,,new ,,work ,,on ,,painting4 ,just ready1 in small #hvo1 with ,frontispiece and ,vignette1 ,,painting ,,popularly ,,explained2 ,,with ,the ,practice of the ,art1 ,,and ,,historical ,,notices ,,of ,,its ,,progress4 ,,by ,,thomas ,j4 ,,gullick1 ,,painter1 ,,and ,,john ,,timbs1 ,f4,s4,a4 ,the plan of this work is thus sketched in the ,introduction3 8,there have been in the history of ,art1 four grand styles of imitating ,nature--,tempera1 ,encaustic1 ,fresco1 and ,oil4 ,these1 together with the minor modes of ,painting1 we propose arranging in something like chronological sequence2 but our design being to offer an explanation of the ,art derived from practical acquaintance1 rather than attempt to give its history1 we shall confine ourselves for the most part to so much only of the ,history of ,painting as is necessary to elucidate the origin of the different practices which have obtained at different periods40 ,by this means1 the ,authors hope to produce a work which may be valuable to the ,amateur1 and interesting to the ,connoisseur1 the ,artist1 and the ,general ,reader4 ,,london3 ,,kent ,,co4 7,,late ,,bogue71 ,,fleet ,,street4 ,illustration3 ,,mouth ,,of ,,the ,,great ,,rosse ,,telescope1 ,,at ,,parsonstown4 ,,from ,a ,,photograph4 ,things not generally ,known ,familiarly ,explained4 ,,curiosities ,,of ,,science1 ,past and ,present4 ,a ,,book ,,for ,,old ,,and ,,young4 ,,by ,,john ,,timbs1 ,f4,s4,a4 ,,author ,,of ,,things ,,not ,,generally ,,known2 ,,and ,,editor ,,of ,,the ,,year-,,book ,,of ,,facts4 ,illustration3 ,model of the ,safety-,lamp1 made by ,sir ,humphry ,davy's own hands2 in the possession of the ,royal ,society4 ,,london3 ,,kent ,,and ,,co4 7,,late ,,bogue71 ,,fleet ,,street4 ,,mdccclviii4 ,the ,author reserves the right of authorising a ,translation of this ,work4 ,,london3 ,,printed ,,by ,,levey1 ,,robson1 ,,and ,,franklyn1 ,great ,new ,street and ,fetter ,lane4 ,,gentle ,,reader1 ,the volume of 8,,curiosities0 which ,i here present to your notice is a portion of the result of a long course of reading1 observation1 and research1 necessary for the compilation of thirty volumes of 8,arcana of ,science0 and 8,year-,book of ,facts10 published from #ahbh to #aheh4 ,throughout this period--nearly half of the ,psalmist's 8days of our years0--,i have been blessed with health and strength to produce these volumes1 year by year 7with one exception71 upon the appointed day2 and this with unbroken attention to periodical duties1 frequently rendered harassing or ungenial4 ,nevertheless1 during these three decades ,i have found my account in the increasing approbation of the reading public1 which has been so largely extended to the series of 8,,things ,,not ,,generally ,,known10 of which the present volume of 8,,curiosities ,,of ,,science0 is an instalment4 ,i need scarcely add1 that in its progressive preparation ,i have endeavoured to compare1 weigh1 and consider1 the contents1 so as to combine the experience of the ,past with the advantages of the ,present4 ,in these days of universal attainments1 when ,science becomes not merely a luxury to the rich1 but bread to the poor1 and when the very amusements as well as the conveniences of life have taken a scientific colour1 it is reasonable to hope that the present volume may be acceptable to a large class of seekers after 8things not generally known40 ,for this purpose1 ,i have aimed at soundness as well as popularity2 although1 for myself1 ,i can claim little beyond being one of those industrious 8ants of science0 who garner facts1 and by selection and comparison adapt them for a wider circle of readers than they were originally expected to reach4 ,in each case1 as far as possible1 these 8,,curiosities0 bear the mint-mark of authority2 and in the living list are prominent the names of ,humboldt and ,herschel1 ,airy and ,whewell1 ,faraday1 ,brewster1 ,owen1 and ,agassiz1 ,maury1 ,wheatstone1 and ,hunt1 from whose writings and researches the following pages are frequently enriched4 ,the sciences here illustrated are1 in the main1 ,astronomy and ,meteorology2 ,geology and ,paleontology2 ,physical ,geography2 ,sound1 ,light1 and ,heat2 ,magnetism and ,electricity1--the latter with special attention to the great marvel of our times1 the ,electro-magnetic ,telegraph4 ,i hope1 at no very distant period1 to extend the 8,,curiosities0 to another volume1 to include branches of ,natural and ,experimental ,science which are not here presented4 ,i4 ,t4 ,november #aheh4 ,,contents4 ,,page ,,introductory #a-aj ,,physical ,,phenomena #aa-bf ,,sound ,,and ,,light #bg-ec ,,astronomy #ed-ajc ,,geology ,,and ,,paleontology #ajd-ade ,,meteorological ,,phenomena #adf-afi ,,physical ,,geography ,,of ,,the ,,sea #agj-aib ,,magnetism ,,and ,,electricity #aic-bai ,,the ,,electric ,,telegraph #bbj-bbh ,,miscellanea #bbi-bda ,the ,frontispiece4 ,,the ,,great ,,rosse ,,telescope4 ,the originator and architect of this magnificent instrument had long been distinguished in scientific research as ,lord ,oxmantown2 and may be considered to have gracefully commemorated his succession to the ,earldom of ,rosse1 and his ,presidency of the ,royal ,society1 by the completion of this marvellous work1 with which his name will be hereafter indissolubly associated4 ,the ,great ,reflecting ,telescope at ,birr ,castle 7of which the ,frontispiece represents a portion#a7 will be found fully described at pp4 #if-ii of the present volume of ,curiosities of ,science4 ,this matchless instrument has already disclosed 8forms of stellar arrangement indicating modes of dynamic action never before contemplated in celestial mechanics40 8,in these departments of research1--the examination of the configurations of nebul1 and the resolution of nebul into stars 7says the ,rev4 ,dr4 ,scoresby71--the six-feet speculum has had its grandest triumphs1 and the noble artificer and observer the highest rewards of his talents and enterprise4 ,altogether1 the quantity of work done during a period of about seven years--including a winter when a noble philanthropy for a starving