exactly one half of the stone shall project above the face of the block4 ,divide the limb close to this cavity 7a circle having been drawn round it for a meridian7 into #d quadrants1 and each of these into #ij degrees4 ,let the terminus of the quadrants on the limb be near the centre of a quadrant described on the block1 also divided into #ij degrees4 ,at that centre let a short1 slender versorium 7its other end being rather sharp and elongated like a pointer7 be placed in quilibrio on a suitable pin4 ,it is manifest that when the poles of the stone are at the starting points of the quadrants1 then the versorium lies straight1 as if in quilibrio1 over the terrella4 ,but if you move the terrella1 so that the pole on the left hand rises1 then the versorium rises on the meridian in proportion to the latitude1 and turns itself as a magnetick body2 and on the quadrant described on the flat surface of the wood1 the degree of its turning or of the declination is shown by the versorium4 ,the rim of the cavity represents a meridional circle1 to which corresponds some meridian circle of the terrella1 since the poles on both sides are within the circumference of the rim itself4 ,these things clearly always happen on the same plan on the earth itself when there is no variation2 but when there is variation1 either in the direction or in the declination 7a disturbance1 as it were1 in the true turning1 on account of causes to be explained later71 then there is some difference4 ,let the quadrant be near the limb1 or have its centre on the limb itself1 and let the versorium be very short1 so as not to touch the terrella1 because with a versorium that is longer or more remote1 there is some error2 for it has a motion truly proportionate to the terrella only on the surface of the terrella4 ,but if the quadrant1 being far distant from the terrella1 were moved within the orbe of virtue of the terrella toward the pole on some circle concentrick with the terrella1 then the versorium would indicate the degrees of declination on the quadrant1 in proportion to and symmetrically with that circle1 not with the terrella4 99 99 99 99 99 #aid ,,chap4 ,,iiii4 ,concerning the length of a versorium convenient for declination on a terrella4 ,declination being investigated on the earth itself by means of a declination instrument1 we may use either a short or a very long versorium1 if only the magnetick virtue of the stone that touches it is able to permeate through the whole of its middle and through all its length4 ,for the greatest length of a versorium has no moment or perceptible proportion to the earth's semi-diameter4 ,on a terrella1 however1 or in a plane near a meridian of a terrella1 a short versorium is desirable1 of the length1 say1 of a barleycorn2 for longer ones 7because they reach further7 dip and turn toward the body of the terrella suddenly and irregularly in the first degrees of declination4 ,illustration ,for example1 as soon as the long versorium is moved forward from the aequator ,a to ,c1 it catches on the stone with its cusp 7as if with a long extended wing71 when the cusp reaches to the parts about ,b1 which produce a greater rotation than at ,c4 ,and the extremities of longer wires also and rods turn irregularly1 just as iron wires and balls of iron and other orbicular loadstones are likewise turned about irregularly by a long non-orbicular loadstone4 ,just so magneticks or iron bodies on the surface of a terrella ought not to have too long an axis1 but a very short one2 so that they may make a declination on the terrella truly and naturally proportionate to that on the earth4 ,a long versorium also close to a terrella with difficulty stands steady in a horizontal direction on a right sphere1 and1 beginning to waver1 it dips immediately to one side1 especially the end that was touched1 or 7if both were touched7 the one which felt the stone last4 99 99 99 99 99 #aie ,,chap4 ,v4 ,that declination does not arise from the attraction of the loadstone1 but from a disposing and rotating influence4 ,in the universe of nature that marvellous provision of its ,maker should be noticed1 whereby the principal bodies are restrained within certain habitations and fenced in1 as it were 7nature controlling them74 ,for this reason the stars1 though they move and advance1 are not thrown into confusion4 ,magnetical rotations also arise from a disposing influence1 whether in greater and dominating quantity1 or in a smaller1 and compliant quantity1 even though it be very small4 ,for the work is not accomplished by attraction1 but by an incitation of each substance1 by a motion of agreement toward fixed bounds1 beyond which no advance is made4 ,for if the versorium dipped by reason of an attractive force1 then a terrella made from a very strong magnetick stone would cause the versorium to turn toward itself more than one made out of an average stone1 and a piece of iron touched with a vigorous loadstone would dip more4 ,this1 however1 never happens4 ,moreover1 an iron snout placed on a meridian in any latitude does not raise a spike more toward the perpendicular than the stone itself1 alone and unarmed2 although when thus equipped1 it plucks up and raises many greater weights#bcd4 ,but if a loadstone be sharper toward one pole1 toward the other blunter1 the sharp end or pole allures a magnetick needle more strongly1 the blunt1 thick end makes it rotate more strongly2 but an orbicular stone 99 makes it rotate strongly and truly1 in accordance with magnetick rules and its globular form4 ,a long stone1 on the other hand1 extended from pole to pole1 moves a versorium toward it irregularly2 for in this case the pole of the versorium always looks down on the pole itself4 ,similarly also1 if the loadstone have been made in the shape of a circle1 and its poles are on the circumference1 whilst the body of it is plane1 not globular1 if the plane be brought near a versorium1 the versorium does not move with the regular magnetick rotation1 as on a terrella2 but it turns looking always toward the pole of the loadstone1 which has its seat on the circumference of the plane4 ,moreover1 if the stone caused the versorium to rotate by attracting it1 then in the first degrees of latitude1 it would attract the end of a short versorium toward the body itself of the terrella2 yet it does not so attract it that they are brought into contact and unite2 but the versorium rotates just so far as nature demands1 as is clear from this example4 #aif ,illustration 99 ,for the cusp of a versorium placed in a low latitude does not touch the stone or unite with it1 but only inclines toward it4 ,moreover1 when a magnetick body rotates in dipping1 the pole of the versorium is not stayed or detained by the pole of the earth or terrella2 but it rotates regularly1 and does not stop at any point or bound1 nor point straight to the pole toward which the centre of the versorium is advancing1 unless on the pole itself1 and once only between the pole and the quator2 but it dips as it advances1 according as the change of position of its centre gives a reason for its inclination in accordance with rules magnetical4 ,the declination of a magnetick needle in water also1 as demonstrated in the following pages1 is a fixed quantity#bce2 the magnetick needle does not descend to the bottom of the vessel1 but remains steady in the middle1 rotated on its centre according to its due amount of declination4 ,this would not happen1 if the earth or its poles by their attraction drew down the end of the magnetick needle1 so that it dipped in this way4 99 99 99 99 99 ,,chap4 ,,vi4 ,on the proportion of declination to latitude#bcf1 and the cause of it4 ,concerning the making of an instrument for finding declination1 the causes and manner of declination1 and the different degrees of rotation in different places1 the inclination of the stone1 and concerning an instrument indicating by the influence of a stone the degree of declination from any horizon we have already spoken4 ,then we spoke about needles on the meridian of a stone1 and their rotation shown for various latitudes by their rise toward the perpendicular4 ,we must now1 however1 treat more fully of the causes of the degree of that inclination4 ,whilst a loadstone and a magnetick iron wire are moved along a meridian from the aequator toward the pole1 they rotate toward a round loadstone1 as also toward the earth with a circular movement4 ,on a right horizon 7just as also on the quinoctial of #aig the stone7 the axis of the iron1 which is its centre line1 is a line parallel to the axis of the earth4 ,when that axis reaches the pole1 which is the centre of the axis1 it stands in the same straight line with the axis of the earth4 ,the same end of the iron which at the quator looks south turns to the north4 ,for it is not a motion of centre to centre1 but a natural turning of a magnetick body to a magnetick body1 and of the axis of the body to the axis2 it is not in consequence of the attraction of the pole itself that the iron points to the earth's polar point4 ,under the quator the magnetick needle remains in quilibrio horizontally2 but toward the pole on either side1 in every latitude from the beginning of the first degree right up to the ninetieth1 it dips4 ,the magnetick needle does not1 however1 in proportion to any number of degrees or any arc of latitude fall below the horizon just that number of degrees or a similar arc1 but a very different one3 because this motion is not really a motion of declination1 but is in ,illustration reality a motion of rotation1 and it observes an arc of rotation according to the arc of latitude4 ,therefore a magnetick body ,a1 while it is advancing over the earth itself1 or a little earth or terrella1 from the quinoctial ,g toward the pole ,b1 rotates on its own centre1 and halfway on the progress of its centre#bcg from the quator to the pole ,b it is pointing toward the quator at ,f1 midway between the two poles4 ,much more quickly1 therefore1 must the versorium rotate than its centre advances1 in order that by rotating it may face straight toward the point ,f4 ,wherefore the motion of this rotation is rapid in the first degrees from the quator1 namely1 from ,a to ,l2 but more tardy in the later degrees from ,l to ,b1 when facing from the quator at ,f to ,c4 ,but if the declination were equal to the latitude 7i4e41 always just as many degrees from the horizon1 as the centre of the versorium has receded from the quator71 then the magnetick needle would be following some potency and peculiar virtue of the centre1 as if it #aih were a point operating by itself4 ,but it pays regard to the whole1 both its mass1 and its outer limits2 the forces of both uniting1 as well of the magnetick versorium as of the earth4 99 99 99 99 99 99 ,,chap4 ,,vii4 ,explanation of the diagram of the rotation of a magnetick needle4 ,illustration ,suppose ,a ,c ,d ,l to be the body of the earth or of a terrella1 its centre ,m1 quator ,a ,d1 ,axis ,c ,l1 ,a ,b the ,horizon1 which changes according to the place4 ,from the point ,f on a ,horizon distant from the quator ,a by the length of ,c ,m1 the semi-diameter of the earth or terrella1 an arc is described to ,h as the limit of the quadrants of declination2 for #aii all the quadrants of declination serving the parts from ,a to ,c begin from that arc1 and terminate at ,m1 the centre of the earth4 ,the semi-diameter of this arc is a chord drawn from the quator ,a to the pole ,c2 and a line produced along the horizon from ,a to ,b1 equal to that chord1 gives the beginning of the arc of the limits of arcs of rotation and revolution1 which is continued as far as ,g4 ,for just as a quadrant of a circle about the centre of the earth 7whose beginning is on the horizon1 at a distance from the quator equal to the earth's semi-diameter7 is the limit of all quadrants of declination drawn from each several horizon to the centre2 so a circle about the centre from ,b1 the beginning of the first arc of rotation1 to ,g is the limit of the arcs of rotation4 ,the arcs of rotation and revolution of the magnetick needle are intermediate between the arcs of rotation ,b ,l and ,g ,l4 ,the centre of the arc is the region itself or place in which the observation is being made2 the beginning of the arc is taken from the circle which is the limit of rotations1 and it stops at the opposite pole2 as1 for example1 from ,o to ,l1 in a latitude of #de degrees4 ,let any arc of rotation be divided into #ij equal parts from the limit of the arcs of rotation toward the pole2 for whatever is the degree of latitude of the place1 the part of the arc of rotation which the magnetick pole on or near the terrella or the earth faces in its rotation is to be numbered similarly to this4 ,the straight lines in the following larger diagram show this4 ,the magnetick rotation at the middle point in a latitude of #de degrees is directed toward the quator1 in which case also that arc is a quadrant of a circle from the limit to the pole2 but previous to this all the arcs of rotation are greater than a quadrant1 whilst after it they are smaller2 in the former the needle rotates more quickly1 but in the succeeding positions gradually more slowly4 ,for each several region there is a special arc of rotation1 in which the limit to which the needle rotates is according to the number of degrees of latitude of the place in question2 so that a straight line drawn from the place to the point on that arc marked with the number of degrees of latitude shows the magnetick direction1 and indicates the degree of declination at the intersection of the quadrant of declination which serves the given place4 ,take away the arc of the quadrant of declination drawn from the centre to the line of direction2 that which is left is the arc of declination below the horizon4 ,as1 for example1 in the rotation of the versorium ,n1 whose line respective proceeds to ,d1 from the quadrant of declination1 ,s ,m1 take away its arc ,r ,m2 that which is left is the arc of declination3 how much1 that is1 the needle dips in the latitude of #de degrees4 99 99 99 99 99 #bjj ,,chap4 ,,viii4 ,diagram of the rotation of a magnetick needle1 indicating magnetical declination in all latitudes1 and from the rotation and declination1 the latitude itself4 ,in the more elaborate diagram a circle of rotations and a circle of declinations are adjusted to the body of the earth or terrella1 with a first1 a last1 and a middle arc of rotation and declination4 ,now from each fifth division of the arc which limits all the arcs of rotation 7and which are understood#bch as divided into #ij equal parts7 arcs are drawn to the pole1 and from every fifth degree of the arc limiting the quadrants of declination1 quadrants are drawn to the centre2 and at the same time a spiral line is drawn1 indicating 7by the help of a movable quadrant7 the declination in every latitude4 ,straight lines showing the direction of the needle are drawn from those degrees which are marked on the meridian of the earth or a terrella to their proper arcs and the corresponding points on those arcs4 ,to ascertain the elevation of the pole or the latitude of a place anywhere in the world1 by means of the following diagram1 turned into a magnetick instrument1 without the help of the coelestial bodies1 sun1 planets1 or fixed stars1 in fog and darkness4 ,illustration ,we may see how far from unproductive magnetick philosophy is1 how agreeable1 how helpful1 how divine6 ,sailors when tossed about on the waves with continuous cloudy weather1 and unable by means of the coelestial luminaries to learn anything about the place or the region in which they are1 with a very slight effort and with a small instrument are comforted1 and learn the latitude of the place4 ,with a declination instrument the degree of declination of the magnetick needle below the horizon is observed2 that degree is noted on the inner arc of the quadrant1 and the quadrant is turned round about the centre of the instrument until that degree on the quadrant touches the spiral line2 then in the open space ,b at the centre of the quadrant the latitude of the region on #bja the circumference of the globe is discerned by means of the fiducial line ,a ,b4 ,let the diagram be fixed on a suitable flat board1 and let the centre of the corner ,a of the quadrant be fastened to the centre of it1 so that the quadrant may rotate on that centre4 ,but it must be understood that there is also in certain places a variation in the declination on account of causes already mentioned 7though not a large one71 which it will be an assistance also to allow for on a likely estimate2 and it will be especially helpful to observe this variation in various places1 as it seems to present greater difficulty than the variation in direction2 but it is easily learnt with a declination instrument1 when it dips more or less than the line in the diagram4 ,illustration ,to observe magnetick declination at sea4 ,set upon our variation instrument a declination instrument2 a wooden disc being placed between the round movable #bjb compass and the declination instrument3 but first remove the versorium1 lest the versorium should interfere with the dipping needle4 ,in this way 7though the sea be rough7 the compass box will remain upright at the level of the horizon4 ,the stand of the declination instrument must be directed by means of the small versorium at its base1 which is set to the point respective of the variation1 on the great circle of which 7commonly called the magnetick meridian71 the plane of the upright box is arranged2 thus the declinatorium 7by its versatory nature7 indicates the degree of declination4 ,in a declination instrument the magnetick needle1 which in a meridional position dips1 if turned along a parallel hangs perpendicularly4 ,in a proper position a magnetick needle1 while by its rotatory nature conformed to the earth1 dips to some certain degree below the horizon on an oblique sphere4 ,but when the plane of the instrument is moved out of the plane of the meridian1 the magnetick needle 7which tends toward the pole7 no longer remains at the degree of its own declination1 but inclines more toward the centre2 for the force of direction is stronger than that of declination1 and all power of declination is taken away1 if the plane of the instrument is on a parallel4 ,for then the magnetick needle1 because it cannot maintain its due position on account of the axis being placed transversely1 faces down perpendicularly to the earth2 and it remains only on its own meridian1 or on that which is commonly called the magnetick meridian4 99 99 99 99 99 ,,chap4 ,,ix4 ,demonstration of direction1 or of variation from the true direction1 at the same time with declination1 by means of only a single motion in water1 due to the disposing and rotating virtue4 ,illustration ,fix a slender iron wire of three digits length through 99 a round cork1 so that the cork may support the iron in water4 ,let this water be in a good-sized glass vase or bowl4 ,pare the round cork little by little with a very sharp knife 7so that it may remain round71 until it will stay motionless one or two digits below the face of the water2 and let the wire be evenly balanced4 #bjc #bci,rub one end of the wire thus prepared on the boreal end of a loadstone and the other on the southern part of the stone 7very skilfully1 so that the cork may not be moved ever so little from its place7 and again place it in the water2 then the wire will dip with a circular motion on its own centre below the plane of the horizon1 in proportion to the latitude of the region2 and1 even while dipping1 will also show the point of variation 7the true direction being perturbed74 ,let the loadstone 7that with which the iron is rubbed7 be a strong one1 such as is needed in all experiments on magnetick declination4 ,when the iron1 thus put into the water and prepared by means of the loadstone1 has settled in the dip1 the lower end remains at the point of variation on the arc of a great circle or magnetick meridian passing through the ,zenith or vertex1 and the point of variation on the horizon1 and the lowest point of the heavens1 which they call the ,nadir4 ,this fact is shown by placing a rather long magnetick versorium on one side a little way from the vase4 ,this is a demonstration of a more absolute conformity of a magnetick body with the earth's body as regards unity2 in it is made #bjd apparent1 in a natural manner1 the direction1 with its variation1 and the declination4 ,but it must be understood that as it is a curious and difficult experiment1 so it does not remain long in the middle of the water1 but sinks at length to the bottom1 when the cork has imbibed too much moisture4 99 99 99 99 99 ,,chap4 ,x4 ,on the variation of the declination4 ,direction has been spoken of previously1 and also 99 variation1 which is like a kind of dragging aside of the direction4 ,now in declination such irregular motion is also noticed1 when the needle dips beyond the proper point or when sometimes it does not reach its mark4 ,there is therefore a variation of declination1 being the arc of a magnetick meridian between the true and apparent declination4 ,for as1 on account of terrestrial elevations1 magnetick bodies are drawn away from the true meridian1 so also the needle dips 7its rotation being increased a little7 beyond its genuine position4 ,for as variation is a deviation of the direction1 so also1 owing to the same cause1 there is some error of declination1 though often very slight4 ,sometimes1 also1 when there is no variation of direction in the horizontal1 there may nevertheless be variation of the declination2 namely1 either when more vigorous parts of the earth crop out exactly meridionally1 i4e4 under the very meridian2 or when those parts are less powerful than nature in general requires2 or when the virtue is too much intensified in one part1 or weakened in another1 just as one may observe in the vast ocean4 ,and this discrepant nature and varying effect may be easily seen in certain parts of almost any round loadstone4 ,inquality of power is recognized in any part of a terrella by trial of the demonstration in chap4 #b of this book4 ,but the effect is clearly demonstrated by the instrument for showing declination in chap4 #c of this book4 99 99 99 99 99 #bje ,,chap4 ,,xi4 ,on the essential magnetick activity sphrically effused4 ,discourse hath often been held concerning the 99 poles of the earth and of the stone1 and concerning the quinoctial zone2 whilst lately we have been speaking about the declining of magneticks toward the earth and toward the terrella1 and the causes of it4 ,but while by various and complicated devices we have laboured long and hard to arrive at the cause of this declination1 we have by good fortune found out a new and admirable 7beyond the marvels of all virtues magnetical7 science of the orbes themselves4 ,for such is the power of magnetick globes1 that it is diffused and extended into orbes outside the body itself1 the form being carried beyond the limits of the corporeal substance2 and a mind diligently versed in this study of nature will find the definite causes of the motions and revolutions4 ,the same powers of a terrella exist also within the whole orbe of its power2 and these orbes at any distance from the body of the terrella have in themselves1 in proportion to their diameter and the magnitude of their circumference1 their own limits of influences1 or points wherein magnetick bodies rotate2 but they do not look toward the same part of the terrella or the same point at any distance from the same 7unless they be on the axis of the orbes and of the terrella72 but they always tend to those points of their own orbes1 which are distant by similar arcs from the common axis of the orbes4 ,as1 for example1 in the following diagram1 we show the body of a terrella1 with its poles and quator2 and also a versorium on three other concentrick orbes around the terrella at some distance from it4 ,in these orbes 7as in all those which we may imagine without end7 the magnetick body or versorium conforms to its own orbe in which it is located1 and to its diameter and poles and quator1 not to those of the terrella2 and it is by them and according to the magnitude of their orbes that the magnetick body is governed1 rotated1 and directed1 in any arc of that orbe1 both while the centre of the magnetick body stands still1 and also while it moves along4 ,and yet we do not mean that the magnetick forms and orbes exist in air or water or in any medium that is not magnetical2 as if the air or the water were susceptible of them1 or were induced by them2 for the forms are only effused and really subsist when magnetick substances are there2 whence a magnetick body is laid hold of within the forces and limits of the orbes2 and within the orbes magneticks #bjf dispose magneticks and incite them1 as if the orbes of virtue were solid and material loadstones4 ,for the magnetick force does not pass through the whole medium or really exist as in a continuous body2 so the orbes are magnetick1 and yet not real orbes nor existent by themselves4 ,diagram of motions in magnetick orbes4 ,illustration ,a ,b is the axis of the terrella and of the orbes1 ,c ,d the quator4 ,on all the orbes1 as on the terrella1 at the equator the versorium arranges itself along the plane of the horizon2 on the axis it everywhere looks perpendicularly toward the centre2 in the intermediate spaces ,e looks toward ,d2 and ,g looks toward ,h1 not toward ,f1 as the versorium ,l does on the surface of the terrella4 ,but as is the relation of ,l to ,f on the surface of the terella1 so is that of ,g to ,h on its orbe and of ,e to ,d on its orbe2 also all the rotations on #bjg the orbes toward the termini of the orbes are such as they are on the surface of the terrella1 or toward the termini of its surface4 ,but if in the more remote orbes this fails somewhat at times1 it happens on account of the sluggishness of the stone1 or on account of the feebler forces due to the too great distance of the orbes from the terrella4 ,demonstration4 ,set upon the instrumental diagram described farther back chap4 #c a plate or stiff circle of brass or tin1 on which may be described the magnetick orbes1 as in the diagram above2 and in the middle let a hole be made according to the size of the terrella1 so that the plate may lie evenly on the wood about the middle of the terrella on a meridional circle4 ,then let a small versorium of the length of a barley-corn be placed on any orbe2 upon which1 when it is moved to various positions on the same circle1 it will always pay regard to the dimensions of that orbe1 not to those of the stone2 as is shown in the diagram of the effused magnetick forms4 ,while some assign occult and hidden virtues of substances1 others a property of matter1 as the causes of the wonderful magnetical effects2 we have discovered the primary substantive form of globes1 not from a conjectural shadow of the truth of reasons variously controverted2 but we have laid hold of the true efficient cause1 as from many other demonstrations1 so also from this most certain diagram of magnetick forces effused by the form4 ,though this 7the form7 has not been brought under any of our senses1 and on that account is the less perceived by the intellect1 it now appears manifest and conspicuous even to the eyes through this essential activity which proceeds from it as light from a lamp4 ,and here it must be noted that a magnetick needle1 moved on the top of the earth or of a terrella or of the effused orbes1 makes two complete rotations in one circuit of its centre1 like some epicycle about its orbit4 99 99 99 99 99 #bjh ,,chap4 ,,xii4 ,magnetick force is animate1 or imitates life2 and in many things surpasses human life1 while this is bound up in the organick body4 ,a loadstone is a wonderful thing in very many experiments1 and like a living creature4 ,and one of its remarkable virtues is that which the ancients considered to be a living soul in the sky1 in the globes and in the stars1 in the sun and in the moon4 ,for they suspected that such various motions could not arise without a divine and animate nature1 immense bodies turned about in fixed times1 and wonderful powers infused into other bodies2 whereby the whole universe flourishes in most beautiful variety1 through this primary form of the globes themselves4 ,the ancients1 as ,thales1 ,heraclitus1 ,anaxagoras1 ,archelaus1 ,pythagoras1 ,empedocles1 ,parmenides1 ,plato1 and all the ,platonists1 and not only the older ,greeks1 but the ,egyptians and ,chaldans1 seek for some universal life in the universe1 and affirm that the whole universe is endowed with life4 ,aristotle affirms that not the whole universe is animate1 but only the sky2 but he maintains that its elements are inanimate2 whilst the stars themselves are animate4 ,we1 however1 find this life in globes only and in their homogenic parts2 and though it is not the same in all globes 7for it is much more eminent in the sun and in certain stars than in others of less nobility7 yet in very many the lives of the globes agree in their powers4 ,for each several homogenic part draws to its own globe in a similar manner1 and has an inclination to the common direction of the whole in the universe2 and the effused forms extend outward in all1 and are carried out into an orbe1 and have bounds of their own2 hence the order and regularity of the motions and rotations of all the planets1 and their courses1 not wandering away1 but fixed and determined4 ,wherefore ,aristotle concedes life to the sphres themselves and to the orbes of the heavens 7which he feigns71 because they are suitable and fitted for a circular motion and actions1 and are carried along in fixed and definite courses4 ,it is surely wonderful1 why the globe of the earth alone with its emanations is condemned by him and his followers and cast into exile 7as senseless and lifeless71 and driven out of all the perfection of the excellent universe4 ,it is treated as a small corpuscle in comparison with the whole1 and in the numerous concourse of many thousands it is obscure1 disregarded1 and unhonoured4 #bji ,with it also they connect the kindred elements1 in a like unhappiness1 wretched and neglected4 ,let this therefore be looked upon as a monstrosity in the ,aristotelian universe1 in which everything is perfect1 vigorous1 animated2 whilst the earth alone1 an unhappy portion1 is paltry1 imperfect1 dead1 inanimate1 and decadent4 ,but on the other hand ,hermes1 ,zoroaster1 ,orpheus1 recognize a universal life4 ,we1 however1 consider that the whole universe is animated1 and that all the globes1 all the stars1 and also the noble earth have been governed since the beginning by their own appointed souls and have the motives of self-conservation4 ,nor are there wanting1 either implanted in their homogenic nature or scattered through their homogenic substance1 organs suitable for organic activity1 although these are not fashioned of flesh and blood as animals1 or composed of regular limbs1 which are also hardly perceptible in certain plants and vegetables2 since regular limbs are not necessary for all life4 ,nor can any organs be discerned or imagined by us in any of the stars1 the sun1 or the planets1 which are specially operative in the universe2 yet they live and imbue with life the small particles in the prominences on the earth4 ,if there be anything of which men can boast1 it is in fact life1 intelligence2 for the other animals are ennobled by life2 ,god also 7by whose nod all things are ruled7 is a living soul4 ,who therefore will demand organs for the divine intelligences1 which rise superior to every combination of organs and are not restrained by materialized organs8 ,but in the several bodies of the stars the implanted force acts otherwise than in those divine existences which are supernaturally ordained2 and in the stars1 the sources of things1 otherwise than in animals2 in animals again otherwise than in plants4 ,miserable were the condition of the stars1 abject the lot of the earth1 if that wonderful dignity of life be denied to them1 which is conceded to worms1 ants1 moths1 plants1 and toadstools2 for thus worms1 moths1 grubs would be bodies more honoured and perfect in nature2 for without life no body is excellent1 valuable1 or distinguished4 ,but since living bodies arise and receive life from the earth and the sun1 and grass grows on the earth apart from any seeds thrown down 7as when soil is dug up from deep down in the earth1 and put on some very high place or on a very high tower1 in a sunny spot1 not so long after various grasses spring up unbidden7 it is not likely that they can produce what is not in them2 but they awaken life1 and therefore they are living4 ,therefore the bodies of the globes1 as important parts of the universe1 in order that they might be independent and that they might continue in that condition1 had a need for souls to be united with them1 without which there can be neither life1 nor primary activity1 nor motion1 nor coalition1 nor controlling power1 nor harmony1 nor endeavour1 nor sympathy2 and without which there would be no generation #baj of anything1 no alternations of the seasons1 no propagation2 but all things would be carried this way and that1 and the whole universe would fall into wretchedest ,chaos1 the earth in short would be vacant1 dead1 and useless4 ,but it is only on the superficies of the globes that the concourse of living and animated beings is clearly perceived1 in the great and pleasing variety of which the great master-workman is well pleased4 ,but those souls which are restrained within a kind of barrier and in prison cells1 as it were1 do not emit immaterial effused forms outside the limits of their bodies2 and bodies are not moved by them without labour and waste4 ,they are brought and carried away by a breath2 and when this has calmed down or been suppressed by some untoward influence1 their bodies lie like the dregs of the universe and as the refuse of the globes4 ,but the globes themselves remain and continue from year to year1 move1 and advance1 and complete their courses1 without waste or weariness4 ,the human soul uses reason1 sees many things1 inquires about many more2 but even the best instructed receives by his external senses 7as through a lattice7 light and the beginnings of knowledge4 ,hence come so many errors and follies1 by which our judgments and the actions of our lives are perverted2 so that few or none order their actions rightly and justly4 ,but the magnetick force of the earth and the formate life or living form of the globes1 without perception1 without error1 without injury from ills and diseases1 so present with us1 has an implanted activity1 vigorous through the whole material mass1 fixed1 constant1 directive1 executive1 governing1 consentient2 by which the generation and death of all things are carried on upon the surface4 ,for1 without that motion1 by which the daily revolution is performed1 all earthly things around us would ever remain savage and neglected1 and more than deserted and absolutely idle4 ,but those motions in the sources of nature are not caused by thinking1 by petty syllogisms1 and theories1 as human actions1 which are wavering1 imperfect1 and undecided2 but along with them reason1 instruction1 knowledge1 discrimination have their origin1 from which definite and determined actions arise1 from the very foundations that have been laid and the very beginnings of the universe2 which we1 on account of the infirmity of our minds1 cannot comprehend4 ,wherefore ,thales1 not without cause 7as ,aristotle relates in his book ,de ,anima71 held that the loadstone was animate1 being a part and a choice offspring of its animate mother the earth4 99 99 99 99 99 #baa ,illustration ,,book ,,sixth4 ,,chap4 ,i4 ,,on ,,the ,,globe ,,of ,,the ,,earth1 ,,the great magnet4 ,hitherto our subject hath been the loadstone and things magnetical3 how they conspire together1 and are acted upon1 how they conform themselves to the terrella and to the earth4 ,now must we consider separately the globe itself of the earth4 ,those experiments which have been proved by means of the terrella1 how magnetick things conform themselves to the terrella1 are all or at least the principal and most important of them1 displayed by means of the earth's ,body3 ,and to the earth things magnetical are in all respects associate4 ,first1 as in the terrella the quator1 meridians1 parallels1 axis1 poles are natural boundaries1 as numerous experiments make plain3 ,so also in the earth these boundaries are natural1 not mathematical only 7as all before us used to suppose74 ,these boundaries the same experiments display and establish in both cases alike1 in the earth no less than in the terrella4 ,just as on the periphery of a terrella a loadstone or a magnetick piece of iron is directed to its proper pole3 so on the earth's surface are there turnings-about1 peculiar1 manifest1 and constant on either side of the quator4 ,iron is indued with verticity by being extended toward a pole of the earth1 just as toward a pole of the terrella3 ,by its being placed down also1 and cooling toward the earth's pole after the pristine verticity has #bab been annulled by fire1 it acquires new verticity1 conformable to its position earthward4 ,iron rods also1 when placed some considerable time toward the poles1 acquire verticity merely by regarding the earth2 just as the same rods1 if placed toward the pole of a loadstone1 even without touching it1 receive polar virtue4 ,there is no magnetick body that in any way runs to the terrella which does not also wait upon the earth4 ,as a loadstone is stronger at one end on one side or other#bdj of its quator3 so is the same property displayed by a small terrella upon the surface of a larger terrella4 ,according to the variety and artistick skill in the rubbing of the magnetick iron upon the terrella1 so do the magnetick things perform their function more efficiently or more feebly4 ,in motions toward the earth's body1 as toward the terrella a variation is displayed due to the unlikeness1 inequality1 and imperfection of its eminences3 ,so every variation of the versorium or mariners' compass1 everywhere by land or by sea1 which thing has so sorely disturbed men's minds1 is discerned and recognized as due to the same causes4 ,the magnetick dip 7which is the wonderful turning of magnetick things to the body of the terrella7 in systematick course1 is seen in clearer light to be the same thing upon the earth4 ,and that single experiment1 by a wonderful indication1 as with a finger1 proclaims the grand magnetick nature of the earth to be innate and diffused through all her inward parts4 ,a magnetick vigour exists then in the earth just as in the terrella1 which is a part of the earth1 homogenic in nature with it1 but rounded by ,art1 so as to correspond with the earth's globous shape and in order that in the chief experiments it might accord with the globe of the earth4 99 99 99 99 99 ,,chap4 ,,ii4 ,the ,magnetick axis of the ,earth persists invariable4 ,as in the very first beginnings of the moving world1 the earth's magnetick axis passed through the midst of the earth3 so now it tends through the centre to the same points of the superficies2 the circle and plane of the quinoctial line also persisting4 ,for not without the vastest overthrow of the terrene mass can these natural boundaries be changed1 as it is easy to gather from magnetick demonstrations4 ,wherfore the opinion of ,dominicus ,maria of ,ferrara1 a most talented man1 who was the teacher of ,nicolas ,copernicus1 must be cancelled2 a view #bac which1 according to certain observations of his own1 is as follows4#bda ,i1 he says1 in former years while studying ,ptolemy's ,geographia discovered that the elevations of the ,north pole placed by him in the several regions1 fall short of what they are in our time by one degree and ten minutes3 which divergence can by no means be ascribed to an error of the tables3 ,for it is not credible that the whole series in the book is equally wrong in the figures of the tables3 ,hence it is necessary to allow that the ,north pole has been tilted toward the vertical point4 ,accordingly a lengthy observation has already begun to disclose to us things hidden from our forefathers2 not indeed through any sloth of theirs1 but because they lacked the prolonged observation of their predecessors3 ,for before ,ptolemy very few places were observed with regard to the elevations of the pole1 as he himself also bears witness at the beginning of his ,cosmographia3 7,for1 says he7 ,hipparchus alone hath handed down to us the latitudes of a few places1 but a good many have noted those of distances2 especially those which lie toward sunrise or sunset were received by some general tradition1 not owing to any sloth on the part of authors themselves1 but to the fact that there was as yet no practice of more exact mathematicks4 ',tis accordingly no wonder1 if our predecessors did not mark this very slow motion3 ,for in one thousand and seventy years it shows itself to be displaced scarce one degree toward the apex of dwellers upon the earth4 ,the strait of ,gibraltar shows this1 where in ,ptolemy's time the ,north pole appears elevated #cf degrees and a quarter from the ,horizon3 whereas now it is #cg and two-fifths4 ,the like divergence is also shown at ,leucopetra in ,calabria1 and at particular spots in ,italy1 namely those which have not changed from ,ptolemy's time to our own4 ,and so by reason of this movement1 places now inhabited will some day become deserted1 while those regions which are now parched at the torrid zone will1 though long hence1 be reduced to our temper of climate4 ,thus1 as in a course of three hundred and ninety five thousands of years1 is that very slow movement completed4 ,thus1 according to these observations of ,dominicus ,maria1 the ,north pole is at a higher elevation1 and the latitudes of places are greater than formerly2 whence he argues a change of latitudes4 ,now1 however1 ,stadius1 taking just the contrary view1 proves by observations that the latitudes have decreased4 ,for he says3 ,the latitude of ,rome in ,ptolemy's ,geographia is #da degrees #b_/c3 and that you may not suppose any error of reckoning to have crept in on the part of ,ptolemy1 on the day of the quinox in the city of ,rome1 the ninth part of the gnomon of the sun-dial is lacking in shadow1 as ,pliny relates and ,vitruvius witnesseth in his ninth book4 ,but the observation of moderns 7according to ,erasmus ,rheinholdus7 gives the same in our time as #da degrees with a sixth3 so that you are in doubt as to half of one degree in #bad the centre of the world1 whether you show it to have decreased by the earth's obliquity of motion4 ,one may see then how from inexact observations men rashly conceive new and contradictory opinions and imagine absurd motions of the mechanism of the earth4 ,for since ,ptolemy only received certain latitudes from ,hipparchus1 and did not in very many places make the observations himself2 it is likely that he himself1 knowing the position of the places1 formed his estimate of the latitude of cities from probable conjecture only1 and then placed it in the maps4 ,thus one may see1 in the case of our own ,britain1 that the latitudes of cities are wrong by two or three degrees1 as experience teaches4 ,wherefore all the less should we from those mistakes infer a new motion1 or let the noble magnetick nature of the earth be debased for an opinion so lightly conceived4 ,moreover1 those mistakes crept the more readily into geography1 from the fact that the magnetick virtue was utterly unknown to those geographers4 ,besides1 observations of latitudes cannot be made sufficiently exactly1 except by experts1 using also finer instruments1 and taking into account the refraction of the lights4 99 99 99 99 99 ,,chap4 ,,iii4 ,on the magnetick diurnal revolution of the ,earth's globe1 as a probable assertion against the time-honoured opinion of a ,primum ,mobile4 ,among the ancients ,heraclides of ,pontus and ,ecphantus1 afterwards the ,pythagoreans1 as ,nicetas of ,syracuse and ,aristarchus of ,samos1 and some others 7as it seems71 used to think that the earth moves1 and that the stars set by the interposition of the earth and rose by her retirement4 ,in fact they set the earth moving and make her revolve around her axis from west to east1 like a wheel turning on its axle4 ,philolaus the ,pythagorean#bdb would have the earth to be one of the stars1 and believed that it turned in an oblique circle around fire1 just as the sun and moon have their own courses4 ,he was a distinguished mathematician1 and a most able investigator of nature4 ,but after ,philosophy became a subject treated of by very many and was popularized1 theories adapted to the vulgar intelligence or based on sophistical subtility occupied the minds of most men1 and prevailed like a torrent1 the multitude consenting4 ,thereupon many valuable discoveries of the ancients were rejected1 and were dismissed to perish in banishment2 or at least by not being further cultivated and developed became obsolete4 ,so that ,copernicus#bdc 7among later discoverers1 a man most deserving of literary honour7 is the first who attempted to illustrate the ,greek3 phainomena of #bae moving bodies by new hypotheses3 and these demonstrations of reasons others either follow or observe in order that they may more surely discover the phnomenal harmony of the movements2 being men of the highest attainments in every kind of learning4 ,thus supposed and imaginary orbs of ,ptolemy and others for finding the times and periods of the motions are not necessarily to be admitted to the physical inquiries of philosophers4 ,it is then an ancient opinion and one that has come down from old times1 but is now augmented by important considerations that the whole earth