population absorbed the keenest interests of science--has been decidedly great2 and the new knowledge acquired concerning the handiwork of the great ,creator amply satisfying of even sanguine expectation40 ,the ,vignette4 ,,sir ,,humphry ,,davy',s ,,own ,,model ,,of ,,his ,,safety-,,lamp4 ,of the several contrivances which have been proposed for safely lighting coal-mines subject to the visitation of fire-damp1 or carburetted hydrogen1 the ,safety-,lamp of ,sir ,humphry ,davy is the only one which has ever been judged safe1 and been extensively employed4 ,the inventor first turned his attention to the subject in #ahae1 when ,davy began a minute chemical examination of fire-damp1 and found that it required an admixture of a large quantity of atmospheric air to render it explosive4 ,he then ascertained that explosions of inflammable gases were incapable of being passed through long narrow metallic tubes1 and that this principle of security was still obtained by diminishing their length and increasing their number4 ,this fact led to trials upon sieves made of wire-gauze2 when ,davy found that if a piece of wire-gauze was held over the flame of a lamp1 or of coal-gas1 it prevented the flame from passing2 and he ascertained that a flame confined in a cylinder of very fine wire-gauze did not explode even in a mixture of oxygen and hydrogen1 but that the gases burnt in it with great vivacity4 ,these experiments served as the basis of the ,safety-,lamp4 ,the apertures in the gauze1 ,davy tells us in his work on the subject1 should not be more than #a_/bb;d of an inch square4 ,the lamp is screwed on to the bottom of the wire-gauze cylinder4 ,when it is lighted1 and gradually introduced into an atmosphere mixed with fire-damp1 the size and length of the flame are first increased4 ,when the inflammable gas forms as much as #a_/abth of the volume of air1 the cylinder becomes filled with a feeble blue flame1 within which the flame of the wick burns brightly1 and the light of the wick continues till the fire-damp increases to #a_/fth or #a_/eth2 it is then lost in the flame of the fire-damp1 which now fills the cylinder with a pretty strong light2 and when the foul air constitutes one-third of the atmosphere it is no longer fit for respiration1--and this ought to be a signal to the miner to leave that part of the workings4 ,sir ,humphry ,davy presented his first communication respecting his discovery of the ,safety-,lamp to the ,royal ,society in #ahae4 ,this was followed by a series of papers remarkable for their simplicity and clearness1 crowned by that read on the #aath of ,january #ahaf1 when the principle of the ,safety-,lamp was announced1 and ,sir ,humphry presented to the ,society a model made by his own hands1 which is to this day preserved in the collection of the ,royal ,society at ,burlington ,house4 ,from this interesting memorial the ,vignette has been sketched4 ,there have been several modifications of the ,safety-,lamp1 and the merit of the discovery has been claimed by others1 among whom was ,mr4 ,george ,stephenson2 but the question was set at rest forty-one years since by an examination1--attested by ,sir ,joseph ,banks1 ,p4,r4,s41 ,mr4 ,brande1 ,mr4 ,hatchett1 and ,dr4 ,wollaston1--and awarding the independent merit to ,davy4 ,a more substantial1 though not a more honourable1 testimony of approval was given by the coal-owners1 who subscribed #bejjl4 to purchase a superb service of plate1 which was suitably inscribed and presented to ,davy4#b ,meanwhile the ,report by the ,parliamentary ,committee 8cannot admit that the experiments 7made with the ,lamp7 have any tendency to detract from the character of ,sir ,humphry ,davy1 or to disparage the fair value placed by himself upon his invention4 ,the improvements are probably those which longer life and additional facts would have induced him to contemplate as desirable1 and of which1 had he not been the inventor1 he might have become the patron40 ,the principle of the invention may be thus summed up4 ,in the ,safety-,lamp1 the mixture of the fire-damp and atmospheric air within the cage of wire-gauze explodes upon coming in contact with the flame2 but the combustion cannot pass through the wire-gauze1 and being there imprisoned1 cannot impart to the explosive atmosphere of the mine any of its force4 ,this effect has been erroneously attributed to a cooling influence of the metal4 ,professor ,playfair has eloquently described the ,safety-,lamp of ,davy as a present from philosophy to the arts2 a discovery in no degree the effect of accident or chance1 but the result of patient and enlightened research1 and strongly exemplifying the great use of an immediate and constant appeal to experiment4 ,after characterising the invention as the shutting-up in a net of the most slender texture a most violent and irresistible force1 and a power that in its tremendous effects seems to emulate the lightning and the earthquake1 ,professor ,playfair thus concludes3 8,when to this we add the beneficial consequences1 and the saving of the lives of men1 and consider that the effects are to remain as long as coal continues to be dug from the bowels of the earth1 it may be fairly said that there is hardly in the whole compass of art or science a single invention of which one would rather wish to be the author4444 ,this10 says ,professor ,playfair1 8is exactly such a case as we should choose to place before ,bacon1 were he to revisit the earth2 in order to give him1 in a small compass1 an idea of the advancement which philosophy has made since the time when he had pointed out to her the route which she ought to pursue40 ,,curiosities ,,of ,,science4 ,introductory4 ,,science ,,of ,,the ,,ancient ,,world4 ,in every province of human knowledge where we now possess a careful and coherent interpretation of nature1 men began by attempting in bold flights to leap from obvious facts to the highest point of generality--to some wide and simple principle which after-ages had to reject4 ,thus1 from the facts that all bodies are hot or cold1 moist or dry1 they leapt at once to the doctrine that the world is constituted of four elements--earth1 air1 fire1 water2 from the fact that the heavenly bodies circle the sky in courses which occur again and again1 they at once asserted that they move in exact circles1 with an exactly uniform motion2 from the fact that heavy bodies fall through the air somewhat faster than light ones1 it was assumed that all bodies fall quickly or slowly exactly in proportion to their weight2 from the fact that the magnet attracts iron1 and that this force of attraction is capable of increase1 it was inferred that a perfect magnet would have an irresistible force of attraction1 and that the magnetic pole of the earth would draw the nails out of a ship's bottom which came near it2 from the fact that some of the finest quartz crystals are found among the snows of the ,alps1 it was inferred that the crystallisation of gems is the result of intense and long-continued cold3 and so on in innumerable instances4 ,such anticipations as these constituted the basis of almost all the science of the ancient world2 for such principles being so assumed1 consequences were drawn from them with great ingenuity1 and systems of such deductions stood in the place of science4--,edinburgh ,review1 ,no4 #baf4 ,,science ,,at ,,oxford ,,and ,,cambridge4 ,the earliest science of a decidedly ,english school is due1 for the most part1 to the ,university of ,oxford1 and specially to ,merton ,college1--a foundation of which ,wood remarks1 that there was no other for two centuries1 either in ,oxford or ,paris1 which could at all come near it in the cultivation of the sciences4 ,but he goes on to say that large chests full of the writers of this college were allowed to remain untouched by their successors for fear of the magic which was supposed to be contained in them4 ,nevertheless1 it is not difficult to trace the liberalising effect of scientific study upon the ,university in general1 and ,merton ,college in particular2 and it must be remembered that to the cultivation of the mind at ,oxford we owe almost all the literary celebrity of the middle ages4 ,in this period the ,university of ,cambridge appears to have acquired no scientific distinction4 ,taking as a test the acquisition of celebrity on the continent1 we find that ,bacon1 ,sacrobosco1 ,greathead1 ,estwood1 c4 were all of ,oxford4 ,the latter ,university had its morning of splendour while ,cambridge was comparatively unknown2 it had also its noonday1 illustrated by such men as ,briggs1 ,wren1 ,wallis1 ,halley1 and ,bradley4 ,the age of science at ,cambridge may be said to have begun with ,francis ,bacon2 and but that we think much of the difference between him and his celebrated namesake lies more in time and circumstances than in talents or feelings1 we would rather date from #afjj with the former than from #abej with the latter4 ,praise or blame on either side is out of the question1 seeing that the earlier foundation of ,oxford1 and its superiority in pecuniary means1 rendered all that took place highly probable2 and we are in a great measure indebted for the liberty of writing our thoughts1 to the cultivation of the liberalising sciences at ,oxford in the dark ages4 ,with regard to the ,university of ,cambridge1 for a long time there hardly existed the materials of any proper instruction1 even to the extent of pointing out what books should be read by a student desirous of cultivating astronomy4 ,,plato',s ,,survey ,,of ,,the ,,sciences4 ,plato1 like ,francis ,bacon1 took a review of the sciences of his time3 he enumerates arithmetic and plane geometry1 treated as collections of abstract and permanent truths2 solid geometry1 which he 8notes as deficient0 in his time1 although in fact he and his school were in possession of the doctrine of the 8five regular solids20 astronomy1 in which he demands a science which should be elevated above the mere knowledge of phenomena4 ,the visible appearances of the heavens only suggest the problems with which true astronomy deals2 as beautiful geometrical diagrams do not prove1 but only suggest geometrical propositions4 ,finally1 ,plato notices the subject of harmonics1 in which he requires a science which shall deal with truths more exact than the ear can establish1 as in astronomy he requires truths more exact than the eye can assure us of4 ,in a subsequent paper ,plato speaks of ,dialectic as a still higher element of a philosophical education1 fitted to lead men to the knowledge of real existences and of the supreme good4 ,here he describes dialectic by its objects and purpose4 ,in other places dialectic is spoken of as a method or process of analysis2 as in the ,phdrus1 where ,socrates describes a good dialectician as one who can divide a subject according to its natural members1 and not miss the joint1 like a bad carver4 ,xenophon says that ,socrates derived dialectic from a term implying to divide a subject into parts1 which ,mr4 ,grote thinks unsatisfactory as an etymology1 but which has indicated a practical connection in the ,socratic school4 ,the result seems to be that ,plato did not establish any method of analysis of a subject as his dialectic2 but he conceived that the analytical habits formed by the comprehensive study of the exact sciences1 and sharpened by the practice of dialogue1 would lead his students to the knowledge of first principles4--,dr4 ,whewell4 ,,folly ,,of ,,atheism4 ,morphology1 in natural science1 teaches us that the whole animal and vegetable creation is formed upon certain fundamental types and patterns1 which can be traced under various modifications and transformations through all the rich variety of things apparently of most dissimilar build4 ,but here and there a scientific person takes it into his foolish head that there may be a set of moulds without a moulder1 a calculated gradation of forms without a calculator1 an ordered world without an ordering ,god4 ,now1 this atheistical science conveys about as much meaning as suicidal life3 for science is possible only where