rotates with a daily revolution in the space of #bd hours4 ,well then1 since we see the ,sun and ,moon and other planets and the glory of all the stars approach and retire within the space of one natural day1 either the ,earth herself must needs be set in motion with a diurnal movement from ,west to ,east1 or the whole heaven and the rest of nature from ,east to ,west4 ,but1 in the first place1 it is not likely that the highest heaven and all those visible splendours of the fixed stars are impelled along that most rapid and useless course4 ,besides1 who is the ,master who has ever made out that the stars which we call fixed are in one and the same sphere1 or has established by reasoning that there are any real and1 as it were1 adamantine sphres8 ,no one has ever proved this as a fact2 nor is there a doubt but that just as the planets are at unequal distances from the earth1 #bddso are those vast and multitudinous lights separated from the ,earth by varying and very remote altitudes2 they are not set in any sphrick frame or firmament 7as is feigned71 nor in any vaulted body3 accordingly the intervals of some are from their unfathomable distance matter of opinion rather than of verification2 others do much exceed them and are very far remote1 and these being located in the heaven at varying distances1 either in the thinnest ther or in that most subtile quintessence1 or in the void3 how are they to remain in their position during such a mighty swirl of the vast orbe of such uncertain substance4 ,there have been observed by astronomers #ajbb stars2 besides these1 numberless others are visible1 some indeed faint to our senses1 in the case of others our sense is dim and they are hardly perceived and only by exceptionally keen eyes1 and there is no one gifted with excellent sight who does not when the ,moon is dark and the air at its rarest1 discern numbers and numbers dim and wavering with minute lights on account of the great distance3 hence it is credible both that these are many and that they are never all included in any range of vision4 ,how immeasurable then must be the space which stretches to those remotest of fixed stars6 ,how vast and immense the depth of that imaginary sphere6 ,how far removed from the ,earth must the most widely separated stars be and at a distance transcending all sight1 all skill and thought6 ,how monstrous then such a motion #baf would be6 ,it is evident then that all the heavenly bodies set as if in destined places are there formed into sphres1 that they tend to their own centres1 and that round them there is a confluence of all their parts4 ,and if they have motion1 that motion will rather be that of each round its own centre1 as that of the ,earth is2 or a forward movement of the centre in an orbit1 as that of the ,moon3 there would not be circular motion in the case of a too numerous and scattered flock4 ,of these stars some situate near the quator would seem to be borne around at a very rapid rate1 others nearer the pole to have a somewhat gentler motion1 others1 apparently motionless1 to have a slight rotation4 ,yet no differences in point of light1 mass or colours are apparent to us3 for they are as brilliant1 clear1 glittering and duskish toward the poles1 as they are near the quator and the ,zodiack3 those which remain set in those positions do not hang1 and are neither fixed1 nor bound to anything of the nature of a vault4 ,all the more insane were the circumvolution of that fictitious ,primum ,mobile1 which is higher1 deeper1 and still more immeasurable4 ,moreover1 this inconceivable ,primum ,mobile ought to be material and of enormous depth1 far surpassing all inferior nature in size3 for nohow else could it conduct from ,east to ,west so many and such vast bodies of stars1 and the universe even down to the ,earth3 and it requires us to accept in the government of the stars a universal power and a despotism perpetual and intensely irksome4 ,that ,primum ,mobile bears no visible body1 is nohow recognizable1 is a fiction believed in by those people1 accepted by the weak-minded folk1 who wonder more at our terrestrial mass than at bodies so vast1 so inconceivable1 and so far separated from us4 ,but there can be no movement of infinity and of an infinite body1 and therefore no diurnal revolution of that vastest ,primum ,mobile4 ,the ,moon being neighbour to the ,earth revolves in #bg days2 ,mercury and ,venus have their own moderately slow motions2 ,mars finishes a period in two years1 ,jupiter in twelve years1 ,saturn in thirty4 ,and those also who ascribe a motion to the fixed stars make out that it is completed in #cf1jjj years1 according to ,ptolemy1 in #be1haf years1 according to ,copernicus' observations2 so that the motion and the completion of the journey always become slower in the case of the greater circles4 ,and would there then be a diurnal motion of that ,primum ,mobile which is so great and beyond them all immense and profound8 ',tis indeed a superstition and in the view of philosophy a fable now only to be believed by idiots1 deserving more than ridicule from the learned3 and yet in former ages1 that motion1 under the pressure of an importunate mob of philosophizers1 was actually accepted as a basis of computations and of motions1 by mathematicians4 ,the motions of the bodies 7namely planets7 seem to take place eastward and following the order of the signs4 #bag ,the common run of mathematicians and philosophers also suppose that the fixed stars in the same manner advance with a very slow motion3 and from ignorance of the truth they are forced to join to them a ninth sphre4 ,whereas now this first and unthinkable ,primum ,mobile1 a fiction not comprehended by any judgment1 not evidenced by any visible constellation1 but devised of imagination only and mathematical hypothesis1 unfortunately accepted and believed by philosophers1 extended into the heaven and beyond all the stars1 must needs with a contrary impulse turn about from ,east to ,west1 in opposition to the inclination of all the rest of the ,universe4 ,whatsoever in nature is moved naturally1 the same is set in motion both by its own forces and by the consentient compact of other bodies4 ,such is the motion of parts to their whole1 of all interdependent sphres and stars in the universe3 such is the circular impulse in the bodies of the planets1 when they affect and incite one another's courses4 ,but with regard to the ,primum ,mobile and its contrary and exceeding rapid movement1 what are the bodies which incite it or propel it8 ,what is the nature that conspires with it8 ,or what is that mad force beyond the ,primum ,mobile8 ,since it is in bodies themselves that acting force resides1 not in spaces or intervals4 ,but he who thinks that those bodies are at leisure and keeping holiday1 while all the virtue of the universe appertains to the very orbits and sphres1 is on this point not less mad than he who1 in some one else's house1 thinks that the walls and floors and roof rule the family rather than the wife and thoughtful paterfamilias4 ,therefore not by the firmament are they borne along1 or are moved1 or have their position2 much less are those confused crowds of stars whirled around by the ,primum ,mobile1 nor are they torn away and huddled along by a contrary and extremely rapid movement4 ,ptolemy of ,alexandria seems to be too timid and weak-minded in dreading the dissolution of this nether world1 were the ,earth to be moved round in a circle4 ,why does he not fear the ruin of the ,universe1 dissolution1 confusion1 conflagration1 and infinite disasters celestial and super-celestial1 from a motion transcending all thoughts1 dreams1 fables1 and poetic licences1 insurmountable1 ineffable1 and inconceivable8 ,wherefore we are carried along by a diurnal rotation of the earth 7a motion for sure more congruous71 and as a boat moves above the waters1 so do we turn about with the earth1 and yet seem to ourselves to be stationary1 and at rest4 ,great and incredible it seems to some philosophers1 by reason of inveterate prejudice1 that the ,earth's vast body should be swirled wholly round in the space of #bd hours4 ,but it would be more incredible that the ,moon should travel through her orbit1 or complete an entire course in a space of #bd hours2 more so the ,sun or ,mars2 still more ,jupiter and ,saturn2 more than marvellous would be the velocity in the case of the #bah fixed stars and the firmament2 what in the world they would have to wonder at in the case of their ninth sphere1 let them imagine as they like4 ,but to feign a ,primum ,mobile and to attribute to the thing thus feigned a motion to be completed in the space of #bd hours1 and not to allow this motion to the ,earth in the same interval of time1 is absurd4 ,for a great circle of the ,earth is to the ambit of the ,primum ,mobile less than a furlong to the whole ,earth4 ,if the diurnal rotation of the ,earth seem headlong1 and not admissible in nature by reason of its rapidity1 worse than insane will be the movement of the ,primum ,mobile both for itself and the whole universe1 agreeing as it does with no other motion in any proportion or likeness4 ,it seems to ,ptolemy and the ,peripateticks that nature must be disordered1 and the framework and structure of this globe of ours be dissolved1 by reason of so swift a terrestrial revolution4 ,the ,earth's diameter is #agah ,german miles2 the greatest elongation of the new ,moon is #fe1 the least is #ee semi-diameters of the ,earth3 the greatest altitude of the half moon is #fh1 the least #eb3 yet it is probable that its sphre is still larger and deeper4 ,the sun in its greatest eccentricity has a distance of #aadb semi-diameters of the ,earth2 ,mars1 ,jupiter1 ,saturn1 being slower in motion1 are so proportionately further remote from the ,earth4 ,the distances of the firmament and of the fixed stars seem to the best mathematicians inconceivable4 ,leaving out the ninth sphre1 if the convexity of the ,primum ,mobile be duly estimated in proportion to the rest of the sphres1 the vault of the ,primum ,mobile must in one hour run through as much space as is comprised in #cjjj great circles of the ,earth1 for in the vault of the firmament it would complete more than #ahjj2 but what iron solidity can be imagined so firm and tough as not to be disrupted and shattered to fragments by a fury so great and a velocity so ineffable4 ,the ,chaldans indeed would have it that the heaven consists of light4 ,in light1 however1 there is no so-great firmness1 neither is there in ,plotinus' fiery firmament1 nor in the fluid or aqueous or supremely rare and transparent heaven of the divine ,moses1 which does not cut off from our sight the lights of the stars4 ,we must accordingly reject the so deep-set error about this so mad and furious a celestial velocity1 and the forced retardation of the rest of the heavens4 ,let theologians discard and wipe out with sponges those old women's tales of so rapid a spinning round of the heavens borrowed from certain inconsiderate philosophers4 ,the sun is not propelled by the sphre of ,mars 7if a sphre there be7 and by his motion1 nor ,mars by ,jupiter1 nor ,jupiter by ,saturn4 ,the sphre1 too1 of the fixed stars1 seems well enough regulated except so far as motions which are in the ,earth are ascribed to the heavens1 and bring about a certain change of phnomena4 ,the superiors do not exercise a despotism over the inferiors2 for the heaven of #bai philosophers1 as of theologians1 must be gentle1 happy1 and tranquil1 and not at all subject to changes3 nor shall the force1 fury1 swiftness1 and hurry of a ,primum ,mobile have dominion over it4 ,that fury descends through all the celestial sphres1 and celestial bodies1 invades the elements of our philosophers1 sweeps fire along1 rolls along the air1 or at least draws the chief part of it1 conducts the universal ther1 and turns about fiery impressions 7as if it were a solid and firm body1 when in fact it is a most refined essence1 neither resisting nor drawing71 leads captive the superior4 ,o marvellous constancy of the terrestrial globe1 the only one unconquered2 and yet one that is holden fast1 or stationary1 in its place by no bonds1 no heaviness1 by no contiguity with a grosser or firmer body1 by no weights4 ,the substance of the terrestrial globe withstands and sets itself against universal nature4 ,aristotle feigns for himself a system of philosophy founded on motions simple and compound1 that the heavens revolve in a simple circle1 its elements moving with a right motion1 the parts of the earth seeking the earth in straight lines1 falling on its surface at right angles1 and tending together toward its centre1 always1 however1 at rest therein2 accordingly also the whole ,earth remains immovable in its place1 united and compacted together by its own weight4 ,that cohsion of parts and aggregation of matter exist in the ,sun1 in the ,moon1 in the planets1 in the fixed stars1 in fine in all those round bodies whose parts cohre together and tend each to their own centres2 otherwise the heaven would fall1 and that sublime ordering would be lost3 yet these coelestial bodies have a circular motion4 ,whence the ,earth too may equally have her own motion3 and this motion is not 7as some deem it7 unsuitable for the assembling or adverse to the generation of things4 ,for since it is innate in the terrestrial globe1 and natural to it2 and since there is nothing external that can shock it1 or hinder it by adverse motions1 it goes round without any ill or danger1 it advances without being forced1 there is nothing that resists1 nothing that by retiring gives way1 but all is open4 ,for while it revolves in a space void of bodies1 or in the incorporeal ther1 all the air1 the exhalations of land and water1 the clouds and pendent meteors1 are impelled along with the globe circularly3 that which is above the exhalations is void of bodies3 the finest bodies and those which are least cohrent almost void are not impeded1 are not dissolved1 while passing through it4 ,wherefore also the whole terrestrial globe1 with all its adjuncts1 moves bodily along1 calmly1 meeting no resistance4 ,wherefore empty and superstitious is the fear that some weak minds have of a shock of bodies 7like ,lucius ,lactantius1 who1 in the fashion of the unlettered rabble and of the most unreasonable men scoffs at an ,antipodes and at the sphrick ordering of the ,earth all round74 ,so for these reasons1 not only probable but manifest1 does the diurnal rotation of the earth seem1 #bbj since nature always acts through a few rather than through many2 and it is more agreeable to reason that the ,earth's one small body should make a diurnal rotation1 than that the whole universe should be whirled around4 ,i pass over the reasons of the ,earth's remaining motions1 for at present the only question is concerning its diurnal movement1 according to which it moves round with respect to the ,sun1 and creates a natural day 7which we call a nycthemeron#bde74 ,and indeed ,nature may be thought to have granted a motion very suitable to the ,earth's shape1 which 7being sphrical7 is revolved about the poles assigned it by ,nature much more easily and fittingly than that the whole universe1 whose limit is unknown and unknowable1 should be whirled round2 and than there could be imagined an orbit of the ,primum ,mobile1 a thing not accepted by the ancients1 which ,aristotle even did not devise or accept as in any shape or form existing beyond the sphre of the fixed stars2 which finally the sacred scriptures do not recognize any more than they do the revolution of the firmament4 99 99 99 99 99 ,,chap4 ,,iiii4 ,that the ,earth moves circularly4 ,if then the philosophers of the common sort1 with an unspeakable absurdity1 imagine the whole heaven and the vast extent of the universe to rotate in a whirl1 it yet remains that the earth performs a diurnal change4 ,for in no third way can the apparent revolutions be explained4 ,this day1 then1 which is called natural1 is a revolution of some meridian of the ,earth from ,sun to ,sun4 ,it revolves indeed in an entire course1 from a fixed star round to that star again4 ,those bodies which in nature are moved with a circular1 quable and constant motion1 are furnished1 in their parts1 with various boundaries4 ,but the ,earth is not a ,chaos nor disordered mass2 but by reason of its astral virtue1 it has boundaries which subserve the circular motion1 poles not mathematical1 an quator not devised by imagination1 meridians also and parallels2 all of which we find permanent1 certain and natural in the ,earth3 which by numerous experiments the whole magnetick philosophy sets forth4 ,for in the earth there are poles set in fixed bounds1 and at them the verticity mounts up on either side from the plane of the ,earth's quator1 with forces which are mightier and prpotent from the common action of the whole2 and with these poles the diurnal revolution is in agreement4 ,but in no turnings-about of bodies1 in none of the motions of the planets are there to be recognized1 beheld1 or assured to us by any reasoning any sensible or natural poles in the firmament1 or in any ,primum #bba ,mobile2 but those are the conception of an unsettled imagination4 ,wherefore we1 following an evident1 sensible and tested cause1 do know that the earth moves on its own poles1 which are apparent to us by many magnetick demonstrations4 ,for not only on the ground of its constancy1 and its sure and permanent position1 is the ,earth endowed with poles and verticity3 for it might be directed toward other parts of the universe1 toward ,east or ,west or some other region4 ,by the wondrous wisdom then of the ,builder forces1 primarily animate1 have been implanted in the ,earth1 that with determinate constancy the ,earth may take its direction1 and the poles have been placed truly opposite#bdf1 that about them as the termini1 as it were1 of some axis1 the motion of diurnal turning might be performed4 ,but the constancy of the poles is regulated by the primary soul4 ,wherefore1 for the ,earth's good1 the collimations of her verticities do not continually regard a definite point of the firmament and of the visible heaven4 ,for changes of the quinoxes take place from a certain deflection of the ,earth's axis2 yet in regard to that deflection1 the ,earth has a constancy of motion ,illustration derived from her own forces4 ,the ,earth1 that she may turn herself about in a diurnal revolution1 leans on her poles4 ,for since at ,a and ,b there is constant verticity1 and the axis is straight2 at ,c and ,d 7the quinoctial line7 the parts are free1 the whole forces on either side being spread out from the plane of the quator toward the poles1 in ther which is free from renitency1 or else in a void2 and ,a and ,b remaining constant1 ,c revolves toward ,d both from innate conformity and aptitude1 and for necessary good1 and the avoidance of evil2 but being chiefly moved forward by the diffusion of the solar orbes of virtues1 and by their lights4 ,and 'tis borne around1 not upon a new and strange course1 but 7with the #bbb tendency common to the rest of the planets7 it tends from ,west to ,east4 ,for all planets have a like motion ,eastward according to the succession of the signs1 whether ,mercury and ,venus revolve beneath the ,sun1 or around the ,sun4 ,that the ,earth is capable of and fitted for moving circularly its parts show1 which when separated from the whole are not only borne along with the ,illustration straight movement taught by the ,peripateticks1 but rotate also4 ,a loadstone fixed in a wooden vessel is placed on water so as to swim freely1 turn itself1 and float about4 ,if the pole ,b of the loadstone be set contrary to nature toward the ,south1 ,f1 the ,terrella is turned about its own centre with a circular motion in the plane of the ,horizon1 toward the ,north1 ,e1 where it rests1 not at ,c or ,d4 ,so does a small stone if only of four ounces2 it has the same motion also and just as quick1 if it were a strong magnet of one hundred pounds4 ,the largest magnetical mountain will possess the same turning-power also1 if launched in a wide river or deep sea3 and yet a magnetick body is much more hindered by water than the whole ,earth is by the ther4 ,the whole ,earth would do the same1 if the ,boreal pole were to be diverted from its true direction2 for the ,boreal pole would run back with the circular motion of the whole around the centre toward the ,cynosure4 ,but this motion by which the parts naturally settle themselves in their own #bbc resting-places is no other than circular4 ,the whole ,earth regards the ,cynosure with her pole according to a steadfast law of her nature3 and thus each true part of it seeks a like resting-place in the world1 and is moved circularly toward that position4 ,the natural movements of the whole and of the parts are alike3 wherefore when the parts are moved in a circle1 the whole also has the potency of ,illustration moving circularly4 ,a sphrical loadstone placed in a vessel on water moves circularly around its centre 7as is manifest7 in the plane of the ,horizon1 into conformity#bdg with the earth4 ,so also it would move in any other great circle if it could be free2 as in the declination instrument1 a circular motion takes place in the meridian 7if there were no variation71 or1 if there should be some variation1 in a great circle drawn from the ,zenith through the point of variation on the horizon4 ,and that circular motion of the magnet to its own just and natural position shows that the whole ,earth is fitted and adapted1 and is sufficiently furnished with peculiar forces for diurnal circular motion4 ,i omit what ,peter ,peregrinus#bdh constantly affirms1 that a terrella suspended above its poles on a meridian moves circularly1 making an entire revolution in #bd hours3 which1 however1 it has not happened to ourselves as yet to see2 and we even doubt this motion on account of the weight of the stone itself1 as well as because the whole ,earth1 as she is moved of herself1 so also is she propelled by other stars3 and this does not happen in proportion 7as it does in the terrella7 #bbd in every part4 ,the ,earth is moved by her own primary form and natural desire1 for the conservation1 perfection1 and ordering of its parts1 toward things more excellent3 and this is more likely than that the fixed stars1 those luminous globes1 as well as the ,wanderers1 and the most glorious and divine ,sun1 which are in no way aided by the ,earth1 or renewed1 or urged by any virtue therein1 should circulate aimlessly around the ,earth1 and that the whole heavenly host should repeat around the ,earth courses never ending and of no profit whatever to the stars4 ,the ,earth1 then1 which by some great necessity1 even by a virtue innate1 evident1 and conspicuous1 is turned circularly about the ,sun1 revolves2 and by this motion it rejoices in the solar virtues and influences1 and is strengthened by its own sure verticity1 that it should not rovingly revolve over every region of the heavens4 ,the ,sun 7the chief agent in nature7 as he forwards the courses of the ,wanderers1 so does he prompt this turning about of the ,earth by the diffusion of the virtues of his orbes1 and of light4 ,and if the ,earth were not made to spin with a diurnal revolution1 the ,sun would ever hang over some determinate part with constant beams1 and by long tarriance would scorch it1 and pulverize it1 and dissipate it1 and the ,earth would sustain the deepest wounds2 and nothing good would issue forth2 it would not vegetate1 it would not allow life to animals1 and mankind would perish4 ,in other parts1 all things would verily be frightful and stark with extreme cold2 whence all high places would be very rough1 unfruitful1 inaccessible1 covered with a pall of perpetual shades and eternal night4 ,since the ,earth herself would not choose to endure this so miserable and horrid appearance on both her faces1 she1 by her magnetick astral genius1 revolves in an orbit1 that by a perpetual change of light there may be a perpetual alternation of things1 heat and cold1 risings and settings1 day and night1 morn and eve1 noon and midnight4 ,thus the ,earth seeks and re-seeks the ,sun1 turns away from him and pursues him1 by her own wondrous magnetick virtue4 ,besides1 it is not only from the ,sun that evil would impend1 if the ,earth were to stay still and be deprived of solar benefit2 but from the ,moon also serious dangers would threaten4 ,for we see how the ocean rises and swells beneath certain known positions of the ,moon3 ,and if there were not through the daily rotation of ,earth a speedy transit of the ,moon1 the flowing sea would be driven above its level into certain regions1 and many shores would be overwhelmed with huge waves4 ,in order then that ,earth may not perish in various ways1 and be brought to confusion1 she turns herself about by magnetick and primary virtue3 and the like motions exist also in the rest of the ,wanderers1 urged specially by the movement and light of other bodies4 ,for the ,moon also turns herself about in a monthly course1 to receive in succession the ,sun's beams in which she1 like the ,earth1 #bbe rejoices1 and is refreshed3 nor could she endure them for ever on one particular side without great harm and sure destruction4 ,thus each one of the moving globes is for its own safety borne in an orbit either in some wider circle1 or only by a rotation of its body1 or by both together4 ,but it is ridiculous for a man a philosopher to suppose that all the fixed stars and the planets and the still higher heavens revolve to no other purpose1 save the advantage of the ,earth4 ,it is the ,earth1 then1 that revolves1 not the whole heaven1 and this motion gives opportunity for the growth and decrease of things1 and for the generating of things animate1 and awakens internal heat for the bringing of them to birth4 ,whence matter is quickened for receiving forms2 and from the primary rotation of the ,earth natural bodies have their primary impetus and original activity4 ,the motion then of the whole ,earth is primary1 astral1 circular1 around its own poles1 whose verticity arises on both sides from the plane of the quator1 and whose vigour is infused into opposite termini1 in order that the ,earth may be moved by a sure rotation for its good1 the ,sun also and the stars helping its motion4 ,but the simple straight motion downwards of the ,peripateticks is a motion of weight1 a motion of the aggregation of disjoined parts1 in the ratio of their matter1 along straight lines toward the body of the ,earth3 which lines tend the shortest way toward the centre4 ,the motions of disjoined magnetical parts of the ,earth1 besides the motion of aggregation1 are coition1 revolution1 and the direction of the parts to the whole1 for harmony of form1 and concordancy4 99 99 99 99 99 ,,chap4 ,v4 ,arguments of those denying the ,earth's motion1 and their confutation4 ,now it will not be superfluous to weigh well the arguments of those who say the ,earth does not move2 that we may be better able to satisfy the crowd of philosophizers who assert that this constancy and stability of the ,earth is confirmed by the most convincing arguments4 ,aristotle does not allow that the ,earth moves circularly1 on the ground that each several part of it would be affected by this particular motion2 that whereas now all the separate parts of the ,earth are borne toward the middle in straight lines1 that circular motion would be violent1 and strange to nature1 and not enduring4 ,but it has been before proved that all actual portions of the ,earth move in a circle1 and that all magnetick bodies 7fitly disposed7 are borne around in an orbe4 ,they are borne1 however1 toward the centre of the ,earth in a #bbf straight line 7if the way be open7 by a motion of aggregation as though to their own origin3 they move by various motions agreeably to the conformation of the whole3 a terrella is moved circularly by its innate forces4 ,besides 7says he71 all things which are borne in an orbe1 afterwards would seem to be abandoned by the first motion1 and to be borne by several motions besides the first4 ,the ,earth must also be borne on by two sorts of motion1 whether it be situate around a mid-point1 or in the middle site of the universe3 and if this were so1 there must needs be at one time an advance1 at another time a retrogression of the fixed stars3 ,this1 however1 does not seem to be the case1 but they rise and set always the same in the same places4 ,but it by no means follows that a double motion must be assigned to the ,earth4 ,but if there be but one diurnal motion of the ,earth around its poles1 who does not see that the stars must always in the same manner rise and set at the same points of the horizon1 even although there be another motion about which we are not disputing3 since the mutations in the smaller orbit cause no variation of aspect in the fixed stars owing to their great distance1 unless the axis of the ,earth have varied its position1 concerning which we raise a question when speaking of the cause of the prcession of the quinoxes4 ,in this argument are many flaws4 ,for if the ,earth revolve1 that we asserted must needs occur not by reason of the first sphre1 but of its innate forces4 ,but if it were set in motion by the first sphre1 there would be no successions of days and nights1 for it would continue its course along with the ,primum ,mobile4 ,but that the ,earth is affected by a double movement at the time when it rotates around its own centre1 because the rest of the stars move with a double motion1 does not follow4 ,besides1 he does not well consider the argument1 nor do his interpreters understand the same4 ,greek3 toutou de sumbainontos1 anankaion gignesthai parodous kai tropas tn endedemenn astrn4 7,arist4 de ,coelo1 ii4 chap4 #ad47 ,that is1 ,if this be so1 there must needs be changes1 and retrogressions of the fixed stars4 ,what some interpret as retrogressions or regressions1 and changes of the fixed stars1 others explain as diversions3 which terms can in no way be understood of axial motion1 unless he meant that the ,earth moved by the ,primum ,mobile is borne and turned over other poles diverse even from those which correspond to the first sphre1 which is altogether absurd4 ,other later theorists suppose that the eastern ocean ought to be impelled so into western regions by that motion1 that those parts of the ,earth which are dry and free from water would be daily flooded by the eastern ocean4 ,but the ocean is not acted upon by that movement1 since nothing opposes it2 and even the whole atmosphere is carried round3 ,and for that reason in the ,earth's course all the things in the air are not left behind by us nor do they seem to move toward the ,west3 ,wherefore also the clouds #bbg are at rest in the air1 unless the force of the winds drive them2 and objects which are projected into the air fall again into their own place4 ,but those foolish folk who think that towers1 temples1 and buildings must necessarily be shaken and overthrown by the ,earth's motion1 may fear lest men at the ,antipodes should slip off into an opposite orbe1 or that ships when sailing round the entire #bdi;globe should 7as soon as they have dipped under the plane of our horizon7 fall into the opposite region of the sky4 ,but those follies are old wives' gossip1 and the rubbish of certain philosophizers1 men who1 when they essay to treat of the highest truths and the fabrick of the universe1 and hazard anything1 can scarce understand aught ultra crepidam4 ,they would have the ,earth to be the centre of a circle2 and therefore to rest motionless amid the rotation4 ,but neither the stars nor the wandering globes move about the ,earth's centre3 the high heaven also does not move circularly round the ,earth's centre2 nor if the ,earth were in the centre1 is it a centre itself1 but a body around a centre4 ,nor is it confident with reason that the heavenly bodies of the ,peripateticks should attend on a centre so decadent and perishable as that of the ,earth4 ,they think that ,nature seeks rest for the generation of things1 and for promoting their increase while growing2 and that accordingly the whole ,earth is at rest4 ,and yet all generation takes place from motion1 without which the universal nature of things would become torpid4 ,the motion of the ,sun1 the motion of the ,moon1 cause changes2 the motion of the ,earth awakens the internal breath of the globe2 animals themselves do not live without motion1 and the ceaseless activity of the heart and arteries4 ,for of no moment are the arguments for a simple straight motion toward the centre1 that this is the only kind in the ,earth1 and that in a simple body there is one motion only and that a simple one4 ,for that straight motion is only a tendency toward their own origin1 not of the parts of the ,earth only1 but of those of the ,sun also1 of the ,moon1 and of the rest of the sphres which also move in an orbit4 ,joannes ,costus1 who raises doubts concerning the cause of the ,earth's motion1 looking for it externally and internally1 understands magnetick vigour to be internal1 active1 and disponent2 also that the ,sun is an external promotive cause1 and that the ,earth is not so vile and abject a body as it is generally considered4 ,accordingly there is a diurnal movement on the part of the ,earth for its own sake and for its advantage4 ,those who make out that that terrestrial motion 7if such there be7 takes place not only in longitude1 but also in latitude1 talk nonsense4 ,for ,nature has set in the ,earth determinate poles1 and definite unconfused revolutions4 ,thus the ,moon revolves with respect to the ,sun in a monthly course2 yet having her own definite poles1 facing determinate parts of the heaven4 ,to suppose that the air moves the ,earth would be #bbh ridiculous4 ,for air is only exhalation1 and is an enveloping effluvium from the ,earth itself2 the winds also are only a rush of the exhalations in some part near the ,earth's surface2 the height of its motion is slight1 and in all regions there are various winds unlike and contrary4 ,some writers1 not finding in the matter of the ,earth the cause 7for they say that they find nothing except solidity and consistency71 deny it to be in its form2 and they only admit as qualities of the ,earth cold and dryness1 which are unable to move the ,earth4 ,the ,stoicks attribute a soul to the ,earth1 whence they pronounce 7amid the laughter of the learned7 the ,earth to be an animal4 ,this magnetick form1 whether vigour or soul1 is astral4 ,let the learned lament and bewail the fact that none of those old ,peripateticks1 nor even those common philosophizers heretofore1 nor ,joannes ,costus1 who mocks at such things1 were able to apprehend this grand and important natural fact4 ,but as to the notion that surface inequality of mountains and valleys would prevent the ,earth's diurnal revolution1 there is nothing in it3 for they do not mar the ,earth's roundness1 being but slight excrescences compared with the whole ,earth2 nor does the ,earth revolve alone without its emanations4 ,beyond the emanations1 there is no renitency4 ,there is no more labour exerted in the ,earth's motion than in the march of the rest of the ,stars3 nor is it excelled in dignity by some stars4 ,to say that it is frivolous to suppose that the ,earth rather seeks a view of the ,sun1 than the ,sun of the ,earth1 is a mark of great obstinacy and unwisdom4 ,of the theory of the rotation we have often spoken4 ,if anyone seek the cause of the revolution1 or of other tendency of the ,earth1 from the sea surrounding it1 or from the motion of the air1 or from the ,earth's gravity1 he would be no less silly as a theorist than those who stubbornly ground their opinions on the sentiments of the ancients4 ,ptolemy's reasonings are of no weight2 for when our true principles are laid down1 the truth comes to light1 and it is superfluous to refute them4 ,let ,costus recognize and philosophers see how unfruitful and vain a thing it becomes then to take one's stand on the principles and unproved opinions of certain ancients4 ,some raise a doubt how it can be that1 if the ,earth move round its own axis1 a globe of iron or of lead dropped from the highest point of a tower falls exactly perpendicularly to a spot of the ,earth below itself4 ,also how it is that cannon balls from a large culverin1 fired with the same quantity and strength of powder1 in the same direction and at a like elevation through the same air1 would be cast at a like distance from a given spot both ,eastward and ,westward1 supposing the ,earth to move ,eastward4 ,but those who bring forward this kind of argument are being misled3 not attending to the nature of primary globes1 and the combination of parts with their globes1 even though they be not adjoined by solid parts4 ,whereas the motion of the ,earth in the diurnal revolution does not involve the separation of her more #bbi solid circumference from the surrounding bodies2 but all her effluvia surround her1 and in them heavy bodies projected in any way by force1 move on uniformly along with the ,earth in general coherence4 ,and this also takes place in all primary bodies1 the ,sun1 the ,moon1 the ,earth1 the parts betaking themselves to their first origins and sources1 with which they connect themselves with the same appetence as terrene things1 which we call heavy1 with the ,earth4 ,so lunar things tend to the ,moon1 solar things to the ,sun1 within the orbes of their own effluvia4 ,the emanations hold together by continuity of substance1 and heavy bodies are also united with the ,earth by their own gravity1 and move on together in the general motion3 especially when there is no renitency of bodies in the way4 ,and for this cause1 on account of the ,earth's diurnal revolution1 bodies are neither set in motion1 nor retarded2 they do not overtake it1 nor do they fall short behind it when violently projected toward ,east or ,west4 ,illustration ,let ,e ,f ,g be the ,earth's globe1 ,a its centre1 ,l ,e the ascending effluvia3 ,just as the orbe of the effluvia progresses with the ,earth1 so also does the unmoved part of the circle at the straight line ,l ,e progress along with the general revolution4 ,at ,l and ,e1 a heavy body1 ,m1 falls perpendicularly toward ,e1 taking the shortest way to the centre1 nor is that right movement of weight1 or of aggregation compounded with a circular movement1 but is a simple right motion1 never leaving the line ,l ,e4 ,but when thrown with an equal force from ,e toward ,f1 and from ,e toward ,g1 it completes an equal distance on either side1 even though the daily rotation of the ,earth is in process3 just as twenty paces of a man mark an equal space whether toward ,east or ,west3 so the ,earth's diurnal motion #bcj is by no means refuted by the illustrious ,tycho ,brahe1 through arguments such as these4 ,illustration ,the tendency toward its origin 7which1 in the case of the ,earth1 is called by ,philosophers weight7 causes no resistance to the diurnal revolution1 nor does it direct the ,earth1 nor does it retain the parts of the ,earth in place1 for in regard to the ,earth's solidity they are imponderous1 nor do they incline further1 but are at rest in the mass4 ,if there be a flaw in the mass1 such as a deep cavity 7say #ajjj fathoms71 a homogenic portion of the ,earth1 or compacted terrestrial matter1 descends through that space 7whether filled with water or air7 toward an origin more assured than air or water1 seeking a solid globe4 ,but the centre of the ,earth1 as also the ,earth as a whole1 is imponderous2 the separated parts tend toward their own origin1 but that tendency we call weight2 the parts united are at rest2 and even if they were ponderable1 they would introduce no hindrance to the diurnal revolution4 ,for if around the axis ,a ,b1 there be a weight at ,c1 it is balanced from ,e2 if at ,f1 from ,g2 if at ,h1 from ,i4 ,so internally at ,l1 they are balanced from ,m3 the whole globe1 then1 having a natural axis1 is balanced in quilibrio1 and is easily set in motion by the slighted cause1 but especially because the ,earth in her own place is nowise heavy nor lacking in balance4 ,therefore weight neither hinders the diurnal revolution1 nor influences either the direction or continuance in position4 ,wherefore it is manifest that no sufficiently strong reason has yet been found out by ,philosophers against the motion of the ,earth4 99 99 99 99 99 #bca ,,chap4 ,,vi4 ,on the cause of the definite time1 of an entire rotation of the ,earth4 ,diurnal motion is due to causes which have now to be sought1 arising from magnetick vigour and from the confederated bodies2 that is to say1 why the diurnal rotation of the ,earth is completed in the space of twenty-four hours4 ,for no curious art1 whether of ,clepsydras or of sand-clocks1 or those contrivances of little toothed wheels which are set in motion by weights1 or by the force of a bent steel band1 can discover any degree of difference in the time4 ,but as soon as the diurnal rotation has been gone through1 it at once begins over again4 ,but we would take as the day the absolute turning of a meridian of the ,earth1 from sun to sun4 ,this is somewhat greater than one whole revolution of it2 in this way the yearly course is completed in #cfe and nearly turnings with respect to the sun4 ,from this sure and regular motion of the ,earth1 the number and time of #cfe days1 #e hours1 #ee minutes1 in solar tropical years is always certain and definite1 except that there are some slight differences due to other causes4 ,the ,earth therefore revolves not fortuitously1 or by chance1 or precipitately2 but with a rather high intelligence1 equably1 and with a wondrous regularity1 in no other way than all the rest of the movable stars1 which have definite periods belonging to their motions4 ,for the ,sun himself being the agent and incitor of the universe in motion1 other wandering globes set within the range of his forces1 when acted on and stirred1 also regulate each its own proper courses by its own forces2 and they are turned about in periods corresponding to the extent of their greater rotation1 and the differences of their effused forces1 and their intelligence for higher good4 ,and for that cause ,saturn1 having a wider orbit1 is borne round it in a longer time1 ,jupiter a shorter1 and ,mars still less2 while ,venus takes nine months1 ,mercury #hj days1 on the hypotheses of ,copernicus2 the ,moon going round the ,earth with respect to the ,sun in #bi days1 #ab hours1 #dd minutes4 ,we have asserted that the ,earth moves circularly about its centre1 completing a day by an entire revolution with respect to the ,sun4 ,the ,moon revolves in a monthly course around the ,earth1 and1 repeating a conjunction with the ,sun after a former synodic conjunction1 constitutes the month or ,lunar day4 ,the ,moon's mean concentrick orbit1 according to numerous observations of ,copernicus and later astronomers1 is found to be distant #bi and about #e_/f diameters of the ,earth from the ,earth's centre4 ,the ,moon's revolution with respect to the ,sun takes place in #bi days and #dd minutes of time4 ,we reckon the motion with respect to the sun1 not the periodic motion1 #bcb just as a day is one entire revolution of the ,earth with respect to the ,sun1 not one periodick revolution2 because the ,sun is the cause of lunar as of terrestrial motion3 also1 because 7on the hypotheses of later observers7 the synodical month is truly periodic1 on account of the ,earth's motion in a great orbit4 ,the proportion of diameters to circumferences is the same4 ,and the concentrick orbit of the ,moon contains twice over #bi and great circles of the ,earth a little more4 ,the ,moon the ,earth1 then1 agree together in a double proportion of motion2 the ,earth moves in the space of twenty-four hours1 in its diurnal motion2 because the ,moon has a motion proportional to the ,earth1 but the ,earth a motion agreeing with the lunar motion in a nearly double proportion4 ,there is some difference in details1 because the distances of the stars in details have not been examined sufficiently exactly1 nor are mathematicians as yet agreed about them4 ,the ,earth therefore revolves in a space of #bd hours1 as the ,moon in her monthly course1 by a magnetick confederation of both stars1 the globes being forwarded in their movement by the ,sun1 according to the proportion of their orbits1 as ,aristotle allows1 de ,coelo1 bk4 ii41 chap4 #aj4 ,it happens 7he says7 that the motions are performed through a proportion existing between them severally1 namely1 at the same intervals in which some are swifter1 others slower1 ,but it is more agreeable to the relation between the ,moon and the ,earth1 that that harmony of motion should be due to the fact that they are bodies rather near together1 and very like each other in nature and substance1 and that the ,moon has more evident effects upon the ,earth than the rest of the stars1 the ,sun excepted2 also because the ,moon alone of all the planets conducts her revolutions1 directly 7however diverse even71 with reference to the ,earth's centre1 and is especially akin to the ,earth1 and bound to it as with chains4 ,this1 then1 is the true symmetry and harmony between the motions of the ,earth and the ,moon2 not that old oft-besung harmony of coelestial motions1 which assumes that the nearer any sphre is to the ,primum ,mobile and that fictitious and pretended rapidest ,prime ,motion1 the less does it offer resistance thereto1 and the slower it is borne by its own motion from west to east3 but that the more remote it is1 the greater is its velocity1 and the more freely does it complete its own movement2 and therefore that the ,moon 7being at the greatest distance from the ,primum ,mobile7 revolves the most swiftly4 ,those vain tales have been conceded in order that the ,primum ,mobile may be accepted1 