there are ideas1 and ideas are only possible where there is mind1 and minds are the offspring of ,god2 and atheism itself is not merely ignorance and stupidity1--it is the purely nonsensical and the unintelligible4--,professor ,blackie2 ,edinburgh ,essays1 #ahef4 ,,the ,,art ,,of ,,observation4 ,to observe properly in the very simplest of the physical sciences requires a long and severe training4 ,no one knows this so feelingly as the great discoverer4 ,faraday once said1 that he always doubts his own observations4 ,mitscherlich on one occasion remarked to a man of science that it takes fourteen years to discover and establish a single new fact in chemistry4 ,an enthusiastic student one day betook himself to ,baron ,cuvier with the exhibition of a new organ--a muscle which he supposed himself to have discovered in the body of some living creature or other2 but the experienced and sagacious naturalist kindly bade the young man return to him with the same discovery in six months4 ,the ,baron would not even listen to the student's demonstration1 nor examine his dissection1 till the eager and youthful discoverer had hung over the object of inquiry for half a year2 and yet that object was a mere thing of the senses4--,north-,british ,review1 ,no4 #ah4 ,,mutual ,,relations ,,of ,,phenomena4 ,in the observation of a phenomenon which at first sight appears to be wholly isolated1 how often may be concealed the germ of a great discovery6 ,thus1 when ,galvani first stimulated the nervous fibre of the frog by the accidental contact of two heterogeneous metals1 his contemporaries could never have anticipated that the action of the voltaic pile would discover to us in the alkalies metals of a silver lustre1 so light as to swim on water1 and eminently inflammable2 or that it would become a powerful instrument of chemical analysis1 and at the same time a thermoscope and a magnet4 ,when ,huyghens first observed1 in #afgh1 the phenomenon of the polarisation of light1 exhibited in the difference between two rays into which a pencil of light divides itself in passing through a doubly refracting crystal1 it could not have been foreseen that a century and a half later the great philosopher ,arago would1 by his discovery of chromatic polarisation1 be led to discern1 by means of a small fragment of ,iceland spar1 whether solar light emanates from a solid body or a gaseous covering2 or whether comets transmit light directly1 or merely by reflection4--,humboldt's ,cosmos1 vol4 i4 ,,practical ,,results ,,of ,,theoretical ,,science4 ,what are the great wonders1 the great sources of man's material strength1 wealth1 and comfort in modern times8 ,the ,railway1 with its mile-long trains of men and merchandise1 moving with the velocity of the wind1 and darting over chasms a thousand feet wide2 the ,electric ,telegraph1 along which man's thoughts travel with the velocity of light1 and girdle the earth more quickly than ,puck's promise to his master2 the contrivance by which the ,magnet1 in the very middle of a strip of iron1 is still true to the distant pole1 and remains a faithful guide to the mariner2 the ,electrotype process1 by which a metallic model of any given object1 unerringly exact1 grows into being like a flower4 ,now1 all these wonders are the result of recent and profound discoveries in theoretical science4 ,the ,locomotive ,steam-engine1 and the ,steam-engine in all its other wonderful and invaluable applications1 derives its efficacy from the discoveries1 by ,watt and others1 of the laws of steam4 ,the ,railway ,bridge is not made strong by mere accumulation of materials1 but by the most exact and careful scientific examination of the means of giving the requisite strength to every part1 as in the great example of ,mr4 ,stephenson's ,britannia ,bridge over the ,menai ,strait4 ,the ,correction of the ,magnetic ,needle in iron ships it would have been impossible for ,mr4 ,airy to secure without a complete theoretical knowledge of the laws of ,magnetism4 ,the ,electric ,telegraph and the ,electrotype process include in their principles and mechanism the most complete and subtle results of electrical and magnetical theory4--,edinburgh ,review1 ,no4 #baf4 ,,perpetuity ,,of ,,improvement4 ,in the progress of society all great and real improvements are perpetuated3 the same corn which1 four thousand years ago1 was raised from an improved grass by an inventor worshiped for two thousand years in the ancient world under the name of ,ceres1 still forms the principal food of mankind2 and the potato1 perhaps the greatest benefit that the old has derived from the new world1 is spreading over ,europe1 and will continue to nourish an extensive population when the name of the race by whom it was first cultivated in ,south ,america is forgotten4--,sir ,h4 ,davy4 ,,the ,,earliest ,,english ,,scientific ,,treatise4 ,geoffrey ,chaucer1 the poet1 wrote a treatise on the ,astrolabe for his son1 which is the earliest ,english treatise we have met with on any scientific subject4 ,it was not completed2 and the apologies which ,chaucer makes to his own child for writing in ,english are curious2 while his inference that his son should therefore 8pray ,god save the king that is lord of this language10 is at least as loyal as logical4 ,,philosophers' ,,false ,,estimates ,,of ,,their ,,own ,,labours4 ,galileo was confident that the most important part of his contributions to the knowledge of the solar system was his ,theory of the ,tides--a theory which all succeeding astronomers have rejected as utterly baseless and untenable4 ,descartes probably placed far above his beautiful explanation of the rainbow1 his priori theory of the existence of the vortices which caused the motion of the planets and satellites4 ,newton perhaps considered as one of the best parts of his optical researches his explanation of the natural colour of bodies1 which succeeding optical philosophers have had to reject2 and he certainly held very strongly the necessity of a material cause for gravity1 which his disciples have disregarded4 ,davy looked for his greatest triumph in the application of his discoveries to prevent the copper bottoms of ships from being corroded4 ,and so in other matters4--,edinburgh ,review1 ,no4 #baf4 ,,relics ,,of ,,genius4 ,professor ,george ,wilson1 in a lecture to the ,scottish ,society of ,arts1 says3 8,the spectacle of these things ministers only to the good impulses of humanity4 ,isaac ,newton's telescope at the ,royal ,society of ,london2 ,otto ,guericke's air-pump in the ,library at ,berlin2 ,james ,watt's repaired ,newcomen steam-engine in the ,natural-,philosophy class-room of the ,college at ,glasgow2 ,fahrenheit's thermometer in the corresponding class-room of the ,university of ,edinburgh2 ,sir ,h4 ,davy's great voltaic battery at the ,royal ,institution1 ,london1 and his safety-lamp at the ,royal ,society2 ,joseph ,black's pneumatic trough in ,dr4 ,gregory's possession2 the first wire which ,faraday made rotate electro-magnetically1 at ,st4 ,bartholomew's ,hospital2 ,dalton's atomic models at ,manchester2 and ,kemp's liquefied gases in the ,industrial ,museum of ,scotland1--are alike personal relics1 historical monuments1 and objects of instruction1 which grow more and more precious every year1 and of which we never can have too many40 ,,the ,,royal ,,society3 ,,the ,,natural ,,and ,,supernatural4 ,the ,royal ,society was formed with the avowed object of increasing knowledge by direct experiment2 and it is worthy of remark1 that the charter granted by ,charles ,,ii4 to this celebrated institution declares that its object is the extension of natural knowledge1 as opposed to that which is supernatural4 ,dr4 ,paris 7,life of ,sir ,h4 ,davy1 vol4 ii4 p4 #agh7 says3 8,the charter of the ,royal ,society states that it was established for the improvement of natural science4 ,this epithet natural was originally intended to imply a meaning1 of which very few persons1 ,i believe1 are aware4 ,at the period of the establishment of the society1 the arts of witchcraft and divination were very extensively encouraged2 and the word natural was therefore introduced in contradistinction to supernatural40 ,,the ,,philosopher ,,boyle4 ,after the death of ,bacon1 one of the most distinguished ,englishmen was certainly ,robert ,boyle1 who1 if compared with his contemporaries1 may be said to rank immediately below ,newton1 though of course very inferior to him as an original thinker4 ,boyle was the first who instituted exact experiments into the relation between colour and heat2 and by this means not only ascertained some very important facts1 but laid a foundation for that union between optics and thermotics1 which1 though not yet completed1 now merely waits for some great philosopher to strike out a generalisation large enough to cover both1 and thus fuse the two sciences into a single study4 ,it is also to ,boyle1 more than to any other ,englishman1 that we owe the science of hydrostatics in the state in which we now possess it4#c ,he is also the original discoverer of that beautiful law1 so fertile in valuable results1 according to which the elasticity of air varies as its density4 ,and1 in the opinion of one of the most eminent modern naturalists1 it was ,boyle who opened up those chemical inquiries which went on accumulating until1 a century later1 they supplied the means by which ,lavoisier and his contemporaries fixed the real basis of chemistry1 and enabled it for the first time to take its proper stand among those sciences that deal with the external world4--,buckle's ,history of ,civilization1 vol4 i4 ,,sir ,,isaac ,,newton',s ,,rooms ,,and ,,laboratory ,,in ,,trinity ,,college1 ,,cambridge4 ,of the rooms occupied by ,newton during his early residence at ,cambridge1 it is now difficult to settle the locality4 ,the chamber allotted to him as ,fellow1 in #affg1 was 8the ,spiritual ,chamber10 conjectured to have been the ground-room1 next the chapel1 but it is not certain that he resided there4 ,the rooms in which he lived from #afhb till he left ,cambridge1 are in the north-east corner of the great court1 on the first floor1 on the right or north of the gateway or principal entrance to the college4 ,his laboratory1 as ,dr4 ,humphrey ,newton tell us1 was 8on the left end of the garden1 near the east end of the chapel2 and his telescope 7refracting7 was five feet long1 and placed at the head of the stairs1 going down into the garden40#d ,the east side of ,newton's rooms has been altered within the last fifty years3 ,professor ,sedgwick1 who came up to college in #ahjd1 recollects a wooden room1 supported on an arcade1 shown in ,loggan's view1 in place of which arcade is now a wooden wall and brick chimney4 ,dr4 ,humphrey ,newton relates that in college ,sir ,isaac very rarely went to bed till two or three o'clock in the morning1 sometimes not till five or six1 especially at spring and fall of the leaf1 when he used to employ about six weeks in his laboratory1 the fire scarcely going out either night or day2 he sitting up one night1 and ,humphrey another1 till he had finished his chemical experiments4 ,dr4 ,newton describes the laboratory as 8well furnished with chymical materials1 as bodyes1 receivers1 heads1 crucibles1 c41 which was made very little use of1 ye crucibles excepted1 in which he fused his metals3 he would sometimes1 though very seldom1 look into an old mouldy book1 which lay in his laboratory2 ,i think it was titled ,agricola de ,metallis1 the transmuting of metals being his chief design1 for which purpose antimony was a great ingredient40 8,his brick furnaces1 pro re nata1 he made and altered himself without troubling a bricklayer40 8,what observations he might make with his telescope1 ,i know not1 but several of his observations about comets and the planets may be found scattered here and there in a book intitled ,the ,elements of ,astronomy1 by ,dr4 ,david ,gregory40#e ,,newton',s 8,,apple-,,tree40 ,curious and manifold as are the trees associated with the great names of their planters1 or those who have sojourned in their shade1 the ,tree which1 by the