and be thought to have certain effects in retarding the motions of the lower heavens2 as though the motion of the stars arose from retardation1 and were not inherent and natural2 and as though a furious force were perpetually driving the rest of the heaven 7except only the ,primum ,mobile7 with frenzied incitations4 ,much more likely is it that the stars are borne around symmetrically by their own forces1 with a certain mutual concert and harmony4 99 99 99 99 99 #bcc ,,chap4 ,,vii4 ,on the primary magnetick nature of the ,earth1 whereby its poles are parted from the poles of the ,ecliptick4 ,primarily having shown the manner and causes of the diurnal revolution of the ,earth1 which is partly brought about from the vigour of the magnetick virtue1 partly effected by the pr-eminence and light of the ,sun2 there now follows an account of the distance of its poles from the poles of the ,ecliptick--a supremely necessary fact4 ,for if the poles of the universe or of the ,earth remained fast at the poles of the ,zodiack1 then the quator of the ,earth would lie exactly beneath the line of the ,ecliptick1 and there would be no variation in the seasons of the year1 no ,winter1 no ,summer1 nor ,spring1 nor ,autumn3 but one and the same invariable aspect of things would continue4 ,the direction of the axis of the ,earth has receded therefore from the pole of the ,zodiack 7for lasting good7 just so far as is sufficient for the generation and variety of things4 ,accordingly the declination of the tropicks and the inclination of the ,earth's pole remain perpetually in the twenty-fourth degree2 though now only #bc degrees #bh minutes are counted2 or1 as others make out1 #bi minutes3 ,but once it was #bc degrees #eb minutes1 which are the extreme limits of the declinations hitherto observed4 ,and that has been prudently ordained by nature1 and is arranged by the primary excellence of the ,earth4 ,for if those poles 7of the ,earth and the ,ecliptick7 were to be parted by a much greater distance1 then when the ,sun approached the tropick1 all things in the other deserted part of the globe1 in some higher latitude1 would be desolate and 7by reason of the too prolonged absence of the ,sun7 brought to destruction4 ,as it is1 however1 all is so proportioned that the whole terrestrial globe has its own varying seasons in succession1 and alternations of condition1 appropriate and needful3 either from the more direct and vertical radiation of light1 or from its increased tarriance above the horizon4 ,around these poles of the ,ecliptick the direction of the poles of the ,earth is borne3 and by this motion the prcession of the quinoxes is apparent to us4 99 99 99 99 99 #bcd ,,chap4 ,,viii4 ,on the ,prcession of the quinoxes1 from the magnetick motion of the poles of the ,earth1 in the ,arctick and ,antarctick circle of the ,zodiack4 ,primitive mathematicians1 since they did not pay attention to the inequlities of the years1 made no distinction between the quinoctial1 or solstitial revolving year1 and that which is taken from some one of the fixed stars4 ,even the ,olympick years1 which they used to reckon from the rising of the dogstar1 they thought to be the same as those counted from the solstice4 ,hipparchus of ,rhodes was the first to call attention to the fact that these differ from each other1 and discovered that the year was longer when measured by the fixed stars than by the quinox or solstice3 whence he supposed that there was in the fixed stars also some motion in a common sequence2 but very slow1 and not at once perceptible4 ,after him ,menelaus1 a ,roman geometer1 then ,ptolemy1 and long afterward ,mahometes ,aractensis1 and several more1 in all their literary memoirs1 perceived that the fixed stars and the whole firmament proceeded in an orderly sequence1 regarding as they did the heaven1 not the earth1 and not understanding the magnetical inclinations4 ,but we shall demomstrate that it proceeds rather from a certain rotatory motion of the ,earth's axis1 than that that eighth sphre 7so called7 the firmament1 or non-moving empyrean1 revolves studded with innumerable globes and stars1 whose distances from the ,earth have never been proved by anyone1 nor can be proved 7the whole universe gliding1 as it were74 ,and surely it should seem much more likely that the appearances in the heavens should be clearly accounted for by a certain inflection and inclination of the comparatively small body of the ,earth1 than by the setting in motion of the whole system of the universe2 especially if this motion is to be regarded as ordained solely for the ,earth's advantage3 ,while for the fixed stars1 or for the planets1 it is of no use at all4 ,for this motion the rising and settings of stars in every ,horizon1 as well as their culminations at the height of the heavens1 are shifted so much that the stars which once were vertical are now some degrees distant from the zenith4 ,for nature has taken care1 through the ,earth's soul or magnetick vigour1 that1 just as it was needful in tempering1 receiving1 and warding off the sun's rays and light1 by suitable seasons1 that the points toward which the ,earth's pole is directed should be #bc degrees and more #bce from the poles of the ,ecliptick#bej3 so now for moderating and for receiving the luminous rays of the fixed stars in due turn and succession1 the ,earth's poles should revolve at the same distance from the ,ecliptick at the ,ecliptick's arctick circle2 or rather that they should creep at a gentle pace1 that the actions of the stars should not always remain at the same parallel circles1 but should have a rather slow mutation4 ,for the influences of the stars are not so forceful as that a swifter course should be desired4 ,slowly1 then1 is the ,earth's axis inflected2 and the stars' rays1 falling upon the face of the ,earth1 shift only in so long a time as a diameter of the arctick or polar circle is extended3 whence the star at the extremity of the tail of the ,cynosure1 which once was #ab degrees #bd minutes 7namely1 in the time of ,hipparchus7 distant from the pole of the universe1 or from that point which the pole of the ,earth used to face1 is now only #b degrees and #eb minutes distant from the same point2 whence from its nearness it is called by the moderns ,polaris4 ,some time it will be only degree away from the pole3 afterward it will begin to recede from the pole until it will be #dh degrees distant2 and this1 according to the ,prutenical tables1 will be in ,anno ,domini #aejjj4 ,thus ,lucida ,lyr 7which to us southern ,britons now almost culminates7 will some time approach to the pole of the world1 to about the fifth degree4 ,so all the stars shift their rays of light at the surface of the ,earth1 through this wonderful magnetical inflection of the ,earth's axis4 ,hence come new varieties of the seasons of the year1 and lands become more fruitful or more barren2 hence the characters and manners of nations are changed2 kingdoms and laws are altered1 in accordance with the virtue of the fixed stars as they culminate1 and the strength thence received or lost in accordance with the singular and specifick nature of each2 or on account of new configurations with the planets in other places of the ,zodiack2 on account also of risings and settings1 and of new concurrences at the meridian4 ,the ,prcession of the quinoxes arising from the aequable motion of the ,earth's pole in the arctick circle of the ,zodiack is here demonstrated4 ,let ,a ,b ,c ,d be the ,ecliptick line2 ,i ,e ,g the arctic circle of the ,zodiack4 ,then if the ,earth's pole look to ,e1 the quinoxes are at ,d1 ,c4 ,let this be at the time of ,metho1 when the horns of ,aries were in the quinoctial colure4 ,now if the ,earth's pole have advanced to ,i2 then the quinoxes will be at ,k1 ,l2 and the stars in the ecliptick ,c will seem to have progressed1 in the order of the signs1 along the whole arc ,k ,c3 ,l will be moved on by the prcession1 against the order of the signs1 along the arc ,d ,l4 ,but this would occur in the contrary order1 if the point ,g were to face the poles of the earth1 and the motion were from ,e to ,g3 for then the quinoxes would be ,m ,n1 and the fixed stars would anticipate the same at ,c and ,d1 counter to the order of the signs4 ,illustration 99 99 99 99 99 #bcf ,,chap4 ,,ix4 ,on the anomaly of the ,prcession of the ,equinoxes1 and of the obliquity of the ,zodiack4 ,at one time the shifting of the quinoxes is quicker1 at another slower1 being not always equal3 because the poles of the earth travel unequally in the arctick and antarctick circle of the ,zodiack2 and decline on both sides from the middle path3 whence the obliquity of the ,zodiack to the quator seems to change4 ,and as this has become known by means of long observations1 so also has it been perceived1 that the true quinoctial points have been elongated from the mean quinoctial points1 on this side and on that1 by #gj minutes 7when the prostaphresis is greatest73 but that the solstices either approach the equator unequally #ab minutes nearer1 or recede as far behind2 so that the nearest approach is #bc degrees #bh minutes1 and the greatest elongation #bc degrees #eb minutes4 ,astronomers have given various explanations to account for this inequality of the prcession and also of the obliquity of the tropicks4 ,thebit1 with the view of #bcg laying down a rule for such considerable inequalities in the motion of the stars1 explained that the eighth sphre does not move with a continuous motion from west to east2 but is shaken with a certain motion of trepidation1 by which the first points of ,aries and ,libra in the eighth heaven describe certain small circles with diameters equal to about nine degrees1 around the first points of ,aries and ,libra in the ninth sphre4 ,but since many things absurd and impossible as to motion follow from this motion of trepidation1 that theory of motion is therefore long since obsolete4 ,others therefore are compelled to attribute the motion to the eighth sphre1 and to erect above it a ninth heaven also1 yea1 and to pile up yet a tenth and an eleventh3 ,in the case of mathematicians1 indeed1 the fault may be condoned2 for it is permissible for them1 in the case of difficult motions1 to lay down some rule and law of equality by any hypotheses4 ,but by no means can such enormous and monstrous celestial structures be accepted by philosophers4 ,and yet here one may see how hard to please are those who do not allow any motion to one very small body1 the ,earth2 and notwithstanding they drive and rotate the heavens1 which are huge and immense above all conception and imagination3 ,i declare that they feign the heavens to be three 7the most monstrous of all things in ,nature7 in order that some obscure motions forsooth#bea may be accounted for4 ,ptolemy1 who compares with his own the observations of ,timocharis and ,hipparchus1 one of whom flourished #bfj years1 the other #dfj years before him1 thought that there was this motion of the eighth sphre1 and of the whole firmament2 and proved by help of numerous phenomena that it took place over the poles of the ,zodiack1 and1 supposing its motion to be so far quable1 that the non-planetary stars in the space of #ajj years completed just one degree beneath the ,primum ,mobile4 ,after him #gej years ,albategnius discovered that one degree was completed in a space of #ff years1 so that a whole period would be #bc1gfj years4 ,alphonsus made out that this motion was still slower1 completing one degree and #bh minutes only in #bjj years2 and that thus the course of the fixed stars went on1 though unequally4 ,at length ,copernicus1 by means of the observations of ,timocharis1 ,aristarchus of ,samos1 ,hipparchus1 ,menelaus1 ,ptolemy1 ,mahometes ,aractensis1 ,alphonsus1 and of his own1 detected the anomalies of the motion of the ,earth's axis3 though ,i doubt not that other anomalies also will come to light some ages hence4 ,so difficult is it to observe motion so slow1 unless extending over a period of many centuries2 on which account we still fail to understand the intent of ,nature1 what she is driving after through such inequality of motion4 ,let ,a be the pole of the ,ecliptick1 ,b ,c the ,ecliptick1 ,d the quator2 when the pole of the ,earth near the arctick circle of the ,zodiack faces the point ,m1 then there is an anomaly of the prcession of the quinox at ,f2 #bch but when it faces ,n1 there is an anomaly of the prcession at ,e4 ,but when it faces ,i directly1 then the maximum obliquity ,g is observed at the solstitial colure2 but when it faces ,l1 there is the minimum obliquity ,h at the solstitial colure4 ,illustration ,copernicus' contorted circlet in the ,arctick circle of the ,zodiack4 ,let ,f ,b ,g be the half of the ,arctick circle described round the pole of the ,zodiack3 ,a ,b ,c the solstitial colure3 ,a the pole of the ,zodiack2 ,d ,e the anomaly of longitude #adj minutes at either side on both ends3 ,b ,c the anomaly of obliquity #bd minutes3 ,b the greater obliquity of #bc degrees #eb minutes3 ,d the mean obliquity of #bc degrees #dj minutes3 ,c the minimum obliquity of #bc degrees #bh minutes4 #bci ,illustration ,illustration #bdj ,the period of motion of the prcession of the quinoxes is #be1haf gyptian years2 the period of the obliquity of the ,zodiack is #cdcd years1 and a little more4 ,the period of the anomaly of the prcession of the quinoxes is #agag years1 and a little more4 ,if the whole time of the motion ,,ai were divided into eight equal parts3 in the first eighth the pole is borne somewhat swiftly from ,a to ,b2 in the second eighth1 more slowly from ,b to ,c2 in the third1 with the same slowness from ,c to ,d2 in the fourth1 more swiftly again from ,d to ,e2 in the fifth1 with the same swiftness from ,e to ,f2 again more slowly from ,f to ,g2 and with the same slowness from ,g to ,h2 in the last eighth1 somewhat swiftly again from ,h to ,i4 ,and this is the contorted circlet of ,copernicus1 fused with the mean motion into the curved line which is the path of the true motion4 ,and thus the pole attains the period of the anomaly of the prcession of the quinoxes twice2 and that of the declination or obliquity once only4 ,it is thus that by later astronomers1 but especially by ,copernicus 7the ,restorer of ,astronomy7#beb1 the anomalies of the motion of the ,earth's axis are described1 so far as the observations of the ancients down to our own times admit2 but there are still needed more and exact observations for anyone to establish aught certain about the anomaly of the motion of the prcessions1 and at the same time that also of the obliquity of the ,zodiack4 ,for ever since the time at which1 by means of various observations1 this anomaly was first observed1 we have only arrived at half a period of the obliquity4 ,so that all the more all these matters about the unequal motion both of the prcession and of the obliquity are uncertain and not well known3 wherefore neither can we ourselves assign any natural causes for it1 and establish it for certain4 ,wherefore also do we to our reasonings and experiments magnetical here set an end and period4#bec ,illustration 99 99 99 99 99 #bda ,,index4 ,abano1 ,pietro di 7,apponensis or ,apianus71 #b4 ,abbas1 ,hali 7',al ibn ,al ',abbas1 ,al ,majsi1 #b1 #f4 ,abohalis1 #dg4 ,see also ,avicenna4 aciarium or acies1 also aciare1 #ah1 #bc1 #cc1 #cf4 ,acosta1 ,josephus1 #e4 adamant1 #aa4 quator1 the magnetick1 #ac1 #gi4 ,aetius ,amidenus1 #b4 ,affaytatus1 ,fortunius1 #f4 agate1 non electrick1 #ea1 #ec4 ,agricola1 ,georgius1 #b1 #c1 #aj1 #ai1 #bf1 #aaa1 #aab4 ,agrippa1 ,h4 ,cornelius1 #c4 aimant1 #aa4 ,albategnius 7,muhammad ibn ,jabir1 ,al-,battani1 #bcg4 ,albertus ,magnus1 #b1 #g1 #ah1 #aaa4 ,alexander ,aphrodiseus1 #c1 #dh1 #ib4 ,alexandria1 ,hero of1 #eh4 ,alfonso1 ,diego1 #agh4 ,alfonsus the ,wise 7,alphonsus ,x471 #bcg4 ,amalfians said to have first constructed the compass1 #d4 ,amatus ,lusitanus1 #b4 amber1 #dg1 #di-fj1 #he1 #aab1 #aaf4 amethyst1 electrical properties of1 #dh4 amianth1 #aa4 ,amidenus1 ,aetius1 #b4 amphitane1 #aaa4 ,anatolismus1 or ,northeasting1 #afg4 ,anaxagoras1 #fa1 #bjh4 ,andrea ,doria 7,admiral71 #d4 ,antonius de ,fantis1 #ajg4 ,antonius ,musa ,brasavolus1 #b4 ,antony1 the denarius of1 #aaj4 ,apianus4 ,see ,abano4 ,apponensis4 ,see ,abano4 ,aquinas1 ,thomas1 #c1 #fd4 ,aractensis1 ,mahometes1 #bcd1 #bcg4 ,archelaus1 #bjh4 ,ardoynis1 ,santes de1 #b4 ,arias ,montanus1 #d4 ,aristarchus1 #bad1 #bcg4 ,aristotle3 ,de ,anima1 #a1 #aa1 #fa1 #baj4 ,de ,coelo1 #bbf1 #bcb4 ,de ,mirabilibus ,auscultationibus1 #bb4 ,meteorologica1 #ce1 #ci4 on material of the metals1 #ai1 #bj4 on the element of earth1 #dc4 on motions1 #de1 #bai1 #bbe4 on primary form1 #fe4 on the ,primum ,mobile1 #bbj4 on animate nature of planets1 #bjh4 armature1 #hg4 armed loadstones1 #hf1 #hg1 #hh1 #hi4 ,arnaldus de ,villa nova1 #b1 #g4 ,arsinoe1 ,temple of1 #b4 ,attraction1 #df1 #fj1 #fd1 #fh1 #ij1 #ih1 #aji4 ,avicenna 7,abu ',ali ,husain ibn ',abd ,allah1 ,ibn ,sn2 also called ,abohalis73 writes on the magnet1 #b4 on falling masses of iron1 #bf4 alleges loadstone an antidote to iron poison1 #ce4 on the property of attraction1 #di4 ,augsburgers 7,augustani71 the1 prescribe loadstone in plaster1 #cc4 axis1 the magnetick1 #ac1 #ha1 #bab4 ,azores1 variation of compass at the1 #d1 #aed1 #aef1 #afg4 ,bacon1 ,roger1 #e4 ,bambola1 or ,bilbilis1 #bc4 ,baptista ,montanus1 #b4 ,baptista ,porta4 ,see ,porta4 ,barbarus1 ,hermolaus1 #c4 ,barlowe1 ,william 7,rev4 ,archdeacon71 his book1 ,the ,navigators ,supply1 #h4 basil leaves alleged not to be attracted1 #dh4 belemnites are electrical1 #dh4 ,bencora 7,thabit ibn ,kurrah1 ,al ,harrani2 also called ,thebitius71 #aag1 #bcf4 ,benedictus1 ,joannes ,baptista 7,giambattista ,benedetti71 #afg4 beryl1 electrick properties of1 #dh4 ,bessardus 7,toussaincte de ,bessard71 #e1 #aaf1 #aec4 ,blondus1 ,flavius1 the historian1 #d4 ,borough1 ,william1 his book on the ,variation of the ,compass1 #h4 ,borrholybicum 7,north-north-west71 #afj4 ,brahe1 ,tycho1 #agd1 #bbi4 ,brandoe1 the island of1 #aha4 ,brasavolus1 ,antonius ,musa1 #b4 ,bristolla1 or ,bristol gem1 #dh4 burnt clay1 magnetick properties of1 #bf1 #dc4 #bdb ,cabot1 ,sebastian1 #d4 ,clius ,calcagninus1 #g4 ,csare1 or ,cesare1 ,giulio1 #ada4 ,calaber1 ,hannibal ,rosetius1 #c1 calamita or kalamita1 #aa4 ,calcagninus1 ,clius1 #g4 ,camillus ,leonhardus1 #c4 ,candish1 or ,cavendish1 ,thomas1 99iij1 #aag4 cap of iron for a loadstone1 #hf1 #hi1 #ij1 #ie4 carabe1 or karabe1 #dg4 carbuncle1 electrick properties of1 #dh1 #aaa4 ,cardan1 ,hieronymo1 #b4 ,de ,proportionibus3 on iron and earth1 #dc1 #fb1 #fg4 on distance of centre of cosmos1 #afi4 ,de ,rerum ,varietate3 on fall of meteorick iron1 #bf4 on attraction of amber1 #di4 on a perpetual motion engine1 #ajg4 ,de ,subtilitate3 alleges magnet to feed on iron1 #cg1 #fc1 #ib4 on magnet that draws silver1 #aaj4 on magnetick influence of star in tail of ,ursa ,minor1 #e1 #aaf1 #aec4 carnelian1 the1 #ea1 #ee4 catoblepas1 the antelope called1 #fc4 ,cesare1 ,giulio1 #ada4 chalybs1 #ah1 #be1 #cc4 chatochitis1 #aaa4 chemists1 the1 #ai1 #bj1 #ba1 #bd1 #cg1 #ff4 ,china1 #d1 #h1 #i1 #aa1 #ag1 #cb1 #aai4 ,chinocrates1 #b4 circumpulsion1 doctrine of1 #c1 #fa4 clamps 7open kilns71 #bf4 clay when burnt is magnetick1 #bf1 #dc1 #ig4 clepsydra1 #bca4 ,coimbra1 ,college of1 #e4 coition 7mutual attraction71 #de1 #df1 #fj1 #fe1 #fg1 #fh1 #ha1 #ih1 #ii1 #ajc1 #aji1 #aca4 definition of1 99vj1 #fh4 orbe of1 99vj4 colours of loadstones1 #i1 #aj1 #bg4 ,como1 #bc4 compass1 alleged invention of1 by ,amalfians1 #d4 origin of the compass-card1 #d1 #afe4 the mariners' 7pyxis71 #c1 #aae1 #adg1 #afe1 #agb4 the little 7pyxidula71 #aha1 #bjb4 different forms of1 ,italian1 ,baltic1 ,portuguese1 ,english1 #afe1 #aff1 #agg1 #aha4 conduction1 magnetick1 #he1 #ajd1 #abe4 consequent poles1 #abi1 #adb4 ,copernican system1 #bca4 ,copernicus1 ,nicolas1 #bab1 #bad1 #baf1 #bca1 #bcg1 #bch1 #bdj4 ,cordus1 ,valerius1 #aj4 ,cornelius ,agrippa1 #c4 ,cornelius ,gemma1 #fc4 ,cornelius ,tacitus1 #be4 corolla insorta1 or contorted circlet1 #bch1 #bdj4 ,cortes1 ,martin1 #e1 #aaf1 #aeb4 ,corvo1 ,island of1 #afg4 ,costa1 ,filippo 7of ,mantua71 #ada4 ,costus1 ,joannes1 #c1 #fb1 #bbg1 #bbh4 creagus1 the1 or flesh-magnet1 #aaj4 crystal1 rock1 #dh1 #eb1 #ei1 #aaa ,curtius1 ,nicolaus1 #ce4 ,cusan 7,michael ,khrypffs71 ,cardinal de ,cusa1 #c1 #fd1 #ajh4 ,cynosure1 the1 or ,pole-star1 #ad1 #ha1 #aag1 #bbb1 #bce4 ,dean1 ,forest of1 loadstone found in the1 #aa4 decay of the magnetick virtue1 #ah1 #cg1 #abd1 #ach1 #adi4 declination1 the1 or dip1 #ahd4 denarius of ,antony1 #aaj4 diamond1 an electrick1 #dh1 #ej1 #ei1 #aaa4 alleged power to attract iron1 #aji1 #aab4 alleged antipathy to magnet1 #b1 #g1 #aji1 #adc4 experiments upon1 #adc4 ,diego ,alfonso1 #agh4 ,differences between electricks and magneticks1 #dg1 #fj1 #fe4 ,dioscorides1 #a1 #b1 #i1 #cb4 dip1 the1 also called declination1 #h1 #df1 #ahd-bjd4 dipping-needle1 or declination instrument1 #ahe1 #bjc4 direction1 or directive force1 #da1 #df1 #aae1 #aai4 dividing a loadstone1 #af1 #gb1 #ajj1 #aba1 #abb1 #abg1 #acj1 #acf1 #ade1 #adf4 ,dominicus ,maria ,ferrariensis1 #bab1 #bac4 ,doria1 ,andrea 7,admiral71 #d4 ,drake1 ,sir ,francis1 99iij bis1 #aag4 ,du ,puys 7also called ,puteanus71 #c1 #fc4 ,earth1 the1 a great magnet1 #ch1 #ci1 #dj1 #da1 #dd1 #aai1 #baa4 echeneis 7the sucking fish71 #g1 #fc1 #aaj4 ,ecphantus1 #bad4 effluvia1 electrical1 #eb1 #ec1 #ei1 #ff4 magnetical1 #fa4 electrical attraction1 #ej1 #ea1 #aaa4 electrick force1 definition of1 #eb4 electricks1 99vj1 #df-fj4 electrum 7,greek3 lektron71 #dg4 emerald is non-electrick1 #ea4 emery1 #bb1 #ea4 ,empedocles1 #bjh4 ,encelius 7or ,entzelt1 ,christoph471 #c1 #aaa4 ,epicurius1 #fa1 #fb4 ,erasmus ,rheinholdus1 #bac4 ,erastus1 ,thomas1 #c1 #bb4 errors in navigation1 #aff1 #agg4 ,evax1 ,king of ,arabia1 #aaa4 ,euripides1 #i1 #aa1 #ah4 #bdc ,fallopius1 ,gabriellus1 #c1 #cd1 #ce1 #aab4 ,fantis1 ,antonius de1 #ajg4 ,fernelius1 ,joannes ,franciscus1 #d4 ,ficinus1 ,marsilius 7or ,marsiglio ,ficino71 #c1 #g1 #aaf #aec4 filings of iron1 #cg1 #fi1 #ij1 #ia1 #ib1 #ajd4 ,filippo ,costa4 ,see ,costa4 fire destroys magnetick properties1 #ff1 #fg1 #ia1 #abd4 flame destroys electrification1 #ei4 flame hinders not magnetick attractions1 #ff4 ,flavius ,blondus4 ,see ,blondus4 flies in amber1 #dg4 form versus matter1 #eb1 #fe4 ,fra ,paolo1 #f4 ,fracastorio1 ,hieronymo1 #e1 #ej1 #fg1 #ga1 #ia1 #aaj1 #aac1 #aeb4 ,franciscus ,maurolycus4 ,see ,maurolycus4 ,franciscus ,rueus4 ,see ,rueus4 ,gagates4 ,see jet4 ,galen1 #b1 #i1 #cb1 #ce1 #ci1 #df1 #di1 #fa1 #fb1 #fc4 ,gallus1 ,marbodus1 #b1 #g4 garlick1 its reputed antagonism to magnetism1 #b1 #cb1 #fd4 ,gartias ab ,horto1 #cb4 ,gaudentius ,merula1 #g4 ,gauricus1 ,lucas1 #g4 ,geber 7,jabir ibn ,hiyn1 ,al-,tarsusi7 #ba4 ,gemma1 ,cornelius1 #fc4 gems1 electrick properties of1 #dh1 #ea4 geniter1 #dg4 ,georgius ,agricola4 ,see ,agricola4 ,gilbert1 ,adrian1 #aa4 ,gilgil ,mauritanus1 #ai4 ,gioia1 or ,goia1 of ,amalfi1 #d4 ,giulio ,csare1 #ada4 glass1 an electrick by friction1 #dh1 #ed1 #ei4 use of loadstone in making1 #aaa4 goat's blood1 #g4 ,gonzalus ,oviedus1 #d4 ,goropius1 ,henricus ,becanus1 #d4 ,grotius1 ,hugo1 #afg1 #afh4 ,haematite1 #bb1 #ea4 ,hali ,abbas 7',ali ibn ,al ',abbs1 ,al ,masf71 #b1 #f4 ,hannibal ,rosetius ,calaber1 #c4 ,hariot1 ,thomas1 #g4 ,heat1 effect of on loadstone1 #ff1 #fg1 #ic1 #abc1 #abd4 ,helmshuda1 #afg4 ,heraclea1 the city of1 #h4 ,heraclean stone1 or stone of ,hercules1 #h1 #dc1 #fa1 #afi4 ,heraclides1 #bad4 ,heraclitus1 #bjh4 ,hermes1 #bji4 ,hermolaus ,barbarus1 #c4 ,hero of ,alexandria1 #eh4 ,hipparchus1 #bac1 #bad1 #bcd1 #bce1 #bcg4 ,hippocrates1 #h1 #ce1 #ea1 #fa4 horizon1 the magnetick1 defined1 #hj4 ,horto1 ,gartias ab1 #cb4 ,horus1 the bone of1 or ,os ,ori1 #i4 hot iron not magnetick1 #ff4 ,hues1 ,robert1 #g4 ,hugo ,grotius1 #afg1 #afh4 ,inclination4 ,see dip4 interposition of bodies1 #ec1 #ff1 #hc1 #he1 #hi1 #acg4 iris gem1 the1 #dh4 iron1 its nature and occurrence1 #ai1 #bj1 #bb1 #be4 filings of1 #cg1 #fi1 #ij1 #ia1 #ib1 #ajd4 its various names and qualities1 #bc1 #cc1 #cf4 its various uses1 #bc1 #bd1 #ci1 #hf1 #ij1 #ie4 medical uses of1 #cc1 #ce4 surpasses loadstone1 #fi1 #ie4 verticity in1 #he1 #abc1 #aci4 iron ore is magnetick1 #ah1 #bg1 #ch1 #dc4 has poles1 #bh4 islands1 magnetick influence of1 #e1 #aec1afa4 ,jacobus ,severtius1 #e4 jet1 #dg1 #dh1 #ec1 #ee1 #hf4 ,joannes ,baptista ,porta4 ,see ,porta4 ,joannes ,baptista ,montanus1 #b4 ,joannes ,costus4 ,see ,costus4 ,joannes ,franciscus ,offusius1 #df4 ,joannes ,goia4 ,see ,gioia4 ,joannes ,langius1 #c4 ,joannes ,taisner1 or ,taisnier4 ,see ,taisnier4 ,jofrancus ,offusius1 #df4 ,josephus ,acosta1 #e4 ,julius ,csar ,moderatus1 #ada4 ,julius ,csar ,scaliger4 ,see ,scaliger4 ,kendall1 ,abraham1 #g1 #agh4 ,korrah1 ,thebitius ,ben4 ,see ,bencora4 ,lactantius1 ,lucius1 #bai4 ,lagos1 ,rodriguez de1 #agg4 ,langius1 ,joannes1 #c4 lapis magnetis1 #h4 lapis specularis1 muscovy stone1 or mica1 #aa1 #dh1 #eb4 latitude in relation to dip1 #aif1 #bjj4 ,leonardus 7or ,leonhardus71 ,camillus1 #c4 ,levinus ,lemnius1 #c4 #bdd lifting power of loadstones1 #hf1 #hi1 #ig4 lily of the compass1 #aag1 #aeb1 #afe1 #agg4 liquids1 electrical attraction of1 #ee4 attraction on surface of1 #eg4 ,livio ,sanuto1 #e1 #aec1 #afg4 loadstone armed and unarmed1 #hf1 #hg1 #hh4 as medicine1 #cb4 in plasters1 #cc4 rock1 the1 #e1 #f1 #ah1 #aaf1 #aeb4 various names of1 #aa4 colours of1 #i1 #aj1 #bg4 various sources of1 #h1 #be1 #cb4 ,london1 magnetick variation at1 #aed1 #afc4 longitude1 magnetick finding at1 #aff4 long magnets1 advantage of1 #hb1 #hc1 #ii1 #aja ,lucania1 fall of meteorick stones in1 #bf4 ,lucas ,gauricus1 #g4 ,lucretius1 #b1 #c1 #h1 #di1 #fa4 ,lusitanus1 ,amatus1 #b4 ,lynschoten1 ,hugo van1 99iiij4 ,magnes1 ,greek3 magns1 ,greek3 magntis1 #aa4 ,magnesia1 #h4 ,magnetick axis of terrella1 #ha1 #bab4 axis of earth1 #ac1 #ha1 #bab4 horizon1 #hj4 meridian1 #gi1 #aeb4 mountains or rocks1 #e1 #f1 #ah1 #aaf1 #aeb4 islands1 #e1 #aec1 #afa4 motions1 the five1 #de4 ,magnus1 ,albertus4 ,see ,albertus4 ,magnus1 ,olaus1 #e1 #f4 ,mahometes ,aractensis1 #bcd1 #bcg4 ,mahomet's tomb1 #b4 ,manardus1 ,joannes1 #ce4 ,marbodus ,gallus1 #b1 #g4 ,marcellus ,empiricus1 #b4 ,marco ,polo 7,paulus ,venetus71 #d4 mariners' compass4 ,see compass4 ,mars1 saffron of 7,crocus ,martis71 #cd1 #ia4 ,marsiglio ,ficino4 ,see ,ficinus4 ,martin ,cortes1 #e1 #aaf1 #aeb4 matter and form1 #eb1 #fe4 ,matthus ,silvaticus1 #c4 ,matthiolus1 ,petrus1 #b1 #c4 ,mauritanus1 ,gilgil1 #ai4 ,mauritanus1 ,serapio1 #b1 #f4 ,maurolycus1 ,franciscus1 #e1 #db1 #aec1 #ahj4 medicinal use of iron1 #cc4 of loadstone1 #cb4 ,medina1 ,pedro de1 #aff4 ,menelaus1 #bcd1 #bcg4 meridian1 magnetick1 #gi1 #aeb1 #afc4 ,merula1 ,gaudentius1 #g4 meteorick stones1 falls of1 #bf1 #bg4 mica 7or muscovy stone71 #aa1 #dh1 #eb4 ,greek3 mikrog4 ,see terrella4 moisture stops electrick action1 #ec1 #ef4 ,montagnana1 ,b41 #ce4 ,montanus1 ,arias1 #d4 ,montanus1 ,joannes ,baptista1 #b4 ,moors1 ,serapio and the1 #f4 mountains1 magnetick1 #e1 #f1 #ah1 #aaf1 #aeb4 movement of trepidation1 #aag4 ,musa ,brasavolus1 ,antonius1 #b4 muscovy stone1 #aa1 #dh1 #eb4 ,see also mica4 myths of the magnet1 #b1 #c1 #e1 #f1 #g1 #ah1 #cb1 #fc1 #ajg1 #aji1 #aaj1 #aaa1 #aaf1 #adc1 #aec1 #bbh motions1 the various magnetical1 #df4 ,names of amber1 #dg4 names of the loadstone1 #aa4 names given to the magnetick poles1 #ae1 #aae1 #abe1 #abi4 ,nicander of ,colophon1 #h1 #i4 ,nicetas1 #bad4 ,nicolas ,copernicus1 #bab1 #bad1 #baf1 #bca1 #bcg1 #bch1 #bdj ,nicolaus ,myrepsus1 or ,prpositas1 #cc4 non-electrick bodies1 #ea1 #ee4 ,nonius1 ,petrus 7,pedro ,nuez71 #aff4 ,norman1 ,robert1 #e1 #h1 #aec1 #afa1 #afb4 supposes a point respective1 #e1 #aec1 #afa1 #afb4 his ,newe ,attractive1 #h4 discoverer of the dip1 #h4 ,norumbega1 the city of1 #aed4 ,nova ,zembla1 #aeb1 #agi4 ,offusius1 ,jofrancus1 #df4 ,olaus ,magnus1 #e1 #f4 opal becomes electrical1 #dh4 orbe of virtue1 #gf1 #if1 #aia1 #bje orbes of planets1 #bjh1 #bae4 ,oribasius1 #b4 ,orpheus1 #aa1 #fa1 #bji4 ,oviedus1 ,gonzalus 7,gonzalo ,fernandez de ,oviedo y ,valds71 #d4 ,pantarbes1 #aaa4 ,paolo 7,paulus gin71 #ce4 ,paolo1 ,rev4 ,maestro 7,fra ,paolo ,sarpi71 #f ,paolo the ,venetian 7,marco ,polo71 #d4 ,paracelsus 7,bombast von ,hohenheim74 asserts the stars to attract iron1 #c4 his emplastrum of loadstone1 #cc4 his method of strengthening loadstones1 #ic4 ,parmenides1 #bjh4 pearls are not electrick1 #ea1 #ee4 ,pedro de ,medina1 #aff4 percussion excites verticity1 #aci4 ,peregrinus1 ,peter1 his book1 #e4 on cause of magnetick direction1 #e1 #aaf1 #aec4 on perpetual motion engine1 #ajg4 affirms a terrella to revolve daily1 #bbc4 #bde ,peripateticks1 the1 #bj1 #da1 #dc1 #de1 #fe1 #bah1 #bbb1 #bbe1 #bbg1 #bbh4 perpetual motion machine1 #ajg4 ,peter ,peregrinus4 ,see ,peregrinus4 ,peter ,plancius4 ,see ,plancius4 ,petrus ,apponensis4 ,see ,abano1 ,pietro di4 ,petrus ,nonius4 ,see ,nonius or ,nuez4 ,philolaus1 #bad4 ,philostratus1 #aaa4 ,pictorio1 ,g41 #f1 #di4 piedramant1 #aa4 ,plancius1 ,peter1 99v bis4 planets1 influence of1 #bj1 #acg1 #adb4 plasters1 magnetick1 #cb1 #cc4 ,plato1 #c4 in the ,io1 discusses name and properties of the magnet1 #a1 #i1 #aa1 #ah4 in the ,timus1 suggests the theory of circumpulsion1 #fa4 his ,atlantis1 #aei4 on life in the universe1 #bjh4 ,pliny 7,c4 ,plinius ,secundus74 on loadstone fables1 #a1 #b1 #i1 #ah4 his mistake about thiopian loadstones1 #ag4 on the five kinds of loadstones1 #i4 on the alleged discovery of the loadstones1 #h4 on the alleged magnetick mountains1 #ah4 on a locality where loadstone was found1 #aa4 on the occurrence of iron in ,spain1 #be4 on the ,sagda and the ,catochites1 #aaa4 on the silver denarius of ,antony1 #aaj4 on the use of loadstone by glass-makers1 #aaa4 on the shadow of a gnomon of a sun-dial at ,rome1 #bac4 ,plotinus1 #bah4 ,plutarch1 ,claudius4 on the garlick fable1 #cb4 says something flammable exists in amber1 #ed4 his theory of circumpulsion1 #c1 #fb4 polarity4 ,see verticity4 pole1 the1 elevation of1 #bjj1 #bac4 poles1 magnetick1 of a loadstone1 #ac1 #da1 #gb1 #ha1 #add4 poles are not points1 #ab1 #da1 #gb1 #if4 ,polo1 ,marco1 #d4 ,porta1 ,joannes ,baptista 7,giambattista della ,porta74 his narration of marvels1 #f4 on various tempering of iron1 #bd4 asserts loadstone a mixture of stone and iron1 #fc4 on his assertion that loadstones have hairs1 #ff4 asserts vapour to be cause of attraction1 #fg4 his error as to change of verticity1 #gc4 suspends iron upwards by a thread1 #ib4 his error as to centre of the orbe of virtue1 #ie4 his error as to the polarity which causes repulsion1 #ajb4 his error as to magnetick opposing forces1 #ajc4 experiment with a balance1 #ajh4 his error as to iron being intoxicated1 #ach4 his error as to iron excited by a diamond1 #adc4 his error as to the pointing of a magnet1 #add4 proportion between loadstone and iron1 #adi4 his error as to variation and longitude1 #aff4 prcession of the quinoxes1 #bcd1 #bcf4 primum mobile1 the1 #gi1 #bad1 #baf1 #bah1 #bbj1 #bbf1 #bcb1 #bcg4 prostaphresis1 #agd1 #bcf4 ,prutenical ,tables1 the1 #bce4 ,ptolemus1 ,claudius4 on loadstone fables1 #b1 #cb4 on the occurrence of loadstone and of iron1 #i1be4 on the dissolution of the earth1 #ia1 #bag1 #bah4 alleged relation of regions with the planets1 #acg4 on the elevation of the pole at different latitudes1 #bac1 #bad4 on the ,primum ,mobile1 and the diurnal movement of the stars1 #baf1 #bbh1 #bcd4 on the anomalies of the earth's motion1 #bcg4 ,puteanus1 ,gulielmus 7,du ,puys71 #c1 #fc4 pyrimachus 7i4e41 pyrites71 #bc4 ,pythagoras1 #eg1 #bjh4 pyxidula1 #d1 #aha4 pyxis1 #c1 #aae1 #adg1 #afe1 #agb4 ,radius1 the1 of the earth's orbit1 #bah4 ,rasis4 ,see ,rhazes4 rays of magnetick virtue1 #ie4 ,reinoldus1 ,erasmus 7or ,rheinholdus71 #bac4 remora1 the 7or sucking fish71 #g1 #fc1 #aaj4 resin becomes electrical by friction1 #dh1 #eb4 respective points1 #e1 #aec1 #afa1 #afb4 reversal of polarity1 #aja1 #acg4 revolution of the globe1 #df1 #ha1 #ia1 #bbj4 repulsion1 electrical1 denied to exist1 #aac4 ,rhazes 7,muhammad ibn ,zakariya71 #cd1 #ce4 rings1 on the verticity of1 #abi4 ,rodriguez de ,lagos1 #agg4 ,rosetius ,calaber1 ,hannibal1 #c4 ,ruellius1 ,joannes1 #g4 ,rueus1 ,franciscus 7de la ,rue71 #f4 ,saffron of ,mars1 #cd1 #ia1 #ic4 sagda1 or sagdo1 the1 #aaa4 ,sanuto1 ,livio1 #e1 #aec1 #afg4 sapphire1 the1 #dh4 scales of iron1 #bb4 ,scaliger1 ,julius ,csar4 on cause of magnetick direction1 #e1 #fd1 #aec4 on a fall of meteorick iron1 #bf4 on preservation of loadstones1 #cg4 on amber1 #dg4 on magnetick attraction1 #gj4 admits the loadstone to have a soul1 #fh4 on diamond attracting iron1 #aab4 scoria or slag of iron1 #cd1 #ce4 sealing wax is electrical1 #dh1 #ec4 ,sebastian ,cabot4 ,see ,cabot4 ,serapio1 or ,serapio ,mauritania 7,yuhann ibn ,sarapion71 #b1 #f4 ,severtius1 ,jacobus1 #e4 shielding1 magnetick1 by iron plate1 #hc1 #he4 #bdf siderites 7,greek3 siderits7 #h1 #aa1 #adc4 siegelstein #aa4 silk suspension for magnetick iron1 #bi1 #cj4 ,silvaticus1 ,matthus1 #c4 silver1 loadstone for1 #aji1 #aaj4 similars1 doctrine of attraction of1 #ej1 #fb4 ,simon ,stevinus1 99v bis1 #afg1 #afh4 slate1 magnetick properties of1 #dc4 smeargel 7emery71 #bb4 ,solinus1 ,caius ,julius1 #a1 #i1 #aaa4 ,solomon the ,king1 #d4 ,sotacus1 #i4 ,stadius1 #bac4 stars are at various distances1 #bae4 steel1 #bc1 #ci1 #fi1 #ga1 #ic1 #ie1 #adg4 ,stevinus1 ,simon1 99v bis1 #afg1 #afh4 stomoma 7,greek3 stomma7 #bc1 #cc1 #cf4 ,strabo1 #be4 succinum4 ,see amber4 ,sudini1 or ,sudavienses1 #dg4 sulphur1 electrical by friction1 #dh1 #ec1 #ef1 #ei4 ,greek3 sundrom1 99vj4 ,greek3 sunentelecheia1 #fh4 ,sussex1 iron ore in1 #bb4 sympathy and antipathy1 #fe1 #fh1 #aab4 ,tacitus1 ,cornelius1 #be4 ,taisner1 or ,taisnier1 ,joannes1 #e1 #ajg4 ,tariassiona or ,tarazona1 #bc4 terrella4 definition of1 99vj1 #ab1 #ac4 poles and axis of1 #ac1 #gb1 #ha1 #add4 divided into two parts1 #gb4 magnetick vigour1 diagram of1 #gd1 #ge4 how small pieces of iron behave toward1 #ge1 #gf4 orbe of virtue of1 #gf1 #gg1 #ajd4 geography of1 #gh4 quinoctial circle of1 #gi1 #add4 parallels of1 #hj1 #baa4 magnetick horizon of1 #hj4 proportion of the forces in1 #ha1 #hb4 experiment with iron sphere1 #he4 small iron sphere and rod1 #id1 #ajb4 centre of magnetick virtue in1 #ie4 irregular terrella to exhibit variation1 #aee1 #aeg4 to illustrate the dip of the needle1 #aij1 #aib4 analogy of1 with the earth1 #da1 #gh1 #aai1 #baa4 testing loadstones1 methods of1 #ajh4 ,thales of ,miletus1 #aa1 #fa1 #fh1 #bjh1 #baj4 theamedes1 the1 #ah4 ,thebitius1 or ,thebit ben ,korrah1 #aag1 #bcf4 ,themistius1 #ga4 ,theophrastus1 #a1 #i1 #aa4 ,thomas ,aquinas1 #c1 #fd4 tides1 the cause of1 #hf4 ,tycho ,brahe1 #agd1 #bbi4 ,variation of the compass1 #g1 #df1 #gi1 #aaf1 #aea-afc1 #aff1 #afg1 #ahj4 variation at the ,azores1 #d1 #aed1 #aef1 #afg4 versorium1 magnetick1 definition of1 99vj4 use of1 #ac1 #aae1 #adg4 versorium1 non-magnetick1 use of1 #dh1 #di1 #ej4 verticity1 #bh1 #aae1 #aai-adg4 acquired1 #fg1 #fh1 #hd1 #he1 #ajd1 #abc1 #abe1 #abi1 #ach1 #aci1 #ada1 #adb1 #baa4 in iron plates touched by loadstone1 #hd4 in iron sphere1 #he4 how1 in iron1 #abc1 #aci1 #bab4 in bracket in tower of ,st4 ,augustine's ,church1 ,rimini1 #ada4 similar at ends of rod touched in middle1 #hd1 #abi4 by percussion1 #aci4 through interposed matter1 #fg4 not in bodies other than magnetick1 #adb4 quator separates two kinds of1 #gi4 possessed by the earth1 as a ,cause1 #aag4 change of1 through change of mass1 #gb4 definition of1 99vj4 described1 #aai1 #abj1 #aba4 destroyed by heat1 #ff1 #ic1 #abd4 earth produces it in loadstone and iron1 #db1 #adj1 #baa1 #bab4 excited through greater distances in iron than in air1 #ajd4 exists in all shapes of loadstone1 #gf4 helps the earth to keep its orbit1 #bbd4 inhrent in wrought iron1 #ca1 #aae4 as a magnetick motion1 #df4 mutation of1 #abj1 #acg4 magnitude of earth prevents variation of1 #afc1 #afd4 none acquired by iron rubbed on quator of terrella1 #adh4 not affected by position of loadstone1 #add4 of one loadstone as affected by another1 #fi1 #ach4 opposite1 acquired by iron touched by loadstone1 #aae1 #abe1 #abi4 parts having same repel1 #abb1 #acc4 pole of1 where last contact is1 #adi4 strengthened in versoria1 #adg-aej4 strength of1 decreases at once in both poles1 #adf4 ,villa nova1 ,arnaldus de1 #b1 #g4 vincentina1 the1 #dh4 ,vincent's ,rock1 gem of1 #ed4 ,weather affects electricks1 #dh1 #ec1 #ee1 #ef4 weighing the magnetick force1 #ajh4 ,wright1 ,edward1 his prefatory address1 99iij bis1 #g4 wrought iron is magnetick1 #bi1 #aci4 ,youth preserved by loadstone1 #cb4 ,zeilam1 the king of1 #cb4 ,zimiri1 #aa4 ,zoroaster1 #bji4 #bdg ,,this ,,treatise ,,by ,,william ,,gilbert1 ,,of ,,colchester1 ,,physician ,,of ,,london1 ,,on ,,the ,,magnet1 ,,was ,,first ,,publisht ,,in ,,the ,,latin ,,tongue ,,in ,,london ,,in ,,the ,,year ,,of ,,our ,,lord ,m4,d4,c42 ,,this ,,english ,,translation1 ,,which ,,was ,,completed ,,in ,,the ,,year ,m4,c4,m41 ,,is ,,printed ,,for ,,the ,,gilbert ,,club1 ,,to ,,the ,,number ,,of ,,two ,,hundred ,,and ,,fifty ,,copies1 ,,by ,,charles ,,whittingham ,,and ,,company1 ,,at ,,the ,,chiswick ,,press1 ,,tooks ,,court1 ,,chancery ,,lane1 ,,london4 ,illustration 99 99 99 99 99 ,,notes ,,on ,,the ,,de ,,magnete ,,of ,,dr4 ,,william ,,gilbert ,illustration ,,privately ,,printed ,,london ,,mcmi ,for out of olde feldes1 as men seith1 ,cometh al this newe corn fro yeer to yere2 ,and out of olde bokes1 in good feith1 ,cometh al this newe science that men lere4 --,chaucer4 ,i finde that you have vsed in this your traslation greate art1 knowledge1 and discretion4 ,for walking as it were in golden fetters 7as al ,translators doe7 you notwithstanding so warilie follow your ,auctor1 that where he trippeth you hold him vp1 and where he goeth out of the way1 you better direct his foote4 ,you haue not only with the ,bee sucked out the best iuyce from so sweete a flower1 but with the ,silke-worme as it were wouen out of your owne bowels1 the finest silke2 that which is more1 not rude raw silke1 but finely died with the fresh colour of your owne ,art1 ,invention1 and ,practise4 ,if these ,adamantes draw you not to effect this which you haue so happilie begunne3 then let these spurres driue you forward3 viz4 ,your owne promise1 the expectation of your friends1 the losse of some credit if you should steppe backe1 the profit which your labours may yeeld to many1 the earnest desire which you yourselfe haue to reviue this ,arte1 and the vndoubted acceptation of your paines1 if you performe the same4--7,prefatory epistle of ,john ,case1 ,d4 of ,physicke1 printed in ,r4 ,haydocke's translation of ,the ,artes of ,curious ,painting1 of ,lomatius1 ,oxford1 #aeih47 ,this booke is not for every rude and unconnynge man to see1 but for clerkys and very gentylmen that understand gentylness and scyence4--,caxton4 ,,chiswick ,,press3 ,,charles ,,whittingham ,,and ,,co4 ,,tooks ,,court1 ,,chancery ,,lane1 ,,london4 99 99 99 99 99 ij ,illustration ,,bibliography ,,of ,,de ,,magnete4 ,i4 7,,the ,,london ,,folio ,,of #afjj47 ,fol4 99j4 title ,,gvilielmi ,,gil berti colcestren sis1 medici londi- nensis1 ,,de ,,magnete1 ,,magneti- cisqve corporibvs1 et de mag- no magnete tellure2 ,physiologia noua1 plurimis argumentis1 expe- rimentis demonstrata4 ,printer's ,mark ,londini excudebat ,petrvs ,short anno ,,mdc4 99j verso ,gilbert's coat of arms4 99ij ,ad ,lectorem 99iij verso ,ad gravissimvm doctissimvmqve 444 99vj ,verborum quorundam interpretatio4 99vj verso ,index capitum4 p4 #a4 ,,gvilielmi ,,gilberti ,,de ,,magnete1 ,,lib4 ,i4 p4 #bdj4 ,,finis4 ,errata4 ,without any colophon1 printer's ,mark1 or date at end4 ,folio4 #h ll4 of preliminary matter4 ,,abcdefghiklmnopqrstv1 all ternions1 making #abj numbered leaves4 ,one blank leaf at front and one at end4 ,page #aad at end of ,liber ,,ii4 blank4 ,a folded woodcut plate inserted between p4 #bjj and p4 #bja4 ,woodcut initials1 headlines and diagrams4 ,all known copies except one have ink corrections in several pages1 particularly pp4 #aa1 #bb1 #dg4 ,,ii4 7,,the ,,stettin ,,quarto ,,of #afbh47 ,four preliminary unnumbered leaves1 viz4 7#a7 ,bastard title ,,gulielmi ,,gilberti ,tractatus ,,de ,,magnete verso blank2 7#b7 ,engraved title4 ,,tractatvs ,siue ,,physiologia ,,nova ,,de ,,magnete1 ,,magneticisqve ,,corpo- ,,ribvs ,,et ,,magno ,,magnete tellure ,sex libris comprehensus ,guilielmo ,gilberto ,colcestrensi1 ,medico ,londinensi 444 ,omnia nunc diligenter recognita emen- datius quam ante in lucem edita1 aucta figu- ris illustrata oper studio ,wolfgangi ,,lochmans ,i4,u4,d4 ,mathemati3 ,ad calcem libri adjunctus est ,index ,capi- tum ,rerum et ,verborum locupletissimus ,,excvsvs ,,sedini ,typis ,gotzianis ,sumptibus ,ioh3 ,hallervordij4 ,anno ,,mdc4,,xxviii verso blank2 7#c7 ,prfatio2 7#d7 ,amicorum ,acclamationes 7verses7 verso blank4 ,sig4 ,a ,ad ,lectorem ,candidum4 ,sig4 ,a#b verso ,ad ,gravissimum ,doctissimumq ,virum4 ,sig4 ,b#b ,verborum quorundam interpretatio4 ,verso blank1 followed by twelve engraved plates numbered ,i4 to ,,xii4 ,sig4 ,b#c is numbered as p4 #a1 and begins ,,gvilielmi ,,gilberti ,,de ,,magnete4 ,,liber ,i4 ,sig4 ,c begins as p4 #e2 ,sig4 ,d as p4 #ac2 and so forth4 ,the collation therefore is3 #d ll4 unnumbered1 ,a,b,c,d,e,f,g,h,i,k,l,m,n,o,p,q,r,s,t,v ,x,y,z,aa,bb,cc,dd,ee,ff,gg,hh,ii,kk,ll, mm1 all fours4 ,pagination ends on p4 #bcb1 which has ,sig4 ,h#c in error for ,hh#c1 being the end of the text4 ,verso of ,hh#c blank4 ,index capitum begins fol4 ,hh#d and with ,index ,verborum continues to verso of ,mm#c4 ,last leaf ,mm#d contains ,errata1 and instructions to binder to place plates3 verso blank4 ,quarto4 ,woodcut initials and diagrams4 ,without any colophon1 printer's ,mark1 or date at end4 ,in some copies the engraved title differs1 having the words ,ioh3 ,hallervordij4 replaced by the word ,authoris4 iij ,,iii4 7,,the ,,stettin ,,quarto ,,of #afcc47 ,four preliminary unnumbered leaves1 viz41 7#a7 title4 ,tractatus1 sive ,physiologia ,nova de ,,magnete1 ,magneticisq2 corporibus magno ,magnate tellure1 sex libris comprehensus1 a ,,guilielmo ,,gilberto ,colce- strensi1 ,medico ,londinensi4 444 ,omnia nunc diligenter recognita1 emendatius quam ante in lucem edita1 aucta figuris illustrata1 opera studio ,d4 ,,wolfgangi ,,lochmans1 ,i4,u4,d4 ,mathematici4 ,ad calcem libri adiunctus est ,index capitum1 ,rerum ,verborum locupletissimus1 qui in priore ditione desiderabatur ,,sedini1 ,typis ,,gotzianis4 ,,anno ,m4,,dc4 ,,xxxii4 verso blank2 7#b7 ,prfatio2 7#c7 ,amicorum acclamationes 7verses7 verso ,claudianus de ,magnete 7verses72 7#d7 ibid4 ,sig4 ,a ,ad ,lectorem ,candidum4 ,sig4 ,a#b verso ,ad ,gravissimum ,doctissimumq4 ,virum4 ,sig4 ,b#b ,verborum quorundam interpretatio2 verso blank4 ,sig4 ,b#c is numbered as p4 #a1 and begins ,,gvilielmi ,,gilberti ,,de ,,magnete4 ,,liber ,i4 ,sig4 ,c begins as p4 #e2 ,sig4 ,d as p4 #ac2 and so forth4 ,the ,collation therefore is3 #d ll4 unnumbered1 ,a to ,mm1 all fours4 ,pagination ends on p4 #bcb1 which bears ,sig4 ,h#c in error for ,hh#c4 ,verso of ,sig4 ,hh#c4 ,errata4 ,index capitum begins ,hh#d1 and with ,index ,verborum extends to verso of ,mm#c4 ,the last leaf ,mm#d bears the ,instructions to binder1 with verso blank4 ,there is no colophon1 printer's ,mark1 or date at end4 ,quarto4 ,woodcut initials1 and diagrams4 ,twelve etched plates of various sizes inserted4 ,with the exception of the preliminary matter and the ,instructions to binder1 the pagination is the same as in the edition of #afbh1 the pages in the body of the work being reprinted word for word2 though with exceptions4 ,for example1 p4 #ah in ,ed4 #afcc is one line shorter than in ,ed4 #afbh4 ,the etched plates are entirely different4 ,it has been thought from the pagination being alike that these two editions were really the same with different plates1 titles1 and preliminary matter4 ,but they are really different4 ,the spacing of the words1 letters and lines is different throughout1 and there are different misprints4 ,the watermarks of the paper also differ4 ,,iv4 7,,the ,,berlin ,,facsimile ,,folio ,,of #ahib47 ,this is a photozincograph reproduction of the ,london folio of #afjj4 ,it lacks the ink emendations on pages #aa1 #bb1 #dg1 c41 found in the original1 and is wanting also in some of the asterisks in the margins4 ,v4 7,,the ,,american ,,translation ,,of #ahic47 ,frontispiece portrait p4 i4 title ,,william ,,gilbert ,,of ,,colchester1 physician of ,london1 on the ,loadstone and ,magnetic ,bodies1 and on the great magnet the earth4 ,a new ,physiology1 demonstrated with many arguments and experiments4 ,a translation by ,p4 ,fleury ,mottelay1 444 ,new ,york3 ,john ,wiley ,sons1 #ec ,east ,tenth ,street #ahic4 p4 ii bears imprint of ,ferris ,bros4 ,printers1 #cbf ,pearl ,street1 ,new ,york4 p4 iii4 reduced reproduction of title of #afjj edition verso the ,gilbert arms p4 v4 ,translator's ,preface p4 ix4 ,biographical ,memoir p4 xxxi4 ,contents p4 xxxvii4 ,address of ,edward ,wright p4 xlvii4 ,author's ,preface4 p4 liii4 ,explanation of some terms4 pp4 #a-ceh text of the work4 p4 #cei reduced reproduction of title of #afbh edition4 p4 #cfj ditto of #afcc edition4 p4 #cfa ditto of ,gilbert's ,de ,mundo ,nostro of #afea4 pp4 #cfc to #cfh ,general ,index4 ,pages xxx1 xlvi1 lii1 and #cfb are blanks4 ,there are no signatures4 ,octavo4 ,diagrams reduced from woodcuts of the folio of #afjj4 ,some copies bear on title the imprint ,london3 ,bernard ,quaritch1 #ae ,piccadilly4 99 99 99 99 99 #a ,illustration ,,notes ,,on ,,the ,,de ,,magnete ,,of ,,dr4 ,,william ,,gilbert4 ,during the work of revising and editing the ,english translation of ,de ,magnete1 many points came up for discussion1 requiring critical consideration1 and the examination of the writings of contemporary or earlier authorities4 ,discrepancies between the texts of the three known editions--the ,london