falling of its fruit1 suggested to ,newton the idea of ,gravity1 is of paramount interest4 ,it appears that1 in the autumn of #affe1 ,newton left his college at ,cambridge for his paternal home at ,woolsthorpe4 8,when sitting alone in the garden10 says ,sir ,david ,brewster1 8and speculating on the power of gravity1 it occurred to him1 that as the same power by which the apple fell to the ground was not sensibly diminished at the greatest distance from the centre of the earth to which we can reach1 neither at the summits of the loftiest spires1 nor on the tops of the highest mountains1 it might extend to the moon and retain her in her orbit1 in the same manner as it bends into a curve a stone or a cannon-ball when projected in a straight line from the surface of the earth40--,life of ,newton1 vol4 i4 p4 #bf4 ,sir ,david ,brewster notes1 that neither ,pemberton nor ,whiston1 who received from ,newton himself his first ideas of gravity1 records this story of the falling apple4 ,it was mentioned1 however1 to ,voltaire by ,catherine ,barton1 ,newton's niece2 and to ,mr4 ,green by ,martin ,folkes1 ,president of the ,royal ,society4 ,sir ,david ,brewster saw the reputed apple-tree in #ahad1 and brought away a portion of one of its roots4 ,the tree was so much decayed that it was cut down in #ahbj1 and the wood of it carefully preserved by ,mr4 ,turnor1 of ,stoke ,rocheford4 ,de ,morgan 7in ,notes and ,queries1 #b;d series1 ,no4 #aci1 p4 #afi7 questions whether the fruit was an apple1 and maintains that the anecdote rests upon very slight authority2 more especially as the idea had for many years been floating before the minds of physical inquirers2 although ,newton cleared away the confusions and difficulties which prevented very able men from proceeding beyond conjecture1 and by this means established universal gravitation4 ,,newton',s 8,,principia40 8,it may be justly said10 observes ,halley1 8that so many and so valuable philosophical truths as are herein discovered and put past dispute were never yet owing to the capacity and industry of any one man40 8,the importance and generality of the discoveries10 says ,laplace1 8and the immense number of original and profound views1 which have been the germ of the most brilliant theories of the philosophers of this 7#ahth7 century1 and all presented with much elegance1 will ensure to the work on the ,mathematical ,principles of ,natural ,philosophy a preminence above all the other productions of human genius40 ,,descartes' ,,labours ,,in ,,physics4 ,the most profound among the many eminent thinkers ,france has produced1 is ,rn ,descartes1 of whom the least that can be said is1 that he effected a revolution more decisive than has ever been brought about by any other single mind2 that he was the first who successfully applied algebra to geometry2 that he pointed out the important law of the sines2 that in an age in which optical instruments were extremely imperfect1 he discovered the changes to which light is subjected in the eye by the crystalline lens2 that he directed attention to the consequences resulting from the weight of the atmosphere2 and that he moreover detected the causes of the rainbow4 ,at the same time1 and as if to combine the most varied forms of excellence1 he is not only allowed to be the first geometrician of the age1 but by the clearness and admirable precision of his style1 he became one of the founders of ,french prose4 ,and1 although he was constantly engaged in those lofty inquiries into the nature of the human mind1 which can never be studied without wonder1 he combined with them a long course of laborious experiment upon the animal frame1 which raised him to the highest rank among the anatomists of his time4 ,the great discovery made by ,harvey of the ,circulation of the ,blood was neglected by most of his contemporaries2 but it was at once recognised by ,descartes1 who made it the basis of the physiological part of his work on man4 ,he was likewise the discoverer of the lacteals by ,aselli1 which1 like every great truth yet laid before the world1 was at its first appearance1 not only disbelieved1 but covered with ridicule4--,buckle's ,history of ,civilization1 vol4 i4 ,,conic ,,sections4 ,if a cone or sugar-loaf be cut through in certain directions1 we shall obtain figures which are termed conic sections3 thus1 if we cut through a sugar-loaf parallel to its base or bottom1 the outline or edge of the loaf where it is cut will be a circle4 ,if the cut is made so as to slant1 and not be parallel to the base of the loaf1 the outline is an ellipse1 provided the cut goes quite through the sides of the loaf all round2 but if it goes slanting1 and parallel to the line of the loaf's side1 the outline is a parabola1 a conic section or curve1 which is distinguished by characteristic properties1 every point of it bearing a certain fixed relation to a certain point within it1 as the circle does to its centre4--,dr4 ,paris's ,notes to ,philosophy in ,sport1 c4 ,,power ,,of ,,computation4 ,the higher class of mathematicians1 at the end of the seventeenth century1 had become excellent computers1 particularly in ,england1 of which ,wallis1 ,newton1 ,halley1 the ,gregorys1 and ,de ,moivre1 are splendid examples4 ,before results of extreme exactness had become quite familiar1 there was a gratifying sense of power in bringing out the new methods4 ,newton1 in one of his letters to ,oldenburg1 says that he was at one time too much attached to such things1 and that he should be ashamed to say to what number of figures he was in the habit of carrying his results4 ,the growth of power of computation on the ,continent did not1 however1 keep pace with that of the same in ,england4 ,in #afif1 ,de ,laguy1 a well-known writer on algebra1 and a member of the ,academy of ,sciences1 said that the most skilful computer could not1 in less than a month1 find within a unit the cube root of #fifecfdhccahfdjjcejgcfdajcg4--;,de ,morgan4 8,,the ,,science ,,of ,,the ,,cosmos40 ,humboldt1 characterises this 8uncommon but definite expression0 