folio of #afjj1 and the two ,stettin quartos of #afbh and #afcc respectively--demanded investigation4 ,passages relating to astrology1 to pharmacy1 to alchemy1 to geography1 and to navigation1 required to be referred to persons acquainted with the early literature of those branches4 ,phrases of non-classical ,latin1 presenting some obscurity1 needed explanation by scholars of medival writings4 ,descriptions of magnetical experiments needed to be interpreted by persons whose knowledge of magnetism enabled them to infer the correct meaning to be assigned to the words in the text4 ,in this wise a large amount of miscellaneous criticism has been brought to bear1 and forms the basis for the following notes4 ,to make them available to all students of ,gilbert1 the references are given to page and line both of the ,latin folio of #afjj and of the ,english edition of #aijj4 ,s4 ,p4 ,t4 #a ,,the ,,glossary3 ,gilbert's glossary is practically an apology for the introduction into the ,latin language of certain new words1 such as the nouns terrella1 versorium1 and verticitas1 and the adjectival noun magneticum1 which either did not exist in classical ,latin or had not the technical meaning which he now assigns to them4 ,his terrella1 or ,greek3 mikrog1 as he explains in detail on p4 #ac1 is a little magnetic model of the earth1 but in the glossary he simply defines it as magnes globosus4 ,neither terrella nor versorium appears in any ,latin dictionary4 ,no older writer had used either word1 though ,peter ,peregrinus 7,de ,magnete1 ,augsburg1 #aeeh7 had described experiments with globular loadstones1 and pivotted magnetic needles suitable for use in a compass had been known for nearly three centuries4 ,yet the pivotted needle was not denominated versorium4 ,blondo 7,de ,ventis1 ,venice1 #aedf7 does not use the term4 ,norman 7,the ,newe ,attractiue1 ,london1 #aeha7 speaks of the needle or compasse1 and of the wyre4 ,barlowe 7,the ,navigators ,supply1 ,london1 #aeig7 speaks of #b the flie1 or the wier4 ,the term versorium 7literally1 the turn-about7 is ,gilbert's own invention4 ,it was at once adopted into the science1 and appears in the treatises of ,cabeus1 ,philosophia ,magnetica 7,ferrara1 #afbi71 and of ,kircher1 ,magnes sive de ,arte ,magnetica 7,coloni1 #afdc71 and other writers of the seventeenth century4 ,curiously enough1 its adoption to denote the pivotted magnetic needle led to the growth of an erroneous suggestion that the mariners' compass was known to the ancients because of the occurrence in the writings of ,plautus of the term versoriam1 or vorsoriam4 ,this appears twice as the accusative case of a feminine noun versoria1 or vorsoria1 which was used to denote part of the gear of a ship used in tacking-about4 ,forcellini defines versoria as funiculus quo extremus veli angulus religatur2 while versoriam capere is equivalent to reverti1 or 7metaphorically7 sententiam mutare4 ,the two passages in ,plautus are3 ,,eut4 ,si huc item properes1 ut istuc properas1 facias rectius1 ,huc secundus ventus nunc est2 cape modo vorsoriam2 ,hic ,favonius serenu'st1 istic ,auster imbricus3 ,hic facit tranquillitatem1 iste omnes fluctus conciet4 7in ,mercat4 ,act4 ,v41 sc4 #b47 ,,charm4 ,stasime1 fac te propere celerem recipe te ad dominum domum2 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 ,cape vorsoriam ,recipe te ad herum4 7in ,trinum4 ,act4 ,,iv41 sc4 #c47 ,the word magneticum is also of ,gilbert's own coinage1 as a noun2 as an adjective it had been certainly used before1 at least in its ,english form1 magneticall1 which appears on the title-page of ,william ,borough's ,discourse of the ,variation of the ,compasse 7,london1 #aeif74 ,gilbert does not use anywhere the noun magnetismus1 magnetism4 ,the first use of that noun occurs in ,william ,barlowe's ,magneticall ,aduertisements 7#afaf71 in the ,epistle ,dedicatorie1 wherein1 when speaking of ,dr4 ,gilbert1 he says vnto whom ,i communicated what ,i had obserued of my selfe1 and what ,i had built vpon his foundation of the ,magnetisme of the earth4 ,gilbert speaks of the virtus magnetica1 or vis magnetica2 indeed1 he has a rich vocabulary of terms1 using1 beside virtus and vis1 vires1 robur1 potestas1 potentia1 efficientia1 and vigor for that which we should now call magnetism or the magnetic forces4 ,nor does he use the verb magnetisare1 or its participle1 magnetisatus3 he speaks of ferrum tactum1 or of ferrum excitatum a magnete4 ,in spite of certain obscurities which occur in places in his work1 he certainly shows a nice appreciation of words and their use1 and a knowledge of style4 ,one finds occasionally direct quotations from1 and overt references to1 the classic authors1 as in the references to ,plato and ,aristotle on page #a1 and in the passage from the ,georgics of ,vergil on p4 #ba4 ,but here and there one finds other traces of unmistakable scholarship1 as in the reference to goat's wool on p4 #ce1 or in the use1 on p4 #baj1 of the word perplacet1 which occurs in the letter of ,cicero ad ,atticum1 or in that of commonstrabit1 occurring on p4 #bjc1 and found only in ,cicero1 ,terence and ,plautus2 whilst the phrase on p4 #c1 in which ,gilbert rallies the smatterers on having lost both their oil and their pains1 has a delightfully classical echo4 #c ,the term orbis virtutis1 defined by ,gilbert in the glossary1 and illustrated by the cuts on pages #gf1 #gg1 and #if1 might be effectively translated by sphere of influence1 or orbit within which there is sensible attraction4 ,it has been preferred1 however1 to translate it literally as the orbe of virtue1 or orbe of magnetick virtue4 ,this choice has been determined by the desire to adopt such an ,english phrase as ,gilbert would himself have used had he been writing ,english4 ,t4 ,hood1 writing in #aeib in his book ,the ,vse of both the ,globes1 in using the word orbe1 says that the word globe signifies a solid body1 while a sphere is hollow1 like two dishes joyned by the brimme2 ,the ,latines properly call ,orbis an ,orbe2 ,moreouer the word ,sphaera signifieth that instrument made of brasen hoopes 7wee call it commonly a ringed ,sphere7 wherewith the ,astronomers deliuer unto the nouices of that ,science the vnderstanding of things which they imagine in the heauen4 ,further1 ,dr4 ,marke ,ridley in his ,treatise of ,magneticall ,bodies and ,motions 7#afac71 has a chapter 7,,xiiii7 ,of the distance and ,orbe of the ,magnets vertue1 throughout which the term ,orbe is retained4 ,sir ,thomas ,browne also writes of the orb of their activities4 ,the word ,coitio1 used by ,gilbert for the mutual force between magnet and iron1 has been retained in its ,english form1 coition4 ,gilbert evidently adopted this term after much thought4 ,the ,newtonian conception of action and reaction being necessarily equal had not dawned upon the medival philosophers4 ,the term attraction had been used in a limited sense to connote an action in which a force was conceived of as being exerted on one side only4 ,diogenes of ,apollonia1 ,alexander ,aphrodiseus1 ,democritus1 and others1 conceived the magnet to draw at the iron without the iron in any way contributing to that action4 ,saint ,basil specially affirms that the magnet is not drawn by iron4 ,on the other hand1 ,albertus ,magnus had conceived the idea that the iron sought the magnet by a one-sided effort in which the magnet took no part4 ,gilbert had the wit to discern that the action was mutual1 and to mark the new conception he adopted the new term1 and defined it as it stands in his glossary4 ,it is a concourse or concordancy of both1 and to emphasize his meaning he adds1 not as if there were an ,greek3 helktik dunamis but a ,greek3 sundrom not a tractile power1 but a running together4 ,the adjective ,greek3 helktik is obviously related to the verb ,greek3 helk1 ,i draw3 but its meaning puzzled the subsequent editors of the text1 for in the two ,stettin editions of #afbh and #afcc1 the phrase appears in the respective forms of ,greek3 heltik dunamis and ,greek3 helkustik dunamis4 ,in ,creech's ,english version of ,lucretius 7edition of #agbb1 p4 #gb;a1 in the footnote7 is the commentary ,galen1 disputing against ,epicurus1 uses the term ,greek3 helkein1 which seems likewise too violent4 ,it may be noted that the same verb occurs in the passage from the ,io of ,plato quoted below4 ,the term ,greek3 sundrom applied by ,gilbert to explain his term ,coitio is used by ,diodorus for the mutual onset of two hostile forces4 ,a picturesque sentence from ,sir ,thomas ,browne's ,pseudodoxia ,epidemica 7,london1 #afej1 p4 #ea7 sets the matter succinctly forth4 ,if in two skiffs of cork1 a ,loadstone and ,steel be placed within the orb of their activities1 the one doth not move the other standing still1 but both hoist sayle and steer unto each other2 so that if the ,loadstone attract1 the ,steel hath also its attraction2 for in this action the ,alliency is reciprocall1 which jointly felt1 they mutually approach and run into each others arms4 #d ,the page and line references given in these notes are in all cases first to the ,latin edition of #afjj1 and secondly to the ,english edition of #aijj4 #b ,,page #a1 ,,line #bh4 ,page #a1 line #bh4 ,plato in ,ione4--,the passage in the ,io of ,plato is in chap4 v4 ,socrates addressing the poet ,io tells him that his facility in reciting ,homer is not really an art3 ,greek3 theia de dunamis1 h se kinei hsper en ti lithi1 hn ,euripids men ,magntin nomasen1 hoi de polloi ,hrakleian4 kai gar aut h lithos ou monon autous tous daktulious agei tous sidrous1 alla kai dunamin entithsi tois daktuliois1 st au dunasthai tautou touto poiein1 hoper h lithos1 allous agein daktulious1 hst' enioth' hormathos makros panu sidrin kai daktulin ex allln rttai pasi de toutois ex ekeins ts lithou h dunamis anrttai4 ,the idea is that as the loadstone in attracting an iron ring will make it into a magnet1 which can in turn act magnetically on another ring1 and this on yet another1 so the inspiration of the ,muse is transferred to the poet1 who in turn hands on the inspiration through the reciter to the listener4 ,after further expanding the same idea of the transference of influence1 ,socrates again mentions the magnet 7chap4 vii473 ,greek3 ,oisth' oun hoti outos estin ho theats tn daktulin ho eschatos1 hn eg elegon hupo ts ,hrakleitidos lithou ap' allln tn dunamin lambanein1 ho de mesos su ho rhapsdos kai hupokrits1 ho de prtos autos ho poits8 ho de theos dia pantn toutn helkei tn psuchn hopoi an boultai tn anthrpn1 k4t4l4 7,edition ,didot of #ahef1 vol4 i41 p4 #cia2 or ,stephanus1 p4 #ecc ,d74 ,there is another reference in ,plato to the magnet1 namely1 in the ,timus 7p4 #bdj1 vol4 ii41 ,edit4 citat474 ,see the ,note to p4 #fa4 ,the reference by ,euripides to the magnet occurs in the lost play of ,oeneus1 in a fragment preserved by ,suidas4 ,see ,fragmenta ,euripidis 7,ed4 ,didot1 #ahdf1 p4 #geg1 or ,nauck's edition1 ,no4 #efg74 ,greek3 hs ,euripids en ,oinei2 tas brotn gnmas skopn1 hste ,magntis lithos tn doxan helkei kai methistsin palin4 #c ,,page #a1 ,,line #bh4 ,page #a1 line #bi4 ,the brief passage from ,aristotle's ,de ,anima referring to ,thales is quoted by ,gilbert himself at the bottom of p4 #aa4 #d ,,page #b1 ,,line #a4 ,page #a1 line #bi4 ,the edition of #afbh inserts commas between ,theophrastus and ,lesbius1 and between ,julius and ,solinus1 as though these were four persons instead of two4 #e ,,page #b1 ,,line #h4 ,page #b1 line #e4 si allio magnes illitus fuerit1 aut si adamas fuerit4 ,an excellent version of this myth is to be found in ,julius ,solinus1 ,polyhistor1 ,de ,memorabilibus1 chap4 lxiv41 of which the ,english version of #aehg1 by ,a4 ,golding1 runs thus3 ,the ,diamonde will not suffer the ,lodestone to drawe yron unto him3 or if ye ,lodestone haue alreadie drawne a peece of yron to it1 the ,diamond snatcheth and pulleth away as hys bootye whatsoever the ,lodestone hath taken hold of4 ,saint ,augustine repeats the diamond myth in his ,de ,civitate ,dei1 lib4 xxi4 ,baptista ,porta says 7p4 #baa of the ,english version of #afeh73 ,it is a common ,opinion amongst ,sea-men1 ,that ,onyons and ,garlick are at odds with the ,loadstone3 and ,steers-men1 and such as tend the ,mariners ,card are forbid to eat ,onyons or ,garlick1 lest they make the ,index of the ,poles drunk4 ,but when ,i tried all these things1 found them to be false3 for not onely breathing and belching upon the ,loadstone after eating of ,garlick1 did not stop its vertues3 but when it was all anoynted over with the juice of ,garlick1 it did perform its office as well as if it had never been touched with it3 and ,i could observe almost not the least difference1 lest ,i should make void the endeavours of the ,ancients4 #e ,and again1 ,when ,i enquired of ,marines1 whether it were so1 that they were forbid to eat ,onyons and ,garlick for that reason2 they said1 they were old ,wives fables1 and things ridiculous2 and that ,sea-men would sooner lose their lives1 then abstain from eating ,onyons and ,garlick4 ,the fables respecting the antipathy of garlick and of the diamond to the operation of the magnet1 although already discredited by ,ruellius and by ,porta1 died hard4 ,in spite of the exposure and denunciations of ,gilbert--compare p4 #cb--these tales were oft repeated during the succeeding century4 ,in the appendix to ,sir ,hugh ,plat's ,jewel ,house of ,art and ,nature1 in the edition of #afec1 by ,d4 ,b4 ,gent1 it is stated there 7p4 #bah73 ,the ,loadstone which 444 hath an admirable vertue not onely to draw ,iron to it self1 but also to make any ,iron upon which it is rubbed to draw iron also1 it is written notwithstanding1 that being rubbed with the juyce of ,garlick1 it loseth that vertue1 and cannot then draw iron1 as likewise if a ,diamond be layed close unto it4 ,pliny wrote of the alleged antipathy between diamond and goat's blood4 ,the passage as quoted from the ,english version of ,pliny's ,natural ,historie of the ,world1 translated by ,philemon ,holland 7,london1 #afja1 p4 #faj1 chap1 iv471 runs3 ,but ,i would gladly know whose invention this might be to soake the ,diamond in ,goats bloud1 whose head devised it first1 or rather by what chance was it found out and knowne8 ,what conjecture should lead a man to make an experiment of such a singular and admirable secret1 especially in a goat1 the filthiest beast 444 in the whole world8 ,certes ,i must ascribe both this invention and all such like to the might and beneficence together of the divine powers3 neither are we to argue and reason how and why ,nature hath done this or that8 ,sufficient is it that her will was so1 and thus she would have it4 #f ,,page #b1 ,,line #bb4 ,page #b1 line #bb4 ,machometis sacellum4 ,gilbert credits ,matthiolus 7the well-known herbalist and commentator on ,dioscorides7 with producing the fable as to ,mahomet's coffin being suspended in the air by a magnet4 ,sir ,richard ,burton1 in his famous pilgrimage to ,el ,mednah in #ahee1 effectually disposed of this myth4 ,the reputed sarcophagus rests simply on bricks on the floor4 ,but it had long been known that aerial suspension1 even of the lightest iron object1 in the air1 without contact above or below1 was impossible by any magnetic agency4 ,in ,barlowe's ,magneticall ,aduertisements 7,london1 #afaf1 p4 #de7 is the following3 ,as for the ,turkes ,mahomet1 hanging in the ayer with his yron chest it is a most grosse untruth1 and utterly impossible it is for any thing to hange in the ayer by any magneticall power1 but that either it must touch the stone it selfe1 or else some intermediate body1 that hindreth it from comming to the stone 7like as before ,i haue shewed7 or else some stay below to keepe it from ascending1 as some small wier that may scantly bee seene or perceived4 #g ,,page #b1 ,,line #bf4 ,page #b1 line #bf4 ,arsinoes templum4--,the account in ,pliny of the magnetic suspension of the statue of ,arsinoe in the temple built by ,chinocrates is given as follows in the ,english version 7,london1 #afja7 of ,philemon ,holland 7p4 #eae73 ,and here ,i cannot chuse but acquaint you with the singular invention of that great architect and master deviser1 of ,alexandria in gypt ,dinocrates1 who began to make the arched roufe of the temple of ,arsinoe all of ,magnet or this ,loadstone1 to the end1 that within that temple the statue of the said princesse made of yron1 might seeme to hang in the aire by nothing4 ,but prevented he was by death #f before hee could finish his worke1 like as king ,ptolome also1 who ordained that temple to be built in the honour of the said ,arsinoe his sister4 ,there are a number of similar myths in ,ausonius1 ,claudian1 and ,cassiodorus1 and in the writings of later ecclesiastical historians1 such as ,rusinus and ,prosper ,aquitanus4 ,the very meagre accounts they have left1 and the scattered references to the reputed magical powers of the loadstone1 suggest that there existed amongst the primitive religions of mankind a magnet-worship1 of which these records are traces4 #h ,,page #b1 ,,line #cg4 ,page #b1 line #da4 ,brasevolus or ,brasavola4--,the list of authorities here cited consists mostly of well-known medival writers on materia medica or on minerals3 the last on the list1 ,hannibal ,rosetius ,calaber1 has not been identified4 ,the following are the references in the order named by ,gilbert3 ,antonio ,musa ,brasavola4 ,examen omnium simplicium medicamentorum1 ,section #ddg 7,lugdun41 #aecg74 ,joannes ,baptista ,montanus4 ,metaphrasis summaria eorum qu ad medicamentorum doctrin attinet 7,august ,rhetic1 #aeea74 ,amatus ,lusitanus4 ,amati ,lusitani in ,dioscoridis ,anazarbei de materia medica libros quinque 7,venet41 #aeeg1 p4 #ejg74 ,oribasius4 ,oribasii ,sardiani ad ,eunapium libri #d quibus 444 facultates simplicium 444 continentur 7,venet41 #aeeh74 ,aetius ,amidenus4 ,aetii ,amideni ,librorum medicinalium 444 libri octo nunc primum in lucem editi 7,greek text1 ,aldine edition1 ,venet41 #aecd74 ,a ,latin edition appeared in ,basel1 #aece4 ,see also his tetrabiblos ex veteribus medicin 7,basil41 #aedb74 ,avicenna 7,ibn ,sin74 ,canona ,medicin 7,venice1 #adhf71 liber ii41 cap4 #dgd4 ,serapio ,mauritanus 7,yuhann ,ibn ,sarapion74 ,in hoc volumine continentur 444 ,ioan4 ,sarapionis ,arabis de ,simplicibus ,medicinis opus prclarum et ingens 444 7edited by ,brunfels1 ,argentorati1 #aeca1 p4 #bfj74 ,hali ,abbas 7',al ,ibn ,al ',abbas74 ,liber totius medicin necessaria cotinens 444 quem ,haly filius ,abbas edidit 444 et a ,stephano ex arabica lingua reductus 7,lugd41 #aebc1 p4 #agf verso74 ,santes de ,ardoniis 7or ,ardoynis74 ,incipit liber de venenis quem magister santes de ardoynis 444 edere cepit venetiis die octauo nouebris1 #adbd 7,venet41 #adib74 ,petrus ,apponensis 7or ,petrus de ,abano74 ,the loadstone is referred to in two works by this author4 7#a7 ,conciliator differentiarum philosophorum3 et precipue medicorum clarissimi viri ,petri de ,abano ,patauini feliciter incipit 7,venet41 #adif1 p4 #gb1 verso1 ,qustio ,,li474 7#b7 ,tractatus de ,venenis 7,roma1 #adij1 cap4 xi474 ,marcellus 7called ,marcellus ,empiricus74 ,de ,medicamentis1 in the volume ,medici antiqui omnes 7,venet41 #aedg1 p4 #hi74 ,arnaldus 7,arnaldus de ,villa ,nova74 ,incipit ,tractatus de virtutibus herbarum 7,venet41 #adii74 ,see also ,arnaldi ,villanovani ,opera omnia 7,basil41 #aehe74 ,marbodeus ,gallus4 ,marbodei ,galli poetae vetustissimi de lapidibus pretiosis ,enchiridion 7,friburgi1 #aecj #aeca1 p4 #da74 ,albertus ,magnus4 ,de ,mineralibus et rebus metallicis 7,venet41 #aedb1 lib4 ii41 de lapidibus preciosis1 p4 #aib74 ,there is a reference to the loadstone #g also in a work attributed falsely to ,albertus1 but now ascribed to ,henricus de ,saxonia1 ,de virtutibus herbarum1 de virtutibus lapidum1 etc4 7,rouen1 #aejj1 and subsequent editions74 ,an ,english version1 ,the ,secrets of ,albertus ,magnus of the vertues of hearbs stones and certaine beasts was publisht in ,london in #afag4 ,matthus ,silvaticus4 ,pandect ,medicin 7,lugduni1 #aeda1 cap4 #ddf74 ,hermolaus ,barbarus4 ,his work1 ,hermolai ,barbari ,patritii ,veneti et ,aqvileiensis patriarch ,corollarii ,libri quinque 444 ,venet41 #aeaf1 is an early herbal4 ,on p4 #ajc are to be found descriptions of lapis gagatis and lapis magnes4 ,the latter is mostly taken from ,pliny1 and mentions the alleged theamedes1 and the myth of the floating statue4 ,camillus ,leonardus4 ,speculum ,lapidum 7,venet41 #aejb1 fol4 xxxviii474 ,an ,english translation1 ,the ,mirror of ,stones1 appeared in ,london in #agej4 ,cornelius ,agrippa4 ,henrici ,cor4 ,agripp ab ,nettesheym 444 ,de ,occulta ,philosophia ,libri ,tres 7,antv41 #aeca74 ,the ,english version ,of the ,vanitie and uncertaintie of ,artes was publisht in ,london1 #aefi1 and again later4 ,fallopius 7,gabriellus74 ,g4 ,f4 de simplicibus medicamentis purgantibus tractatus 7,venet41 #aeff74 ,see also his ,tractatus de compositione medicamentorum 7,venet41 #aegj74 ,johannes ,langius4 ,epistolarum medicinalium volumen tripartitum 7,paris1 #aehi1 p4 #gib74 ,cardinalis ,cusanus 7,nicolas ,khrypffs1 ,cardinal de ,cusa74 ,nicolai ,cusani de staticis experimentis dialogus 7,argentorati1 #aeej74 ,the ,english edition1 entitled ,the ,idiot in four books1 is dated ,london1 #afej4 #i ,,page #c1 ,,line #a4 ,page #b1 line #db4 ,marcellus4--,marcellus ,empiricus1 mdecin de ,thodose-le-,grand1 dit que l'aimant1 appel antiphyson1 attire et repousse le fer4 7,klaproth1 ,sur l'invention de la boussole1 #ahcd1 p4 #ab47 ,the passage from ,marcellus runs3 ,magnetes lapis1 qui antiphyson dicitur1 qui ferrum trahit et abjicit1 et magnetes lapis qui sanguinem emittit et ferrum ad se trahit1 collo alligati aut circa caput dolori capitis medentur4 7,marcellus1 de ,medicamentis3 in the volume ,medici antiqui omnes1 qui latinis literis morborum genera persecuti sunt4 ,venet41 #aedg1 p4 #hi47 #aj ,,page #c1 ,,line #aa4 ,page #c1 line #i4 ,thomas ,erastus4--,the work in question is ,dispvtationvm de ,medicina nova ,philippi ,paracelsi1 ,pars ,prima3 in qua qu de remediis svperstitiosis ,magicis curationibus ille prodidit1 prcipu examinantur ,thoma ,erasto in ,schola ,heydebergensi1 professore4 7,basili1 #aegb4 ,parts #b and #c appeared the same year1 and ,part #d in #aegc47 ,gilbert had no more love for ,paracelsus than for ,albertus ,magnus or others of the magic-mongers4 ,indeed the few passages in ,paracelsus on the magnet are sorry stuff4 ,they will mostly be found in the seventh volume of his collected works 7,opera omnia1 ,frankfurt1 #afjc74 ,a sample may be taken from the ,english work publisht in ,london1 #afej1 with the title3 ,of the ,nature of ,things1 ,nine ,books2 written by ,philipp ,theophrastus of ,hohenheim1 called ,paracelsvs4 ,for any ,loadstone that ,mercury hath but touched1 or which hath been smeered with ,mercuriall oyle1 or only put into ,mercury will never draw ,iron more 7p4 #bc74 ,the life of the ,loadstone is the spirit of ,iron2 which may bee extracted1 and taken away with spirit of ,wine 7p4 #cb74 #aa ,,page #c1 ,,line #ac4 ,page #c1 line #aa4 ,encelius 7or ,entzelt1 ,christoph7 #h wrote a work publisht in #aeea at ,frankfurt1 with the title ,de re metallica1 hoc est1 de origine1 varietate1 et natura corporum metallicorum1 lapidum1 gemmarum1 atque aliarum qu ex fodinis eruuntur1 rerum1 ad medicine usum deservientium1 libri iii4 ,this is written in a singular medley of ,latin and ,german4 ,gilbert undoubtedly took from it many of his ideas about the properties of metals4 ,see the note to p4 #bg on plumbum album4 #ab ,,page #c1 ,,line #bj4 ,page #c1 line #ba4 ,thomas ,aquinas4--,the reference is to his commentaries upon the ,physica of ,aristotle4 ,the passage will be found on p4 #if bis of the ,giunta edition 7,venet41 #aeci74 ,the essential part is quoted by ,gilbert himself on p4 #fd4 #ac ,,page #c1 ,,line #ci4 ,page #c1 line #de4 pyxidem4--,the word pyxis1 which occurs here1 and in the next sentence as pyxidem nauticam1 is translated compass4 ,eleven lines lower occurs the term nautica pyxidula4 ,this latter word1 literally the little compass1 certainly refers to the portable compass used at sea4 ,compare several passages in ,book ,,iv4 where a contrasting use is made of these terms2 for example1 on pp4 #agg and #bjb4 ,calcagninus1 ,de re nautica1 uses the term pyxidecula for an instrument which he describes as vitro intecta4 ,on p4 #aeb1 line #i1 ,gilbert uses the non-classical noun compassus1 boreale lilium compassi 7quod ,boream respicit71 and again on p4 #agh1 line #c4 #ad ,,page #d1 ,,line #b4 ,page #d1 line #b4 ,melphitani4--,the inhabitants of ,amalfi in the kingdom of ,naples4 ,the claim of the discovery or invention of the mariners' compass in the year #acjb by one ,joannes ,goia1 or ,gioia1 also named as ,flavio ,goia1 has been much disputed4 ,in ,guthrie's ,new ,system of ,modern ,geography 7,london1 #agib1 p4 #ajcf71 in the ,chronology1 is set down for the year #acjb3 ,the mariner's compass invented1 or improved by ,givia1 of ,naples4 ,the flower de luce1 the arms of the ,duke of ,anjou1 then ,king of ,naples1 was placed by him at the point of the needle1 in compliment to that prince4 ,in #ahjh an elaborate treatise was printed at ,naples1 by ,flaminius ,venanson with the title1 ,de l'invention de la ,boussole ,nautique4 ,venanson1 who cites many authorities1 endeavours to prove that if ,gioia did not discover magnetic polarity he at least invented the compass1 that is to say1 he pivotted the magnetic needle and placed it in a box1 with a card affixed above it divided into sixteen parts bearing the names of the sixteen principal winds4 ,he alleges in proof that the compass-card is emblazoned in the armorial bearings of the city of ,amalfi4 ,this view was combatted in the famous letter of ,klaproth to ,humboldt publisht in ,paris in #ahcd4 ,he shows that the use of the magnetized needle was known in ,europe toward the end of the twelfth century2 that the ,chinese knew of it and used it for finding the way on land still earlier2 that there is no compass-card in the arms of the city of ,amalfi2 but he concedes that ,gioia may have improved the compass in #acjb by adding the wind-rose card4 ,the most recent contributions to the question are a pamphlet by ,signorelli1 ,sull' invenzione della ,bussola nautica1 ragionamento di ,pietro ,napoli ,signorelli1 segretario perpetuo della ,societ ,pontaniana2 letto nella seduta del #cj settembre #ahfj2 ,matteo ,camera's ,memorie ,storico-diplomatiche dell' antica citt e ducato di ,amalfi 7,salerno1 #ahgf72 and ,admiral ,luigi ,fincati's work ,il ,magnete1 la ,calamita1 e la ,bussola 7,roma1 #ahgh74 ,an older mention of ,gioia is to be found in ,blundevile's ,exercises 7#crd edition1 #afjf1 pp4 #beg-beh74 ,see also ,crescentio della ,nautica ,mediterranea1 7,roma1 #afjg1 p4 #bec71 and ,azuni1 ,dissertazione sull' origine della bussola nautica 7,venezia1 #agig74 #i ,there appears to be a slip in ,gilbert's reference to ,andrea ,doria1 as he has confounded the town of ,amalfi in ,principato ,citra with ,melfi in ,basilicata4 ,one of the sources relied upon by historians for ascribing this origin of the compass is the ,compendia dell' ,istoria del ,regno di ,napoli1 of ,collenuccio 7,venet41 ,,mdxci471 p4 #e4 ,n in questo tacer ,amalfi1 picciola terra1 capo della costa di ,picentia1 alia quale tutti quelli1 che'l mar caualcano1 vfficiosamente eterno gratie debono referire1 essendo prima in quella terra trovato l'vso1 l'artificio della calamita1 del bussolo1 col quale i nauiganti1 la stella ,tramontana infallibilmente mirando1 direzzano il lor corso1 si come publica fama1 gli ,amalfitani si gloriano1 n senza ragione dalli piu si crede1 essendo cosa certa1 che gli antichi tale instromento non hebbero2 n essendo mai in tutto falso quello1 che in molto tempo da molti si diuolga4 ,another account is to be found in the ,historiarum sui temporis1 etc41 of ,paulus ,jovius 7,florent41 #aeeb71 tom4 ii41 cap4 #be1 p4 #db4 ,quum essem apud ,philippum superuenit ,ioachinus ,leuantius ,ligur a ,lotrechio missus1 qui deposceret captiuos2 sed ille negauit se daturum1 quando eos ad ipsum ,andream ,auriam ammirantem deducendos esse iudicaret4 ,vgonis uer cadauer1 ut illudentium ,barbarorum contumeliis eriperetur1 ad ,amalphim urbem delatum est1 in deque ,andre apostoli1 tumultuariis exequiis tumulatum4 ,in hac urbe citriorum medicorum odoratis nemoribus qu peramoena celebri1 ,magnetis usum nauigantibus hodie familiarem necessarium1 adinuentum suisse incol asserunt4 ,flavius ,blondus1 whom ,gilbert cites1 gives the following reference1 in which ,gioia's name is not mentioned1 in the section upon ,campania ,felix of his ,italy 7,blondi ,flavii ,forlinensis 444 ,italia ,illustrata1 ,basili1 #aeca1 p4 #dbj74 ,sed fama est qua ,amalphitanos audiuimus gloriari1 magnetis usum1 cuius adminiculo nauigantes ad arcton diriguntur1 ,amalphi suisse inuentum1 quicquid uero habeat in ea re ueritas1 cert est id noctu nauigandi auxilium priscis omnino suisse incognitum4 ,there is a further reference to the alleged ,amalphian in ,caelius ,calcagninus ,de re nautica commentatio4 7,see ,thesaurus ,grcarum ,antiquitatum1 #afig1 vol4 xi41 p4 #gfa47 ,on the other hand ,baptista ,porta1 who wrote in ,naples in #aeeh 7,magia ,naturalis7 distinctly sets aside the claim as baseless4 ,william ,barlowe1 in ,the ,navigators ,supply 7#aeig1 p4 ,a#c71 says3 ,who was the first inuentor of this ,instrument miraculous1 and endued1 as it were1 with life1 can hardly be found4 ,the lame tale of one ,flauius at ,amelphis1 in the kingdome of ,naples1 for to haue deuised it1 is of very slender probabilitie4 ,pandulph ,collenutius writing the ,neapolitane historie telleth vs1 that they of ,amelphis say1 it is a common opinion there1 that it was first found out among them4 ,but ,polidore ,virgil1 who searched most diligently for the ,inuentors of things1 could neuer heare of this opinion 7yet himselfe being an ,italian7 and as he confesseth in the later ende of his third booke de inventoribus rerum1 could neuer vnderstand anything concerning the first inuention of this instrument4 ,according to ,park ,benjamin 7,intellectual ,rise in ,electricity1 p4 #adf7 the use of the pivotted compass arose and spread not from ,amalfi at the hands of ,italians in the fourteenth century1 but from ,wisbuy1 at the hands of the ,finns1 in the middle of the twelfth century4 #aj ,hakewill 7,an ,apologie or ,declaration of the ,power and ,providence of ,god1 ,london1 #afgc1 pp4 #bhd-bhe7 says3 ,but ,blondus1 who is therein followed by ,pancirollus1 both ,italians1 will not haue ,italy loose the praise thereof1 telling vs that about #cjj yeares agoe it was found out at ,malphis or ,melphis1 a ,citty in the ,kingdome of ,naples in the ,province of ,campania1 now called ,terra di ,lovorador4 ,but for the ,author of it1 the one names him not1 and the other assures vs1 he is not knowne3 yet ,salmuth out of ,ciezus ,gomara confidently christens him with the name of ,flavius1 and so doth ,du ,bartas in those excellent verses of his touching this subject4 ',w' are not to ,ceres so much bound for bread1 ,neither to ,bacchus for his clusters red1 ,as ,signior ,flavio to thy witty tryall1 ,for first inventing of the ,sea-mans dyall1 ,th' vse of the needle turning in the same1 ,divine device1 ,o admirable frame6' ,it may well be then that ,flavius the ,melvitan was the first inventor of guiding the ship by the turning of the needle to the ,north3 but some ,german afterwards added to the ,compasse the #cb points of the winde in his owne language1 whence other ,nations haue since borrowed it4 #ae ,,page #d1 ,,line #ad4 ,page #d1 line #ad4 ,paulum ,venetum4--,the reference is to ,marco ,polo4 ,he returned in #abie from his famous voyage to ,cathay4 ,but the oft-repeated tale that he first introduced the knowledge of the compass into ,europe on his return is disposed of by several well-established facts4 ,klaproth 7op4 citat41 p4 #eg7 adduces a mention of its use in #abdj in the ,eastern ,mediterranean1 recorded in a work written in #abdb by ,bailak of ,kibdjak4 ,and the passages in the ,iceland ,chronicle1 and in ,alexander of ,neckham are still earlier4 #af ,,page #d1 ,,line #ag4 ,page #d1 line #ag4 ,goropius4 ,see ,hispanica ,ioannis ,goropii ,becani 7,plantin edition1 ,antv41 #aehj71 p4 #bi4 ,this is a discussion of the etymologies of the names of the points of the compass3 but is quite unauthoritative4 #ag ,,page #d1 ,,line #bc4 ,page #d1 line #bf4 ,paruaim4--,respecting this reference1 ,sir ,philip ,magnus has kindly furnisht the following note4 ,a clue to the meaning of ,parvaim1 which should be written in ,english letters with a v1 not a u1 will be found in #b ,chronicles1 iii4 #f4 ,in the verse quoted the author speaks of gold as the gold of ,parvaim1 ,hebrew3 ,,whazahab ,,zhab ,,parwayim1 and ,hebrew3 ,,prwym ,parvaim is taken as a gold-producing region4 ,it is regarded by some as the same as ,ophir4 ,the word is supposed to be cognate with a ,sanskrit word prva signifying prior1 anterior1 oriental4 ,there is nothing in the root indicating gold4 ,a form similar to ,parvaim1 and also a proper name1 is ,sepharvaim1 found in #b ,kings1 xix4 #ac1 and in ,isaiah1 xxxvii4 #ac1 and supposed to be the name of a city in ,assyria4 #ah ,,page #d1 ,,line #ce4 ,page #d1 line #da4 ,cabot's observation of the variation of the compass is narrated in the ,geografia of ,livio ,sanuto 7,vinegia1 #aehh1 lib4 i41 fol4 #b74 ,see also ,fournier's ,hydrographie1 lib4 xi41 cap4 #aj4 #ai ,,page #d1 ,,line #cf4 ,page #d1 line #db4 ,gonzalus ,oviedus4--,the reference is to ,gonzalo ,fernandez de ,oviedo y ,valds4 ,summario de la ,historia general y natural de las ,indias occidentales1 #aebe1 p4 #dh1 where the author speaks of the crossing of la linea del ,diametro1 donde las ,agujas hacen la #aa diferencia del ,nordestear1 ,noroestear1 que es el parage de las ,islas de los ,aores4 #bj ,,page #e1 ,,line #h4 ,page #e1 line #aa4 ,petri cujusdam ,peregrini4--,this opusculum is the famous letter of ,peter ,peregrinus written in #abfi1 of which some twenty manuscript copies exist in various libraries in ,oxford1 ,rome1 ,paris1 etc41 and of which the oldest printed edition is that of #aeeh 7,augsburg74 ,see also ,libri1 ,histoire des ,sciences ,mathmatiques 7#ahch72 ,bertelli in ,boncompagni's ,bull4 d4 ,bibliogr4 ,t4 ,i4 and ,t4 ,,iv4 7#ahfh and #ahga71 and ,hellmann's ,rara ,magnetica 7#ahih74 ,a summary of the contents of ,peregrinus's book will be found in ,park ,benjamin's ,intellectual ,rise in ,electricity 7#ahie71 pp4 #afd-ahe4 #ba ,,page #e1 ,,line #ab4 ,page #e1 line #ae4 ,johannes ,taisner ,hannonius4--,taisnier1 or ,taysnier1 of ,hainault1 was a plagiarist who took most of the treatise of ,peregrinus and publisht it in his ,opusculum444 de ,natura ,magnetis 7,coloni1 #aefb71 of which an ,english translation by ,richard ,eden was printed by ,r4 ,jugge in #aegi4 #bb ,,page #e1 ,,line #ah4 ,page #e1 line #bc4 ,collegium ,conimbricense4--,this is a reference to the commentaries on ,aristotle by the ,jesuits of ,coimbra4 ,the work is ,colegio de ,coimbra da ,companhia de ,jesu1 ,cursus ,conimbricensis in ,octo libros ,physicorum 7,coloni1 sumptibus ,lazari ,ratzneri1 #aeii74 ,other editions3 ,lugd4 #aeid2 and ,colon41 #aeif4 ,the later edition of #afji1 in the ,british ,museum1 has the title ,commentariorum ,collegii ,conimbricensis in octo libros physicorum4 #bc ,,page #e1 ,,line #be4 ,page #e1 line #ca4 ,martinus ,cortesius4--,his ,arte de ,navegar 7,sevilla1 #aeef7 went through various editions in ,spanish1 ,italian1 and ,english4 ,eden's translation was publisht #aefa1 and again in #afji4 #bd ,,page #e1 ,,line #bf4 ,page #e1 line #cc4 ,bessardus4--,toussaincte de ,bessard wrote a treatise1 ,dialogue de la ,longitude 7,rouen1 #aegd71 which gives some useful notes of nautical practice1 and of the ,french construction of the compass4 ,speaking of the needle he says3 ,elle ne tire pas au pole du monde3 ains regarde1 au ,pole du ,zodiaque1 comme il sera discoursu1 cy apres 7p4 #cd74 ,on p4 #ej he speaks of l'aiguille ,aymantine4 ,on p4 #ajh he refers to ,mercator's ,carte ,gnrale1 and denies the existence of the alleged loadstone rock4 ,on p4 #ae he gives the most nave etymologies for the terms used3 thus he assigns as the derivation of ,sud the ,latin sudor1 because the south is hot1 and as that of ,ouest that it comes from ,ou and ,est4 ,come1 qui diroit1 ,ou est-il8 scauoir le ,soleil1 qui estoit nagueres sur la terre4 #be ,,page #e1 ,,line #bh4 ,page #e1 line #ce4 ,jacobus ,severtius4--,jacques ,severt1 whose work1 ,de ,orbis ,catoptrici sev mapparvm mvndi principiis descriptione ac usu libri tres 7,paris1 #aeih71 would have probably lapsed into obscurity1 but being just newly publisht was mentioned by ,gilbert for its follies4 #bf ,,page #e1 ,,line #cj4 ,page #e1 line #ch4 ,robertus ,norman4--,author of the rare volume ,the ,newe ,attractiue1 publisht in ,london1 #aeha1 and several times reprinted4 ,this work contains an account of ,norman's discovery of the ,dip of the magnetic needle1 and of his investigation of it by means of the ,dipping-needle1 which he invented4 ,he was a compassmaker of the port of ,london1 and lived at ,limehouse4 #bg ,,page #e1 ,,line #cb4 ,page #e1 line #dj4 ,franciscus ,maurolycus4--,the work to which the myth of the magnetic mountains is thus credited is1 ,d4 ,francisci ,abbatis ,messanensis ,opuscula ,mathematica1 etc4 7,venet1 ,,mdlxxv1 p4 #abb;a74 ,sed cur sagitta1 vel obelus vero ,septentrione1 quandoque ad dextram1 #ab quandoque ad sinistram declinat8 ,an quia sagitta1 sicut magnes 7cuius est simia7 non verum ,septentrionem1 sed insulam quandam 7quam ,olaus ,magnus ,gothus in sua geographia vocat insulam magnetum7 semper ex natura inspicere cogitur8 #bh ,,page #e1 ,,line #ce4 ,page #e1 line #dc4 ,olaus ,magnus4--,the famous ,archbishop of ,upsala1 who wrote the history of the northern nations 7,historia de ,gentibus ,septentrionalibus71 of which the best edition1 illustrated with many woodcuts1 appeared in ,rome in #aeee4 ,an ,english edition entitled ,a ,compendious ,history of the ,goths1 ,swedes1 and ,vandals1 and ,other ,northern ,nations was printed in ,london in #afeh2 but it is much abbreviated and has none of the quaint woodcuts4 ,the reference on p4 #e appears to be to the following passage on p4 #dji 7ed4 #aeee74 ,demum in suppolaribus insulis magnetum montes reperiuntur1 quorum fragmentis ligna fagina certo tempore applicata1 in saxeam duritiem1 et vim attractivam convertuntur1 or the following on p4 #hi3 ,magnetes enim in extremo ,septentrionis veluti montes1 unde nautica directio constat1 reperiuntur3 quorum etiam magnetum tam vehemens est operatio1 ut certis lignis fagineis conjuncti1 ea vertunt in sui duritiem1 naturam attractivam4 ,on p4 #cdc is a woodcut depicting the penalties inflicted by the naval laws upon any one who should maliciously tamper with the compass or the loadstone1 qui malitios nauticum gnomonem1 aut compassum1 prcipu portionem magnetis1 unde omnium directio dependet1 falsaverit4 ,he was to be pinned to the mast by a dagger thrust through his hand4 ,it will be noted that the ships carried both a compass1 and a piece of loadstone wherewith to stroke the needle4 ,there is in the ,basel edition of this work1 #aefg1 a note ad lectorem1 on the margin of ,carta #af;a1 as follows3 ,insula #cj milliarium in longitud4 latitud4 ,polo arctico subjecta4 ,vltra quam directorium nauticum bossolo dicu uires amittit3 propterea qud ilia insula plena est magnetum4 ,this myth of the magnetic mountains1 probably originating with ,nicander1 appears1 possibly from an independent source1 in the ,east1 in ,china1 and in the tales of the ,arabian ,nights4 ,ptolemy gives the following account in his ,geographia 7lib4 vii41 cap4 #b73 ,greek3 ,pherontai de kai allai sunecheis deka nsoi kaloumenai ,maniolai en ais phasi ta sidrous echonta hlous ploia katechesthai1 mpote ts ,hrikleias lithou peri autas genomens1 kai dia touto epiourois naupgeisthai4 ,some editions omit the name of the ,manioles from the passage4 ,no two authorities agree as to the place of these alleged magnetic mountains4 ,some place them in the ,red ,sea4 ,fracastorio1 ,de ,sympathia et ,antipathia1 cap4 #g 7,opera omnia1 ,giunta edition1 #aegd1 p4 #fc71 gives the following reason for the variation of the compass3 ,nos igitur diligentius rem considertes dicimus causam1 q perpendiculum illud ad polum vertatur1 esse montes ferri1 magnetis1 qui sub polo sunt1 vt negociatores affirmant1 quorum species per incredibilem distantiam vsque ad maria nostra propagata ad perpendiculum vsq21 vbi est magnes1 consuetam attractionem facit3 propter distantiam autem quum debilis sit1 non moueret quidem magnetem1 nisi esset in perpendiculo3 quare si non trahit vsq2 ac4 principium1 vnde effluxit1 at mouet tame1 propinquiorem facit1 quo potest4 ,quod si naues sorte vll propinquiores sint illis montibus1 ferrum omne earu cuellitur1 propter quod nauigijs incol vtuntur clauis ligneis astrictis4 ,in the last chapter of his ,de ,sympathia1 ,fracastorio returns to the subject #ac in consequence of some doubts expressed by ,giambattista ,rhamnusio1 seeing that the loadstones in the ,island of ,elba do not sensibly deflect the magnet4 ,fracastorio replies thus 7p4 #gf1 op4 citat473 ,primum igitur vtrum sub ,polo sint4 ,magnetis mtes1 nec ne1 sub ambiguo relinquamus1 scimus enim esse1 qui scribt planas magis esse eas regiones1 de quo ,paulus ,iouius ,epus ,nucerinus ,luculetus historiaru nostri teporis scriptor1 circa e ,sarmati partem1 qu ,moscouia nuc dicitur1 diligente inquisitionem ab incolis fecit1 qui ne eos eti inueniri montes retulere1 qui ,rhyphei ab antiquis dicti sunt3 meminimus tame nos quasdam chartas vidisse earum1 quas mundi mappas appellt1 in quibus sub polo montes notati erant 7qui ,magnetis montes inscripti fuerant74 ,siue igitur sint1 siue non sint ij montes1 nihil ad nos in prsentiarum attinet1 quando per montes polo subiectos cathenam illam montium intelligimus1 qui ad septentrionem spectant tanti1 tam vasti1 ac ,ferri ,magnetis feraces3 qui1 si magis distant nostro mari1 q ,ilu insul montes1 potentiores tamen sunt ad mouendum perpendiculum propter abundantiam copi ,ferri1 ,magnetis4 ,fortasse autem1 qui in ,ilua est ,magnes1 non mult actionis est in ea minera3 multi enim du in minera sunt1 minus valent1 q extracti1 q spirituales species sua habeant impedimenta3 signum autem parum valere in sua minera ,ilu insul ,magnetem1 q tam propinquus quum sit nauigijs illac prtereuntibus1 perpendiculum tamen non ad se cuertit4 ,aldrovandi in the ,musum ,metallicum 7,bonon41 #afdh1 p4 #eed7 gives another version of the fable3 ,nonnulli1 animadversa hac ,magnetis natura1 scripserunt naves1 quibus in ,calecutanam regionem navigatur1 clavis ferreis non figi1 ob magneticorum frequentiam scopulorum1 quoniam facil dissolverentur4 ,sed ,garzias in ,historia ,aromatum id fabulosum esse tradidit3 quandoquidem plures naues ,calecutan regionis1 illius tractus1 ferreis clauis iunctas obseruauit3 imm addidit naues in insulis ,maldiuis ligneis quidem clauis copulari1 non quia ,magnete sibi metuant1 sed quoniam ferri inopia laborant4 ,according to ,aldrovandi 7p4 #efc1 op4 citat47 the magnetic mountains are stated by ,sir ,john ,mandeville to be in the region of ,pontus4 ,lipenius in his ,navigatio ,salomonis ,ophritica illustrata 7,witteb41 #affj71 which is a mine of curious learning1 in discussing the magnetic mountains quotes the reply of ,socrates to the inquirer who asked him as to what went on in the infernal regions1 saying that he had never been there nor had he ever met any one who had returned thence4 ,the loadstone rock figures in several early charts4 ,in ,nordenskild's ,facsimile ,atlas 7,stockholm1 #ahhi7 is given a copy of the ,map of ,johan ,ruysch from an edition of ,ptolemy1 publisht in ,rome in #aejh1 which shows four islands within the ice-bound ,arctic regions4 ,south of these islands and at the east of the coast of ,greenland is the inscription3 ,hic compassus navium non tenet1 nec naves qu ferrum tenent revertere valent4 ,to which 7on p4 #fc7 ,nordenskild adds the comment3 ,sagan on magnetberg1 som skulle draga till sig fartyg frande jern1 r gamal4 ,and he recalls the reference of ,ptolemy to the magnetic rocks in the ,manioles4 ,a second inscription is added to ,ruysch's map in the ornamental margin that borders the ,arctic islands4 ,legere est in libro de inventione fortunati sub polo arctico rupem esse excelsam ex lapide magnete #cc miliarium germanorum ambitu4 ,this refers to a matter recorded in ,hakluyt's ,principall ,navigations 7,lond41 #aehi1 p4 #bdi71 namely3 ,a ,testimonie of the learned ,mathematician1 maister ,john ,dee1 #ad touching the foresaid voyage of ,nicholas de ,linna4 ,anno #acfj a frier of ,oxford1 being a good ,astronomer1 went in companie with others to the most ,northren islands of the world1 and there leaving his company together1 he travelled alone1 and purposely described all the ,northern islands1 with the indrawing seas3 and the record thereof at his return he delivered to the king of ,england4 ,the name of which booke is ,inventio ,fortunata 7aliter fortun7 qui liber incipit a gradu #ed usq4 ad polum4 ,the situation of the alleged loadstone rock is thus described by ,t4 ,blundevile in his ,exercises in the chapter entitled ,a plaine and full description of ,peter ,plancius his vniuersall ,map1 seruing both for sea and land1 and by him lately put foorth in the yeare of our ,lord1 #aeib4444 ,written in our mother tongue by ,m4 ,blundeuill1 ,anno ,domini #aeid4 ,the passage is quoted from p4 #bec of the third edition 7#afjf73 ,now betwixt the #gb4 and #hf4 degrees of ,north latitude he setteth downe two long ,ilands extending from the ,west towardes the ,east somewhat beyond the first ,meridian1 and from the saide ,meridian more ,eastward he setteth downe other two long ,ilandes 444 and hee saith further that right under the ,north pole there is a certaine blacke and most high rocke which hath in circuite thirtie and three leagues1 which is nintie and nine miles1 and that the long ,iland next to the ,pole on the ,west is the best and most healthfull of all the ,north parts4 ,next to the foresaide ,ilandes more ,southward hee setteth downe the ,ilandes of ,crocklande and ,groynelande1 making them to haue a farre longer and more slender shape then all other mappes doe4444 ,moreouer at the ,east end of the last ,ilande somewhat to the ,southwarde1 he placeth the ,pole of the ,lodestone which is called in ,latine ,magnes1 euen as ,mercator doth in his ,mappe who supposing the first ,meridian to passe through ,saint ,marie or ,saint ,michael1 which are two of the outermost ,ilandes of the ,azores ,eastwarde1 placeth the ,pole of the stone in the seuentie fiue degree of ,latitude1 but supposing the first ,meridian to passe through the ,ile ,coruo1 which is the furthest ,ile of the ,azores ,westwarde1 he placeth the ,pole of the ,lodestone in the seuentie seuen degree of ,latitude4 ,further1 in the chapter on ,the ,arte of ,nauigation in the same work 7p4 #ccb1 ed4 citat471 ,blundevile says3 ,but whereas ,mercator affirmeth that there should bee a mine or great rocke of ,adamant1 wherunto all other lesser rockes or ,needles touched with the ,lodestone doe incline as to their chiefe fountaine1 that opinion seemeth to mee verie straunge1 for truely ,i rather beleeue with ,robert ,norman that the properties of the ,stone1 as well in drawing steele1 as in shewing the ,north ,pole1 are secret vertues given of ,,god to that stone for mans necessarie vse and behoofe1 of which secrete vertues no man is able to shewe the true cause4 ,the following is one of the inscriptions in the compartments of the great ,chart of ,mercator entitled ,ad ,usum ,navigantium1 published in #aefi3 ,testatur ,franciscus ,diepanus peritissimus nauarchus volubiles libellas1 magnetis virtute infectas recta mundi polum respicere in insulis ,c4 ,viridis1 ,solis1 ,bonauista1 et ,maio1 cui proxime astipulantur qui in ,tercera1 aut ,s4 ,maria 7insul sunt inter ,aores7 id fieri dicunt1 pauci in earundem occidentalissima ,corvi nomine id contingere opinantur4 ,quia vero locorum longitudinis a communi magnetis et mundi meridiano iustis de causis initium sumere oportet1 plurium testimonium sequutus primum meridianum per dictas ,c4 ,viridis insulas protraxi1 et quum alibi plus minusque a polo deuiante #ae magnete polum aliquum peculiarem esse oporteat quo magnetes ex omni mundi parte despiciant1 euum hoc quo assignaui loco existere adhibita declinatione magnetis ,ratisbon obseruata didici4 ,supputaui autem eius poli situm etiam respectu insul ,corui1 ut iuxta extremo primi meridiani positus extremi etiam termini1 intra quos polum hunc inueniri necesse est1 conspicui fierent1 donec certius aliquod nauclerorum obseruatio attulerit4 ,not all the map-makers were as frank as ,paulus ,merula1 the author of a ,cosmographia ,generalis1 printed by ,plantin in #afje1 at ,leyden4 ,for in the description of his tabula universalis 7op4 citat4 lib4 iii41 cap4 #i7 he says that he does not believe in the magnetic islands2 but that he has put them into his chart lest unskilful folk should think that he had been so careless as to leave them out6 ,in the well-known myth of ,ogier the ,dane1 immortalized by ,william ,morris in the ,earthly ,paradise 7,london1 #ahfi1 vol4 i41 p4 #fbe71 the loadstone rock is an island in the far ,north4 ,but this story is not one of the ,scandinavian sagas1 and belongs to the ,carlovingian cycle of heroic poems1 of which the chief is the ,chanson de ,roland2 and ,ogier le ,danois is really not a ,dane but an ,ardennois4 ,in the ,middle-,high ,german epic of ,kudrun1 the adventures of the fleet of ,queen ,hilda when attracted by the loadstone mountain at ,givers1 in the ,north ,sea1 are narrated at some length4 7,see ,kudrun1 herausgegeben und erklrt von ,ernst ,martin4 ,halle1 #ahgb47 ,one stanza will serve as a sample3 #aabf4 ,ze ,givers vor dem berge lac daz ,hilden her4 swie guot ir anker wren1 an daz vinster mer4 magnten die steine heten si gezogen4 ir guote segelboume stuonden alle gebogen4 which may be rendered3 #aabf4 ,at ,givers before the mountain lay ,hilda's ships by4 ,though good their anchors were1 upon the murky sea4 ,magnets the stones were had drawn them thither4 ,their good sailing masts stood all bent together4 ,recent magnetic research has shown that while there are no magnetic mountains that would account for the declination of the compass in general1 yet there are minor local variations that can only be accounted for by the presence of magnetic reefs or rocks4 ,the reader is referred to the account of the magnetic survey of ,great ,britain in the ,philosophical ,transactions 7#ahij7 by ,professors ,rcker and ,thorpe4 ,the well-known rocky peak the ,riffelhorn above ,zermatt1 in ,switzerland1 produces distinct perturbations in the direction of the compass within half a mile of its base4 ,such local perturbations are regularly used in ,sweden for tracing out the position of underground lodes of iron ore4 ,see ,thaln1 ,sur la ,recherche des ,mines de ,fer l'aide de ,mesures magntiques 7,soc4 ,royale des ,sciences d',upsal1 #ahgg72 or ,b4 ,r4 ,brough1 ,the ,use of the ,magnetic ,needle in exploring for ,iron ,ore 7,scientific ,american1 ,suppl4 ,no4 #fjh1 p4 #igjh1 ,aug4 #bg1 #ahhg74 ,quite recently ,dr4 ,henry ,wilde1 ,f4,r4,s41 has endeavoured to elucidate the deviations of the compass as the result of the configurations of land and sea on the globe1 by means of a model globe in which the ocean areas are covered with thin sheet iron4 ,this apparatus ,dr4 ,wilde calls a ,magnetarium4 ,see ,proc4 ,roy4 ,soc41 ,june1 #ahij1 ,jan41 #ahia1 and ,june1 #ahia4 #af ,an actual magnetic rock exists in ,scandinavia1 the following account of it being given in the ,electrical ,review of ,new ,york1 ,may #c1 #ahii3 ,the island of ,bornholm in the ,baltic1 which consists of a mass of magnetic iron ore1 is much feared by mariners4 ,on being sighted they discontinue steering by compass1 and go instead by lighthouses4 ,between ,bornholm and the mainland there is also a dangerous bank of rock under water4 ,it is said that the magnetic influence of this ore bank is so powerful that a balanced magnetic needle suspended freely in a boat over the bank will take a vertical position4 #bi ,,page #e1 ,,line #ce4 ,page #e1 line #dc4 ,josephus ,costa4--,this is unquestionably a misprint for ,acosta 7,joseph de71 the ,jesuit1 whose work ,historia natural y moral de las ,indias was publisht at ,seville in #aeij4 ,an ,italian edition appeared at ,venice in #aeif4 ,the ,english edition1 translated by ,e4 ,grimestone1 ,the ,naturall and ,morall ,historie of the ,east and ,west ,indies1 was publisht in ,london in #afjd and #ahgh4 ,there are in ,gilbert's book references to two writers of the name of ,costa or ,costus1 ,joannes ,costa of ,lodi1 who edited ,galen and ,avicenna 7see pp4 #c and #fb71 and ,filippo ,costa of ,mantua1 who wrote on antidotes and medicaments 7see p4 #ada74 ,the passage to which ,gilbert refers is in ,acosta's ,historia 7ed4 #aeij1 p4 #fd74 ,deziame a mi vn piloto muy diestro ,portugues q eran quatro puntos en todo el orbe1 donde se afixaua el aguja con el ,norte1 y contaualas por sus nombres1 de que no me acuerdo bien4 ,vno destos es el paraje de la ,isla del ,cueruo1 en las ,terceras1 o ,islas de ,aores1 como es cosa y a muy sabida4 ,passando di alli a mas altura1 ,noruestea1 que es dezir1 q declina al ,poniente 444 que me dig la causa desta efecto8444 ,porque vn poco de hierro de fregarse c la piedra ,iman 444 ,mejor es1 como dize ,gregorio ,theologo1 que a la ,fe se sujete la razon1 pues aun en su casa no sabe bien entenderse4444 #cj ,,page #e1 ,,line #cf4 ,page #e1 line #de4 ,livius ,sanutus4--,livio ,sanuto publisht at ,venice in #aehh a folio work1 ,geografia distinta in xii ,libri2 ne' quali1 oltre l'esplicatione di nostri luoghi di ,tolomeo1 della ,bussola e dell' ,aguglia1 si dichiarono le provincie 444 dell' ,africa4 ,in this work all ,liber i4 7pages #a-ac7 deals with observations of the compass1 mentioning ,sebastian ,cabot1 and other navigators4 ,he gives a map of ,africa1 showing the central lakes out of which flow the ,zaires fluvius and the ,zanberes fluvius4 #ca ,,page #f1 ,,line #b4 ,page #f1 line #e4 ,fortunius ,affaitatus4--,the work of ,affaytatus1 ,physic ac astronomi considerationes1 was publisht in ,venice in #aedi4 #cb ,,page #f1 ,,line #c4 ,page #f1 line #f4 ,baptista ,porta4--,the reference is to his celebrated ,magia naturalis1 the first edition of which came out in #aeeh at ,naples4 ,an ,english edition1 ,natural ,magick by ,john ,baptista ,porta1 a ,neapolitaine1 was printed in ,london1 #afeh4 ,book seven of this volume treats ,of the wonders of the ,load-stone4 ,in the proem to this book ,porta says3 ,i knew at ,venice ,r4 ,m4 ,paulus1 the ,venetian1 that was busied in the same study3 he was ,provincial of the ,order of servants1 but now a most worthy ,advocate1 from whom ,i not only confess1 that ,i gained something1 but ,i glory in it1 because of all the men ,i ever saw1 ,i never saw any man more learned1 or more ingenious1 having obtained the whole body of learning2 and is not only the ,splendor and ,ornament of ,venice or ,italy1 but of the whole world4 ,the reference is to ,fra ,paolo ,sarpi1 better known as the historian of the ,council of ,trent4 ,sarpi was himself known to ,gilbert4 #ag ,his relations with ,gilbert are set forth in the memoir prefixt to the edition of his works1 ,opere di ,fra ,paolo ,sarpi1 ,servita 444 in ,helmstat1 ,,mdcclxi1 p4 #hc4 ,fino a questi giorni continuava il ,sarpi a raccorre osservazioni sulla declinazione dell' ,ago ,calamitato2 e poi ch' egli1 atteso il variare di tal declinazione1 assurdit alcuna non trovava riguardo al pensamento dell' ,inglese ,guglielmo ,gilberto1 cio1 che l'interno del nostro ,globo fosse gran ,calamita4444 ,here follows a quotation from a letter of ,sarpi to ,lescasserio3 444 ,unde cuspidem trahi a tanta mole terrena1 qu supereminet non absurde putavit ,gullielmus ,gilbertus1 et in eo meridiano respicere recta polum1 cave putes observatorem errasse4 ,est ,vir accuratissimus1 et interfuit omnibus observationibus1 quas plures olim fecimus1 et aliquas in sui gratiam1 et cum arcubus vertici cupreo innitentibus1 et cum innatantibus aqu1 et cum brevibus1 et cum longis1 quibus modis omnibus et ,hierapoli usus suit4 ,sarpi had correspondence with ,gilbert1 ,bacon1 ,grotius1 and ,casaubon4 ,he also wrote on magnetism and other topics in materia di ,fisica1 but these writings have perisht4 ,he appears to have been the first to recognize that fire destroyed the magnetic properties4 7,see ,fra ,paolo ,sarpi1 the greatest of the ,venetians by the ,rev4 ,alexander ,robertson1 ,london1 #ahid2 see also the notice of ,sarpi in ,park ,benjamin's ,intellectual ,rise in ,electricity47 #cc ,,page #f1 ,,line #g4 ,page #f1 line #aa43 ,r4 ,m4 ,paulus ,venetus4 ,see preceding note4 #cd ,,page #f1 ,,line #ba4 ,page #f1 line #bh43 ,franciscus ,rueus4--,francois de la ,rue1 author of ,de ,gemmis ,aliquot 444 7,paris1 #aedg74 ,amongst other fables narrated by ,rueus is that if a magnet is hung on a balance1 when a piece of iron is attracted and adheres to the magnet1 it adds nothing to the weight6 #ce ,,page #f1 ,,line #be4 ,page #f1 line #cc43 ,serapio4--,this account of the magnetic mountains will be found in an early pharmacology printed in #aeca 7,argentorati1 ,g4 ,ulricher ,andlenus71 with the title ,in hoc volumine continetur insignium medicorum ,joan4 ,serapionis ,arabis de ,simplicibus ,medicinis opus prclarum et ingens1 ,averrois ,arabis de eisdem liber eximius1 ,rasis filius ,zachari de eisdem opusculum perutile4 ,it was edited by ,otho ,brunsels4 ,achilles ,p4 ,gasser1 in his ,appendix to the ,augsburg edition of ,peregrinus1 gives a reference to ,serapio ,mauritanus1 parte #b1 cap4 #cid1 libri de medicinis compositis4 #cf ,,page #f1 ,,line #cj4 ,page #f1 line #ci43 ,olaus ,magnus4 ,see note to p4 #e4 #cg ,,page #f1 ,,line #cd4 ,page #f1 line #dd43 ,hali ,abas4--,a reference is given in ,gasser's 7#aeeh7 edition of ,peregrinus to ,haliabbas ,arabs1 lib4 #b1 practic cap4 #de1 ,regalis ,dispositionis ,medicin4 ,the passage to which ,gilbert refers is found in the volume ,liber totius medicin necessaria cotinens 444 quem ,haly filius ,abbas 444 edidit 444 et a ,stephano ex arabica lingua reductus4 7,lugd41 #aebc1 #dto47 ,liber ,primus4 ,practice1 ,cap xlv4 de speciebus lapidum1 #dff4 ,lapis magnetes filis e vtute sadenego3 aiunt qm si teneatr in manu mitigat q sunt in pedibs ipis dolores ac spasmu4 ,mr4 ,a4 ,g4 ,ellis identifies the noun sadenegum as a ,latin corruption of the ,arabic name of hmatite1 shdanaj4 #ch ,,page #f1 ,,line #cf4 ,page #f1 line #df43 ,pictorius4--,his poem was publisht at ,basel1 #aefg4 ,see also note on ,marbodus1 p4 #g1 line #bj1 below4 #ci ,,page #f1 ,,line #cf4 ,page #g1 line #a43 ,albertus ,magnus4--,albertus1 the celebrated ,archbishop of ,ratisbon1 is responsible for propagating sundry of the myths of the magnet2 and ,gilbert never loses a chance of girding at him4 #ah ,the following examples are taken from the treatise ,de mineralibus et rebus metallicis 7,liber ,,ii4 de lapidibus preciosis71 ,venet41 #aedb4 p4 #aga4 ,et quod mirabile videtur multis his lapis adamas quando ,magneti supponitur ligat ,magnetem et non permittit ipsum ferrum trahere4 p4 #aic4 ,vnctus aute lapis alleo non trahit1 si superponitur ei ,adamas iterum non attrahit1 ita quod paruus ,adamas magnu ligat ,magnete4 ,inventus aute est nostris teporibus ,magnes qui ab uno angulo traxit ferru et ab alio fugavit1 et hunc ,aristot4 ponit aliud genus esse ,magnetis4 ,narrauit mihi quidam ex nostris sociis experimetator quod uidit ,federicum ,imperatorem habere ,magnetem qui non traxit ferrum1 sed ferrum uiceuersa traxit lapidem4 ,the first edition of this work de mineralibus appears to have been publisht in ,venice as a folio in #adie4 #dj ,,page #g1 ,,line #i4 ,page #g1 line #ae4 ,gaudentius ,merula4--,this obscure passage is from ,liber ,,iiii41 cap4 xxi41 ,lapides1 of the work ,memorabilium ,gaudentii ,merul444 7,lugd41 #aeef71 where we find3 ,qui magneti vrs sculpserit imaginem1 qudo ,luna melius illuc aspiciat1 filo ferreo suspederit1 compos fiet vrs clestis virtutis3 verm cum ,saturni radiis vegetetur1 satius fuerit eam imaginem non habere3 scribunt enim ,platonici malos dmones septentrionales esse 7p4 #bhg74 ,trahit autem magnes ferrum ad se1 quod ferro sit ordine superior apud vrsum 7p4 #bhg74 ,the almost equally obscure passage in the ,de triplici vita of ,marsiglio ,ficino 7,basil41 #aecb7 runs3 ,videmus in specula nautarum indice poli libratum acum affectum in extremitate ,magnete moueri ad ,vrsam1 illuc uidelicet trahente ,magnete3 quoniam in lapide hoc prualet uirtus ,vrs1 hinc transfertur in ferrum1 ad ,vrsam trahit utrunq24 ,virtus autem eiusmodi tum ab initio infusa est1 tum continue ,vrs radijs uegetatur1 ,forsitan ita se habet ,succinum ad polum alterum ad paleas4 ,sed dic interea1 ,cur ,magnes trahit ubiq2 ferrum8 non quia simile1 alioquin ,magnetem ,magnes traheret multo magis1 ferrumq2 ferru3 non quia superior in ordine corporum1 im superius est lapillo metallum 444 ,ego autem quum hc explorata hactenus habuissem admodum gratulabar1 cogitabamq2 iuuenis adhuc ,magneti pro uiribus inscluperet 7sic7 coelestis ,vrs figuram1 quando ,luna melius illuc aspiciat1 ferro tuc filo collo suspendere4 ,sperabam equidem ita demum uirtutis me sideris illius compotem fore1 c4 7p4 #agb74 #da ,,page #g1 ,,line #ad4 ,page #g1 line #bj4 ,ruellius4--,joannes ,ruellius wrote a herbal ,de ,natura ,stirpium1 ,paris1 #aecf1 which contains a very full account of amber1 and a notice of the magnet 7p4 #abe7 and of the fable about garlic4 ,but on p4 #ecj of the same work he ridicules ,plutarch for recording this very matter4 #db ,,page #g1 ,,line #bj4 ,page #g1 line #bg4 ,marbodus ,gallus4--,this rare little book is entitled ,marbodei ,galli ,poet vetustissimi de lapidibus pretiosis ,enchiridion4 ,it was printed at ,paris in #aeca4 ,the ,freiburg edition1 also of #aeca1 has the commentaries of ,pictorius4 ,the poem is in ,latin hexameters4 ,after a preface of twenty-one lines the virtues of stones are dealt with1 the paragraph beginning with a statement that ,evax1 king of the ,arabs1 is said to have written to ,nero an account of the species1 names and colours of stones1 their place of origin and their potencies2 and that this work formed the basis of the poem4 ,the alleged magical powers of the magnet are recited in ,caput ,i41 ,adamas4 ,caput ,,xliii41 ,magnes1 gives further myths4 #ai ,the commentary of ,pictorius gives references to earlier writers1 ,pliny1 ,dioscorides1 ,bartholomus ,anglicus1 ,solinus1 ,serapio1 and to the book de lapidibus erroneously ascribed to ,aristotle4 ,the following is a specimen of the poem of ,marbodeus3 ,magnetes lapis est inuentus apud ,trogloditas1 ,que lapida genetrix nihilominus ,india mittit4 ,hic ferruginei cognoscitur esse coloris1 ,et ui natur uicinum tollere ferrum4 ,ededon magus hoc primum fer dicitur usus1 ,conscius in magica nihil esse potentius arte4 ,post illum fertur famosa uenefica ,circe ,hoc in prstigijs magicis specialiter usa4 ,this poem was reprinted 7#ahed7 in ,migne's ,patrologia4 ,in #agii ,johann ,beckmann issued an annotated variorum edition of ,marbodeus 7,marbodi ,liber ,lapidvm sev de ,gemmis4441 ,gtting1 #agii71 in which there is a bibliography of the poem1 the first edition of which appears to have been publisht in #aeaa1 at ,vienna1 thirteen other editions being described4 ,beckmann adds many illustrative notes1 and a notice of the ,arabian ,evax1 who is supposed to have written the treatise de lapidibus4 ,not the least curious part is a ,french translation alleged to have been written in #ajif1 of which ,chap4 ,,xix4 on the ,magnet begins thus3 ,magnete trovent ,trogodite1 ,en ,inde e precieus est ditte4 ,fer resemble e si le trait1 ,altresi cum laimant fait4 ,dendor lama mult durement4 ,qi lusoit a enchantement4 ,circe lus a dot mult chere1 ,cele merveillose forciere1 c4 #dc ,,page #g1 ,,line #ba4 ,page #g1 line #bh4 echeneidis4--,the echeneis1 or sucking-fish1 reputed to have magical or magnetic powers1 is mentioned by many writers4 ,as an example1 see ,fracastorio1 ,de ,sympathia et ,antipathia1 lib4 i41 cap4 #h1 ,de ,echineide1 quomodo firmare nauigia possit 7,giunta edition1 ,venet41 #aegd1 p4 #fc74 ,for other references to the ,echeneis see ,gaudentius ,merula 7op4 citat47 p4 #bji4 ,also ,dr4 ,walter ,charleton1 ,physiologia ,epicuro ,gassendo-,charltoniana 7,lond41 #afed71 p4 #cge4 ,compare p4 #fc1 line #c4 #dd ,,page #g1 ,,line #cc4 ,page #g1 line #dc4 ,thomas ,hariotus1 etc4--,the four ,englishmen named were learned men who had contributed to navigation by magnetic observations4 ,harriot's account of his voyage to ,virginia is printed in ,hakluyt's ,voyages4 ,robert ,hues 7or ,hood7 wrote a treatise on ,globes1 the ,latin edition of which appeared in #aeic 7dedicated to ,sir ,walter ,raleigh71 and the ,english edition in #afch4 ,it was republisht by the ,hakluyt ,society1 #ahhi4 ,edward ,wright1 the mathematician and writer on navigation1 also wrote the preface to ,gilbert's own book4 ,abraham ,kendall1 or ,abram ,kendal was ,portulano1 or sailing-master of ,sir ,robert ,dudley's ship the ,bear1 and is mentioned in ,dudley's ,arcano del ,mare4 ,on the return of ,dudley's expedition in #aeie1 he joined ,drake's last expedition1 which sailed that year1 and died on the same day as ,drake himself1 #bh ,january1 #aeif4 7,see ,hakluyt1 ed4 #ahji1 iv41 p4 #gc47 #de ,,page #g1 ,,line #cf4 ,page #h1 line #a4 ,guilielmus ,borough4--,borough's book has the title3 ,a ,discours of the ,variation of the ,cumpas1 or magneticall #bj ,needle4 ,wherein is ,mathematically shewed1 the manner of the obseruation1 effectes1 and application thereof1 made by ,w4 ,b4 ,and is to be annexed to ,the ,newe ,attractive of ,r4 ,n41 #aeha 7,london74 #df ,,page #g1 ,,line #cg4 ,page #h1 line #b4 ,guilielmus ,barlo4--,archdeacon ,william ,barlowe 7author1 in #afaf1 of the ,magneticall ,aduertisements7 wrote in #aeig a little work called ,the ,navigators ,supply4 ,it gives a description of the ordinary compass1 and also one of a special form of meridian compass provided with sights for taking the bearings by the sun4 #dg ,,page #g1 ,,line #cg4 ,page #h1 line #c4 ,robertus ,normannus4 ,see ,note to p4 #e4 #dh ,,page #h1 ,,line #ad4 ,page #h1 line #ba4 illo fabuloso ,plinij bubulco4--,the following is ,pliny's account from ,philemon ,holland's ,english version of #afja 7p4 #ehf73 ,as for the name ,magnes that it hath1 it tooke it 7as ,nicander saith7 of the first inventor and deviser thereof1 who found it 7by his saying7 upon the mountaine ,ida 7for now it is to be had in all other countries1 like as in ,spaine also27 and 7by report7 a ,neat-heard he was3 who1 as he kept his beasts upon the aforesaid mountaine1 might perceive as he went up and downe1 both the hob-nailes which were on his shoes1 and also the yron picke or graine of his staffe1 to sticke unto the said stone4 #di ,,page #i1 ,,line #bb4 ,page #i1 line #cj4 ,differenti priscis ex colore4--,pliny's account of the loadstones of different colours which came from different regions is mainly taken from ,sotacus4 ,the white magnet1 which was friable1 like pumice1 and which did not draw iron1 was probably simply magnesia4 ,the blue loadstones were the best4 ,see p4 #ehg of ,holland's translation of ,pliny1 ,london1 #afja4 ,st4 ,isidore 7,originum seu ,etymologiarum1 lib4 xvi41 cap4 #d7 says3 ,omnis autem magnes tanta melior est1 quanto magis cruleus est4 #ej ,,page #aj1 ,,line #bi4 ,page #aj1 line #db4 ,suarcebergo 444 ,snebergum ,annbergum4--,in the ,stettin editions of #afbh and #afcc these are spelled ,swarcebergs 444 ,schnebergum ,annebergum4 ,the ,cordus given as authority for these localities is ,valerius ,cordus1 the commentator on ,dioscorides4 #ea ,,page #aa1 ,,line #c4 ,page #aa1 line #ab4 ,adriani ,gilberti viri nobilis4--,adrian ,gylbert of ,sandridge in the ,countie of ,devon1 ,gentleman is the description of the person to whom ,queen ,elizabeth granted a patent for the discovery of a ,north-,west passage to ,china4 ,see ,hakluyt's ,voyages1 vol4 iii41 p4 #if4 #eb ,,page #aa1 ,,line #ag4 ,page #aa1 line #bh4 ,dicitur a ,grcis ,greek3 raklios4--,the discussion of the names of the magnet in different languages by ,gilbert in this place is far from complete4 ,he gives little more than is to be found in ,pliny4 ,for more complete discussions the reader is referred to ,buttmann1 ,bemerkungen ber die ,benennungen einiger ,mineralien bei den ,alten1 vorzglich des ,magnetes und des ,basaltes 7,musum der ,alterthumswissenschaft1 ,bd4 ,,ii41 pp4 #e-eb1 and #ajb-ajd1 #ahjh72 ,g4 ,fournier1 ,hydrographie 7livre xi41 chap4 ,i1 #afdc72 ,ulisse ,aldrovandi1 ,musum ,metallicum 7,bononi1 #afdh1 lib4 iv41 cap4 #b1 p4 #eed72 ,klaproth1 ,lettre ,m4 le ,baron ,a4 de ,humboldt1 sur l'invention de la ,boussole1 ,paris1 #ahcd2 ,t4 ,s4 ,davies1 ,the ,history of ,magnetical ,discovery 7,thomson's ,british ,annual1 #ahcg1 pp4 #bej-beg72 ,th4 ,henri ,martin1 ,de l',aimant1 de ses noms divers et de ses varits suivant les ,anciens 7,mmoires prsents par divers savants a l',academie des ,inscriptions et ,belles-lettres1 ,ire srie1 t4 vi41 ,ire partie1 #ahfa72 ,g4 ,a4 ,palm1 ,der ,magnet in ,alterthum 7,programm des k4 wrttembergischen ,seminars ,maulbronn1 ,stuttgart1 #ba #ahfg74 ,of these works1 those of ,klaproth and of ,martin are by far the most important4 ,klaproth states that in modern ,greek1 in addition to the name ,greek3 magntis1 the magnet also has the names ,greek3 adamas and ,greek3 kalamita4 ,the former of these1 in various forms1 adamas1 adamant1 aimant1 yman1 and piedramon1 has gone into many languages4 ,originally the word ,greek3 adamas 7the unconquered7 was applied by the ,greeks to the hardest of the metals with which they were acquainted1 that is to say1 to hard-tempered iron or steel1 and it was subsequently because of its root-signification also given by them to the diamond for the same reason2 it was even given to the henbane because of the deadly properties of that plant4 ,in the writings of the middle ages1 in ,st4 ,augustine1 ,st4 ,isidore1 ,marbodeus1 and even in ,pliny1 we find some confusion between the two uses of adamas to denote the loadstone as well as the diamond4 ,certainly the word adamas1 without ceasing to be applied to the diamond1 also designated the loadstone4 ,at the same time 7says ,martin7 the word magnes was preserved1 as ,pliny records1 to designate a loadstone of lesser strength than the adamas4 ,on the other hand1 the word diamas1 or deamans1 had already in the thirteenth century been introduced into ,latin to signify the diamond as distinguisht from the magnet4 ,adamas was rendered aymant in the romance version of the poem of ,marbodeus on stones 7see ,beckmann's variorum edition of #agii1 p4 #ajb71 and in this form it was for a time used to denote both the magnet and the diamond4 ,then it gradually became restricted in use to the stone that attracts iron4 ,some confusion has also arisen with respect to the ,hebrew name of the magnet4 ,sir ,w4 ,snow ,harris makes the following statement 7,magnetism1 p4 #e73 ,in the ,talmud it the loadstone is termed achzhb'th1 the stone which attracts2 and in their ancient prayers it has the ,european name magnes4 ,on this point ,dr4 ,a4 ,lwy has furnisht the following notes4 ,the loadstone is termed in one of the ,talmudical sections and in the ,midrash1 ,eben ,shoebeth 7lapis attrahens74 ,this would of course be written ,hebrew3 ',,bn ,,shw',,bt4 ,omitting the ,hebrew3 ,w which marks the participial construction1 the words would stand thus3 ,hebrew3 ',,bn ,,sh',,bt ,a person referring to ,buxtorf's ,lexicon ,talmudicum would in the index look out for ,lapis magnesius1 or for magnes4 ,he would then1 in the first instance1 be referred to the two words already quoted4 ,not knowing the value of the letters of the ,hebrew alphabet1 he reads ,hebrew3 ',,bn ,,sh',,bt thus3 ,hebrew3 ',,kzsh',,bt achzhab'th4 ,it is true that ,buxtorf has inserted in his ,lexicon the vocable ,hebrew3 ,,magniyseis1 corruptum ex gr4 ,greek3 magns1 magnts1 magntis1 named after the ,asiatic city ,magnesia4 ,he goes on to say1 ,inde ,achilles ,statius istum lapidem vocavit ,greek3 magnsian lithon4 ,hinc ,hebrew3 ',,bn ,,hmgnjss ,,chmshwk ,,hbrzl4 ,lapis ,magnesius trahit ferrum4 ,here he quotes from 7,sepher7 ,ikkarem ,,iv41 cap4 #ce4 ,kircher1 in his ,magnes1 sive de ,arte magnetica 7,coloni1 #afdc71 gives several other references to ,hebrew literature4 ,others have supposed that the word ,hebrew3 ,,chlmysh khallamish1 which signifies pebble1 rock1 or hard rock1 to be used for the magnet4 ,as to the other ,greek name1 ,greek3 sidritis1 or ,greek3 lithos sidritis this was given not only to the loadstone but also to non-magnetic iron4 ,in the ,etymologicum magnum 7under the word ,greek3 magntis71 and in ,photius 7,qust4 amphiloch41 q4 #aca71 it is stated that the name sideritis was given to the loadstone either because of its action on iron1 or of its resemblance in aspect to iron1 or rather1 they say1 because the loadstone was originally found in the mines of this metal4 ,alexander of ,aphrodisias expressly says 7,qutiones ,physic1 ,,ii4 #bc7 that #bb the loadstone appears to be nothing else than ,greek3 g sidritis1 the earth which yields iron1 or the earth of iron4 #ec ,,page #aa1 ,,line #ai4 ,page #aa1 line #bi4 ab ,orpheo4--,the reference is to v4 #cja-cbh of the ,greek3 ,lithika4 ,the passage1 as given in ,abel's edition 7,berol41 #ahha71 begins3 ,greek3 ,tolma d' athanatous kai henei meilissethai ,greek3 magnssi1 tn d' exoch' ephilato thousios ,ars1 ,greek3 houneken1 hoppote ken pelasi polioio sidrou1 ,greek3 ute parthenik terenochroa chersin helousa ,greek3 itheon sterni prosptussetai himeroenti1 ,greek3 hs hg' harpazousa poti spheteron demas haiei ,greek3 aps palin ouk ethelei methemen polemista sidron4 #ed ,,page #aa1 ,,line #bj4 ,page #aa1 line #ca4 ,gallis aimant4--,the ,french word aimant1 or aymant1 is generally supposed to be derived from adamas4 ,nevertheless ,klaproth 7op4 citat41 p4 #ai7 suggests that the word aimant is a mere literal translation into ,french of the ,chinese word thsu chy1 which is the common name of the magnet1 and which means loving stone1 or stone that loves4 ,all through the east the names of the magnet have mostly the same signification1 for example1 in ,sanskrit it is thoumbaka 7the kisser71 in ,hindustani tchambak4 #ee ,,page #aa1 ,,line #bj4 ,page #aa1 line #cb4 ,italis calamita4--,the name calamita1 universal in ,italian for the magnet1 is also used in ,roumanian1 ,croatian1 ,bosnian1 and ,wendish4 ,its supposed derivation from the ,hebrew khallamsh is repudiated by ,klaproth1 who also points out that the use of ,greek3 kalamita in ,greek is quite modern4 ,he adds that the only reasonable explanation of the word calamita is that given by ,father ,fournier 7op4 citat471 who says3 ,ils 7les marins franais7 la nomment aussi calamite1 qui proprement en franais signifie une grenouille verte1 parce qu'avant qu'on ait trouv l'invention de suspendre et de balancer sur un pivot l'aiguille aimante1 nos anctres l'enfermaient dans une fiole de verre demi-remplie d'eau1 et la faisaient flotter1 par le moyen de deux petits ftus1 sur l'eau comme une grenouille4 ,klaproth adds that he entirely agrees with the learned ,jesuit1 but maintains that the word calamite1 to designate the little green frog1 called to-day le graisset1 la raine1 or la rainette1 is essentially ,greek4 ,for we read in ,pliny 7,hist4 ,nat4 lib4 xxxii41 ch4 x473 ,ea rana quam ,grci calamiten vocant1 quoniam inter arundines1 fruticesque vivat1 minima omnium est et viridissima4 #ef ,,page #aa1 ,,line #bj4 ,page #aa1 line #cb4 ,anglis loadstone adamant stone4 ,the ,english term loadstone is clearly connected with the ,anglo-,saxon verb loedan1 to lead1 and with the ,icelandic leider-stein4 ,there is no doubt that the spelling lodestone would be etymologically more correct1 since it means stone that leads not stone that carries a load4 ,the correct form is preserved in the word lode-star4 ,the word adamant1 from adamas1 the medival word for both loadstone and diamond1 also occurs in ,english for the loadstone1 as witness ,shakespeare3 ,you draw me1 you hard-hearted adamant ,but yet you draw not iron2 for my heart ,is true as steel4 ,midsummer ,night's ,dream1 ,act ,,ii1 ,scene #a4 #eg ,,page #aa1 ,,line #ba4 ,page #aa1 #bc line #cc4 ,germanis magness1 siegelstein4 ,the ,stettin edition of #afbh reads ,germanis ,,magnetstein1 ,belgis ,,seylsteen2 while that of #afcc reads ,germanis ,,magnetstein1 ,belgis ,,sylsteen4 #eh ,,page #aa1 ,,line #bf4 ,page #aa1 line #ci4 ,in this line the ,greek sentence is1 in every known copy of the folio of #afjj1 corrected in ink upon the text1 ,greek3 thals being thus altered into ,greek3 ,thals1 and ,greek3 apomnemonuousi into ,greek3 apomnemoneuousi4 ,four lines lower1 brackets have been inserted around the words 7lapidum specularium modo74 ,these ink corrections must have been made at the printers'1 possibly by ,gilbert's own hand4 ,they have been carried out as errata in the editions of #afbh and #afcc4 ,the facsimile ,berlin reprint of #ahib has deleted them1 however4 ,other ink corrections on pp4 #ad1 #bb1 #ch1 #ci1 #dg1 #acj1 and #bjj of the folio edition of #afjj are noted in due course4 #ei ,,page #aa1 ,,line #bi4 ,page #aa1 line #de4 lapis specularis4 ,this is the medival name for mica1 but in ,elizabethan times known as talc or muscovy stone4 ,cardan1 ,de ,rerum ,varietate 7,basil41 #aeeg1 p4 #dah71 lib4 xiiii41 cap4 lxxii41 mentions the use of lapis specularis for windows4 #fj ,,page #aa1 ,,line #ca4 ,page #aa1 line #df43 ,germanis ,katzensilbar ,talke4--,in the editions of #afbh and #afcc this is corrected to ,germanis ,,katzensilber ,,talcke4 ,goethe1 in ,wilhelm ,meister's ,travels1 calls mica cat-gold4 #fa ,,page #ab1 ,,line #cj4 ,page #ab1 line #ce4 integtum appears to be a misprint for integrum1 which is the reading of editions #afbh and #afcc4 #fb ,,page #ac1 ,,line #d4 ,page #ac1 line #c4 ,greek3 mikrog seu ,terrella4 ,although rounded loadstones had been used before ,gilbert's time 7see ,peregrinus1 p4 #c of ,augsburg edition of #aeeh1 or ,baptista ,porta1 p4 #aid1 of ,english edition of #afeh71 ,gilbert's use of the spherical loadstone as a model of the globe of the earth is distinctive4 ,the name ,terrella remained in the language4 ,in ,pepys's ,diary we read how on ,october #b1 #affc1 he received a letter from ,mr4 ,barlow with a terella4 ,john ,evelyn1 in his ,diary1 ,july1 #afee1 mentions a pretty terella with the circles and showing the magnetic deviations4 ,a ,terrella1 #d inches in diameter1 was presented in #affb by ,king ,charles ,i4 to the ,royal ,society1 and is still in its possession4 ,it was examined in #afhg 7see ,phil4 ,transactions for that year7 by the ,society to see whether the positions of its poles had changed4 ,in ,grew's ,catalogue and ,description of the ,rarities belonging to the ,royal ,society and preserved at ,gresham ,college 7,london1 #afha1 p4 #cfd7 is mentioned a ,terrella contrived by ,sir ,christopher ,wren1 with one half immersed in the centre of a plane horizontal table1 so as to be like a ,globe with the poles in the horizon1 having thirty-two magnet needles mounted in the margin of the table to show the different respect of the ,needle to the several ,points of the ,loadstone4 ,in ,sir ,john ,pettus's ,fleta ,minor1 ,london1 #afhc1 in the ,dictionary of ,metallick ,words at the end1 under the word ,loadstone occurs the following passage3 ,another piece of ,curiosity ,i saw in the ,hands of ,sir ,william ,persal 7since ,deceased also7 viz41 a ,terrella or ,load-stone1 of little more than #f ,inches ,diameter1 turned into a ,globular ,form1 and all the ,imaginery ,lines of our ,terrestrial ,globe1 exactly drawn upon it3 viz4 the ,artick and ,antartick ,circles1 the two ,tropicks1 the two ,colures1 the ,zodiack and ,meridian2 and these ,lines1 and the several ,countryes1 artificially ,painted on it1 and all of them with their true ,distances1 from the two ,polar ,points1 and to find the truth of those ,points1 he took two little pieces of a ,needle1 each of about half #bd an ,inch in length1 and those he laid on the ,meridian line1 and then with ,brass ,compasses1 moved one of them towards the ,artick1 which as it was moved1 still raised it self at one end higher and higher1 keeping the other end fixt to the ,terrella2 and when it had compleated it ,journy to the very ,artick ,points1 it stood upright upon that ,point2 then he moved the other piece of ,needle to the ,antartick ,point1 which had its ,elevations like the other1 and when it came to the ,point1 it fixt it self upon that ,point1 and stood upright1 and then taking the ,terrella in my ,hand1 ,i could perfectly see that the two pieces of ,needles stood so exactly one against the other1 as if it had been one intire long ,needle put through the ,terrella1 which made me give credit to those who held1 ,that there is an ,astral ,influence that darts it self through the ,globe of ,earth from ,north to ,south 7and is as the ,axel-,tree to the ,wheel1 and so called the ,axis of the ,world7 about which the ,globe of the ,earth is turned1 by an ,astral ,power1 so as what ,i thought imaginary1 by this ,demonstration1 ,i found real4 #fc ,,page #ac1 ,,line #bj4 ,page #ac1 line #bb4 ,the editions of #afbh and #afcc give a different woodcut from this3 they show the terrella lined with meridians1 equator1 and parallels of latitude3 and they give the compass needle1 at the top1 pointing in the wrong direction4 #fd ,,page #ad1 ,,line #c4 ,page #ad1 line #c4 ,the ,berlin facsimile reprint omits the asterisk here4 #fe ,,page #ad1 ,,line #e4 ,page #ad1 line #f4 erectus altered in ink in the folio to erecta4 ,but erectus is preserved in editions #afbh and #afcc4 ,in ,cap4 ,,iiii41 on p4 #ad1 both these ,stettin editions insert an additional cut representing the terrella ,a placed in a tub or vessel ,b floating on water4 #ff ,,page #ad1 ,,line #cd4 ,page #ad1 line #ci4 variatione quada4 ,the whole of ,book ,,iiii4 is devoted to a discussion of the variation of the compass4 #fg ,,page #af1 ,,line #bh4 ,page #af1 line #cd4 aqu4--,this curious use of the dative occurs also on p4 #bbb1 line #h4 #fh ,,page #ag1 ,,line #a4 ,page #ag1 line #a4 videbis4--,the reading vibebis of the #afcc edition is an error4 #fi ,,page #ah1 ,,line #bd4 ,page #ah1 line #bg4 ,theamedem4--,for the myth about the alleged ,theamedes1 or repelling magnet1 see ,cardan1 ,de ,subtilitate 7folio ed41 #aeej1 lib4 vii41 p4 #ahf74 ,pliny's account1 in the ,english version of #afja 7p4 #ehg71 runs3 ,to conclude1 there is another mountaine in the same thyopia1 and not farre from the said ,zimiris1 which breedeth the stone ,theamedes that will abide no yron1 but rejecteth and driveth the same from it4 ,martin ,cortes1 in his ,arte de ,nauegar 7,seville1 #aeef71 wrote3 ,and true it is that ,tanxeades writeth1 that in ,ethiope is found another kinde of this stone1 that putteth yron from it 7,eden's translation1 ,london1 #afji74 #gj ,,page #ba1 ,,line #bd4 ,page #ba1 line #be4 ,hic segetes1 c4--,the ,english version of these lines from ,vergil's ,georgics1 ,book ,i41 is by the late ,mr4 ,r4 ,d4 ,blackmore4 #ga ,,page #bb1 ,,line #ah4 ,page #bb1 line #ai4 quale1 altered in ink in the folio text to qualis4 ,the editions of #afbh and #afcc both read qualis4 #gb ,,page #bb1 ,,line #ai4 ,page #bb1 line #bj4 rubrica fabrili3 in ,english ruddle or reddle4 ,see ,sir ,john ,hill1 ,a ,general ,natural ,history1 #agdh1 p4 #dg4 ,in the ,de ,re ,metallica of ,entzelt 7,encelius71 ,frankfurt1 #aeea1 p4 #acd1 is a paragraph headed ,de ,rubrica ,fabrili1 as follows3 ,rubrica fabrilis duplex #be est4 ,germanis at utraque dicitur rottel1 rttelstein1 wie die zimmerlet vnd steynmetzen brauchen4 ,grcis ,greek3 miltos tektonik4 ,est enim alia nativa1 alia factitia4 ,natiua ,germanis propri dicitur berckrottel4 haec apud nos est fossilis4444 ,porro factitia est rubrica fabrilis1 ,germanis braunrottel1 qu fit ex ochra usta1 ut ,theophrastus et ,dioscorides testantur4 #gc ,,page #bb1 ,,line #ai4 ,page #bb1 line #bj4 ,in ,sussexia ,angli4--,in ,camden's ,britannia 7#aehj7 we read concerning the iron industry in the villages in ,sussex3 ,they are full of iron mines in sundry places1 where1 for the making and founding thereof1 there be furnaces on every side2 and a huge deal of wood is yearly burnt4 ,the heavy forge-hammers1 worked by water-power1 stored in hammer-ponds1 ceaselessly beating upon the iron1 fill the neighbourhood round about1 day and night1 with continual noise4 #gd ,,page #bc1 ,,line #a4 ,page #bb1 line #dd4 in libro ,aristotelis de admirandis narrationibus4--,the reference is to the work usually known as the ,de ,mirabilibus ,auscultationibus1 ,cap4 ,,xlviii43 ,fertur autem peculiarissima generatio esse ferri ,chalybici ,amisenique1 ut quod ex sabulo quod a fluviis defertur1 ut perhibent certe1 conflatur4 ,alii simpliciter lotum in fornace excoqui1 alii vero1 quod ex lotura subsedit1 frequentius lotum comburi tradunt adjecto simul et pyrimacho dicto lapide1 qui in ista regio plurimus reperiri fertur4 7,ed4 ,didot1 vol4 ii41 p4 #hg47 ,according to ,georgius ,agricola1 the stone pyrimachus is simply iron pyrites4 #ge ,,page #bc1 ,,line #bb4 ,page #bc1 line #bc4 vt in ,italia ,comi1 c4--,this is mostly taken from ,pliny4 ,compare the following passage from ,philemon ,holland's translation 7#afja71 p4 #ead3 ,but the most varietie of yron commeth by the meanes of the water1 wherein the yron red-hot is eftsoones dipped and quenched for to be hardened4 ,and verely1 water only which in some place is better1 in other worse1 is that which hath ennobled many places for the excellent yron that commeth from them1 as namely1 ,bilbilis in ,spaine1 and ,tarassio1 ,comus also in ,italie2 for none of these places have any yron mines of their owne1 and yet there is no talke but of the yron and steele that commeth from thence4 ,bilbilis is ,bambola1 and ,tariassona the ,tarazona of modern ,spain4 #gf ,,page #bd1 ,,line #bh4 ,page #bd1 line #bg4 ,quare vani sunt illi ,chemici4--,gilbert had no faith in the alchemists4 ,on pp4 #ai and #ba he had poked fun at them for declaring the metals to be constituted of sulphur and quicksilver1 and for pronouncing the fixed earth in iron to be sulphur4 ,on p4 #bj he had denied their proposition that the differences between silver1 gold1 and copper could arise from proportions of their constituent materials2 and he likewise denounced unsparingly the supposed relation between the seven metals and the seven planets4 ,he now denounces the vain dreams of turning all metals into gold1 and all stones into diamonds4 ,later he rejects as absurd the magnetic curing of wounds4 ,his detachment from the pseudo-science of his age was unique if not complete4 #gg ,,page #be1 ,,line #ae4 ,page #be1 line #af4 ,petro-coriis1 ,cabis ,biturgibus4--,the ,petro-corii were a tribe in the neighbourhood of ,perigord2 the ,cubi ,biturges another in that of ,bourges4 #gh ,,page #be1 ,,line #ba4 ,page #be1 line #bc4 ,pliny's account1 as translated by ,p4 ,holland 7ed4 #afja1 p4 #eae71 runs thus3 ,of all mines that be1 the veine of this mettall is largest1 and spreadeth it selfe into most lengths every way3 as we may see in that part of ,biscay that coasteth along the sea1 and upon which the ,ocean beateth3 where there #bf is a craggie mountaine very steep and high1 which standeth all upon a mine or veine of yron4 ,a wonderfull thing1 and in manner incredible1 howbeit1 most true1 according as ,i have shewed already in my ,cosmographie1 as touching the circuit of the ,ocean4 #gi ,,page #bf1 ,,line #ae4 ,page #bf1 line #ab4 quas ,clampas nostri vocant4--,the name clamp for the natural kiln formed by heaping up the bricks1 with ventilating spaces and fuel within the heap1 is still current4 #hj ,,page #bf1 ,,line #ci4 ,page #bf1 line #ch4 ,pluebat in ,taurinis ferrum4--,the occurrence is narrated by ,scaliger1 ,de ,subtilitate1 ,exercitat4 cccxxiii43 ,sed fals lapidis pluviam creas tu ex pulvere hausto nubibus1 atque in lapidem condensato4 ,at ferrum1 quod pluit in ,taurinis1 cuius frustum apud nos extat1 qua ex fodina sustulit nubes8 ,tribus circiter annis ant1 qum ab ,rege provincia illa recepta esset1 pluit ferro multis in locis1 sed raris 7p4 #dcd1 ,editio ,luteti1 #aeeg74 ,during the latter ages of the ,roman ,empire the city of ,augusta ,taurinorum seems to have been commonly known 7as was the case in many instances in ,transalpine ,gaul7 by the name of the tribe to which it belonged1 and is called simply ,taurini in the ,itineraries1 as well as by other writers1 hence its modern name of ,torino or ,turin 7,smith's ,dictionary of ,greek and ,roman ,geographies1 p4 #aaac74 ,there exists a considerable literature respecting falls of meteors and of meteoric iron4 ,livy1 ,plutarch1 and ,pliny all record examples4 ,see also ,remarks concerning stones said to have fallen from the clouds1 by ,edward ,king 7,london1 #agif72 ,chladni1 ,ueber den ,ursprung der von ,pallas gefundenen und anderer ihr hnlicher ,eisenmassen 7,riga1 #agid72 ,philosophical ,transactions1 vol4 lxxviii41 pp4 #cg and #ahc2 vol4 lxxxv41 p4 #ajc2 vol4 xcii41 p4 #agd2 ,humboldt's ,cosmos1 vol4 i4 7p4 #ig of ,london edition1 #ahfj72 ,c4 ,rammelsberg1 ,die chemische ,natur der ,meteoriten 7,berlin1 #ahgi72 ,maskelyne1 ,some lecture-notes on ,meteorites printed in ,nature1 vol4 xii41 pp4 #dhe1 #ejd1 and #ebj1 #ahge4 ,maskelyne denominates as siderites those meteorites which consist chiefly of iron4 ,they usually contain from #hj to #ie per cent4 of iron1 often alloyed with nickel4 ,this meteoric iron is sometimes so pure that it can at once be forged by the smith4 ,an admirable summary of the whole subject is to be found in ,l4 ,fletcher's ,an ,introduction to the study of ,meteorites1 publisht by the ,british ,museum 7,nat4 ,hist471 ,london1 #ahif4 #ha ,,page #bg1 ,,line #c4 ,page #bf1 line #da4 vt ,cardanus 444 scribit4--,the passage runs3 ,vidimus anno ,,mdx cum cecidisset coelo lapides circiter ,,mcc in agrum fluvio ,abdu conterminum1 ex his unum ,,cxx pondo1 alium sexaginta delati fuerunt ad reges ,galloru satrapes1 plurimi3 colos ferrugineus1 durities eximia1 odor sulphureus 7,cardan1 ,de ,rerum ,varietate1 lib4 xiiii41 cap4 lxxii42 ,basil41 #aeeg1 p4 #ede74 #hb ,,page #bg1 ,,line #i4 ,page #bg1 line #b4 aut stannum1 aut plumbum album4 ,although most authorities agree in translating plumbum album or plumbum candidum as tin 7which is unquestionably the meaning in such examples as ,pliny's ,nat4 ,hist41 xxxiv4 #cdg1 and iv4 #af2 or ,strabo1 iii4 #adg71 nevertheless it is certain that here plumbum album is not given as a synonym of stannum and therefore is not tin4 ,that ,gilbert meant either spelter or pewter is pretty certain4 ,he based his metallic terms mainly upon ,encelius 7,christoph ,entzelt7 whose ,de ,re ,metallica was published at ,frankfurt in #aeea4 ,from this work are taken the following passages3 #bg p4 #fa4 ,de ,plumbo candido4 ,cap4 ,,xxxi4 ,veluti plumbum nigru uocatur ,germanis blei simpliciter1 od' schwartzblei3 ita plumbu candidu ab his uocatur weissblei1 od' zi4 ,impropri autem plumbum hoc nostrum candidum zi1 stannum dicitur4 ,et non sunt idem1 ut hactenus voluerunt1 stannum et plumbum candidum1 unser zi4 ,aliud est stannum1 de quo mox agemus3 et aliud plumbum candidum nostrum1 unser zi1 quod nigro plumbo quasi est quidd purius et perfectius4444 p4 #fb4 ,de ,stanno4 ,cap4 ,,xxxii4 ,in prcedenti capite indicauimus aliud esse stannum1 aliud esse plumbu candidu4 ,illa ergo definitio plumbi candidi1 dess zinnes1 eti apud chimistas n de stanno1 sed de