as the treating of 8the assemblage of all things with which space is filled1 from the remotest nebul to the climatic distribution of those delicate tissues of vegetable matter which spread a variegated covering over the surface of our rocks40 ,the word cosmos1 which primitively1 in the ,homeric ages1 indicated an idea of order and harmony1 was subsequently adopted in scientific language1 where it was gradually applied to the order observed in the movements of the heavenly bodies2 to the whole universe2 and then finally to the world in which this harmony was reflected to us4 ,physical ,phenomena4 ,,all ,,the ,,world ,,in ,,motion4 ,humboldt1 in his ,cosmos1#f gives the following beautiful illustrative proofs of this phenomenon3 ,if1 for a moment1 we imagine the acuteness of our senses preternaturally heightened to the extreme limits of telescopic vision1 and bring together events separated by wide intervals of time1 the apparent repose which reigns in space will suddenly vanish2 countless stars will be seen moving in groups in various directions2 nebul wandering1 condensing1 and dissolving like cosmical clouds2 the milky way breaking up in parts1 and its veil rent asunder4 ,in every point of the celestial vault we shall recognise the dominion of progressive movement1 as on the surface of the earth where vegetation is constantly putting forth its leaves and buds1 and unfolding its blossoms4 ,the celebrated ,spanish botanist1 ,cavanilles1 first conceived the possibility of 8seeing grass grow10 by placing the horizontal micrometer wire of a telescope1 with a high magnifying power1 at one time on the point of a bamboo shoot1 and at another on the rapidly unfolding flowering stem of an ,american aloe2 precisely as the astronomer places the cross of wires on a culminating star4 ,throughout the whole life of physical nature--in the organic as in the sidereal world--existence1 preservation1 production1 and development1 are alike associated with motion as their essential condition4 ,,the ,,axis ,,of ,,rotation4 ,it is remarkable as a mechanical fact1 that nothing is so permanent in nature as the ,axis of ,rotation of any thing which is rapidly whirled4 ,we have examples of this in every-day practice4 ,the first is the motion of a boy's hoop4 ,what keeps the hoop from falling8--,it is its rotation1 which is one of the most complicated subjects in mechanics4 ,another thing pertinent to this question is1 the motion of a quoit4 ,every body who ever threw a quoit knows that to make it preserve its position as it goes through the air1 it is necessary to give it a whirling motion4 ,it will be seen that while whirling1 it preserves its plane1 whatever the position of the plane may be1 and however it may be inclined to the direction in which the quoit travels4 ,now1 this has greater analogy with the motion of the earth than any thing else4 ,another illustration is the motion of a spinning top4 ,the greatest mathematician of the last century1 the celebrated ,euler1 has written a whole book on the motion of a top1 and his ,latin treatise ,de motu ,turbinis is one of the most remarkable books on mechanics4 ,the motion of a top is a matter of the greatest importance2 it is applicable to the elucidation of some of the greatest phenomena of nature4 ,in all these instances there is this wonderful tendency in rotation to preserve the axis of rotation unaltered4--,prof4 ,airy's ,lect4 on ,astronomy4 ,,the ,,earth',s ,,annual ,,motion4 ,in conformity with the ,copernican view of our system1 we must learn to look upon the sun as the comparatively motionless centre about which the earth performs an annual elliptic orbit of the dimensions and excentricity1 and with a velocity1 regulated according to a certain assigned law2 the sun occupying one of the foci of the ellipse1 and from that station quietly disseminating on all sides its light and heat2 while the earth travelling round it1 and presenting itself differently to it at different times of the year and day1 passes through the varieties of day and night1 summer and winter1 which we enjoy4--,sir ,john ,herschel's ,outlines of ,astronomy4 ,laplace has shown that the length of the day has not varied the hundredth part of a second since the observations of ,hipparchus1 #bjjj years ago4 ,,stability ,,of ,,the ,,ocean4 ,in submitting this question to analysis1 ,laplace found that the equilibrium of the ocean is stable if its density is less than the mean density of the earth1 and that its equilibrium cannot be subverted unless these two densities are equal1 or that of the earth less than that of its waters4 ,the experiments on the attraction of ,schehallien and ,mont ,cenis1 and those made by ,cavendish1 ,reich1 and ,baily1 with balls of lead1 demonstrate that the mean density of the earth is at least five times that of water1 and hence the stability of the ocean is placed beyond a doubt4 ,as the seas1 therefore1 have at one time covered continents which are now raised above their level1 we must seek for some other cause of it than any want of stability in the equilibrium of the ocean4 ,how beautifully does this conclusion illustrate the language of ,scripture1 8,hitherto shalt thou come1 but no further06 7,job xxxviii4 #aa47 ,,compression ,,of ,,bodies4 ,sir ,john ,leslie observes1 that air compressed into the fiftieth part of its volume has its elasticity fifty times augmented3 if it continued to contract at that rate1 it would1 from its own incumbent weight1 acquire the density of water at the depth of thirty-four miles4 ,but water itself would have its density doubled at the depth of ninety-three miles1 and would attain the density of quicksilver at the depth of #cfb miles4 ,in descending1 therefore1 towards the centre1 through nearly #djjj miles1 the condensation of ordinary substances would surpass the utmost powers of conception4 ,dr4 ,young says1 that steel would be compressed into one-fourth1 and stone into one-eighth1 of its bulk at the earth's centre4--,mrs4 ,somerville4 ,,the ,,world ,,in ,a ,,nutshell4 ,from the many proofs of the