plumbo candido 7ut mihi uidetur7 intelligenda est1 cum dicunt3 ,stannum 7es soll heyssen plumbum candidum7 est metallicum album1 non purum1 lividum4444 p4 #fc4 ,sic uides stannum1 secundum ,serapionem1 metallicum esse quod reperitur in sua propria uena1 ut forsitan apud nos bisemutu3 ectra nostru candidu plumbu1 est ,plinij candidu plumbu1 das zin1 quod cflatur ut plumbum nigrum1 ex pyrite1 galena1 et lapillis nigris4 ,deinde uides stannum ,plinio esse quidd de plumbo nigro1 nempe primum fluorem plumbi nigri1 als wann man vnser bley ertz schmeltzet1 das erst das do flesset1 zwre ,plinio stannum4 ,et hoc docet ,plinius adulterari plubo candido1 mit vnserm zinn1 vnd wann du ihm recht nachdenckest1 daruon die kannen gemacht werden1 das man halbwerck heist4444 ,o ir losen vngelerten1 vnckenbrenner4 ,stannum proculdubio ,arabis metallum est preciosius nostro candido plumbo3 sicuti apud nos bisemuthum quiddam plumbo preciosius4 #hc ,,page #bg1 ,,line #ba4 ,page #bg1 line #ag4 venas 444 venis4--,it is impossible to give in ,english this play on words between veins of ore and veins of the animal body4 #hd ,,page #bh1 ,,line #bc4 ,page #bh1 line #bj4 quem nos verticitatem dicimus4--,see the notes on ,gilbert's glossary1 ante4 ,the word verticity remained in the language4 ,on p4 #adj of ,joseph ,glanvill's ,vanity of ,dogmatizing 7,lond41 #affa7 we read3 ,we believe the verticity of the ,needle1 without a ,certificate from the dayes of old4 #he ,,page #bi1 ,,line #ae4 ,page #bi1 line #af4 ,nos ver diligentis omnia experientes4--,the method of carefully trying everything1 instead of accepting statements on authority1 is characteristic of ,gilbert's work4 ,the large asterisks affixed to ,chapters ,,ix4 ,x4 ,,xi4 ,,xii4 and ,,xiii4 of ,book ,i4 indicate that ,gilbert considered them to announce important original magnetical discoveries4 ,the electrical discoveries of ,book ,,ii41 ,chapter ,,ii41 are similarly distinguished4 ,a rich crop of new magnetical experiments1 marked with marginal asterisks1 large and small1 is to be found in ,book ,,ii41 from ,chapter ,,xv4 to ,chapter ,,xxxiv42 while a third series of experimental magnetical discoveries extends throughout ,book ,,iii4 #hf ,,page #ca1 ,,line #cj4 ,page #ca1 line #be4 verticem4--,the context and the heading of the ,chapter appear to require verticitatem4 ,all editions1 however1 read verticem4 #hg ,,page #cb1 ,,line #ab4 ,page #cb1 line #i4 ,gartias ab horto4--,the passage from ,gartias ab ,horto runs as follows in the ,italian edition of #afaf1 ,dell' ,historia dei ,semplici ,aromati4444 di ,don ,garzia dall' ,horto1 ,medico ,portughese1 444 ,venezia ,,mdcxvi41 p4 #bjh4 ,n meno questa pietra velenosa1 si come molti hanno tenuto2 imperoche le genti di queste bande dicono che la ,calamita presa per bocca1 per in poca #bh quantit1 conserva la giovent4 ,la onde si racconta1 che il ,re di ,zeilan il vecchio' s'haveva fatto fare tutti i vasi1 dove si cocevano le vivde per lui1 di ,calamita4 ,et questo lo disse me colui proprio1 che fu questo officio destinato4 #hh ,,page #cb1 ,,line #bi4 ,page #cb1 line #bi4 ,plutarchus ,c4 ,ptolemus4--,the garlick myth has already been referred to in the note to p4 #a4 ,the originals are ,plutarch1 ,qustiones ,platonic1 lib4 vii41 cap4 #g1 #a2 ,c4 ,ptolemus1 ,opus ,quadripartitum1 bk4 i41 cap4 #c4 ,the ,english translation of the latter1 by ,whalley 7,london1 #agja71 p4 #aj1 runs3 ,for if the ,loadstone be ,rubbed with ,garlick1 the ,iron will not be drawn by it4 #hi ,,page #cb1 ,,line #cb4 ,page #cb1 line #cc4 ,medici nonnulli4--,this is apparently a reference to the followers of ,rhazes and ,paracelsus4 ,the argument of ,gilbert as to the inefficacy of powdered loadstones is reproduced more fully by ,william ,barlowe in his ,magneticall ,aduertisements 7#afaf1 p4 #g71 as follows3 ,it is the goodnesse of the ,loadstone ioyned with a fit forme that will shew great force4 ,for as a very good forme with base substance can doe but very litle1 so the substance of the ,loadstone bee it neuer so excellent1 except it haue some conuenient forme1 is not auaileable4 ,for example1 an excellent loadstone of a pound waight and of a good fashion1 being vsed artificially1 may take vp foure pounds of ,iron2 beate it into small pouder1 and it shall bee of no force to take vp one ounce of ,iron2 yea ,i am very well assured that halfe an ounce of a ,loadstone of good fashion1 and of like vertue will take vp more then that pound will doe being beaten into powder4 ,whence 7to adde this by the way7 it appeareth manifestly1 that it is a great error of those ,physitions and ,surgeons1 which to remedy ruptures1 doe prescribe vnto their ,patients to take the pouder of a ,loadstone inwardly1 and the small filing of iron mingled in some plaister outwardly3 supposing that herein the magneticall drawing should doe great wonders4 #ij ,,page #cc1 ,,line #aa4 ,page #cc1 line #h4 ,nicolaus in emplastrum divinum4444--,nicolaus ,myrepsus is also known as ,prpositas4 ,in his ,liber de compositione medicamentorum 7,ingoldstat1 #aeda1 #dto7 are numerous recipes containing loadstone3 for example1 ,recipe ,no4 #bdf1 called esdra magna1 is a medicine given for inflammation of the stomach and for strangury1 compounded of some forty materials including litho demonis and lapis magnetis4 ,the emplastrum divinum does not1 however1 appear to contain loadstone4 ,in the ,english tractate1 ,prpositas his ,practise1 a worke 444 for the better preservation of the ,health of ,man4 ,wherein are 444 approved ,medicines1 ,receiptes and ,ointmentes4 ,translated out of ,latin in to ,english by ,l4 ,m4 7,london1 #aehh1 #dto71 we read on p4 #ce1 ,an ,emplaister of ,d4 ,n4 ,doctor ,nicolaus which the ,pothecaries call ,divinum4 ,this contains litharge1 bdellium1 and green brasse1 but no loadstone4 ,luis de ,oviedo in his treatise ,methodo de la ,coleccion y reposicion de las ,medicinas simples1 edited by ,gregorio ,gonalez1 ,boticario 7,madrid1 #afbb71 gives 7p4 #ejb7 the following3 ,emplasto de la madre4 ,recibe3 ,nuezes moscadas1 clauos1 cinamono1 artemisia1 piedraimon4 ,de cada uno dos onas4444 ,entre otras differencias que ay de piedraiman se hallan dos4 ,vna que por la parte que mira al ,septentrion1 atrae el hierro1 por lo quel se llama magnes ferrugineus4 ,y otra que atrae la carne1 a la qual llaman magnes creaginus4 ,an ,emplastrum sticticum containing amber1 mummy1 loadstone1 #bi hmatite1 and twenty other ingredients1 and declared to be vulnerum ulcerumque telo inflictorum sticticum emplastrum prstantissimum1 is described on p4 #bfg of the ,basilica chimica of ,oswaldus ,crollius 7,frankfurt1 #afab74 #ia ,,page #cc1 ,,line #ab4 ,page #cc1 line #i4 ,augustani 444 in emplastrum nigrum4444--,amongst the physicians of the ,augsburg school the most celebrated were ,adolphus ,occo1 ,ambrosio ,jung1 and ,gereone ,seyler4 ,this particular reference is to the ,pharmacopoeia ,augustana 444 a ,collegio ,medico recognita1 published at ,augsburg1 and which ran through many editions4 ,the recipe for the emplastrum nigrum vulgo ,stichpflaster will be found on p4 #ahb of the seventh edition 7#afba-b74 ,the recipe begins with oil of roses1 colophony1 wax1 and includes some twenty-two ingredients1 amongst them mummy1 dried earthworms1 and two ounces lapidis magnetis prparati4 ,the recipe concludes3 ,fiat ,emplastrum secundm artem4 ,perqum efficax ad recentia vulnera et puncturas1 vnd denominationem habet4 ,the volume is a handsome folio not unlike ,gilbert's own book1 and bears at the end of the prefatory address ad ,lectorem identically the same cul de lampe as is found on p4 #dd of ,de ,magnete4 ,the contradictions as to the alleged medicinal virtues of loadstone are well illustrated by ,galen1 who in his ,de facultatibus says that loadstone is like hmatite1 which is astringent1 while in his ,de simplici medicina he says it is purgative4 #ib ,,page #cc1 ,,line #ad4 ,page #cc1 line #ab4 ,paracelsus in fodicationum emplastrum4--,paracelsus's recipe for a plaster against stab-wounds is to be found in ,wundt vund ,leibartznei 444 ,d4 ,theoph4 ,paracelsus 7,frankf41 #aeee1 pp4 #fc-fg74 #ic ,,page #cc1 ,,line #ag4 ,page #cc1 line #ae4 ,ferri vis medicinalis4--,this chapter on the medicinal virtues of iron is a summary of the views held down to that time4 ,those curious to pursue the subject should consult ,waring's ,bibliotheca ,therapeutica 7,london1 #ahgh74 ,nor should they miss the rare black-letter quarto by ,dr4 ,nicholas ,monardus1 of ,seville1 ,joyfull ,newes out of the ,new-found ,worlde1 translated by ,john ,frampton 7,london1 #aeif71 in which are recited the opinions of ,galen1 ,rhazes1 ,avicenna1 and others1 on the medicinal properties of iron4 ,in addition to the views of the ,arabic authors1 against whom his arguments are directed1 ,gilbert discusses those of ,joannes ,manardus1 ,curtius1 and ,fallopius4 ,the treatise of ,manardus1 ,epistolarum medicinalium libri viginti 7,basil41 #aedi71 is a rsum of the works of ,galen and the ,arabic physicians1 but gives little respecting iron4 ,curtius 7,nicolaus7 was the author of a book1 ,libellus de medicamentis prparatibus et purgantibus 7,giess ,cattorum1 #afad74 ,the works of ,fallopius are ,de ,simplicibus ,medicamentis purgentibus tractatus 7,venet41 #aeff1 #dto71 and ,tractatus de ,compositione ,medicamentorum 7,venet41 #aegj1 #dto74 #id ,,page #cd1 ,,line #g4 ,page #cd1 line #c4 quorund ,arabum opiniones4--,the ,arabian authorities referred to here or elsewhere by ,gilbert are3 ,albategnius 7otherwise known as ,machometes ,aractensis71 ,muhammad ,ibn ,jabir1 ,al-,battani4 ,avicenna 7otherwise ,abohali74 ,abou-',ali al-',hosin ben-',abd-,allah ,ibn-,sin1 or1 shortly1 ,ibn ,sna4 ,averroes4 ,muhammad ,ibn ,ahmed ,ibn-,roschd1 ,abou ,al-,wald4 ,geber4 ,abu ,musa ,jabir ,ibn ,haiyan1 ,al-,tarsusi4 ,hali ,abas4 ',al ,ibn ,al-',abbs1 ,al ,majsi4 #cj ,rhazes1 or ,rasis4 ,muhammad ,ibn ,zakariya4 ,serapio4 ,yuhann ,ibn ,sarapion4 ,thebit ,ben-,kora 7otherwise ,thabit ,ibn ,corrah74 ,abu ,thabit ,ibn ,kurrah1 ,al ,harrani4 #ie ,,page #cd1 ,,line #ch43 ,page #cd1 line #dj4 electuarium de scoria ferri descriptum ,raze4--,rhazes or ,rasis1 whose ,arabic name was ,muhammad ,ibn ,zakariya1 wrote ,de ,simplicibus1 ad ,almansorem4 ,in ,chap4 #fc of this work he gives a recipe for a stomachic1 which includes fennel1 anise1 origanum1 black pepper1 cinammon1 ginger1 and iron slag4 ,in the splendid folio work of ,rhazes publisht at ,venice in #aedb1 with the title ,habes candide lector ,continetem ,rasis1 ,libri ultimi1 cap4 #bie1 under the heading ,de ,ferro1 are set forth the virtues of iron slag3 ,virtus scorie est sicut virtus scorie aeris sed debilior in purgdo3 et erugo ferri est stiptica3 et cu superpositur retinet fluxus menstruoru4444 ,ait ,paulus3 aqua in qua extinguitur ferru calens4444 ,dico3 certificatus sum experientia q valet contra emorryodas diabetem et fluxum menstruorum4 #if ,,page #ce1 ,,line #af43 ,page #ce1 line #ac4 ,paulus4--,this is not ,fra ,paolo ,sarpi1 nor ,marco ,polo1 nor ,paulus ,jovius the historian1 nor ,paulus ,nicolettus ,venetus1 but ,paulus ,aegin4 #ig ,,page #ce1 ,,line #bi43 ,page #ce1 line #bh4 ,sed mal ,avicenna4--,the advice of ,avicenna to administer a draught containing powdered loadstone1 reads as follows in the ,giunta edition 7,venice1 #afjh73 ,lib4 ii41 cap4 #dgj1 p4 #cef4 ,magnes quid est8 ,est lapis qui attrahit ferrum1 quum ergo aduritur1 fit hmatites1 virtus ejus est sicut virtus illius4444 ,datur in potu ad bibitionem limatur ferri1 quum retinetur in ventre scoria ferri4 ,ipse enim extrahit ipsam1 associatur ei apud exitum4 ,et dicitur1 quando in potu sumuntur ex eo tres anulusat cum mellicrato1 educit solutione humorem grossum malum4 ,the passage is identical with that in the ,venetian edition of #adhf1 in both of which the liquid prescribed is mellicratus--mead4 ,gilbert says that the iron is to be given in juice of mercurialis4 ,here he only follows ,matthiolus1 who1 in his ,commentaries on ,dioscorides1 says 7p4 #iih of the ,basil4 edition of #aeih73 ,sed 7vt idem ,auicenna scribit7 proprium hujusce ferrei pharmaci antidotum1 est lapis magnes drachm pondere potus1 ex mercurialis1 vel bet succo4 ,serapio1 in his ,de ,simplicibus ,medicinis 7,brunfels' edition1 ,argentorati1 #aeca71 p4 #bfd1 refers to ,galen's prescription of iron scori1 and under the article de lapide magnetis1 p4 #bfj1 quotes ,dioscorides as follows3 ,et uirtus huius lapidis est1 ut qudo dantur in potu duo onolosat ex eo cu melicrato1 laxat humores grossos4 ,the original passage in ,dioscorides1 ,de ,materia ,medica1 ch4 #adg 7,spengel's edition of #ahbi7 runs3 ,greek3 ,tou de magntou lithou aristos estin ho ton sidron euchers helkn1 kai tn chroan kuanizn1 puknos te kai ouk agan barus4 ,dunamin de echei pachous aggon didomenos meta melikratou tribolou baros2 enioi de touton kaiontes anti haimatitou pipraskousin44 ,in the ,frankfurt edition of ,dioscorides1 translated by ,ruellius 7#aedc71 the passage is3 ,magnes lapis optimus est1 qui ferrum facile trahit1 colore ad coeruleum uergente1 densus1 nec admodum gravis4 ,datur cum aqua mulsa1 trium obolorum pondere1 ut crassos humores eliciat4 ,sunt qui magnetem crematu pro hmatite vendant4444 ,in the ,scholia of ,joannes ,lonicerus upon ,dioscorides ,in ,dioscorid #ca ,anazarbei de re medica libros a ,virgilio ,marcello versos1 ,scholia nova1 ,ioanne ,lonicero autore 7,marburgi1 #aedc1 p4 #gg71 occurs the following3 ,de recremento ferri4 ,cap4 ,,xlix4 ,greek3 ,skria sidrou4 scoria vel recrementum ferri4 ,qu per ignem ferro et cupro sordes separantur ac reijciuntur1 et ab aliis metallis ,greek3 skria uocantur4 ,omnis scoria1 maxime uero ferri exiccat4 ,acerrimo aceto macerauit ,galenus ferri scoriam1 ac deinde excocto1 pharmacum efficax confecit ad purulentas qu multo tempore uexat erant1 aures1 admirando spectantium effectu4 ,ardenti scoria uel recrementum ,greek3 helkusma1 inquit ,galenus4 ,see also the ,enarrationes eruditissim of ,amatus ,lusitanus 7,venet41 #aeig71 pp4 #dhb and #ejg1 upon iron and the loadstone4 #ih ,,page #cf1 ,,line #bg4 ,page #cf1 line #bi4 eijcitur for ejicitur4 #ii ,,page #cg1 ,,line #ah4 ,page #cg1 line #bb4 ut ,cardanus philosophatur4--,cardan's nonsense about the magnet feeding on iron is to be found in ,de ,subtilitate1 lib4 vii4 7,basil41 #afaa1 p4 #cha74 #ajj ,,page #ch1 ,,line #d4 ,page #ch1 line #g4 ferramenta 444 in usum navigantium4--,compare ,marke ,ridley's ,a ,short ,treatise of ,magneticall ,bodies and ,motions 7,lond41 #afac71 p4 a#b in the ,preface ,magneticall1 where he speaks of the iron-workes used in building ships4 ,the phraseology of ,marke ,ridley throws much light on the ,latin terms used by ,gilbert4 #aja ,,page #ch1 ,,line #cf4 ,page #ch1 line #db4 vruntur2 changed in ink to vrantur in the folio of #afjj2 but uruntur appears in the editions of #afbh and #afcc4 #ajb ,,page #ci1 ,,line #ab4 ,page #ci1 line #ab4 virumque2 altered in ink to virunque in all copies of the folio edition of #afjj4 #ajc ,,page #dj1 ,,line #cb4 ,page #dj1 line #cc4 ad tantos labores exantlandos4--,pumping1 as it was in mining before the invention of the steam engine1 may best be realized by examining the woodcuts in the ,de re metallica of ,georgius ,agricola 7,basil41 ,froben1 #aeef74 #ajd ,,page #dj1 ,,line #cd4 ,page #dj1 line #cf4 quingentas orgyas4--,gilbert probably had in his mind the works of the ,rorerbhel1 in the district of ,kitzbhl1 which in the sixteenth century had reached the depth of #c1ajg feet4 ,see ,humboldt's ,cosmos 7,lond41 #ahfj1 vol4 i41 p4 #adi74 #aje ,,page #dc1 ,,line #cd4 ,page #dc1 line #cc4 glis4--,this word1 here translated grit1 does not appear to be classical ,latin2 it may mean ooze or slime4 #ajf ,,page #de1 ,,line #be4 ,page #de1 line #bf4 ,motus igitur 444 quinque4 ,the five kinds of magnetic motions correspond in fact to the remaining sections of the book2 as follows3 ,coitio1 ,book ,,ii42 ,directio1 ,book ,,iii42 ,variatio1 ,book ,,iv42 ,declinatio1 ,book ,v42 and ,revolutio1 ,book ,,vi4 #ajg ,,page #df1 ,,line #g4 ,page #df1 line #h4 ,jofrancus ,offusius4--,the reference is to the treatise ,de divina astrorum faculitate of ,johannes ,franciscus ,offusius 7,paris1 #aegj74 #ajh ,,page #dg1 ,,line #ae4 ,page #dg1 line #ah4 ,grci vocant ,greek3 lektron1 quia ad se paleas trahit4 ,in this discussion of the names given to amber1 ,gilbert apparently conceives ,greek3 lektron to be derived from the verb ,greek3 helkein2 which is manifestly a doubtful etymology4 ,there has been much discussion amongst philologists as to the derivation of ,greek3 lektron or ,greek3 lektron1 and its possible connection with the word ,greek3 lektr4 ,this discussion has been somewhat obscured by the circumstance that the ,greek authors unquestionably used ,greek3 lektron 7and the ,latins their word electrum7 in two different significations1 some of them using these words to mean amber1 others to mean a shining #cb metal1 apparently of having qualities between those of gold and silver1 and probably some sort of alloy4 ,schweigger1 ,ueber das ,elektron der ,alten 7,greifswald1 #ahdh71 has argued that this metal was indeed no other than platinum3 but his argument partakes too much of special pleading4 ,those who desire to follow the question of the derivation of ,greek3 lektron may consult the following authorities3 ,j4 ,m4 ,gessner1 ,de ,electro ,veterum 7,commentt4 ,soc4 ,reg4 ,scientt4 ,goetting41 vol4 iii41 p4 #fg1 #agec72 ,delaunay1 ,mineralogie der ,alten1 ,part ,,ii41 p4 #abe2 ,buttmann1 ,mythologus 7,appendix ,i41 ,ueber das ,elektron71 ,vol4 ,,ii41 p4 #cee1 in which he adopts ,gilbert's derivation from ,greek3 helkein2 ,beckmann1 ,ursprung und ,bedeutung des ,bernsteinnamens ,elektron 7,braunsberg1 #ahei72 ,th4 ,henri ,martin1 ,du ,succin1 de ses noms divers et de ses varits suivant les anciens 7,mmoires de l',acadmie des ,inscriptions et ,belles-lettres1 ,tome ,,vi41 #are srie1 #are partie1 #ahfj72 ,martinus ,scheins1 ,de ,electro ,veterum ,metallico 7,inaugural dissertation1 ,berlin1 #ahga72 ,f4 ,a4 ,paley1 ,gold ,worship in relation to ,sun ,worship 7,contemporary ,review1 ,august1 #ahhd74 ,see also ,curtius1 ,grundzge der griechischen ,etymologie1 pp4 #fef-fei4 ,the net result of the disputations of scholars appears to be that ,greek3 lektr 7he who shines7 is a masculine form to which there corresponds the neuter form ,greek3 lektron 7that which shines74 ,stephanus admits the accentuation used by ,gilbert1 ,greek3 lektron1 to be justified from the ,timus of ,plato2 see ,note to p4 #fa4 #aji ,,page #dg1 ,,line #af4 ,page #dg1 line #ai4 ,greek3 harpax dicitur1 ,greek3 chrusophoron4--,with respect to the other names given to amber1 ,m4 ,th4 ,henri ,martin has written 7see previous note7 so admirable an account of them that it is impossible to better it4 ,it is therefore given here entire1 as follows3 ,le succin a reu chez les anciens des noms trs-divers4 ,sans parler du nom de ,greek3 lunkourion1 lyncurium1 qui peut-tre ne lui appartient pas1 comme nous le montrerons plus loin1 il s'est nomm chez les ,grecs le plus souvent ,greek3 lektron au neutre1#a mais aussi ,greek3 lektros au masculin#b et mme au fminin1#c ,greek3 chruslektros1#d ,greek3 chrusophoros#e et peut-tre1 comme nous l'avons vu1 ,greek3 chalkolithanon2 plus tard ,greek3 souchion#f ou ,greek3 souchinos#g1 et ,greek3 lektrianos lithos2#h plus tard encore ,greek3 berenik1 ,greek3 beronik ou ,greek3 bernik2#i il s'est nomm ,greek3 harpax chez les ,grecs tablis en ,syrie2#aj chez les ,latins succinum1 electrum1 et deux varits1 chryselectrum et sualiternicum #cc ou subalternicum2#aa chez les ,germains1 ,gless2#ab chez les ,scythes1 sacrium2#ac chez les ,egyptiens1 sacal2#ad chez les ,arabes1 karab#ae ou kahraba2#af en persan1 kruba4#ag ,ce mot1 qui appartient bien la langue persane1 y signifie attirant la paille1 et par consquent exprime l'attraction lectrique1 de mme que le mot ,greek3 harpax des ,grecs de ,syrie4 ,en outre1 le nom de haur roumi 7peuplier romain7 tait donn par les ,arabes1 non-seulement l'arbre dont ils croyaient que le succin tait la gomme1 mais au succin lui-mme4 ,haur roumi1 transform en aurum par les traducteurs latins des auteurs arabes1 et consondu mal propos avec ambar ou ambrum1 nom arabe latinis de l'ambre gris1 a produit le nom moderne d'ambre1 nom commun l'ambre jaune ou succin1 qui est une rsine fossile1 et l'ambre gris1 concrtion odorante qui se forme dans les intestines des cachalots4 ,on ne peut dire avec certitude si le nom de basse grcit ,greek3 bernik est la source ou le driv de ,bern1 radical du nom allemand du succin 7,bernstein74 ,quoi qu'il en soit1 le mot ,greek3 bernik a produit vernix1 nom d'une gomme dans la basse latinit1 d'o nous avons fait vernis4#ah #a ,voyez ,hrodote1 ,,iii41 #aae2 ,platon1 ,time1 p4 #hj c2 ,aristote1 ,mtor41 ,,iv41 #aj2 ,thophraste1 ,hist4 des plantes1 ,,ix41 #ah 7#ai71 #b2 ,des pierres1 #bh et #bi2 ,diodore de ,sic41 ,v41 #bc2 ,strabon1 ,,iv41 #f1 no #b1 p4 #bjb 7,casaubon72 ,dioscoride1 ,mat4 md41 ,i41 #aaj2 ,plutarque1 ,questions de table1 ,,ii41 #g1 #a2 ,questions platoniques1 ,,vii41 #a et #g2 ,lucien1 ,du succin et des cygnes2 le mme1 ,de ,pastrologie1 #ai2 ,s4 ,clment1 ,strom4 ,,ii41 p4 #cgj 7,paris1 #afda1 in-fol472 ,alexandre d',aphr41 ,quest4 phys4 et mor41 ,,ii41 #bc2 ,olympiodore1 ,mtor41 ,i41 #h1 fol4 #af1 t4 ,i41 p4 #aig 7,ideler7 et l'abrviateur d',etienne de ,byzance au mot ,greek3 lektrides4 #b ,voyez ,sophocle1 ,antigone1 v4 #ajch1 et dans ,eustathe1 sur l',iliade1 ,,ii41 #hfe2 ,elien1 ,nat4 des animaux1 ,,iv4 #df2 ,quintus de ,smyrne1 ,v41 #fbc2 ,eustathe1 sur la ,prigse de ,denys1 p4 #adb 7,bernhardy71 et sur l',odysse1 ,,iv41 #gc2 et ,suidas au mot ,greek3 hual4 #c ,voyez ,alexandre1 ,problmes1 sect4 #a1 prooem41 p4 #d 7,ideler72 ,eustathe1 sur l',odysse1 ,,iv41 #gc1 et ,tzetzs1 ,chiliade ,,vi41 #fej4 #d ,voyez ,psellus1 ,des pierres1 p4 #cf 7,bernard et ,maussac74 #e ,voyez ,dioscoride1 ,mat4 md41 ,i41 #aaj4 #f ,voyez ,s4 ,clment1 ,strom41 ,,ii41 p4 #cgj 7,paris1 #afda1 in-fol474 ,il parat distinguer l'un de l'autre ,greek3 to souchion et ,greek3 to lektron1 probablement parce qu'il attribue tort au mtal ,greek3 lektron la proprit attractive du succin4 #g ,voyez le faux ,zoroastre1 dans les ,goponiques1 ,,xv41 #a1 #bi4 #h ,voyez le faux ,zoroastre1 au mme endroit4 #i ,voyez ,eustathe1 sur l',odysse1 ,,iv41 #gc2 ,tzetzs1 ,chil4 ,,vi41 #fej2 ,nicolas ,myrepse1 ,antidotes1 ch4 #cbg1 et l',etymol4 ,gud4 au mot ,greek3 lektron4 ,comparez ,saumaise1 ,exert4 plin41 p4 #ggh4 #aj ,voyez ,pline1 ,,xxxvii41 #b1 s4 #aa1 no #cg4 #aa ,voyez ,pline1 ,,xxxvii41 #b1 s4 #aa-ac1 et ,tacite1 ,germanie1 ch4 #de4 ,la forme sualiternicum1 dans ,pline 7s4 #aa1 no #cc71 est donne par le manuscrit de ,bamberg et par ,m4 ,sillig 7t4 ,v41 p4 #cij71 au lieu de la forme subalternicum des ditions antrieures4 #ab ,voyez ,tacite et ,pline1 ll4 cc4 #ac ,voyez ,pline1 ,,xxxvii41 #b1 s4 #aa1 no #dj1 ,comp4 ,j4 ,grimm1 ,gesch4 der deutsch4 ,sprache1 ,kap4 x41 p4 #bcc 7,leipzig1 #ahdh1 in-#h74 #ad ,pline1 l4 c4 #ae ,voyez ,saumaise1 ,de homon4 hyles iatric1 c4 #aja1 p4 #afb 7#afhi1 in-fol474 #af ,voyez ,sprengel1 sur ,dioscoride1 t4 ,,ii41 pp4 #cij-cia4 #ag ,voyez ,m4 de ,sacy1 cit par ,buttmann1 ,mythologus1 t4 ,,ii41 pp4 #cfb-cfc4 #ah ,voyez ,saumaise1 ,ex4 plin41 p4 #ggh4 ,il n'est pas probable que le mot ,greek3 bernik ou ,greek3 berenik nom du succin dans la grcit du moyen ge1 soit li tymologiquement avec le nom propre ,greek3 berenik1 qui vient de l'adjectif macdonien ,greek3 berenikos pour ,greek3 pherenikos4 #aaj ,,page #dg1 ,,line #ag4 ,page #dg1 line #bj4 ,mauri vero ,carabem appellant1 qui solebant in sacrificijs1 deorum cultu ipsum libare4 ,carab enim significat offerre ,arabic2 ita ,carabe1 res oblata2 aut rapiens paleas1 vt ,scaliger ex ,abohali citat1 ex lingu ,arabic1 vel ,persic4--,the printed text1 line #ah1 has ,non rapiens paleas1 but in all copies of the folio of #afjj1 the ,non has been altered in ink into aut1 possibly by ,gilbert's own hand4 ,nevertheless the editions of #afbh and #afcc both read ,non4 ,there appears to be no doubt that the origin of the word ,carabe1 or ,karabe1 as assigned by ,scaliger1 is substantially correct4 ,as shown in the preceding note1 ,martin adopted this view4 ,if any doubt should remain it will be removed by the following notes which are due to ,mr4 ,a4 ,houtum ,schindler 7member of the ,institution of ,electrical ,engineers71 of ,terahan4 ,reference is made to the magnetic and electric properties of stones in three early ,persian lapidaries4 ,there are three stones only mentioned1 amber1 loadstone1 and garnet4 ,the electric property of the diamond is not mentioned4 ,the following extracts are from the ,tansk nmah1 by ,nasr ed dn ,tsi1 ,a4,d4 #abfj4 ,the two other treatises give the first extracts in the same words4 ,khrub1 also ,kahrab ,amber1 ,is yellow and transparent1 and has its name from the property1 which it possesses1 of attracting small1 dry pieces of straw or grass1 after it has been rubbed with cloth and become warm4 ,note4 ,in ,persian1 ,kh straw2 rub the robber1 hence ,khrub the straw-robber4 ,some consider it a mineral1 and say that it is found in the ,mediterranean and ,caspian seas1 floating on the surface1 but this is not correct4 ,the truth is that ,khrub #cd is the gum of a tree1 called jz i rm i4e41 roman nut2 walnut81 and that most of it is brought from ,rm here the ,eastern ,rome and from the confines of ,sclavonia and ,russia4 ,on account of its bright colour and transparency it is made into beads1 rings1 belt-buckles1 c4 444 c4 99 99 99 99 99 ,the properties of attraction and repulsion are possessed by other substances than loadstone1 for instance1 by amber and bjdah1#a which attract straws1 feathers1 etc41 and of many other bodies1 it can be said that they possess the power of attraction4 ,there is also a stone which attracts gold2 it has a pure yellow colour4 ,there is also a stone which attracts silver from distances of three or two yards4 ,there are also the stone which attracts tin1 very hard1 and smelling like asafoetida1 the stone attracting hair1 the stone attracting meat1 etc41 but1 latterly1 no one has seen these stones3 no proof1 however1 that they do not exist4 ,avicenna 7,ibn ,sin7 gives the following under the heading of ,karabe 7see ,canona ,medicin1 ,giunta edition1 ,venet41 #afjh1 lib4 ii41 cap4 #cga1 p4 #ccf73 ,karabe quid est8 ,gumma sicut sandaraca1 tendens ad citrinitatem1 albedinem1 peruietatem1 quandoque declinat ad rubedinem1 qu attrahit paleas1 fracturas plantarum ad se1 propter hoc nominatur ,karabe1 scilicet rapiens paleas1 persic4444 ,karabe confert tremori cordis1 quum bibitur ex eo medietas aurei cum aqua frigida1 prohibet sputum sanguinis valde4444 ,retinet vomitum1 prohibet materias malas a stomacho1 cum mastiche confortat stomachum4444 ,retinet fluxum sanguinis ex matrice1 ano1 fluxum ventris1 confert tenasmoni4 ,scaliger in ,de ,subtilitate1 ,exercitatio ciii41 #ab1 the passage referred to by ,gilbert says3 ,succinum apud ,arabas uocatur1 ,carabe3 quod princeps ,aboali1 rapiens paleas1 interpretatur 7p4 #afc bis1 editio ,luteti1 #aeeg74 #a ,bjdah is classified by ,muhammad ,b4 ,mansr 7,a4,d4 #adgj7 and by ,ibn al ,mubrak 7,a4,d4 #aebj7 under stones resembling ruby2 the ,tansk nmah describes it in a separate chapter4 ,from the description it can be identified with the almandine garnet1 and the method of cutting this stone en cabochon1 with hollow back in order to display its colour better is specially mentioned4 ,the ,tansk nmah only incidentally refers to the electric property of the bjdah in the chapter on loadstone1 but the other two treatises specially refer to it in their description of the stone4 ,the one has3 ,bjdah if rubbed until warm1 attracts straws and other light bodies just as amber does2 the other3 ,bjdah1 if rubbed on the hair of the head1 or on the beard1 attracts straws4 ,surri1 the lexicographer1 who compiled a dictionary in #aeii1 considers the bjdah a red ruby which possesses the property of attraction4 ,other dictionaries do not mention the attractive property1 but some authors confound the stone with amber1 calling it ,kbrub1 the straw-robber4 ,the bjdah is not rubellite 7red tourmaline7 for it is described in the lapidaries as common1 whereas rubellite 7from ,ceylon7 has always been rare1 and was unknown in ,persia in the thirteenth century4 #aaa ,,page #dg1 ,,line #ba4 ,page #dg1 line #be4 ,succinum seu succum4--,dioscorides regarded amber as the inspissated juice of the poplar tree4 ,from the ,frankfurt edition of #aedc 7,de ,medicinali materia1 etc47 edited by ,ruellius1 we have1 liber i41 p4 #ec3 ,populus4 ,cap4 ,,xciii4 444 ,lachrymam populorum commemorant qu in ,padum amnem defluat1 durari1 ac coire in succinum1 quod electrum vocant1 alii chrysophorum4 id attritu jucundum odorem spirat1 et aurum colore imitatur4 tritum potumque stomachi ventrisque fluxiones sistit4 ,to this ,ruellius adds the commentary3 ,succinum seu succina gutta succo dicta1 ,grcis ,greek3 lektrom sic1 esse #ce lachryma populi alb1 vel etiam nigr quibusdam videtur1 ab ejusdem arboris resina4 ,dioscoridi et ,galeno dicta differens et ,greek3 pterugophoros1 id est paleas trahens1 quoque vocatur1 quantum ei quoque ,galenus tribuit li4 #cg1 ca4 #i4 ,succinum scribit quibusdam pinei generis arboribus1 ut gummi cerasis excidere autumno1 et largum mitti ex ,germania septentrionali1 et insulis maris ,germanici4 quod hodie nobis est compertissimum3 ad hc liquata igni valentiore1 quia frigido intensiore concrevit4 pineam aperte olet1 calidum primo gradu1 siccum secundo1 stomachum roborat1 vomitum1 nauseam arcet4 cordis palpitationi prodest4 pravorem humorum generationem prohibet4 ,germani weiss und gelbaugstein et brenstein4 ,galli ambra vocant3 vulgo in corollis precariis frequens4 ,in the scholia of ,johann ,lonicer in his edition of ,dioscorides1 we find1 lib4 i41 cap4 xcviii41 ,de nigra ,populo3 ,greek3 aigeiros1 populus nigra 444 idem electrum vel succinum ,greek3 haigeirou lachrymam esse adseverat ,paulus1 cui prter vires qu ab ,dioscoride recensentur1 tribuit etiam vim sistendi sanguinis1 si tusum in potu sumatur4 ,avicenn ,charabe1 ut colligitur ex ,joanne ,jacobo ,manlio1 est electrum hoc ,dioscoridis1 attestatur ,brunfelsius4 ,lucianus plan nullum electrum apud ,eridanum seu ,padum inveniri tradit1 quandoquidem ne populus quidem illa ab nautis ei demonstrari potuerit4 ,plinius rusticas transpadanas ex electro monilia gestare adfirmat1 quum ,venetis primum agnoscere didicissent adversus nimirum vitia gutturis et tonsillarum4 ,num sit purgamentum maris1 vel lachryma populi1 vel pinus1 vel ex radiis occidentis solis nascatur1 vel ex montibus ,sudinorum profluat1 incertum etiam ,erasmus ,stella relinquit4 ,sudinas tamen ,borussiorum opes esse constat4 ,matthiolus 7in ,p4 ,a4 ,mattioli 444 ,opera qu extant omnia1 hoc est ,commentarii in vi libros ,p4 ,dioscoridis de materia medica1 ,frankfurt1 #aeif1 p4 #acc7 comments on the suggestion of ,galen that amber came from the ,populus alba1 and also comments on the ,arabic1 ,greek1 and ,latin names of amber4 ,the poplar-myth is commemorated by ,addison 7in ,italy7 in the lines3 ,no interwoven reeds a garland made1 ,to hide his brows within the vulgar shade2 ,but poplar wreathes around his temples spread1 ,and tears of amber trickled down his head4 ,amber is1 however1 assuredly not derived from any poplar tree3 it comes from a species of pine long ago extinct1 called by ,gppert the pinites succinifer4 ,gilbert does not go into the medicinal uses1 real or fancied1 that have been ascribed to amber in almost as great variety as to loadstone4 ,pliny mentions some of these in his ,natural ,historie 7,english version of #afja1 p4 #fji73 ,he ,callistratus saith of this yellow ,amber1 that if it be worne about the necke in a collar1 it cureth feavers1 and healeth the diseases of the mouth1 throat1 and jawes3 reduced into pouder and tempered with honey and oile of roses1 it is soveraigne for the infirmities of the eares4 ,stamped together with the best ,atticke honey1 it maketh a singular eyesalve for to help a dim sight3 pulverized1 and the pouder thereof taken simply alone1 or else drunke in water with ,masticke1 is soveraigne for the maladies of the stomacke4 ,nicolaus ,myrepsus 7,recipe #iea1 op4 citat47 gives a prescription for #cf dysentery and diabetes confiding chiefly of ,electri vel succi ,nili 7,nili succum appellant ,arabes ,karabem74 #aab ,,page #dg1 ,,line #bb4 ,page #dg1 line #bf4 ,sudauienses seu ,sudini4--,cardan in ,de ,rerum ,varietate1 lib4 iii41 cap4 xv4 7,editio ,basil41 #aeef1 p4 #aeb71 says of amber3 ,colligitur in quadam pen insula ,sudinorum1 qui nunc uocatur ,brusci1 in ,prussia1 nunc ,borussia1 juxta ,veneticum sinum1 sunt orientaliores ostiis ,vistul fluuii3 ubi triginta pagi huic muneri destinati sunt1 etc4 ,he rejects the theory that it consists of hardened gum4 ,there exists an enormous literature concerning ,amber and the ,prussian amber industry4 ,amongst the earliest works 7after ,theophrastus and ,pliny7 are those of ,aurifaber 7,bericht ber ,agtstein oder ,brnstein1 ,knigsberg1 #aeea72 ,goebel 7,de ,succino1 ,libri duo1 authore ,severino ,goebelio1 ,medico ,doctore1 ,regiomont41 #aeeh72 and ,wigand 7,vera historia de ,succino ,borussico1 ,jena1 #aeij74 ,later on ,hartmann1 ,p4 ,j4 7,succini ,prussici ,physica et civilis ,historia1 ,francofurti1 #afgg72 and the splendid folio of ,nathaniel ,sendel 7,historia ,succinorum corpora aliena involventium1 ,lipsi1 #agdb71 with its wealth of plates illustrating amber specimens1 with the various included fossil fauna and flora4 ,georgius ,agricola 7,de natura ,fossilium1 liber iv471 and ,aldrovandi 7,museum ,metallicum1 pp4 #daa-dab7 must also be mentioned4 ,bibliographies of the earlier literature are to be found in ,hartmann 7op4 citat471 and in ,daniel ,gralath1 ,elektrische ,bibliothek 7,versuche und ,abhandlungen der ,naturforschenden ,gesellschaft in ,danzig1 ,zweiter ,theil1 pp4 #ecg-eci1 ,danzig and ,leipzig1 #aged74 ,see also ,karl ,mllenhoff1 ,deutsche ,altertumskunde1 vol4 i41 ,zweites ,buch1 pp4 #baa-bbd1 ,zinn und ,bernsteinhandel 7,berlin1 #ahgj71 and ,humboldt's ,cosmos 7,bohn's edition1 ,london1 #ahfj1 vol4 ii41 p4 #dic74 ,the ancient ,greek myth according to which amber was the tears of the ,heliades1 shed on the banks of the river ,eridanus over ,phaethon1 is not alluded to by ,gilbert4 ,it is narrated in well-known passages in ,ovid and in ,hyginus4 ,those interested in the modern handling of the myth should refer to ,mllenhoff 7op4 citat41 pp4 #bag-bbc1 der ,bernsteinmythus71 or to that delightful work ,the ,tears of the ,heliades1 by ,w4 ,arnold ,buffum 7,london1 #ahif74 #aac ,,page #dg1 ,,line #cj4 ,page #dg1 line #cf4 quare muscos 444 in frustulis quibusdam comprehensos retinet4--,the occurrence of flies in amber was well known to the ancients4 ,pliny thus speaks of it1 book xxxvii41 chap4 iii4 7p4 #fjh of ,p4 ,holland's translation of #afja73 ,that it doth destill and drop at the first very clear and liquid1 it is evident by this argument1 for that a man may see diverse things within1 to wit1 ,pismires1 ,gnats1 and ,lizards1 which no doubt were entangled and stucke within it when it was greene and fresh1 and so remain enclosed within as it waxed harder4 ,a locust embedded in amber is mentioned in the ,musum ,septalianum of ,terzagus 7,derton1 #affd74 ,martial's epigram 7,epigrammata1 liber vi41 #ae7 is well known3 ,dum ,phaethontea formica vagatur in umbra ,implicuit tenuem succina gutta feram4 ,see also ,hermann 7,daniel71 ,de rana et lacerta ,succino ,borussiaco insitis #cg 7,cracov41 #aehj2 a later edition1 ,rig1 #afjj74 ,the great work on inclusa in amber is1 however1 that of ,nathaniel ,sendel4 ,see the previous note4 ,sir ,thomas ,browne must not be forgotten in this connexion4 ,the ,pseudodoxia 7p4 #fd of the second edition1 #afej7 says3 ,lastly1 we will not omit what ,bellabonus upon his own experiment writ from ,dantzich unto ,mellichius1 as he hath left recorded in his chapter ,de ,succino1 that the bodies of ,flies1 ,pismires and the like1 which are said oft times to be included in ,amber1 are not reall but representative1 as he discovered in severall pieces broke for that purpose4 ,if so1 the two famous ,epigrams hereof in ,martiall are but poeticall1 the ,pismire of ,brassavolus ,imaginary1 and ,cardans ,mousoleum for a flie1 a meer phancy4 ,but hereunto we know not how to assent1 as having met with some whose reals made good their representments4 ,see also ,pope's ,epistle to ,dr4 ,arbuthnot1 line #afi4 #aad ,,page #dg1 ,,line #cd4 ,page #dg1 line #dj4 ,commemorant antiqui quod succinum festucas et paleas attrahit4--,pliny 7book xxxvii41 chap4 ii41 p4 #fjf of the ,english edition of #afja7 thus narrates the point3 ,hee ,niceas writeth also1 that in ,aegypt it amber is engendered4444 ,semblably in ,syria1 the women 7saith hee7 make wherves of it for their spindles1 where they use to call it ,harpax1 because it will catch up leaves1 straws1 and fringes hanging to cloaths4 p4 #fjh4 ,to come to the properties that ,amber hath1 ,if it bee well rubbed and chaufed betweene the fingers1 the potentiall facultie that lieth within1 is set on work1 and brought into actual operation1 whereby you shall see it to drawe chaffe strawes1 drie leaves1 yea1 and thin rinds of the ,linden or ,tillet tree1 after the same sort as loadstone draweth yron4 #aae ,,page #dg1 ,,line #cf4 ,page #dg1 line #db4 ,quod etiam facit ,gagates lapis4--,the properties of ,jet were well known to the medival writers4 ,julius ,solinus writes in ,de ,mirabilibus1 chapter xxxiv41 ,of ,britaine 7,english version of #aehg by ,a4 ,golding73 ,moreover to the intent to passe the large aboundance of sundry mettals 7whereof ,britaine hath many rich mynes on all sides71 ,here is store of the stone called ,geate1 and ye best kind of it4 ,if ye demaund ye beautie of it1 it is a black ,jewell3 if the qualitie1 it is of no weight3 if the nature1 it burneth in water1 and goeth out in ,oyle2 if the power1 rubbe it till it be warme1 and it holdeth such things as are laide to it2 as ,amber doth4 ,the ,realme is partlie inhabited of barbarous people1 who even fr theyr childhoode haue shapes of divers beastes cunninglye impressed and incorporate in theyr bodyes1 so that beeing engraued as it were in theyr bowels1 as the man groweth1 so growe the marks painted vpon him4444 ,pliny describes it as follows 7p4 #ehi1 ,english edition of #afja73 ,the ,geat1 which otherwise we call ,gagates1 carrieth the name of a toune and river both in ,lycia1 called ,gages3 it is said also1 that the sea casteth it up at a full tide or high water into the ,island ,leucola1 where it is gathered within the space of twelve stadia1 and no where else3 blacke it is1 plaine and even1 of a hollow substance in manner of the pumish stone1 not much differing from the nature of wood2 light1 brittle1 and if it bee rubbed or bruised1 of a strong flavour4 7,book xxxvi41 chap4 xviii47 ,in the ,commentary of ,joannes ,ruellius upon ,dioscorides1 ,pedanii ,dioscoridis ,anazarbei de medicinali materia libri sex1 ,ioanne ,ruellio ,suessionensi interprete 444 7,frankfurt1 #aedc1 fol41 liber quintus1 cap4 xcii47 is the following description3 #ch ,in ,gagatarum lapidum genere1 prferendus qui celeriter accenditur1 et odorem bituminis reddit4 niger est plerunque1 et squalidus1 crustosus1 per quam levis4 ,vis ei molliendi1 et discutiendi4 deprehendit sonticum morbum suffitus1 recreatque uulu strangulationes4 fugat serpentes nidore4 podagricis medicaminibus1 et a copis additur4 ,in ,cilicia nasci solet1 qua influens amnis in mare effunditur1 proxime oppidum quod ,plagiopolis dicitur4 vocatur autem et locus et amnis ,gagas1 in cujus faucibus ii lapides inveniuntur4 ,gagates lapis colore atro1 ,germanis ,schwartzer augstein1 voce parum depravata1 dicitur4 odore dum uritur bituminis1 siccat1 glutinat1 digerit admotus1 in corollis precariis et salinis frequens4 ,and in the ,scholia upon ,dioscorides of ,joannes ,lonicer 7,marpurgi1 #afdc1 cap4 xcvii41 p4 #hj7 is the following3 ,de ,gagate ,lapide4 ,ab natali solo1 urbe nimirum ,gagae ,lyciae nomen habet4 ,galenus se flumen isthuc et lapidem non invenisse1 etiamsi naui parua totam ,lyciam perlustravit3 ait1 se autem in caua ,syria multos nigros lapides invenisse glebosos1 qui igni impositi1 exiguam flammam gignerent4 ,meminit hujus ,nicander in ,theriacis nempe suffitum hujus abigere venenata4 ,there is also a good account of ,gagates 7and of ,succinum7 by ,langius1 ,epistola ,,lxxv41 p4 #ded1 of the work ,epistolarum medicinalium volumen tripartitum 7,francofurti1 #aehi74 #aaf ,,page #dg1 ,,line #ci4 ,page #dg1 line #de4 ,multi sunt authores moderni4--,the modern authors who raised ,gilbert's wrath by ignorantly copying out all the old tales about amber1 jet1 and loadstone1 instead of investigating the facts1 were1 as he says at the beginning of the chapter1 some theologians1 and some physicians4 ,he seems to have taken a special dislike to ,albertus ,magnus1 to ,puteanus 7,du ,puys71 and to ,levinus ,lemnius4 #aag ,,page #dg1 ,,line #ci4 ,page #dg1 line #df4 gagate4--,the editions of #afbh and #afcc both read ex gagate4 #aah ,,page #dh1 ,,line #ad4 ,page #dh1 line #af4 ,nam non solum succinum1 gagates 7vt illi putant7 allectant corpuscula4--,the list of bodies known to become electrical by friction was not quite so restricted as would appear from this passage4 ,five1 if not six1 other minerals had been named in addition to amber and jet4 7#a47 ,lyncurium4 ,this stone1 about which there has been more obscurity and confusion than about any other gem1 is supposed by some writers to be the tourmaline1 by others a jacinth1 and by others a belemnite4 ,the ancients supposed it to be produced from the urine of the lynx4 ,the following is the account of ,theophrastus1 ,theophrastus's ,history of ,stones4 ,with an ,english ,version 4441 by ,sir ,john ,hill1 ,london1 #aggd1 p4 #abc1 ch4 xlix4-l4 ,there is some ,workmanship required to bring the ,emerald to its ,lustre1 for originally it is not so bright4 ,it is1 however1 excellent in its ,virtues1 as is also the ,lapis ,lyncurius1 which is likewise used for engraving ,seals on1 and is of a very solid ,texture1 as ,stones are2 it has also an attractive ,power1 like that of ,amber1 and is said to attract not only ,straws and small pieces of ,sticks1 but even ,copper and ,iron1 if they are beaten to thin pieces4 ,this ,diocles affirms4 ,the ,lapis ,lyncurius is pellucid1 and of a fire ,colour4 ,see also ,w4 ,watson in ,philos4 ,trans41 #agei1 ,l4 i41 p4 #cid1 ,observations concerning the ,lyncurium of the ancients4 7#b47 ,ruby4 7#c47 ,garnet4 ,the authority for both these is ,pliny1 ,nat4 ,hist41 book xxxvii41 chap4 vii4 7p4 #fag of ,english edition of #afja74 #ci ,over and besides1 ,i find other sorts of ,rubies different from those above-named2444 which being chaufed in the ,sun1 or otherwise set in a heat by rubbing with the fingers1 will draw unto them chaffe1 strawes1 shreads1 and leaves of paper4 ,the common ,grenat also of ,carchedon or ,carthage1 is said to doe as much1 although it be inferiour in price to the former4 7#d47 ,jasper4 ,affaytatus is the authority1 in ,fortunii ,affaitati ,physici atque ,theologi 444 ,physic ,astronomic cosiderationes 7,venet41 #aedi71 where1 on p4 #bj1 he speaks of the magnet turning to the pole1 likening it to the turning of a palea ab ,ambro vel ,iaspide et hujuscemodi lapillis lucidis4 7#e47 ,lychnis4 ,pliny and ,st4 ,isidore speak of a certain stone lychnis1 of a scarlet or flame colour1 which1 when warmed by the sun or between the fingers1 attracts straws or leaves of papyrus4 ,pliny puts this stone amongst carbuncles1 but it is much more probably rubellite1 that is to say1 red tourmaline4 7#f47 ,diamond4 ,in spite of the confusion already noted1 propos of adamas 7,note to p4 #dg71 between loadstone and diamond1 there seems to be one distinct record of an attractive effect having been observed with a rubbed diamond4 ,this was recorded by ,fracastorio1 ,de sympathia et antipathia rerum 7,giunta edition1 ,venice1 ,,mdlxxiiii1 chap4 v41 p4 #fj verso71 cujus rei illud esse signum potest1 cum confricata qud vt ,succinum1 ,adamas fortius furculos trahunt4 ,and 7on p4 #fb recto72 nam si per similitudine 7vt supra diximus7 fit hc attractio1 cur magnes non potius magnetem trahit1 q ferrum1 ferrum non potius ad ferrum movetur1 qum ad magnetem8 qu nam affinitas est pilorum1 furculorum cum ,electro1 ,adamante8 prsertim q si cum ,electro affines sunt1 quomodo cum ,adamante affinitatem habebunt1 qui dissimilis ,electro est8 ,an incontestable case of the observation of the electrification of the diamond occurs in ,gartias ab ,horto4 ,the first edition of his ,historia dei ,semplici ,aromati was publisht at ,goa in ,india in #aefc4 ,in chapter xlviii4 on the ,diamond1 occur these words 7p4 #bjj of the ,venetian edition of #afaf73 ,questo si bene ho sperimentato io pi volte1 che due ,diamanti perfetti fregati insieme1 si vniscono di modo insieme1 che non di leggiero li potrai separare4 ,et ho parimente veduto il ,diamante dopo di esser ben riscaldato1 tirare se le festuche1 non men1 che si faccia l'elettro4 ,see also ,aldrovandi1 ,musum ,metallicum 7,bonon41 #afdh1 p4 #idg74 ,levinus ,lemnius also mentions the ,diamond along with amber4 ,see his ,occulta natur miracula 7,english edition1 ,london1 #afeh1 p4 #aii74 #aai ,,page #dh1 ,,line #af4 ,page #dh1 line #ah4 ,iris gemma4--,the name iris was given1 there can be little doubt1 to clear six sided prisms of rock-crystal 7quartz71 which1 when held in the sun's beams1 cast a crude spectrum of the colours of the rainbow4 ,the following is the account of it given in ,pliny1 book xxxvii41 chap4 vii4 7p4 #fbc of the ,english version of #afja73 444 there is a stone in name called ,iris3 digged out of the ground it is in a certaine ,island of the red sea1 distant from the city ,berenice three score miles4 ,for the most part it resembleth ,crystall3 which is the reason that some hath tearmed it the root of ,crystall4 ,but the cause why they call it ,iris1 is1 ,that if the beames of the ,sunne strike upon it directly within house1 it doth send from it against the walls that bee neare1 the very resemblance both in forme and also in colour of a rainebow2 and eftsoones it will chaunge the same in much varietie1 to the great admiration of them that behold it4 ,for certain it is knowne1 that six angles it hath in manner of the ,crystall3 but they say that some of them have their sides rugged1 and the same #dj unequally angled3 which if they be laid abroad against the ,sunne in the open aire1 do scatter the beames of the ,sunne1 which light upon them too and fro3 also that others doe yeeld a brightnes from themselves1 and thereby illuminat all that is about them4 ,as for the diverse colours which they cast forth1 it never happeneth but in a darke or shaddowie place3 whereby a man may know1 that the varietie of colours is not in the stone ,iris1 but commeth by the reverberation of the wals4 ,but the best ,iris is that which representeth the greatest circles upon the wall1 and those which bee likest unto rainebowes indeed4 ,in the ,english translation of ,solinus's ,de ,mirabilibus 7,the excellent and pleasant worke of ,julius ,solinus containing the noble actions of humaine creatures1 the secretes and providence of nature1 the descriptions of countries 444 tr4 by ,a4 ,golding1 gent41 ,lond41 #aehg71 chapter xv4 on ,arabia has the following3 ,hee findeth likewise the ,iris in the ,red sea1 sixe cornered as the ,crystall3 which beeing touched with the ,sunnebeames1 casteth out of him a bryght reflexion of the ayre like the ,raynebowe4 ,iris is also mentioned by ,albertus ,magnus 7,de mineralibus1 ,venet41 #aedb1 p4 #ahi71 by ,marbodeus ,gallus 7,de lapidibus1 ,par4 #aeca1 p4 #gh71 who describes it as crystallo simulem sexangulam1 by ,lomatius 7,artes of curious ,paintinge1 ,haydocke's translation1 ,lond41 #aeih1 p4 #aeg71 who says1 444 the ,sunne1 which casting his beames vpon the stone ,iris1 causeth the raine-bowe to appeare therein 4441 and by ,sir ,john ,hill 7,a ,general ,natural ,history1 ,lond41 #agdh1 p4 #agi74 ,figures of the ,iris given by ,aldrovandi in the ,musum ,metallicum clearly depict crystals of quartz4 #abj ,,page #dh1 ,,line #af4 ,page #dh1 line #ah4 ,vincentina1 ,bristolla 7,anglica gemma siue fluor74 ,this is doubtless the same substance as the ,gemma ,vincentij rupis mentioned on p4 #ed1 line #af 7p4 #ed1 line #ah1 of ,english ,version71 and is nothing else than the so-called ,bristol diamond1 a variety of dark quartz crystallized in small brilliant crystals upon a basis of hmatite4 ,to the work by ,dr4 ,thomas ,venner 7,lond41 #afej71 entitled ,via ,recta or the ,bathes of ,bathe1 there is added an appendix1 ,a ,censure concerning the water of ,saint ,vincents ,rocks neer ,bristol 7,urbs pulchra et ,emporium celebre71 in which1 at p4 #cgf1 occurs this passage3 ,this ,water of ,saint ,vincents ,rock is of a very pure1 cleare1 crystalline substance1 answering to those crystalline ,diamonds and transparent stones that are plentifully found in those ,clifts4 ,in the ,fossils ,arranged of ,sir ,john ,hill 7,lond41 #agga71 p4 #abc1 is the following entry3 ,black crystal4 ,small very hard heavy glossy4 ,perfectly black1 opake4 ,bristol 7grottos1 glass7 referring to its use4 ,the name ,vincentina is not known as occurring in any mineralogical book4 ,prof4 ,h4 ,a4 ,miers1 ,f4,r4,s41 writes concerning the passage3 ,anglica gemma sive fluor seems to be a synonym for ,bristolla1 or possibly for ,vincentina et ,bristolla4 ,both quartz and fluor are found at ,clifton4 ,in that case ,vincentina and ,bristolla refer to these two minerals1 and if so one would expect ,bristolla to be the ,bristol ,diamond1 and ,vincentina to be the comparatively rare ,fluor spar from that locality4 ,at the end of the edition of #afec of ,sir ,hugh ,plat's ,jewel ,house of ,art and ,nature1 is appended ,a rare and excellent ,discourse of ,minerals1 ,stones1 ,gums1 and ,rosins2 with the vertues and use thereof1 ,by ,d4 ,b4 ,gent4 ,here1 p4 #bah1 we read3 ,we have in ,england a stone or mineral called a ,bristol stone 7because #da many are found thereabouts7 which much resembles the ,adamant or ,diamond1 which is brought out of ,arabia and ,cyprus2 but as it is wanting of the same hardnesse1 so falls it short of the like vertues4 #aba ,,page #dh1 ,,line #ah4 ,page #dh1 line #ai4 ,crystallus4--,rock-crystal4 ,quartz4 ,pliny's account of it 7,philemon ,holland's version of #afja1 p4 #fjd7 in book xxxvii41 chap1 ii41 is3 ,as touching ,crystall1 it proceedeth of a contrarie cause1 namely of cold2 for a liquor it is congealed by extreame frost in manner of yce2 and for proofe hereof1 you shall find crystall in no place els but where the winter snow is frozen hard3 so as we may boldly say1 it is verie yce and nothing else1 whereupon the ,greeks have give it the right name ,crystallos1 i4 ,yce4444 ,thus much ,i dare my selfe avouch1 that crystall groweth within certaine rockes upon the ,alps1 and these so steepe and inaccessible1 that for the most part they are constrained to hang by ropes that shall get it forth4 #abb ,,page #dh1 ,,line #ah4 ,page #dh1 line #bj4 ,similes etiam attrahendi vires habere videntur vitrum 444 sulphur1 mastix1 cera dura sigillaris4 ,if1 as shown above1 the electric powers of diamond and ruby had already been observed1 yet ,gilbert was the first beyond question to extend the list of electrics beyond the class of precious stones1 and his discovery that glass1 sulphur1 and sealing-wax acted1 when rubbed1 like amber1 was of capital importance4 ,though he did not pursue the discovery into mechanical contrivances1 he left the means of that extension to his followers4 ,to ,otto von ,guericke we owe the application of sulphur to make the first electrical machine out of a revolving globe2 to ,sir ,isaac ,newton the suggestion of glass as affording a more mechanical construction4 ,electrical attraction by natural products other than amber after they have been rubbed must have been observed by the primitive races of mankind4 ,indeed ,humboldt in his ,cosmos 7,lond41 #ahfj1 vol4 i41 p4 #ahb7 records a striking instance3 ,i observed with astonishment1 on the woody banks of the ,orinoco1 in the sports of the natives1 that the excitement of electricity by friction was known to these savage races1 who occupy the very lowest place in the scale of humanity4 ,children may be seen to rub the dry1 flat and shining seeds or husks of a trailing plant 7probably a ,negretia7 until they are able to attract threads of cotton and pieces of bamboo cane4 #abc ,,page #dh1 ,,line #bc4 ,page #dh1 line #be4 arsenicum4--,this is orpiment4 ,see the ,dictionary of metallick words at the end of ,pettus's ,fleta ,minor4 #abd ,,page #dh1 ,,line #bc4 ,page #dh1 line #bf4 in convenienti coelo sicco4--,the observation that only in a dry climate do rock-salt1 mica1 and rock-alum act as electrics is also of capital importance4 ,compare page #ef4 #abe ,,page #dh1 ,,line #bg4 ,page #dh1 line #ca4 ,alliciunt hc omnia non festucas modo paleas4--,gilbert himself marks the importance of this discovery by the large asterisk in the margin4 ,the logical consequence was his invention of the first electroscope1 the versorium non magneticum1 made of any metal1 figured on p4 #di4 #abf ,,page #dh1 ,,line #cd4 ,page #dh1 line #cf4 quod tantum siccas attrahat paleas1 nec folia ocimi4--,this silly tale that basil leaves were not attracted by amber arose in the ,qustiones ,convivales of ,plutarch4 ,it is repeated by ,marbodeus and was quoted by ,levinus ,lemnius as true4 ,gilbert denounced it as nonsense4 ,cardan 7,de ,subtilitate1 ,norimb41 #aeej1 p4 #acb7 had already contradicted the fable4 ,trahit enim1 he says1 omnia levia1 paleas1 festucas1 ramenta #db tenuia metallorum1 ocimi folia1 perperam contradicente ,theophrasto4 ,sir ,thomas ,browne specifically refuted it4 ,for if1 he says1 the leaves thereof or dried stalks be stripped into small strawes1 they arise unto ,amber1 ,wax1 and other ,electricks1 no otherwise then those of ,wheat or ,rye4 #abg ,,page #dh1 ,,line #cd4 ,page #dh1 line #ch4 ,sed vt poteris manifest experiri4444 ,gilbert's experimental discoveries in electricity may be summarized as follows3 #a4 ,the generalization of the class of ,electrics4 #b4 ,the observation that damp weather hinders electrification4 #c4 ,the generalization that electrified bodies attract everything1 including even metals1 water1 and oil4 #d4 ,the invention of the non-magnetic versorium or electroscope4 #e4 ,the observation that merely warming amber does not electrify it4 #f4 ,the recognition of a definite class of non-electrics4 #g4 ,the observation that certain electrics do not attract if roasted or burnt4 #h4 ,that certain electrics when softened by heat lose their power4 #i4 ,that the electric effluvia are stopped by the interposition of a sheet of paper or a piece of linen1 or by moist air blown from the mouth4 #aj4 ,that glowing bodies1 such as a live coal1 brought near excited amber discharge its power4 #aa4 ,that the heat of the sun1 even when concentrated by a burning mirror1 confers no vigour on the amber1 but dissipates the effluvia4 #ab4 ,that sulphur and shell-lac when aflame are not electric4 #ac4 ,that polish is not essential for an electric4 #ad4 ,that the electric attracts bodies themselves1 not the intervening air4 #ae4 ,that flame is not attracted4 #af4 ,that flame destroys the electrical effluvia4 #ag4 ,that during south winds and in damp weather1 glass and crystal1 which collect moisture on their surface1 are electrically more interfered with than amber1 jet and sulphur1 which do not so easily take up moisture on their surfaces4 #ah4 ,that pure oil does not hinder production of electrification or exercise of attraction4 #ai4 ,that smoke is electrically attracted1 unless too rare4 #bj4 ,that the attraction by an electric is in a straight line toward it4 #abh ,,page #dh1 ,,line #ce4 ,page #dh1 line #ci4 qu sunt ill materi4--,gilbert's list of electrics should be compared with those given subsequently by ,cabeus 7#afbi71 by ,sir ,thomas ,browne 7#afdf71 and by ,bacon4 ,the last-named list occurs in his ,physiological ,remains1 published posthumously in #afgi2 it contains nothing new4 ,sir ,thomas ,browne's list is given in the following passage1 which is interesting as using for the first time in the ,english language the noun ,electricities3 ,many stones also both precious and vulgar1 although terse and smooth1 have not this power attractive2 as ,emeralds1 ,pearle1 ,jaspis1 ,corneleans1 ,agathe1 ,heliotropes1 ,marble1 ,alablaster1 ,touchstone1 ,flint and ,bezoar4 ,glasse attracts but weakely though cleere1 some slick stones and thick glasses indifferently3 ,arsenic but weakely1 so likewise glasse of ,antimony1 but ,crocus ,metallorum not at all4 ,saltes generally but weakely1 as ,sal ,gemma1 ,alum1 and also ,talke1 nor very discoverably by any frication3 but if gently warmed at the fire1 and wiped with a dry cloth1 they will better discover their ,electricities4 7,pseudodoxia ,epidemica1 p4 #gi47 ,in the ,philosophical ,transactions1 vol4 xx41 p4 #chd1 is ,a ,catalogue of ,electrical ,bodies by the late ,dr4 ,rob4 ,plot4 ,it begins ,non solum succinum1 and ends alumen rupeum1 being identical with ,gilbert's list except that he calls ,vincentina ,bristolla by the name ,pseudoadamas ,bristoliensis4 #abi ,,page #di1 ,,line #be4 ,page #di1 line #cj4 non dissimili modo4--,the modus #dc operandi of the electrical attractions was a subject of much discussion2 see ,cardan1 op4 citat4 #acj ,,page #ea1 ,,line #b4 ,page #ea1 line #a4 appellunt4--,this appears to be a misprint for appelluntur4 #aca ,,page #ea1 ,,line #bb4 ,page #ea1 line #bc4 smyris4--,emery4 ,this substance is mentioned on p4 #bb as a magnetic body4 #acb ,,page #eb1 ,,line #a4 ,page #ea1 line #df4 gemm 444 vt ,crystallus1 qu ex limpid concreuit4 ,see the note to p4 #dh4 #acc ,,page #eb1 ,,line #cj4 ,page #eb1 line #cb4 ammoniacum4--,ammoniacum1 or ,gutta ,ammoniaca1 is described by ,dioscorides as being the juice of a ferula grown in ,africa1 resembling galbanum1 and used for incense4 ,ammoniack is a kind of ,gum like ,frankincense2 it grows in ,lybia1 where ,ammon's ,temple was4 ,sir ,hugh ,plat's ,jewel ,house of ,art and ,nature 7,ed4 #afec1 p4 #bbc74 #acd ,,page #eb1 ,,line #ch4 ,page #eb1 line #da4 du proposit sunt caus 444 materia forma4--,gilbert had imbibed the schoolmen's ideas as to the relations of matter and form4 ,he had discovered and noted that in the magnetic attractions there was always a verticity1 and that in the electrical attractions the rubbed electrical body had no verticity4 ,to account for these differences he drew the inference that since 7as he had satisfied himself7 the magnetic actions were due to form1 that is to say to something immaterial--to an imponderable as in the subsequent age it was called--the electrical actions must necessarily be due to matter4 ,he therefore put forward his idea that a substance to be an electric must necessarily consist of a concreted humour which is partially resolved into an effluvium by attrition4 ,his discoveries that electric actions would not pass through flame1 whilst magnetic actions would1 and that electric actions could be screened off by interposing the thinnest layer of fabric such as sarcenet1 whilst magnetic actions would penetrate thick slabs of every material except iron only1 doubtless confirmed him in attributing the electric forces to the presence of these effluvia4 ,see also p4 #fe4 ,there arose a fashion1 which lasted over a century1 for ascribing to humours1 or fluids1 or effluvia1 physical effects which could not otherwise be accounted for4 ,boyle's tracts of the years #afgc and #afgd on effluviums1 their determinate nature1 their strange subtilty1 and their great efficacy1 are examples4 #ace ,,page #ec1 ,,line #i4 ,page #ec1 line #aa4 ,magnes vero4444--,this passage from line #i to line #bd states very clearly the differences to be observed between the magnetical and the electrical attractions4 #acf ,,page #ec1 ,,line #cf4 ,page #ec1 line #da4 succino calefacto4--,ed4 #afcc reads succinum in error4 #acg ,,page #ed1 ,,line #i4 ,page #ed1 line #aa4 ,plutarchus 444 in qustionibus ,platonicis4--,the following ,latin version of the paragraph in ,qustio sexta is taken from the bilingual edition publisht at ,venice in #aeeb1 p4 #ag verso1 liber vii41 cap4 #g 7or1 ,qustio ,septima in ,ed4 ,didot1 p4 #abcj74 ,electrum uero qu apposita sunt1 nequaqum trahit1 quem admodum nec lapis ille1 qui sideritis nuncupatur1 nec quicqua seipso ad ea qu in propinquo sunt1 extrinsecus assilit4 ,verum lapis magnes effluxiones quasdam tum graves1 tum etiam spiritales emittit1 quibus aer continuatus iunctus repellitur4 ,is deinceps alium sibi proximum impellit1 qui in orbem circum actus1 atque ad inanem locum rediens1 ui ferrum fecum rapit trahit4 ,at ,electrum uim quandam flamm similem spiritalem continet1 quam quidem #dd tritu summ partis1 quo aperiuntur meatus1 foras eijcit4 ,nam leuissima corpuscula aridissima qu prop sunt1 sua tenuitate atque imbecillitate ad seipsum ducit rapit1 cum non sit adeo ualens1 nec tantum habeat ponderis momenti ad expellendam aeris copiam1 ut maiora corpora more ,magnetis superare possit uincere4 #ach ,,page #ed1 ,,line #af4 ,page #ed1 line #ah4 ,gemma ,vincentij rupis4--,see the note to p4 #dh supra1 where the name ,vincentina occurs4 #aci ,,page #ed1 ,,line #cj4 ,page #ed1 line #ce4 orobi4--,the editions of #afbh and #afcc read oribi4 #adj ,,page #ee1 ,,line #cd4 ,page #ee1 line #db4 in euacuati4--,the editions of #afbh and #afcc read inevacuati4 #ada ,,page #eh1 ,,line #ba4 ,page #eh1 line #be4 assurgentem vndam 444 declinat ab ,f4--,these words are wanting in the ,stettin editions4 #adb ,,page #ei1 ,,line #i4 ,page #ei1 line #i4 fluore4--,this word is conjectured to be a misprint for fluxu but it stands in all editions4 #adc ,,page #ei1 ,,line #bb4 ,page #ei1 line #be4 ,ruunt ad electria4--,this appears to be a slip for electrica1 which is the reading of the editions of #afbh and #afcc4 #add ,,page #fj1 ,,line #g4 ,page #fj1 line #i4 tanq materiales radij4--,the suggestion here of material rays as the modus operandi of electric forces seems to foreshadow the notion of electric lines of force4 #ade ,,page #fj1 ,,line #aj4 ,page #fj1 line #ab4 ,differentia inter magnetica electrica4--,though ,gilbert was the first systematically to explore the differences that exist between the magnetic attraction of iron and the electric attraction of all light substances1 the point had not passed unheeded1 for we find ,st4 ,augustine1 in the ,de ,civitate ,dei1 liber xxi41 cap4 #f1 raising the question why the loadstone which attracts iron should refuse to move straws4 ,the many analogies between electric and magnetic phenomena had led many experimenters to speculate on the possibility of some connexion between electricity and magnetism4 ,see1 for example1 ,tiberius ,cavallo1 ,a ,treatise on ,magnetism1 ,london1 #aghg1 p4 #abf4 ,also the three volumes of ,j4 ,h4 van ,swinden1 ,receuil de ,mmoires sur l',analogie de ,electricit et du ,magntisme1 ,la ,haye1 #aghd4 ,aepinus wrote a treatise on the subject1 entitled ,de ,similitudine vis electric et magnetic 7,petropolis1 #ageh74 ,this was1 of course1 long prior to the discovery1 by ,oersted1 in #ahbj1 of the real connexion between magnetism and the electric current4 #adf ,,page #fj1 ,,line #be4 ,page #fj1 line #ca4 ,coitionem dicimus1 non attractionem4--,see the remarks1 at the outset of these ,notes1 on ,gilbert's definitions of words4 #adg ,,page #fj1 ,,line #cc4 ,page #fa1 line #a4 ,orpheus in suis carminibus4--,this passage is in the chapter ,greek3 ,lithika of ,orpheus1 verses #cja to #cbg4 ,see ,note to p4 #aa1 line #ai4 #adh ,,page #fa1 ,,line #ae4 ,page #fa1 line #ai4 ,platonis in ,timo opinio4--,the passage runs 7edition ,didot1 vol4 ii41 p4 #bdj1 or ,stephanus1 p4 #hj1 ,c473 ,greek3 ,kai d kai ta tn hudatn panta rheumata eti de ta tn keraunn ptmata kai ta thaumazomena lektrn peri ts helxes kai tn ,hraklein lithn1 pantn toutn holk men ouk estin oudeni pote1 to de kenon einai mden perithein te hauta tauta eis allla1 to te diakrinomena kai sunkrinomena pros tn hautn diameibomena hedran hekasta ienai panta1 toutois tois pathmasi pros allla sumplechtheisi tethaumatourgmena ti kata tropon ztounti phansetai4 #adi ,,page #fa1 ,,line #cj4 ,page #fa1 line #ch4 ,the ,english version of the lines of ,lucretius is from ,busby's translation4 #aej ,,page #fb1 ,,line #e4 #de ,page #fb1 line #g4 ,iohannes ,costus ,laudensis4--,joannes ,costa1 of ,lodi1 edited ,galen and ,avicenna4 ,he also wrote a ,de universali stirpium ,natura 7,aug4 ,taurin41 #aegh74 #aea ,,page #fc1 ,,line #c4 ,page #fc1 line #d4 ,cornelius ,gemma #aj4 ,cosmocrit4--,this refers to the work ,de ,natur ,divinis ,characterismis 444 ,libri ii4 ,avctore ,d4 ,corn4 ,gemma 7,antv41 #aege1 lib4 i41 cap4 vii41 p4 #abc74 ,cert vt magnete insensiles radij ferrum ad se attrahunt1 ab echineide paruo pisciculo sistuntur plena nauigia1 catoblepa spiritu non homines solm1 sed alta serpentum genera interimuntur1 saxa dehiscunt4 ,see also ,kircher's ,magneticum ,natur ,regnum 7,amsterodami1 #affg1 p4 #agb71 ,sectio iv41 cap4 iii41 ,de ,magnete ,navium1 qu ,remora seu ,echeneis dicitur4 ,see the note to p4 #g1 line #ba4 #aeb ,,page #fc1 ,,line #f4 ,page #fc1 line #g4 ,guilielmus ,puteanus4--,puteanus 7,du ,puys7 wrote a work ,de ,medicamentorum quomodocunque ,purgantium ,facultatibus1 ,libri ii4 7,lugd41 #aeeb71 in which he talks vaguely about the substantial form of the magnet1 and quotes ,aristotle and ,galen4 #aec ,,page #fc1 ,,line #ba4 ,page #fc1 line #be4 ,baptist ,port4--,the passage in the translation is quoted from the ,english version of #afeh1 pp4 #aia1 #aib4 #aed ,,page #fd1 ,,line #d4 ,page #fd1 line #i4 ,erudit magis ,scaliger4--,gilbert pokes fun at ,scaliger1 whose erudite guess 7that the motion of iron to the magnet was that of the offspring toward the parent7 is to be found in his book ,de ,subtilitate1 ad ,cardanum1 ,exercitatio ,,cii4 7,luteti1 #aeeg1 p4 #aef bis74 #aee ,,page #fd1 ,,line #g4 ,page #fd1 line #aa4 ,diuus ,thomas4--,on p4 #c ,gilbert had already spoken of ,st4 ,thomas ,aquinas as a man of intellect who would have added more about the magnet had he been more conversant with experiments4 ,the passage here quoted is from the middle of ,liber vii4 of his commentaries on the de ,physica of ,aristotle1 ,expositio ,diui ,thome ,aquinatis ,doctoris ,angelici super octo libros ,physicorum ,aristotelis1 etc4 7,venice1 ,giunta edition1 #aeci1 p4 #if verso1 col4 #b74 #aef ,,page #fd1 ,,line #af4 ,page #fd1 line #bd4 ,cardinalis etiam ,cusanus4--,cardinal de ,cusa 7,nicolas ,khrypffs7 wrote a set of dialogues on ,statics1 ,nicolai ,cusani de staticis experimentis dialogus 7#aeej71 of which an ,english version appeared in ,london in #afej with the title1 ,the ,idiot in four books2 the first and second of wisdom1 the third of the minde1 the fourth of statick experiments4 ,by the famous and learned ,c4 ,cusanus4 ,in the fourth book of statick ,experiments1 ,or experiments of the ,ballance1 occurs 7p4 #ahf7 the following3 ,orat4 ,tell me1 if thou hast any device whereby the vertues of stones may be weighed4 ,id4 ,i thinke the vertue of the ,load-stone might be weighed1 if putting some ,iron in one scale1 and a ,load-stone in the other1 untill the ballance were even1 then taking away the ,load-stone1 and some other thing of the same weight being put into the scale1 the ,load-stone were holden over the ,iron1 so that that scale wou'd begin to rise2 by reason of the ,load-stones attraction of the ,iron1 then take out some of the weight of the other scale1 untill the scale wherein the iron is1 doe sinke againe to the quilibrium1 or equality still holding the ,load-stone unmovable as it was2 ,i beleeve that by weight of what was taken out of the contrary scale1 one might come proportionably to the weight of the vertue or power of the ,load-stone4 ,and in like manner1 the vertue of a ,diamond1 might be found hereby1 because #df they say it hinders the ,load-stone from drawing of ,iron2 and so other vertues of other stones1 consideration1 being alwayes had of the greatnesse of the bodyes1 because in a greater body1 there is a greater power and vertue4 ,in the #aehh edition of ,baptista ,porta's ,magi ,naturalis ,libri xx41 in lib4 vii41 cap4 xviii41 occurs the description of the use of the balance to which ,gilbert refers4 #aeg ,,page #fg1 ,,line #ba4 ,page #fg1 line #bb4 aris rigore4--,all editions read thus1 but the sense seems to require frigore4 #aeh ,,page #fg1 ,,line #bg4 ,page #fg1 line #ca4 ,fracastorius4--,see his ,de ,sympathia1 lib4 i41 cap4 #e 7,giunta edition1 #aegd1 p4 #fj74 #aei ,,page #fh1 ,,line #e4 ,page #fh1 line #f4 ,thaletis ,milesij4--,see the note to p4 #aa1 line #bf4 #afj ,,page #fh1 ,,line #cj4 ,page #fh1 line #ce4 ,it coitio magnetica actus est magnetis1 ferri1 non actio vnius4--,see the introductory remarks to these notes4 ,there is a passage in ,scaliger's ,de ,subtilitate ad ,cardanum 7,exercitat4 ,,cii41 cap4 #e1 p4 #aef op4 citat47 which may be compared with ,gilbert's for its use of ,greek terms3 ,n cm uita dicatur actus anim1 acceptus est abs te actus pro actione4 ,sed actus ille est ,greek3 entelecheia1 n autem ,greek3 ergon4 ,at ,magnetis attractio est ,greek3 ergon1 non aute ,greek3 entelecheia4 ,to which ,gilbert retorts3 non actio unius1 utriusque ,greek3 entelecheia2 non ,greek3 ergon1 ,greek3 sunentelecheia et conactus potius quam sympathia4 ,he returns on p4 #gj to the attack on ,scaliger's metaphysical notions4 ,there is a parallel passage in the ,epitome ,naturalis ,scienti of ,daniel ,sennert 7,oxoni1 #affd71 in the chapter ,de ,motu4 #afa ,,page #ga1 ,,line #d4 ,page #ga1 line #h4 vt in #h4 physicorum ,themistius existimat4--,see ,omnia ,themistii ,opera 7,aldine edition1 #aecc1 p4 #fc71 ,book #h of his ,paraphrase on ,aristotle's ,physica4 #afb ,,page #ga1 ,,line #i4 ,page #ga1 line #ad4 ,quod ver ,fracastorius4--,op4 citat41 lib4 i41 cap4 #g1 p4 #fb verso4 #afc ,,page #gc1 ,,line #b4 ,page #gc1 line #b4 si ,a borealis4--,the editions of #afbh and #afcc omit the twelve words next following4 #afd ,,page #gc1 ,,line #i4 ,page #gc1 line #aa4 ex minera4--,minera is not a recognized word1 even in late ,latin4 ,it occurs again1 p4 #ig1 line #ab4 #afe ,,page #gg1 ,,line #b4 ,page #gg1 line #b4 multo magis4--,this is an fortiori argument4 ,it is interesting to find ,gilbert comparing the velocity of propagation of magnetic forces in space with the velocity of light4 ,the parallel is completed in line #ac by the consideration that as the rays of light require to fall upon an object in order that they may become visible1 so the magnetic forces require a magnetic object in order to render their presence sensible4 #aff ,,page #gh1 ,,line #ad4 ,page #gh1 line #af4 ,orbem terrarum distinguunt4--,the editions of #afbh and #afcc here add a figure of a globe marked with meridians and parallels of latitude1 but with an erroneous versorium pointing to the south4 ,these editions also both read existentiam for the word existentium in line #bj4 #afg ,,page #hc1 ,,line #e4 ,page #hc1 line #e4 magnes longior maiora pondera ferri attollit4--,gilbert discovered the advantage1 for an equal mass of loadstone1 of an elongated shape4 ,it is now well known that the specific amount of magnetism retained by elongated forms exceeds that in a short piece of the same material subjected to equal magnetizing forces4 #afh ,,page #hc1 ,,line #bd4 ,page #hc1 line #bh4 ,non obstant crassa tabulata4--,gilbert has several times referred 7e4g41 on p4 #gg7 to the way in which magnetic forces penetrate solid bodies4 ,the experimental investigation in this chapter #dg is the more interesting because it shows that ,gilbert clearly perceived the shielding action of iron to be due to iron conducting aside or diverting the magnetic forces4 #afi ,,page #he1 ,,line #bf4 ,page #he1 line #ca4 non conveniant4--,the editions of #afbh and #afcc both read et conveniant4 #agj ,,page #hf1 ,,line #c4 ,page #hf1 line #c4 illud quod exhalat4--,literally1 that which exhales1 in the sense of that which escapes3 but in modern ,english the verb exhale in the active voice is now not used of the substance that escapes1 but is used of the thing which emits it4 ,it must therefore be rendered that which is exhaled 7i4e41 breathed out74 #aga ,,page #hf1 ,,line #ac4 ,page #hf1 line #ae4 ,ita tota interposita moles terrestris4--,gilbert's notion that the gravitational force of the moon in producing the tides acts through the substance of the earth may seem curiously expressed4 ,but the underlying contention is essentially true to-day4 ,the force of gravity is not cut off or screened off by the interposition of other masses4 ,a recent investigation by ,professor ,poynting1 ,f4,r4,s41 has shown that so far as all evidence goes all bodies1 even the densest1 are transparent with respect to gravitational forces4 #agb ,,page #hf1 ,,line #ah4 ,page #hf1 line #bj4 ,sed de stus ratione alis4--,there is no further discussion of the tides in ,de ,magnete4 ,but a short account is to be found in ,gilbert's posthumous work ,de ,mundo nostro ,sublunari ,philosophia nova 7,amsterdam1 ,elzevir1 #afea71 in ,lib4 v41 the part which in the manuscript was left in ,english1 and was turned into ,latin by his brother4 ,it comprises about fifteen quarto pages1 from ,cap4 ,x4 to ,cap4 ,,xix4 inclusive1 beginning with a characteristic diatribe against ,taisnier1 ,levinus ,lemnius1 and ,scaliger4 ,but in assigning causes he himself goes wide of the mark4 ,proceeding by a process of elimination he first shows that the moon's light cannot be the cause that impels the tides4 ,luna1 he says1 non radio1 non lumine1 maria impellit4 quomodo igitur8 ,sane corporum conspiratione1 acque 7ut similitudine rem exponam7 ,magnetica attractione4 ,this cryptic utterance he proceeds to explain by a diagram1 and adds3 ,quare ,luna non tam attrahit mare1 qum humorem spiritum subterraneum2 nec plus resistit interposita terra1 qum mensa1 aut quicquam aliud densum1 aut crassum1 magnetis viribus4 #agc ,,page #hg1 ,,line #g4 ,page #hg1 line #i4 armatura4--,here this means the cap or snout of iron with which the loadstone was armed4 ,this is apparently the first use of the term in this sense4 ,in the ,dialogues of ,galileo 7p4 #cfi of ,salusbury's ,mathematical ,collections1 ,dialogue iii471 ,sagredus and ,salviatus discuss the arming of the loadstone1 and the increased lifting power conferred by adding an iron cap4 ,salviatus mentions a loadstone in the ,florentine ,academy which1 unarmed1 weighed six ounces1 lifting only two ounces1 but which when armed took up #afj ounces4 ,whereupon ,galileo makes ,salviatus say3 ,i extreamly praise1 admire1 and envy this ,authour1 for that a conceit so stupendious should come into his minde4 444 ,i think him i4e41 ,gilbert moreover worthy of extraordinary applause for the many new and true ,observations that he made1 to the disgrace of so many fabulous ,authours1 that write not only what they do not know1 but whatever they hear spoken by the foolish vulgar1 never seeking to assure themselves of the same by experience1 perhaps1 because they are unwilling to diminish the bulk of their ,books4 #agd ,,page #hg1 ,,line #ab4 ,page #hg1 line #ae4 ,the reference to lib4 #c is #dh a misprint for lib4 #b4 ,it is corrected in the edition of #afcc1 but not in that of #afbh4 #age ,,page #hg1 ,,line #ag4 ,page #hg1 line #ba4 conactu4--,the editions of #afbh and #afcc read conatu4 #agf ,,page #hh1 ,,line #b4 ,page #hh1 line #c4 ,coitio ver non fortior4--,this heading to chap4 xix41 taken with the seven lines that follow1 and the contrast drawn between unitio and coitio1 throw much light on the fundamental sense attached by ,gilbert to the term coitio4 ,it is here clearly used in the sense of mutual tendency toward union4 ,note also the contrasted use in chap4 xx4 of the verbs cohre and adhre4 ,adhrence connotes a one-sided force 7an impossibility in physics71 cohrence a mutual force4 #agg ,,page #ij1 ,,line #i4 ,page #ij1 line #i4 nemp vt alter polus maius pondus arripiat4--,this acute observation is even now not as well known as it ought to be4 ,only so recently as #ahfa ,siemens patented the device of fastening a mass of iron to one end of an electromagnet in order to increase the power of the other end4 ,the fact1 so far as it relates to permanent magnets was known to ,servington ,savery4 ,see ,philos4 ,transactions1 #agbi1 p4 #bie4 #agh ,,page #ib1 ,,line #c4 ,page #ib1 line #d4 ,suspendit in are ferrum ,baptista ,porta4--,porta's experiment is thus described 7,natural ,magick1 ,london1 #afeh1 p4 #bjd73 ,petrus ,pellegrinus saith1 he shewed in another work how that might be done3 but that work is not to be found4 ,why ,i think it extream hard1 ,i shall say afterwards4 ,but ,i say it may be done1 because ,i have now done it1 to hold it fast by an invisible band1 to hang in the air2 onely so1 that it be bound with a small thread beneath1 that it may not rise higher3 and then striving to catch hold of the stone above1 it will hang in the air1 and tremble and wag itself4 #agi ,,page #ig1 ,,line #bi4 ,page #ig1 line #cc4 ,sed quri potest 444--,the question here raised by ,gilbert is whether the lifting-power of magnets of equal quality is proportional to their weight4 ,if a stone weighing a drachm will lift a drachm1 would a stone that weighs an ounce lift an ounce8 ,gilbert erroneously answers that this is so1 and that the lifting-power of a loadstone1 whether armed or unarmed1 is proportional to its mass4 ,the true law of the tractive force or lifting-power of magnets was first given in #agbi by ,james ,hamilton 7afterwards ,earl of ,abercorn7 in a work entitled ,calculations and ,tables ,relating to the ,attractive ,virtue of ,loadstones 444 ,printed at ,london8 in the ,year #agbi4 7,see also a paper in the ,philos4 ,transactions1 #agbi-cj1 vol4 xxxvi41 p4 #bde74 ,this work begins thus3 ,the ,principle upon which these ,tables are formed1 is this3 ,that if ,two ,loadstones are perfectly ,homogeneous1 that is1 if their ,matter be of the same ,specifick ,gravity1 and of the same ,virtue in all ,parts of one ,stone1 as in the other2 and that ,like ,parts of their ,surfaces are ,cap'd or ,arm'd with ,iron2 then the ,weights they sustain will be as the ,squares of the ,cube ,roots of the ,weights of the ,loadstones2 that is1 as their ,surfaces4 ,upon lifting-power see also ,d4 ,bernoulli1 ,acta ,helvetica1 iii41 p4 #bbc1 #ageh2 ,p4 ,w4 ,haecker1 ,zur ,theorie des ,magnetismus1 ,nrnberg1 #ahef2 ,van der ,willigen1 ,arch4 du ,muse ,teyler1 vol4 iv41 ,haarlem1 #ahgh 2 ,s4 ,p4 ,thompson1 ,philos4 ,magazine1 ,july1 #ahhh4 ,in the book of ,james ,hamilton1 p4 #e1 he mentions a small terrella weighing #aci ,english grains1 which would sustain no less than #bc1gfj grains1 and was valued at #ba #acs4 #aj;d4 #di ,in the ,musum ,septalianum of ,terzagus 7,derton1 #affd1 p4 #db7 is mentioned a loadstone weighing twelve ounces which would lift sixty pounds of iron4 ,sir ,isaac ,newton had a loadstone weighing #c grains1 which he wore in a ring4 ,it would lift #gdf grains4 ,thomson's ,british ,annual1 #ahcg1 p4 #ced1 gives the following reference3 ,in the ,records of ,general ,science1 vol4 iii41 p4 #bgb1 there is an interesting description of a very powerful magnet which was sent from ,virginia in #aggf by the celebrated ,dr4 ,franklin to ,professor ,anderson1 of ,glasgow4 ,it is now in the possession of ,mr4 ,crichton4 ,it weighs #b grains1 and is capable of supporting a load of #ghc grains1 which is equivalent to #cac times its own weight4 #ahj ,,page #ii1 ,,line #aj4 ,page #ii1 line #aa4 ,manifestum est4--,in this1 as in many other passages1 ,gilbert uses this expression in the sense that it is demonstrable rather than meaning that it is obvious3 for the fact here described is one that is not at all self-evident1 but one which would become plain when the experiment had been tried4 ,for other instances of this use of manifestum see pages #add1 line #bj2 #aeh1 line #ai2 #afb1 line #aj4 #aha ,,page #ajj1 ,,line #bj4 ,page #ajj1 line #bd4 si per impedimeta 444 pervenire possunt4--,all editions agree in this reading1 but the sense undoubtedly requires non possint4 ,compare p4 #ia1 line #ba4 #ahb ,,page #ajb1 ,,line #d4 ,page #ajb1 line #d4 capite #d4--,this is a misprint for capite #dj1 and is retained in the later editions4 ,in the quotation from ,baptista ,porta1 where the ,english version of #afeh is adhred to1 the words deturbat eam have been omitted by the translator4 #ahc ,,page #ajg1 ,,line #af4 ,page #ajg1 line #ah4 ,cardanus scribit4--,the alleged perpetual motion machine is mentioned in ,de rerum varietate1 lib4 #i1 cap4 xlviii4 7,basil41 #aeha1 p4 #fda74 ,see also the ,note to p4 #bbc4 ,for ,peregrinus and for ,taisnier1 see the note to p4 #e1 lines #h and #ab4 #ahd ,,page #ajg1 ,,line #ai4 ,page #ajg1 line #ba4 ,antonij de ,fantis4--,his work is3 ,tabula generalis scotice subtilitatis octo ,sectionibus vniuersam ,doctoris ,subtilis ,peritia coplectes3 ab excellentissimo doctore ,antonio de ,fatis taruisino edita 444 ,lugd41 #aecj4 #ahe ,,page #ajh1 ,,line #bf4 ,page #ajh1 line #ca4 ,cusani in staticis4--,see the note to p4 #fd1 line #af4 #ahf ,,page #ajh1 ,,line #cc4 ,page #ajh1 line #da4 ,languidi 444 tardis acquiescunt4--,the editions of #afbh and #afcc omit these seven words4 #ahg ,,page #aji1 ,,line #aa4 ,page #aji1 line #ac4 halinitro4--,either native carbonate of soda or native carbonate of potash might be meant1 but not saltpetre4 ,scaliger1 in his ,de ,subtilitate ad ,cardanum 7,lutet41 #aeeg1 p4 #afd71 ,exercitatio ,,ciii41 #ae1 under the title1 ,nitrum non est ,salpetr1 says3 ,more tuo te1 tuaque confundis4 ,salpetr inter salis fossilis ponis hc4 ,mox ,halinitrum inter salis1 nitri naturam1 speciem obtinere4 ,sal nitrum is salt which is boiled out of the earth1 especially fat earth1 as in stables1 or any place of excrements4 7,a ,chymicall ,dictionary explaining ,hard ,places and ,words met withall in the ,writings of ,paracelsus 4441 ,lond41 #afej47 #ahh ,,page #aji1 ,,line #bj4 ,page #aji1 line #bc4 arte ioculatori4--,edition #afbh1 joculatori2 edition #afcc1 jaculatori4 #ahi ,,page #aaj1 ,,line #aa4 ,page #aaj1 line #ab4 qualis fuit ,antonij denarius4--,the ,elizabethan version of ,pliny 7book xxxiii41 ch4 ix41 p4 #dgi7 runs thus3 #ej ,to come now unto those that counterfeit money4 ,antonius whiles hee was one of the three usurping ,triumvirs1 mixed yron with the ,romane silver denier4 ,he tempered it also with the brasen coine1 and so sent abroad false and counterfeit money4 ,georgius ,agricola 7,de ,natura ,fossilium1 p4 #fdf7 says3 ,sed ea fraus capitalis est1 non aliter ac eorum qui adulterinas monetas cudunt1 argento miscentes multam plumbi candidi portionem1 aut etiam ferri1 qualis fuit ,antonii denarius1 ut ,plinius memori tradidit4 ,nunc dicam de candido plumbo1 nam majoris pretii est qum aes4 ,in quod plumbum album1 inquit ,plinius1 addita aeris tertia portione candidi adulteratur stannum4 #aij ,,page #aaa1 ,,line #c4 ,page #aaa1 line #c4 ,meminerunt ,chatochitis lapis ,plinius1 atque ,iulius ,solinus4--,the passage in ,pliny 7,english version of #afja1 book xxxvii41 ch4 x41 p4 #fbe7 runs3 ,catochitis is a stone proper unto the ,island ,corsica3 in bignesse it exceedeth ordinarie pretious stones3 a wonderfull stone1 if all be true that is reported thereof1 and namely1 ,that if a man lay his hand thereon1 it will hold it fast in manner of a glewie gum4 #aia ,,page #aaa1 ,,line #g4 ,page #aaa1 line #g4 ,sagda vel ,sagdo4--,albertus ,magnus in ,de ,mineralibus 7,venet41 #aedb1 p4 #bjb7 says3 ,sarda quem alij dicunt ,sardo lapis est qui se habet ad tabulas ligni sicut magnes ad ferru1 et ideo adhret ita fortiter tabulis nauium qud euelli no possit1 nisi abscindatur cum ipso ea pars tabul cui inhserit1 est aute in colore purissimus nitens4 ,and ,pliny 7op4 citat41 p4 #fbi73 ,sagda is a stone1 which the ,chaldeans find sticking to ships1 and they say it is greene as ,porrets or ,leekes4 #aib ,,page #aaa1 ,,line #h4 ,page #aaa1 line #h4 ,euace4--,evax1 king of the ,arabs1 is said to have written to ,nero a treatise on the names1 colours1 and properties of stones4 ,see the note on ,marbodus1 p4 #g1 line #bj4 #aic ,,page #aac1 ,,line #ad4 ,page #aac1 line #ai4 repulsus sit4 ,the words read thus in all editions1 but the sense requires repulsa sint4 #aid ,,page #aac1 ,,line #bc4 ,page #aac1 line #bi4 ,electrica omnia alliciunt cuncta1 nihil omnin fugant vnquam1 aut propellunt4 ,this denial of electrical repulsion probably arose from the smallness of the pieces of electric material with which ,gilbert worked4 ,he could hardly have failed to notice it had he used large pieces of amber or of sealing-wax4 ,electrical repulsion was first observed by ,nicolas ,cabeus1 ,philosophia ,magnetica1 ,ferrara1 #afbi2 but first systematically announced by ,otto von ,guericke in his treatise ,experimenta ,nova 7ut vocantur7 ,magdeburgica1 de ,vacuo ,spatio 7,amstel41 #afgb74 #aie ,,page #aac1 ,,line #bi4 ,page #aac1 line #cg4 cm de calore quid sit disputabimus4--,the discussion of the nature of heat is to be found in ,gilbert's ,de ,mundo nostro ,sublunari 7,amstel41 #afea71 lib4 i41 cap4 xxvi41 pp4 #gg-hh4 #aif ,,page #aae1 ,,line #bc4 ,page #aae1 line #bc4 trium vel quatuor digitorum4--,here as in all other places in ,gilbert1 digitus means a finger's breadth1 so that three or four digits means a length of two or three inches1 or from six to eight centimetres4 #aig ,,page #aag1 ,,line #bf4 ,page #aag1 line #be4 ille ,thebit ,bencor trepidationis motus4 ,trepidation in the ancient ,astronomy denotes a motion which in the ,ptolemaic system was attributed to the firmament1 in order to account for #ea several changes and motions observed in the axis of the world1 and for which they could not account on any other principle4 7,barlow's ,mathematical ,dictionary47 #aih ,,page #aah1 ,,line #aj4 ,page #aah1 line #h4 cuspis is aut lilium4--,gilbert uses cuspis or lilium always of the ,north-pointing end of the needle4 ,sir ,thomas ,browne speaks of the lilly or northern point2 but he differs from ,gilbert in saying the cuspis or ,southern point 7,pseudodoxia ,epidemica1 #afej1 p4 #df74 ,only in one place 7p4 #aja1 line #e7 does ,gilbert speak of cuspis meridionalis4 ,everywhere else the south-pointing end is called the crux4 #aii ,,page #aah1 ,,line #ae4 ,page #aah1 line #ac4 nam qu potens est4--,later observation showed this view to be incorrect4 ,the horizontal component of the earth's magnetic field is not equally strong all over the globe1 and the sluggishness of the needle's return to its position of rest is not due to the supporting pin becoming blunt with wear4 ,the value of the horizontal component is zero at the north magnetic pole1 and increases toward the magnetic equator4 ,it is greatest near ,singapore and in ,borneo1 being there more than twice as great as it is at ,london4 7,see ,captain ,creak in ,report of ,voyage of ,h4,m4,s4 ,challenger1 ,physics and ,chemistry1 vol4 ii41 part vi41 #ahhi47 #bjj ,,page #aai1 ,,line #e4 ,page #aai1 line #b4 lapis4--,both ,stettin editions read lapidis4 #bja ,,page #aai1 ,,lines #i-aa4 ,page #aai1 lines #g-i4 ,the gist of the whole book is summarized in these lines4 ,they furnish a cardinal example of that inductive reasoning which was practist by ,gilbert1 and of which ,bacon subsequently posed as the apostle4 ,compare pages #da and #baa4 #bjb ,,page #abj1 ,,line #h4 ,page #abj1 line #e4 dicturi sumus4--,change of verticity is treated of in book iii41 chap4 x41 pp4 #acg to #adj4 #bjc ,,page #abe1 ,,line #bd4 ,page #abe1 line #bi4 appositam4--,all editions give this word1 though the sense requires appositum4 #bjd ,,page #abh1 ,,line #i4 ,page #abh1 line #aa4 non nimis longum4--,the editions of #afbh and #afcc read 7wrongly7 minus instead of nimis4 #bje ,,page #acj1 ,,line #ab4 ,page #acj1 line #ad4 ,the word hunc in the folio of #afjj is corrected in ink to tunc1 and the ,stettin editions both read tunc4 #bjf ,,page #acb1 ,,line #i4 ,page #acb1 line #aj4 minimus nullius ponderis4--,the editions of #afbh and #afcc both wrongly read est for 4 #bjg ,,page #acb1 ,,line #bh4 ,page #acc1 line #a4 nutat4--,the editions of #afbh and #afcc both wrongly read mutat4 #bjh ,,page #acd1 ,,line #bb4 ,page #acd1 line #be4 in rect sphr4--,the meaning of the terms a right or direct sphere1 an oblique sphere and a parallel sphere are explained by ,moxon on pages #bi to #ca of his book ,a ,tutor to ,astronomy and ,geography 7,lond41 #afhf73 ,a ,direct ,sphere hath both the ,poles of the ,world in the ,horizon 444 ,it is called a ,direct ,sphere1 because all the ,celestial ,bodies1 as ,sun1 ,moon1 and ,stars1 c4 ,by the ,diurnal ,motion of the ,primum ,mobile1 ascend directly ,above1 and descend directly ,below the ,horizon4 ,they that ,inhabit under the ,equator have the ,sphere thus posited4 ,an ,oblique ,sphere hath the ,axis of the ,world neither ,direct nor ,parallel to the ,horizon1 but lies aslope from it4 ,a ,parallel ,sphere hath one ,pole of the ,world in the ,zenith1 the other in the ,nadir1 and the ,equinoctial ,line in the ,horizon4 #bji ,,page #acf1 ,,line #a4 ,page #acf1 line #a4 prsenti4--,the editions of #afbh and #afcc read sequenti1 to suit the altered position of the figure4 #baj ,,page #acg1 ,,line #bd4 #eb ,page #acg1 line #bh4 atque ille statim4--,the ,stettin editions both wrongly read illi4 #baa ,,page #aci4 ,there is a curious history to this picture of the blacksmith in his smithy striking the iron while it lies north and south1 and so magnetizing it under the influence of the earth's magnetism4 ,woodcuts containing human figures are comparatively rare in ,english art of the sixteenth century2 a notable exception being ,foxe's ,acts and ,monuments with its many crude cuts of martyrdoms4 ,the artist who prepared this cut of the smith took the design from an illustrated book of ,fables by one ,cornelius ,kiliani or ,cornelius van ,kiel entitled ,viridarium ,moralis ,philosophi1 per ,fabulas ,animalibus brutis attributas tradit1 etc4 7,coloni1 #aeid74 ,this rare work1 of which there is no copy in the ,british ,museum1 is illustrated by some #abj fine copper-plate etchings printed in the text4 ,on p4 #acc of this work is an etching to illustrate the fable ,ferrarii fabri et canis1 representing the smith smiting iron on the anvil1 whilst his lazy dog sleeps beneath the bellows4 ,the cut on p4 #aci of ,gilbert gives1 as will be seen by a comparison of the pictures just the same general detail of forge and tools2 but the position of the smith is reversed right for left1 the dog is omitted1 and the words ,septrenio and ,auster have been added4 ,illustration ,in the ,stettin edition of #afbh the picture has again been turned into a copper-plate etching separately printed1 is reversed back again left for right1 while a compass-card is introduced in the corner to mark the north-south direction4 ,in the ,stettin edition of #afcc the artist has gone back to ,kiliani's original #ec plate1 and has re-etched the design very carefully1 but reversing it all right for left4 ,as in the ,london version of #afjj1 the dog is omitted1 and the words ,septentrio and ,auster are added4 ,some of the original details--for example1 the vice and one pair of pincers--are left out1 but other details1 for instance1 the cracks in the blocks that support the water-tub1 and the dress of the blacksmith1 are rendered with slavish fidelity4 ,it is perhaps needless to remark that the twelve copper-plate etchings in the edition of #afbh1 and the twelve completely different ones in that of #afcc1 replace certain of the woodcuts of the folio of #afjj4 ,for example1 take the woodcut on p4 #bjc of the #afjj edition1 which represents a simple dipping-needle made by thrusting a versorium through a bit of cork and floating it1 immersed1 in a goblet of water4 ,in the #afcc edition this appears1 slightly reduced1 as a small inserted copper-plate1 with nothing added2 but in the #afbh edition it is elaborated into a full-page plate 7,no4 xi47 representing the interior1 with shelves of books1 of a library on the floor of which stands the goblet--apparently three feet high--with a globe and an armillary sphere2 while beside the goblet1 with his back to the spectator1 is seated an aged man1 reading1 in a carved armchair4 ,this figure and the view of the library are unquestionably copied--reversed--from a well-known plate in the work ,le ,diverse ,artificiose ,machine of ,agostino ,ramelli 7,paris1 #aeeh74 ,in the ,emblems of ,jacob ,cats 7,alle de ,wercken1 ,amsterdam1 #affe1 p4 #fe7 is given an engraved plate of a smith's forge1 which is also copied--omitting the smith--from ,kiliani's ,viridarium4 #bab ,,page #adj1 ,,line #b44 ,page #adj1 line #b4 prcedenti4--,this is so spelled in all editions1 though the sense requires prcedente4 #bac ,,page #ada1 ,,line #ba4 ,page #ada1 line #bd4 quod in epistol qudam ,italic scribitur4--,the tale told by ,filippo ,costa of ,mantua about the magnetism acquired by the iron rod on the tower of the church of ,st4 ,augustine in ,rimini is historical4 ,the church was dedicated to ,st4 ,john1 but in the custody of the ,augustinian monks4 ,the following is the account of it given by ,aldrovandi1 ,musum ,metallicum 7#afdh1 p4 #acd71 on which page also two figures of it are given3 ,aliquando etiam ferrum suam mutat substantiam1 dum in magnetem conuertitur1 hoc experientia constat1 nam ,arimini supra turrim templi ,s4 ,ioannis erat ,crux a baculo ferreo ponderis centum librarum sustentata1 quod tractu temporis ade naturam ,magnetis est adeptum1 vt1 illivs instar1 ferrum traheret3 hinc magna admiratione multi tenentur1 qua ratione ferrum1 quod est metallum in ,magnetem1 qui est lapis transmutari possit2 ,animaduertendum est id maxima familiaritate sympathia ferri1 magnetis dimanare cum ,aristoteles in habentibus symbolum facilem transitum semper admiserit4 ,hoc in loco damus imaginem frusti ferri in ,magnetem transmutati1 quod clarissimo viro ,vlyssi ,aldrouando ,iulius ,caesar ,moderatus diligens rerum naturalium inquisitor communicauit2 erat hoc frustum ferri colore nigro1 ferrugineo1 crusta exteriori quodammodo albicante4 ,and further on p4 #eeg4 ,preterea id manifestissimum est2 quoniam ,arimini1 in templo ,sancti ,ioannis1 fuit ,crux ferrea1 qu tractu temporis in magnetem conuersa est1 ab vno latere ferrum trahebat1 ab altero respuebat4 ,see also ,sir ,t4 ,browne's ,pseudodoxia ,epidemica 7edition of #afej1 p4 #dh71 and ,boyle's tract1 ,experiments and ,notes about the ,mechanical ,production of ,magnetism 7,london1 #afgf1 p4 #ab74 #ed ,another case is mentioned in ,dr4 ,martin ,lister's ,a ,journey to ,paris 7,lond41 #afii1 p4 #hc74 ,he ,mr4 ,butterfield shewed us a ,loadstone sawed off that piece of the ,iron ,bar which held the ,stones together at the very top of the ,steeple of ,chartres4 ,this was a thick ,crust of ,rust1 part of which was turned into a strong ,loadstone1 and had all the properties of a ,stone dug out of the ,mine4 ,mons4 de la ,hire has ,printed a ,memoir of it2 also ,mons4 de ,vallemont a ,treatise4 ,the very outward ,rust had no ,magnetic ,virtue1 but the inward had a strong one1 as to take up a third part more than its weight unshod4 ,gassendi and ,grimaldi have given other cases4 ,other examples of iron acquiring strong permanent magnetism from the earth are not wanting4 ,the following is from ,sir ,w4 ,snow ,harris's ,rudimentary ,magnetism 7,london1 #ahgb1 p4 #aj74 ,in the ,memoirs of the ,academy of ,sciences for #agca1 we find an account of a large bell at ,marseilles having an axis of iron3 this axis rested on stone blocks1 and threw off from time to time great quantities of rust1 which1 mixing with the particles of stone and the oil used to facilitate the motion1 became conglomerated into a hardened mass3 this mass had all the properties of the native magnet4 ,the bell is supposed to have been in the same position for #djj years4 #bad ,,page #adb1 ,,line #ac4 ,page #adb1 line #ae4 tunc planet corpora coelestia4--,gilbert's extraordinary detachment from all metaphysical and ultra-physical explanations of physical facts1 and his continual appeal to the test of experimental evidence1 enabled him to lift the science of the magnet out of the slough of the dark ages4 ,this passage1 however1 reveals that he still gave credence to the nativities of judicial ,astrology1 and to the supposed influence of the planets on human destiny4 #bae ,,page #add1 ,,line #ad4 ,page #add1 line #ad4 ijdem4--,the editions of #afbh and #afcc erroneously read iisdem4 #baf ,,page #adg1 ,,line #bg4 ,page #adg1 line #bi4 ex optimo aciario4--,gilbert recommended that the compass-needle should be of the best steel4 ,though the distinction between iron and steel was not at this time well established1 there is no reason to doubt that by aciarium was meant edge-steel as used for blades4 ,barlowe1 in his ,magneticall ,advertisements 7,lond41 #afaf71 p4 #ff1 gives minute instructions for the fashioning of the compass-needle4 ,he gives the preference to a pointed oval form1 and describes how the steel must be hardened by heating to whiteness and quenching in water1 so that it is brickle in a manner as glass it selfe1 and then be tempered by reheating it over a bar of red hot iron until it is let down to a blue tint4 ,savery 7,philos4 ,trans41 #agbi7 appears to have been the first to make a systematic examination of the magnetic differences between hard steel and soft iron4 ,instructions for touching the needle are given in the ,arte de ,nauegar of ,pedro de ,medina 7,valladolid1 #aede1 lib4 vi41 cap4 #a74 #bag ,,page #adi1 ,,line #h4 ,page #adi1 line #i4 per multa scula4--,compare ,porta's assertion 7p4 #bjh1 ,english edition7 iron once rubbed will hold the vertue a hundred years4 ,clearly not a matter within the actual experience of either ,porta or ,gilbert4 #bah ,,page #aec1 ,,line #b4 ,page #aec1 line #b4 ,cardani ab ortu stell in cauda vrs4--,what ,cardan said 7,de ,subtilitate1 ,edit4 citat41 p4 #ahg7 was3 ortum stell in cauda urs minoris1 qu quinque partibus orientalior est polo mundi1 respicit4 #bai ,,page #aec1 ,,line #ba4 ,page #aec1 line #bf4 sequitur quod versus terram magnam1 siue continentem 444 vero polo inclinatio magnetica fiat4--,gilbert #ee goes on to point out how1 at that date1 all the way up the west ,european coast from ,morocco to ,norway1 the compass is deflected eastward1 or toward the elevated land4 ,he argued that this was a universal law4 ,in ,purchas his ,pilgrimes 7,lond41 #afbe71 in the ,narrative1 in vol4 iii41 of ,bylot and ,baffin's ,voyage of #afaf1 there is mentioned an island between ,whale-,sound and ,smith's ,sound1 where there had been observed a larger variation than in any other part of the world4 ,purchas1 in a marginal note1 comments on this as follows3 ,variation of the ,compass #ef to the ,west1 which may make questionable ,d4 ,gilbert's rule1 tom4 #a41 l4 #b1 c4 #a1 that where more ,earth is more attraction of the ,compass happeneth by variation towards it4 ,now the known ,continents of ,asia1 c41 must be unspeakably more than here there can be1 yet here is more variation then about ,jepan1 ,brasil1 or ,peru1 c4 ,gilbert's view was in truth founded on an incomplete set of facts4 ,at that time1 as he tells us1 the variation of the compass at ,london was #aa-a_/c degrees eastward4 ,but he did not know of the secular change which would in about fifty-seven years reduce that variation to zero4 ,still less did he imagine that there would then begin a westward variation which in the year #ahaf should reach #bd #cj'1 and which should then steadily diminish so that in the year #aijj it should stand at #af #af' westward4 ,for an early discussion of the changes of the variation see vol4 i4 of the ,philosophical ,transactions 7,abridged71 p4 #ahh4 ,still earlier is the classical volume of ,henry ,gellibrand1 ,a ,discovrse ,mathematical on the ,variation of the ,magneticall ,needle 7,lond41 #afce74 ,gilbert heads chapter iii4 of book iiii4 7p4 #aei7 with the assertion ,variatio uniuscuiusque loci constans est1 declaring that to change it would require the upheaval of a continent4 ,gellibrand combats this on p4 #g of the work mentioned4 ,he says3 ,thus hitherto 7according to the ,tenents of all our ,magneticall ,philosophers7 we have supposed the variations of all particular places to continue one and the same4 ,so that when a ,seaman shall happly returne to a place where formerly he found the same variation1 he may hence conclude he is in the same former ,longitude4 ,for it is the ,assertion of ,mr4 ,dr4 ,gilberts4 ,variatio vnicuiusq2 ,loci constans est1 that is to say1 the same place doth alwayes retaine the same variation4 ,neither hath this ,assertion 7for ought ,i ever heard7 been questioned by any man4 ,but most diligent magneticall observations have plainely offred violence to the same1 and proved the contrary1 namely that the variation is accompanied with a variation4 ,in #afcg ,henry ,bond wrote in the ,sea-,mans ,kalendar that in the year #afeg the variation would be zero at ,london4 ,compare ,bond's ,longitude ,found 7,lond41 #afgf1 p4 #c74 ,as to inconstancy of the variation in one place see further ,fournier's ,hydrographie 7,paris1 #affg1 liv4 xi41 ch4 #ab1 p4 #dac71 and ,kircher1 ,magnes 7,colon4 ,agripp41 #afdc1 p4 #dah74 #bbj ,,page #aeg1 ,,line #d4 ,page #aeg1 line #e4 perfecto4--,though this word is thus in all editions1 it ought to stand perfect1 as in line #aj below4 #bba ,,page #aeg1 ,,line #aa4 ,page #aeg1 line #ac4 varietas1 for variatio4 #bbb ,,page #afj1 ,,line #bj4 ,page #afj1 line #bc4 in ,borrholybicum4--,this name for the ,north-west1 or ,north-,north-,west1 is rarely used4 ,it is found on the chart or windrose of the names of the winds on pp4 #aea and #aeb of the ,mcometrie de l',eyman of ,g4 ,nautonier 7#afjb74 ,here the name ,borrolybicus is given as a synonym for ,nortouest ,galerne1 or ,greek3 ,olumpias1 while the two winds on the points next on the western and northern sides respectively are called ,upocorus and ,upocircius4 #ef ,in ,swan's ,specvlvm ,mundi 7,camb41 #afdc1 p4 #agd7 is this explanation3 ,borrholybicus is the ,north-west wind4 ,in ,kircher's ,magnes 7,colon4 ,agripp41 #afdc1 p4 #dcd7 is a table of the names of the thirty-two winds in six languages1 where ,borrolybicus is given as the equivalent of ,maestro or ,north-,west4 #bbc ,,page #afa1 ,,line #b4 ,page #afa1 line #b4 ,insula in ,oceano variationem non mutat4--,the conclusions derived from the magnetic explorations of the ,challenger expedition1 #ahgc-ahgf1 are briefly these3 ,that in islands north of the magnetic equator there is a tendency to produce a local perturbation1 attracting the north-seeking end of the needle downwards1 and horizontally towards the higher parts of the land2 while south of the magnetic equator1 the opposite effects are observed4 7,see ,challenger ,reports1 ,physics and ,chemistry1 vol4 ii41 part vi41 ,report on the ,magnetical ,results by ,staff-,commander ,creak1 ,f4,r4,s47 #bbd ,,page #afb1 ,,line #b4 ,page #afb1 line #c4 quar respectiuum punctum 444 excogitauit4--,the passage referred to is in ,the newe ,attractiue of ,robert ,norman 7,lond41 #aeha71 chap4 vi4 ,your reason towards the earth carrieth some probabilitie1 but ,i prove that there be no ,attractive1 or drawing propertie in neyther of these two partes1 then is the ,attractive poynt lost1 and falsly called the poynt ,attractive1 as shall be proved4 ,but because there is a certayne point that the ,needle alwayes respecteth or sheweth1 being voide and without any ,attractive propertie3 in my judgment this poynt ought rather to bee called the point ,respective 444 ,this ,poynt ,respective1 is a certayne poynt1 which the touched ,needle doth alwayes ,respect or shew 444 #bbe ,,page #afe1 ,,line #b4 ,page #afe1 line #b4 ,de pyxidis nautic vsitat compositione4--,gilbert's description of the usual construction of the mariner's compass should be compared with those given by ,levinus ,lemnius in ,the ,secret ,miracles of ,nature 7,london1 #afeh72 by ,lipenius in ,navigatio ,salomonis ,ophiritica 7,witteb41 #affj1 p4 #ccc72 and with that given in ,barlowe's ,navigators ,supply 7,london1 #aeig74 ,see also ,robert ,dudley's ,dell' ,arcano del ,mare 7,firenze1 #afdf74 #bbf ,,page #afe deals with the construction2 the process of magnetizing by the loadstone had already been discussed in pp4 #adg to #adi4 ,it is interesting to see that already the magnetized part attached below the compass-card was being specialized in form1 being made either of two pieces bent to meet at their ends1 or of a single oval piece with elongated ends4 ,the marking of the compass-card is particularly described4 ,it was divided into thirty-two points or winds1 precisely as the earlier wind-rose of the geographers1 distinguisht by certain marks1 and by a lily--or fleur-de-lys--indicating the ,north4 ,stevin in the ,havenfinding ,art 7,london1 #aeii71 from which work the passage on p4 #afg is quoted1 speaking on p4 #bj of the ,instrument which we call the ,sea-directorie1 some the nautical box1 444 or the sea compasse1 mentions the ,floure de luce marking the ,north4 ,the legend which assigns the invention of the compass to one ,goia or ,gioja of ,amalfi in #acjb has been already discussed in the ,note to page #d4 ,gilbert generously says that in spite of the adverse evidence he does not wish to deprive the ,amalfians of the honour of the construction adopted in the compasses used in the ,mediterranean4 ,but ,baptista ,porta the ,neapolitan1 who wrote forty years before ,gilbert1 discredited the legend4 ,flavius saith1 an ,italian found it out first1 whose name was ,amalphus1 born in our #eg ,campania4 ,but he knew not the ,mariners ,card1 but stuck the needle in a reed1 or a piece of wood1 cross over2 and he put the needles into a vessel full of water that they might flote freely4 7,porta's ,natural ,magick1 ,english translation1 ,london1 #afeh1 p4 #bjf47 ,see also ,lipenius 7op4 citat4 p4 #cij74 ,the pivotting of the needle is expressly described in the famous ,epistle on the ,magnet of ,peter ,peregrinus1 which was written in #abfi4 ,gasser's edition1 ,epistola ,petri ,peregrini 444 de magnete1 was printed in ,augsburg in #aeeh4 ,in ,part ,,ii41 cap4 #b1 of this letter1 a form of instrument is described for directing one's course to towns and islands1 and any places in fact on land or sea4 ,this instrument consists of a vessel like a turned box 7or pyxis7 of wood1 brass1 or any solid material1 not deep1 but sufficiently wide1 provided with a cover of glass or crystal4 ,in its middle is arranged a slender axis of brass or silver1 pivotted at its two ends into the top and the bottom of the box4 ,this axis is pierced orthogonally with two holes1 through one of which is passed the steel needle1 while through the other is fixed square across the needle another stylus of silver or brass4 ,the glass cover was to be marked with two cross lines north-south and east-west2 and each quadrant was to be divided into ninety degrees4 ,this the earliest described pivotted compass was therefore of the cross-needle type1 a form claimed as a new invention by ,barlowe in #aeig4 ,the first suggestion of suspending a magnetic needle by a thread appears to be in the ,speculum ,lapidum of ,camillus ,leonardus 7,venet41 #aejb1 fig4 k ij1 lines #be-ca73 ,n tacto ferro ex una pte magnetis ex opposita eius pte appropinquato fugat3 ut expietia docet de acu appenso filo4 ,the earliest known examples of the wind-rose are those in certain parchment charts preserved in the ,biblioteca ,marciana in ,venice4 ,these go back to #adbf or #adcf1 the best being ascribed to ,andrea ,bianco4 ,they have the ,north indicated by a fleur-de-lys1 a trident1 a simple triangle1 or a letter ,t2 while the ,east is distinguisht by a cross4 ,the ,west is marked with a ,p4 7see ,fincati1 op4 citat474 ,the eight marks in order1 clock wise1 run thus1 ,lily 7or ,t74 ,g4 ,cross 7or ,l7 ,s4 ,o4 ,a 7or ,l74 ,p4 ,m4 ,the letters correspond to the ,italian names of the principal winds3 ,tramontano ,north4 ,greco ,north-,east4 ,levante ,east4 ,sirocco ,south-,east4 ,ostro ,south4 ,africo or ,libeccio ,south-,west4 ,ponente ,west4 ,maestro ,north-,west4 ,wind-roses marked with the names of the minor winds are found in ,nautonier's ,mcometrie de l',eyman 7,vennes1 #afjb-afjd1 pp4 #aea-aeb71 and ,kircher's ,magnes ,siue de ,arte ,magnetica 7,colon4 ,agripp41 #afdc1 p4 #dcb74 ,the description above given of the early ,venetian wind-roses exactly describes the compass-card as depicted by ,pedro de ,medina in his ,arte de ,nauegar 7,valladolid1 #aede1 folio lxxx471 in the sixth book entitled las aguias de navegar2 while in the ,breve compendio de la sphera of ,martin ,cortes 7,sevilla1 #aeea1 cap4 iii41 de la piedrayman7 a similar wind-rose1 without the letters1 is found4 #eh ,in the ,de ,ventis et navigatione of ,michaele ,angelo ,blondo 7,venet41 #aedf1 p4 #ae7 is given a wind-rose1 described as ,pixis uel ,buxolus instrumentum et dux nauigantium1 having twenty-six points inscribed with the names of the winds1 there being six between north and east1 and six between south and west1 and only five in each of the other quadrants4 ,in the middle is a smaller wind-rose exactly like the early ,italian ones just mentioned4 ,in the ,della ,guerra di ,rhodi of ,jacobo ,fontano 7,venet41 #aede1 pages #ga-gd7 is a chapter ,dei ,venti1 e della ,bvssola di nauicare di ,giovanni ,quintino1 giving a wind-rose1 and a table of the names of the winds1 the north being indicated by a pointer1 at the cusp of which are seven stars1 and the west by an image of the sun4 ,the other cardinal points are marked with letters4 ,barlowe1 in ,the ,navigators ,supply 7,lond41 #aeig71 speaks thus3 ,the merueilous and diuine ,instrument1 called the ,sayling ,compasse 7being one of the greatest wonders that this ,world hath7 is a ,circle diuided commonly into #cb4 partes1 tearmed by our ,seamen ,windes1 ,rumbes1 or ,points of ,compasse4 ,it is a disputed point with whom the method of naming the winds originated4 ,some ascribe it to ,charlemagne4 ,michiel ,coignet 7,instruction novvelle 444 touchant l'art de naviguer1 ,anvers1 #aeha1 p4 #g7 ascribes it to ,andronicus ,cyrrhestes4 ,see ,varro1 ,de ,re ,rustica1 iii41 #e1 #ag1 and ,vitruvius1 i41 #f1 #d4 ,gilbert's complaint of the evil practice of setting the needles obliquely beneath the card1 with the intention of allowing for the variation1 is an echo of a similar complaint in ,norman's ,newe ,attractiue4 ,in chapter x4 of this work ,norman thus enumerates the different kinds of compasses3 ,of these common ,sayling ,compasses1 ,i find heere 7in ,europa7 five sundry sortes or sets4 ,the first is of ,levant1 made in ,scicile1 ,genoa1 and ,venice3 ,and these are all 7for the most parte7 made ,meridionally1 with the ,wyers directlye sette under the ,south1 and ,north of the ,compasse3 ,and therefore1 duely shewing the poynt ,respective1 in all places1 as the bare ,needle4 ,and by this ,compasse are the ,plats made1 for the most part of all the ,levants ,seas4 ,secondly1 there are made in ,danske1 in the ,sound of ,denmarke1 and in ,flanders1 that have the ,wyers set at #c quarters of a point to the ,eastwards of the ,north of the compasse1 and also some at a whole point3 and by these ,compasses they make both the ,plats and ,rutters for the ,sound4 ,thirdly1 there hath beene made in this ,countrey particulary1 for ,saint ,nicholas and ,ruscia1 ,compasses set at #c seconds of a point1 and the first ,plats of that ,discoverie were made by this ,compasse4 ,fourthly the ,compasse made at ,sevill1 ,lisbone1 ,rochell1 ,bourdeaux1 ,roan1 and heere in ,england1 are moste commonly set at halfe a point3 ,and by this ,compasse are the ,plats of the ,east and ,west ,indies made for their ,pylotes1 and also for our ,coastes neere hereby1 as ,france1 ,spayne1 ,portugall1 and ,england3 and therefore best of these ,nations to bee used1 because it is the most common sorte that is generally used in these ,coastes4 ,bessard 7op4 citat41 pages #bb and #dh7 gives cuts of compasses showing the needle displaced one rumbe to the ,east4 ,gallucci1 in his ,ratio fabricandi horaria mobilia et permanentia cum magnetica acu 7,venet41 #aeif71 describes the needle as inclined #aj degrees from the south toward the south-west4 ,the frontispiece of the work of ,pedro ,nuez1 ,instrumenta ,artis ,navigandi1 ,basil41 #aeib1 depicts a compass with the lily set one point to the east4 ,reibelt1 ,de ,physicis et ,pragmaticis ,magnetis ,mysteriis 7,herbipolis1 #agca71 depicts the compass with the needle set about #ab degrees to the ,east of ,north4 ,see also ,fournier1 ,hydrographie 7,paris #affg72 ,de ,lanis1 ,magisterium ,natvr et ,artis 7,brixi1 #afhd72 ,milliet ,deschales1 ,cursus seu ,mundus #ei ,mathematicus 7,lugd41 #afgd74 ,both the latter works give pictures of the compass-cards as used in ,south ,europe1 and in ,north ,europe1 and of the various known shapes of needles4 #bbg ,,page #afh1 ,,line #bi4 ,page #afh1 line #cc4 ,directio igitur inualidior est prop polos4 ,here as in many passages direction means the force which directs4 ,a similar usage prevails with the nouns variation and declination1 meaning frequently the force causing variation or declination respectively4 ,,page #agb1 ,,line #ac4 perquirere4 ,the edition of #afcc reads perquirero1 in error4 #bbh ,,page #agb1 ,,line #bi4 ,page #agb1 line #cc4 ,ad pyxidis nautic ver meridionalis formam 444 fiat instrumentum4--,an excellent form of portable meridian compass1 provided with sights for taking astronomical observations1 is described by ,barlowe 7,the ,navigators ,supply1 ,london1 #aeig71 and is depicted in an etched engraving4 ,an identical engraving is repeated in ,dudley's ,arcano del ,mare 7,firenze1 #afdf74 ,gilbert's new instrument was considerably larger4 #bbi ,,page #agd1 ,,line #ai4 ,page #agd1 line #ba4 addendo vel detrahendo prostaphresin4--,prosthaphresis1 conflata dictione1 ex additione et subtractione speciebus logistices1 nomen habet ab officio1 quia vt in semicirculo altero ad quabilem motum adijcitur1 ita in altero subtrahitur1 vt adparens motus ex quabili taxetur3 atque hinc fit1 qud qu ,prosthaphresis dicitur ,ptolemo1 ea vulg quatio vocetur4 7,stadius1 ,tabul ,bergenses1 ,colon4 ,agripp41 #aefj1 p4 #cg47 #bcj ,,page #agd1 ,,line #bh4 ,page #agd1 line #ca4 ,stell ,lucid4--,according to ,dr4 ,marke ,ridley 7,magneticall ,animadversions1 ,london1 #afag1 p4 #i71 this chapter xii4 of book iv41 with the ,table of ,stars1 was written by ,edward ,wright1 the author of the ,prefatory ,epistle of ,de ,magnete4 ,wright was ,lecturer on ,navigation to the ,east ,india ,company1 and author of sundry treatises on ,navigation4 #bca ,,page #ahg1 ,,line #ad4 ,page #ahg1 line #af4 hic qui versus boream constitit 444 meridionalis est1 non borealis1 quem ant nos omnes existimabant esse borealem4--,earlier on1 on pages #ae and #abe1 ,gilbert had mentioned this point4 ,his insistence caused ,barlowe 7,magneticall ,aduertisements1 #afaf1 p4 #d7 to speak of the south-pointing end of the needle as the true ,north1 and thereby drew on himself the animadversions of ,marke ,ridley4 #bcb ,,page #ahh1 ,,line #ae4 ,page #ahh1 line #af4 in rect sphr4--,see note to p4 #acd4 #bcc ,,page #aij1 ,,line #ad4 ,page #aij1 line #ai4 declinans in ,borealibus4--,dipping as it does in northern regions2 that is1 with the north-seeking or true-south pole downward4 #bcd ,,page #aie1 ,,line #bj4 ,page #aie1 line #bd4 multa maiora pondera4--,many greater weights4 ,all editions read multa1 but the sense requires multo3 much greater weights4 #bce ,,page #aif1 ,,line #aj4 ,page #aif1 line #ab4 constans est4--,this must not be read is constant1 for it is constant only in any given latitude4 #bcf ,,page #aif1 ,,line #ae4 ,page #aif1 line #ah4 ,de proportione declinationis pro latitudinis ratione4--,gilbert here announces1 and proceeds in the next seven pages to develop1 the proposition that to each latitude there corresponds a constant dip to a particular number of degrees4 ,if this were accurately so1 then a traveller by merely measuring the dip would be able to ascertain1 by calculation1 by reference to tables1 or by aid of some geometrical appliance1 #fj the latitude of the place4 ,in this hope ,gilbert fought to perfect the dipping-needle2 and he also worked out1 on pages #aii and #bjj1 an empirical theory1 and a diagram4 ,this theory was still further developed by him1 and given to ,thomas ,blundevile 7see the ,note to p4 #bdj74 ,briggs of ,gresham ,college1 on ,gilbert's suggestion1 calculated a table of ,dip and ,latitude on this theory4 ,it was found1 however1 that the observed facts deviated more or less widely from the theory4 ,kircher 7,magnes1 #afdc1 p4 #cfh7 gives a comparative table of the computed and observed values4 ,further discovery showed the method to be impracticable1 and ,gilbert's hope remained unfulfilled4 #bcg ,,page #aig1 ,,line #ah4 ,page #aig1 line #ba4 progressionis centri4--,note ,gilbert's precision of phrase4 #bch ,,page #bjj1 ,,line #ab4 ,page #bjj1 line #aa4 subintelligutur4--,this is printed subintelligitur1 and is altered in ink in all copies of the folio edition4 ,the editions of #afbh and #afcc read subintelliguntur4 ,similarly in line #ad the word ducit has had a small r added in ink1 making it read ducitur1 as also the other editions4 #bci ,,page #bjc4 ,this figure of the experiment with the simple dipping needle suspended in water in a goblet is due to ,robert ,norman4 ,in his ,newe ,attractiue 7,london1 #aeha1 chap4 vi47 he thus describes it3 ,then you shall take a deepe ,glasse1 ,bowle1 ,cuppe1 or other vessell1 and fill it with fayre water1 setting it in some place where it may rest quiet1 and out of the winde4 ,this done1 cut the ,corke circumspectly1 by little and little1 untill the wyre with the ,corke be so fitted1 that it may remain under the superficies of the water two or three inches1 both ends of the wyer lying levell with the superficies of the water1 without ascending or descending1 like to the beame of a payre of ballance beeing equalie poysed at both ends4 ,then take out of the same the wyer without mooving the ,corke1 and touch it with the ,stone1 the one end with the ,south of the ,stone1 and the other end with the ,north1 and then set it againe in the water1 and you shall see it presentlie turne it selfe upon his owne ,center1 shewing the aforesay'd ,declining propertie1 without descending to the bottome1 as by reason it should1 if there were any ,attraction downewards1 the lower part of the water being neerer that point1 then the superficies thereof4 #bdj ,,page #bab1 ,,line #g4 ,page #bab1 line #h4 ex altera parte4--,the sense seems to require et altera parte1 but all editions read ex4 #bda ,,page #bac1 ,,line #a4 ,page #bac1 line #b4 ,the passage here quoted from ,dominicus ,maria ,ferrariensis1 otherwise known as the astronomer ,novara1 does not occur in any known writing of that famous man4 ,it is1 however1 quoted as being by ,novara in at least three other writings of the same epoch4 ,see the ,tabul secvndorum mobilium coelestium of ,maginus 7,venet41 #aehe1 p4 #bi1 line #ai to p4 #cj1 line #aa72 the ,eratosthenes ,batavvs of ,willebrord ,snell 7,lugd4 ,batav41 #afag1 pp4 #dj-db72 and the ,almagesti novi 7,pars ,posterior7 of ,riccioli 7,bonon41 #afea1 p4 #cdh74 ,the original document appears to have perisht4 ,see a notice by ,m4 ,curtze in ,boncompagni's ,bullettino di ,bibliografia1 ,t4 iv41 ,april1 #ahga4 #bdb ,,page #bad1 ,,line #bf4 ,page #bad1 line #ca4 ,philolaus ,pythagoricus4 ,philolas a le premier dit que la terre se meut en cercle2 d'autres disent que c'est ,nictas de ,syracuse4 ,les uns prtendent que le terre est immobile2 mais ,philolas le pythagoricien dit qu'elle se meut circulairement autour du feu 7central7 et suivant un cercle oblique1 comme le soleil et la lune4--7,chaignet1 ,pythagore et la ,philosophie pythagoricienne1 ,paris1 #ahgc47 ,it appears that the first of these dicta is taken from ,diogenes ,lart41 viii4 #he2 and the second from ,plutarch1 ,placit4 ,philos41 ,,iii4 #g4 ,the latter #fa passage may be compared with ,aristotle1 ,de ,coelo1 ,,ii4 #ac1 who1 referring to the followers of ,pythagoras1 says3 ,they say that the middle is fire1 that the earth is a star1 and that it is moved circularly about this centre2 and that by this movement it produces day and night4 #bdc ,,page #bad1 ,,line #cd4 ,page #bad1 line #db4 ,copernicus4--,his work is ,de revolutionibus orbium coelestium1 libri vi4 7,basil41 #aeff74 #bdd ,,page #bae1 ,,line #bg4 ,page #bae1 line #bd4 qu 444 in clo varijs distantijs collocata sunt4--,this remark appears to be ,gilbert's one contribution to the science of ,astronomy2 the stars having previously been regarded as fixed in the eighth sphere all at the same distance from the central earth1 around which it revolved4 #bde ,,page #bbj1 ,,line #f4 ,page #bbj1 line #f4 quem nycthemeron vocamus4--,the #afbh and #afcc editions read nyctemoron4 #bdf ,,page #bba1 ,,line #aj4 ,page #bba1 line #aa4 poli ver oppositi sint4--,for ver1 the #afbh and #afcc editions read rect4 ,all editions read sint1 though sunt seems to make better sense4 #bdg ,,page #bbc1 ,,line #g4 ,page #bbc1 line #h4 ad telluris conformitatem4--,the word conformitas is unknown in classical ,latin4 #bdh ,,page #bbc1 ,,line #af4 ,page #bbc1 line #ag4 ,omitto quod ,petrus ,peregrinus constanter affirmat1 terrellam super polos suos in meridiano suspensam1 moveri circulariter integr revolutione #bd horis3 ,quod tamen nobis adhuc videre non contingit2 de quo motu etiam dubitamus4 ,this statement that a spherical loadstone pivotted freely with its axis parallel to the earth's axis will of itself revolve on its axis once a day under the control of the heavens1 thus superseding clocks1 is to be found at the end of chap4 x4 of ,peregrinus's ,epistola ,de ,magnete 7,augsb41 #aecg74 ,gilbert1 who doubted this experiment because of the stone's own weight is taken to task by ,galileo1 in the third of his ,dialogues1 for his qualified admission4 ,i will speak of one particular1 to which ,i could have wished that ,gilbert had not lent an ear2 ,i mean that of admitting1 that in case a little ,sphere of ,loadstone might be exactly librated1 it would revolve in it self2 because there is no reason why it should do so 7p4 #cgf of ,salusbury's ,mathematical ,collections1 ,london1 #affa74 ,the ,jesuit ,fathers who followed ,gilbert1 but rejected his ,copernican ideas1 pounced upon this pseudo-experiment1 as though by disproving it they had upset the ,copernican theory4 #bdi ,,page #bbg1 ,,line #f4 ,page #bbg1 line #g4 ,this line is left out in the #afbh edition4 ,in the #afcc edition it was also left out by the printer1 and subsequently printed in in the margin1 being page #bai of that edition4 #bej ,,page #bcd1 ,,line #ce4 ,page #bcd1 line #dj4 vt poli telluris respectus polis4--,if it may be permitted to read respectu for respectus the sense is improved1 and the passage may then be translated thus3 that just as it was needful 444 that the poles of the ,earth as to direction should be #bc degrees and more from the poles of the ,ecliptick2 so now1 c4 #bea ,,page #bcg1 ,,line #ai4 ,page #bcg1 line #bb4 vt motus quidem obscuri saluarentur4--,it has been conjectured that quidem is here a misprint for quidam1 but the adverb quidem adds a satirical flavour to his argument against the folly of those who held the doctrine of the moving spheres4 ,the verb salvare does not occur in classical ,latin4 #beb ,,page #bdj1 ,,line #ac4 ,page #bdj1 line #ag4 ,copernico 7,astronomi instauratore74--,gilbert was the first in ,england to uphold the doctrines of #fb ,copernicus as to the motion of the earth on its axis and its revolution around the sun4 ,he considered that his magnetic observations brought new support to that theory1 and his views are quoted with approbation by ,kepler1 ,epitome ,astronomi ,copernican 444 ,authore ,ioanne ,keplero 444 7,francofurti1 #afce72 and by ,galileo1 ,dialogus de ,systemate ,mundi 7,august ,treboc41 #afce71 an ,english translation of which appeared in ,salusbury's ,mathematical ,collections and ,translations 7,london1 #affa1 pp4 #cfd to #cgg74 ,for this the book ,de ,magnete was considered by many as heretical4 ,many of the copies existing in ,italy are found to be either mutilated or else branded with a cross4 ,for example1 the copy in the library of the ,collegio ,romano in ,rome has book ,,vi4 torn out4 ,galileo states that the ,book of ,gilbert would possibly never have come into his hands if a ,peripatetick ,philosopher1 of great fame1 as ,i believe to free his ,library from its contagion1 had not given it me4 ,in ,england ,barlowe1 in his ,magneticall ,aduertisements 7#afaf71 expressly repudiated ,gilbert's ,copernican notions1 while praising his discoveries in magnetism4 ,marke ,ridley1 while upholding ,gilbert's views1 in his ,magneticall ,animadversions 7#afag7 did not consider him skilfull in ,copernicus4 ,the ,jesuit writers1 ,cabeus1 ,kircher1 ,fonseca1 ,grandamicus1 ,schott1 ,leotaudus1 ,millietus1 and ,de ,lanis1 one and all1 who followed ,gilbert in their magnetic writings1 repudiated the idea that the magnetism of the globe gave support to the heretical modern ,astronomy4 ,the works referred to are3 ,cabeus1 ,philosophia ,magnetica1 in qua ,magnetis natura penitus explicatur 444 auctore ,nicolao ,cabeo ,ferrarensi ,soc4 ,jesv4 7,ferrari1 #afbi74 ,kircher1 ,magnes1 ,siue de ,arte ,magnetica1 ,libri tres1 ,authore ,athanasio ,kirchero 444 e ,soc4 ,iesv4 7,rom1 #afda74 ,grandamicus1 ,nova ,demonstratio immobilitatis terr petita ex virtute magnetica 7,flexi1 #afde74 ,this work is most beautifully illustrated with copper-plate etchings of cupids making experiments with terrellas4 ,schott1 ,gaspar1 ,thaumaturgus ,physicus 7,herbipolis1 #afei74 ,leotaudus1 ,r4 ,p4 ,vincentinii ,leotavdi ,delphinatis1 ,societ4 ,iesv41 ,magnetologia2 in qva exponitvr ,nova de ,magneticis ,philosophia1 7,lvgdvni1 #affh74 ,millietus 7,milliet ,deschales71 ,cursus seu ,mundus ,mathematicus 7,lugd41 #afgd71 ,tomus ,primus1 ,tractatus de ,magnete4 ,de ,lanis1 ,magisterium ,natvr et ,artis4 ,opus ,physico-,mathematicvm ,p4 ,francisci ,tertii de ,lanis1 ,soc4 ,jesv4 7,brixi1 #afhd74 #bec ,,page #bdj1 ,,line #bd4 ,page #bdj1 line #ca4 hic finem periodum imponimus4 ,on ,february #ac #afja ,gilbert wrote to ,barlowe 7see ,magneticall ,aduertisements1 p4 #hh73 ,i purpose to adioyne an appendix of six or eight sheets of paper to my booke after a while1 ,i am in hand with it of some new inventions1 and ,i would haue some of your experiments1 in your name and inuention put into it1 if you please1 that you may be knowen for an augmenter of that arte4 ,this he never did4 ,perhaps his appointment 7in ,february1 #afja7 as chief physician in personal attendance on the ,queen interfered with the project2 or his death1 of the plague1 in #afjc1 intervened before his intention had been carried into effect4 ,but it is probable that the substance of the proposed additions is to be found in the chapter1 publisht in ,gilbert's lifetime1 in ,blundevile's ,theoriques of the seuen ,planets 7,london1 #afjb71 thus described in the title-page of the work3 ,there is also hereto added1 #fc ,the making1 description1 and vse1 of two most ingenious and necessarie ,instruments for ,sea-men1 to find out thereby the latitude of any ,place vpon the ,sea or ,land1 in the darkest night that is1 without the helpe of ,sunne1 ,moone1 or ,starre4 ,first inuented by ,m4 ,doctor ,gilbert1 a most excellent ,philosopher1 and one of the ordinarie ,physicians to her ,maiestie3 and now here plainely set downe in our mother tongue by ,master ,blundeuile4 ,of these two instruments the first consists of a mechanical device1 with movable quadrants1 to be cut out in cardboard1 to be used in connection with the diagram of spiral lines which ,gilbert had given as a folding plate between pages #bjj and #bja of ,de ,magnete4 ,the intention was that the ,sea-man having found by experiment with a dipping-needle the amount of the dip at any place1 should by applying this diagram and its moving quadrants1 ascertain the latitude1 according to the theory expounded in book ,v41 chap4 ,,vii4 ,the second instrument is a simplified portable dipping-needle1 having the degrees engraved on the inner face of a cylindrical brass ring4 ,blundevile adds a ,table1 calculated by ,briggs1 and annexed to the former ,treatise by ,edward ,wright1 at the motion of the right ,worshipful ,m4 ,doctor ,gilbert4 ,this gives the values of the dip for different latitudes1 as calculated from ,gilbert's empirical theory4 ,the other work1 ,de ,mundo nostro ,sublunari ,philosophia ,nova1 which ,gilbert left in manuscript at his death1 does not contain any additional matter on the magnetical investigations4 ,though it contains several direct references to the de ,magnete1 and particularly to ,book ,,vi4 on the rotation of the earth1 it is doubtful whether it was written after or before the publication of de ,magnete4 ,on pages #acg to #add of the posthumous edition 7,amsterdam1 #afea7 ,gilbert refers to ,peregrinus's alleged perpetually revolving sphere1 and denies its possibility4 ,the greater part of the work is an anti-,aristotelian discussion on ,air1 ,meteorology1 ,astronomy1 the ,winds1 ,tides1 and ,springs4 ,illustration 99 99 99 99 99 #fe ,,index ,,to ,,authorities ,abano1 ,pietro di1 #f4 ,acosta1 ,josephus1 #af4 ,addison1 ,joseph1 #ce4 ,aepinus1 #dd4 ,aetius ,amidenus1 #f4 ,affaytatus1 #af1 #ci4 ,agricola1 ,georgius1 #be1 #ca1 #cf1 #ej4 ,agrippa1 ,h4 ,cornelius1 #g4 ,albategnius1 #bi4 ,albertus ,magnus1 #f1 #ag1 #ch1 #ci1 #dj1 #ej4 ,aldrovandi1 ,ulisse1 #ac1 #cf1 #ec4 ,alexander ,aphrodiseus1 #c1 #ba4 ,amatus ,lusitanus1 #f1 #ca4 ,apponensis1 ,petrus1 #f4 ,see ,abano4 ,aquinas1 ,st4 ,thomas1 #h1 #de4 ,ardoynis1 ,santes de1 #f4 ,aristotle1 #d1 #ai1 #be1 #fa4 ,arnaldus de ,villa nova1 #f4 ,augustani1 #bi4 ,augustine1 ,st41 #d1 #ba1 #dc4 ,aurifaber1 #cf4 ,averroes1 #bi4 ,avicenna1 #f1 #bi1 #cj1 #cd4 ,azuni1 #h4 ,bacon1 ,lord1 #ag1 #db4 ,barlow1 ,peter1 #ea4 ,barlowe1 ,william1 #a1 #b1 #e1 #i1 #bj1 #bh1 #ed1 #ef1 #eg1 #eh1 #ei1 #fb4 ,beckmann1 ,johann1 #ai1 #ba1 #cb4 ,bencora1 or ,ben ,korrah 7,thebitius71 #cj4 ,benjamin1 ,park1 #i1 #aa1 #ag4 ,bernoulli1 ,d41 #dh4 ,bertelli1 ,timoteo1 #aa4 ,bessard1 ,toussaincte de1 #aa1 #eh4 ,bianco1 ,andrea1 #eg4 ,blackmore1 ,r4 ,d41 #bd4 ,blondo1 ,michaele ,angelo1 #a1 #eh4 ,blondus1 ,flavius1 #i4 ,blundevile1 ,thomas1 #h1 #ad1 #fj1 #fb1 #fc4 ,bond1 ,henry1 #ee4 ,borough1 ,william1 #b1 #ai4 ,boyle1 ,robert1 #dc1 #ec4 ,brasavolus1 ,antonius ,musa1 #f1 #cg4 ,briggs1 ,henry1 #fj1 #fb4 ,brough1 ,r4 ,b41 #ae4 ,browne1 ,sir ,thomas1 #c1 #cg1 #db1 #ea1 #ec4 ,brunfels1 ,otho1 #ag1 #cj4 ,buffum1 ,w4 ,a41 #cf4 ,burton1 ,sir ,richard ,f41 #e4 ,buttmann1 #bj1 #cb4 ,buxtorf1 #ba4 ,cabeus1 ,nicolas1 #b1 #db1 #ej1 #fb4 ,cabot1 ,sebastian1 #aj1 #af4 ,caesar 7or ,cesare1 ,giulio71 #ec4 ,calaber1 ,hannibal ,rosetius1 #f4 ,calcagninus1 ,clius1 #h1 #i4 ,camden1 ,william1 #be4 ,camera1 ,matteo1 #h4 ,cardan1 ,hieronymo1 #bc1 #bd1 #bf1 #ca1 #cf1 #cg1 #da1 #dc1 #di1 #ed4 ,casaubon1 #ag4 ,cats1 ,jacob1 #ec4 ,cavallo1 ,tiberius1 #dd4 ,chaignet1 #fj4 ,charlemagne1 #eh4 ,charles ,,ii41 #bc4 ,charleton1 ,dr4 ,w41 #ai4 ,chladni1 #bf4 ,coignet1 ,michiel1 #eh4 ,collenuccio1 ,pandolfo1 #i4 ,conimbricenses1 #aa4 ,cordus1 ,valerius1 #bj4 ,cortes1 ,martin1 #aa1 #bd1 #eg4 ,costa1 ,filippo1 #af1 #ec4 ,costa1 ,joseph4 ,see ,acosta4 ,costaeus1 ,joannes1 of ,lodi1 #af1 #de4 ,creak1 ,captain1 #ea1 #ef4 ,creech1 ,t41 #c4 ,crescentius1 #h4 ,crollius1 ,o41 #bi4 ,curtius1 #cb4 ,curtius1 ,n41 #bi4 ,curtze1 ,m41 #fj4 ,cusan 7,cardinal de ,cusa71 #g1 #de1 #di4 ,cyrrhestes1 ,andronicus1 #eh4 ,davies1 ,t4 ,s41 #bj4 ,de la ,hire1 #ed4 ,de ,lanis1 #eh1 #fb4 ,delaunay1 #cb4 ,diogenes ,laertius1 #fj4 ,dioscorides1 #cj1 #cd1 #ce1 #cg1 #ch1 #dc4 ,dominicus ,maria ,ferrariensis 7,novara71 #fj4 ,drake1 ,sir ,francis1 #ai4 ,dudley1 ,sir ,robert1 #ai1 #ef1 #ei4 ,du ,puys 7,puteanus71 #ch1 #de4 #ff ,encelius1 or ,entzelt1 #g1 #bd1 #bf4 ,erastus1 ,thomas1 #g4 ,euripides1 #d4 ,evax1 #ah1 #ej4 ,evelyn1 ,john1 #bc4 ,fallopius1 ,gabriellus1 #g1 #bi4 ,fantis1 ,antonius de1 #di4 ,ficino1 ,marsiglio1 #ah4 ,fincati1 ,admiral1 #h4 ,fletcher1 ,l41 #bf4 ,fonseca1 #fb4 ,fontano1 ,jacopo1 #eh4 ,forcellini1 #b4 ,fournier1 ,g41 #aj1 #bj1 #bb1 #ee1 #eh4 ,foxe1 #eb4 ,fracastorio1 ,hieronymo1 #ab1 #ai1 #bi1 #ea4 ,galen1 #bi1 #cj1 #ca1 #ce4 ,galileo1 #dg1 #fb4 ,gallucci1 #eh4 ,gartias ab ,horto1 #ac1 #bg1 #ci4 ,gassendi1 #ed4 ,gasser1 ,achilles ,p41 #ag1 #eg4 ,geber1 #bi4 ,gellibrand1 ,henry1 #ee4 ,gemma1 ,cornelius1 #de4 ,gessner1 #cb4 ,gilbert1 ,adrian1 #bj4 ,gilbert1 ,william1 de ,mundo nostro ,sublunari1 #dg1 #ej1 #fc4 ,gioia1 or ,goia1 #h1 #ef4 ,glanvill1 ,joseph1 #bg4 ,goebel1 #cf4 ,goethe1 #bc4 ,gonzalus ,oviedus1 #aj4 ,goppert1 #ce4 ,goropius1 ,henricus ,becanus1 #aj4 ,gralath1 ,d41 #cf4 ,grandamicus1 #fb4 ,grew1 ,n41 #bc4 ,grimaldi1 #ed4 ,grotius1 ,hugo1 #ag4 ,guericke1 ,otto von1 #da1 #ej4 ,haecker1 ,p4 ,w41 #dh4 ,hakewill1 ,g41 #aj4 ,hakluyt1 #ac1 #bj4 ,hali ,abbas1 #f1 #ag1 #bi4 ,hamilton1 ,james 7,earl of ,abercorn71 #dh4 ,hariot1 ,thomas1 #ai4 ,harris1 ,sir ,w4 ,snow1 #ba1 #ed4 ,hartmann1 ,p4 ,j41 #cf4 ,hellmann1 ,g41 #aa4 ,hermann1 ,d41 #cf4 ,hermolaus ,barbarus1 #g4 ,hill1 ,sir ,john1 #bd1 #ch1 #dj4 ,hood1 ,t41 #c4 ,hues1 ,robert1 #ai4 ,humboldt1 #bf1 #ca1 #cf1 #da4 ,hyginus1 #cf4 ,isidore1 ,st41 #bj1 #ba1 #ci4 ,kendall1 ,abraham1 #ai4 ,kepler1 #fb4 ,kiel1 ,cornelius van 7or ,kiliani71 #eb4 ,king1 ,edward1 #bf4 ,kircher1 ,athanasius1 #b1 #ba1 #de1 #ee1 #ef1 #eg1 #fb4 ,klaproth1 #g1 #h1 #aj1 #bj1 #ba1 #bb4 ,kudrun1 #ae4 ,langius1 ,joannes1 #g4 ,lanis1 ,f4 de1 #eh1 #fb4 ,leonardus1 ,camillus1 #g1 #eg4 ,leotaudus1 #fb4 ,levinus ,lemnius1 #ch1 #ci1 #da1 #ef4 ,libri1 #aa4 ,linna1 ,nicolas de1 #ad4 ,lipenius1 #ac1 #ef4 ,lister1 ,martin1 #ec4 ,livio ,sanuto1 #aj1 #af4 ,livy1 #bf4 ,lonicer1 ,joannes1 #cj1 #ce1 #ch4 ,lwy1 #ba4 ,lucretius1 #c1 #dd4 ,maginus1 #fj4 ,magnus1 ,sir ,philip1 #aj4 ,manardus1 ,joannes1 #bi4 ,marbodeus1 #f1 #ah1 #ba1 #dj1 #da1 #ej4 ,marcellus ,empiricus1 #f1 #g4 ,marco ,polo1 #aj4 ,martial1 #cf1 #cg4 ,martin1 ,th4 ,henri1 #bj1 #ba1 #cb1 #cc4 ,maskelyne1 ,n4 ,story1 #bf4 ,matthus ,silvaticus1 #g4 ,matthiolus1 ,p41 #e1 #cj1 #ce4 ,maurolycus1 ,franciscus1 #aa4 ,medina1 ,pedro de1 #ed1 #eg4 ,mercator1 #aa1 #ad4 ,merula1 ,gaudentius1 #ah1 #ai4 ,merula1 ,p41 #ae4 ,miers1 ,h4 ,a41 #dj4 ,migne1 #ai4 ,milliet ,deschales1 #eh1 #fb4 ,monardus1 ,nicolas1 #bi4 ,montanus1 ,joannes ,baptista1 #f4 ,morris1 ,william1 #ae4 ,moxon1 ,joseph1 #ea4 ,muellenhoff1 ,k41 #cf4 ,nautonier1 ,g41 #ee1 #eg4 ,neckham1 ,alexander of1 #aj4 ,newton1 ,sir ,isaac1 #da4 ,nicander1 #ch4 ,nicolaus ,myrepsius 7or ,prpositas71 #bh1 #ce4 #fg ,nonius ,petrus 7or ,nuez71 #eh4 ,nordenskjold1 #ac4 ,norman1 ,robert1 #a1 #aa1 #ad1 #bh1 #ef1 #eh1 #fj4 ,novara1 ,dominicus ,maria1 #fj4 ,offusius1 ,joannes ,franciscus1 #ca4 ,olaus ,magnus1 #ab1 #ag4 ,oribasius1 #f4 ,orpheus1 #bb1 #dd4 ,ovid1 #cf4 ,oviedo1 ,luis de1 #bh4 ,oviedus1 ,gonzalus1 #aj4 ,paley1 ,f4 ,a41 #cb4 ,palm1 ,g4 ,a41 #bj4 ,paracelsus 7,bombast von ,hohenheim71 #g1 #bi4 ,paulus ,aegin1 #cj4 ,paulus ,jovius1 #i4 ,paulus ,venetus 7,fra ,paolo ,sarpi71 #ag4 ,pepys1 ,samuel1 #bc4 ,peregrinus1 ,petrus1 #a1 #aa1 #bc1 #dh1 #eg1 #fa4 ,pettus1 ,sir ,john1 #bc1 #da4 ,philolaus1 #fj4 ,photius1 #ba4 ,pictorio1 ,g41 #ah4 ,plancius1 #ad4 ,plat1 ,sir ,hugh1 #e1 #dj1 #dc4 ,plato1 #d1 #dd4 ,plautus1 #b4 ,pliny 7,caius ,plinius ,secundus71 #e1 #bj1 #ba1 #bb1 #bd1 #be1 #bf1 #bg1 #ce1 #cf1 #cg1 #ch1 #ci1 #da1 #di1 #ej4 ,plot1 ,rob41 #db4 ,plutarch1 #bf1 #bh1 #da1 #fj4 ,polo1 ,marco1 #aj4 ,porta1 ,joannes ,baptista 7,giambattista della ,porta71 #d1 #i1 #af1 #bc1 #df1 #dh1 #ed1 #ef1 #eg4 ,poynting1 ,j4 ,h41 #dg4 ,prpositas 7or ,nicolas ,myrepsius71 #bh1 #ce4 ,ptolemy1 #ab1 #bh4 ,purchas1 #ee4 ,puteanus1 ,gulielmus1 #ch1 #de4 ,quintino1 ,giovanni1 #eh4 ,ramelli1 ,agostino1 #ec4 ,rammelsberg1 #bf4 ,reibelt1 #eh4 ,rhazes1 #bh1 #bi1 #cj4 ,riccioli1 #fj4 ,ridley1 ,marke1 #c1 #ca1 #ei1 #fb4 ,robertson1 ,rev4 ,alexander1 #ag4 ,rcker1 ,arthur ,w41 #ae4 ,ruellius1 ,joannes1 #ah1 #cj1 #cd1 #cg4 ,rueus1 ,franciscus1 #ag4 ,ruysch1 ,johan1 #ac4 ,salusbury1 ,t41 #fa1 #fb4 ,santes de ,ardoynis1 #f4 ,sanuto1 ,livio1 #aj1 #af4 ,sarpi1 ,fra ,paolo1 #af1 #ag4 ,savery1 ,servington1 #dh1 #ed4 ,scaliger1 ,j4 ,c41 #bf1 #cc1 #cd1 #de1 #df1 #di4 ,scheins1 ,m41 #cb4 ,schindler1 ,a4 ,houtum1 #cc4 ,schott1 ,g41 #fb4 ,schweigger1 ,j4 ,c41 #cb4 ,sendel1 ,nathaniel1 #cf1 #cg4 ,sennert1 ,daniel1 #df4 ,serapio1 #f1 #ag1 #cj4 ,severt1 ,jacques1 #aa4 ,shakespeare1 ,william1 #bb4 ,siemens1 #dh4 ,signorelli1 #h4 ,silvaticus1 ,matthus1 #g4 ,smith1 ,dr4 ,william1 #bf4 ,snell1 ,willebrord1 #fj4 ,solinus1 ,julius1 #d1 #cg1 #dj4 ,stadius1 #ei4 ,stephanus1 #cb4 ,stevinus1 ,simon1 #ef4 ,strabo1 #bf4 ,swan1 ,john1 #ef4 ,swinden1 ,j4 ,h4 van1 #dd4 ,taisnier1 ,joannes1 #aa1 #dg4 ,terzagus1 #cf1 #di4 ,thaln1 #ae4 ,thales1 #df4 ,thebit ,ben ,korrah1 #cj1 #ej4 ,themistius1 #df4 ,theophrastus1 #cb1 #cf1 #ch4 ,thompson1 ,silvanus ,p41 #dh4 ,thomson1 ,r4 ,d41 #di4 ,thorpe1 ,t4 ,e41 #ae4 ,vallemont1 ,abb de1 #ed4 ,van ,swinden1 #dd4 ,varro1 #eh4 ,venanson1 ,flaminius1 #h4 ,venner1 ,dr4 ,t41 #dj4 ,vergil1 #b1 #bd4 ,virgil1 ,polydore1 #i4 ,vitruvius1 #eh4 ,waring1 ,e4 ,j41 #bi4 ,watson1 ,william1 #ch4 ,wigand1 ,johann1 #cf4 ,wilde1 ,henry1 #ae4 ,willigen1 van der1 #dh4 ,wren1 ,sir ,christopher1 #bc4 ,wright1 ,edward1 #ai1 #ei1 #fb4 ,illustration ,,chiswick ,,press3 ,,charles ,,whittingham ,,and ,,co4 ,,tooks ,,court1 ,,chancery ,,lane1 ,,london4