non-contact of the atoms1 even in the most solid parts of bodies2 from the very great space obviously occupied by pores--the mass having often no more solidity than a heap of empty boxes1 of which the apparently solid parts may still be as porous in a second degree and so on2 and from the great readiness with which light passes in all directions through dense bodies1 like glass1 rock-crystal1 diamond1 c41 it has been argued that there is so exceedingly little of really solid matter even in the densest mass1 that the whole world1 if the atoms could be brought into absolute contact1 might be compressed into a nutshell4 ,we have as yet no means of determining exactly what relation this idea has to truth4--,arnott4 ,,the ,,world ,,of ,,atoms4 ,the infinite groups of atoms flying through all time and space1 in different directions and under different laws1 have interchangeably tried and exhibited every possible mode of rencounter3 sometimes repelled from each other by concussion2 and sometimes adhering to each other from their own jagged or pointed construction1 or from the casual interstices which two or more connected atoms must produce1 and which may be just adapted to those of other figures1--as globular1 oval1 or square4 ,hence the origin of compound and visible bodies2 hence the origin of large masses of matter2 hence1 eventually1 the origin of the world4--,dr4 ,good's ,book of ,nature4 ,the great ,epicurus speculated on 8the plastic nature0 of atoms1 and attributed to this nature the power they possess of arranging themselves into symmetric forms4 ,modern philosophers satisfy themselves with attraction2 and reasoning from analogy1 imagine that each atom has a polar system4--,hunt's ,poetry of ,science4 ,,minute ,,atoms ,,of ,,the ,,elements3 ,,divisibility ,,of ,,matter4 ,so minute are the parts of the elementary bodies in their ultimate state of division1 in which condition they are usually termed atoms1 as to elude all our powers of inspection1 even when aided by the most powerful microscopes4 ,who can see the particles of gold in a solution of that metal in aqua regia1 or those of common salt when dissolved in water8 ,dr4 ,thomas ,thomson has estimated the bulk of an ultimate particle or atom of lead as less than #a_/hhhdibjjjjjjjjjth of a cubic inch1 and concludes that its weight cannot exceed the #a_/cajjjjjjjjjjth of a grain4 ,this curious calculation was made by ,dr4 ,thomson1 in order to show to what degree ,matter could be divided1 and still be sensible to the eye4 ,he dissolved a grain of nitrate of lead in #ejj1jjj grains of water1 and passed through the solution a current of sulphuretted hydrogen2 when the whole liquid became sensibly discoloured4 ,now1 a grain of water may be regarded as being almost equal to a drop of that liquid1 and a drop may be easily spread out so as to cover a square inch of surface4 ,but under an ordinary microscope the millionth of a square inch may be distinguished by the eye4 ,the water1 therefore1 could be divided into #ejj1jjj1jjj1jjj parts4 ,but the lead in a grain of nitrate of lead weighs #jfb of a grain2 an atom of lead1 accordingly1 cannot weigh more than #a_/hajjjjjjjjjjth of a grain2 while the atom of sulphur1 which in combination with the lead rendered it visible1 could not weigh more than #a_/bjaejjjjjjjjj1 that is1 the two-billionth part of a grain4--,professor ,low2 ,jameson's ,journal1 ,no4 #ajf4 ,,weight ,,of ,,air4 ,air can be so rarefied that the contents of a cubic foot shall not weigh the tenth part of a grain3 if a quantity that would fill a space the hundredth part of an inch in diameter be separated from the rest1 the air will still be found there1 and we may reasonably conceive that there may be several particles present1 though the weight is less than the seventeen-hundred-millionth of a grain4 ,,duration ,,of ,,the ,,pyramid4 ,the great reason of the duration of the pyramid above all other forms is1 that it is most fitted to resist the force of gravitation4 ,thus the ,pyramids of ,egypt are the oldest monuments in the world4 ,,inertia ,,illustrated4 ,many things of common occurrence 7says ,professor ,tyndall7 are to be explained by reference to the quality of inactivity4 ,we will here state a few of them4 ,when a railway train is moving1 if it strike against any obstacle which arrests its motion1 the passengers are thrown forward in the direction in which the train was proceeding4 ,such accidents often occur on a small scale1 in attaching carriages at railway stations4 ,the reason is1 that the passengers share the motion of the train1 and1 as matter1 they tend to persist in motion4 ,when the train is suddenly checked1 this tendency exhibits itself by the falling forward referred to4 ,in like manner1 when a train previously at rest is suddenly set in motion1 the tendency of the passengers to remain at rest evinces itself by their falling in a direction opposed to that in which the train moves4 ,,the ,,leaning ,,tower ,,of ,,pisa4#g ,sir ,john ,leslie used to attribute the stability of this tower to the cohesion of the mortar it is built with being sufficient to maintain it erect1 in spite of its being out of the condition required by physics--to wit1 that 8in order that a column shall stand1 a perpendicular let fall from the centre of gravity must fall within the base40 ,sir ,john describes the ,tower of ,pisa to be in violation of this principle2 but1 according to later authorities1 the perpendicular falls within the base4 ,,early ,,presentiments ,,of ,,centrifugal ,,forces4 ,jacobi1 in his researches on the mathematical knowledge of the ,greeks1 comments on 8the profound consideration of nature evinced by ,anaxagoras1 in whom we read with astonishment a passage asserting that the moon1 if the centrifugal force were intermitted1 would fall to the earth like a stone from a sling40 ,anaxagoras likewise applied the same theory of 8falling where the force of rotation had been intermitted0 to all the material celestial bodies4 ,in ,aristotle and ,simplicius may also be traced the idea of 8the non-falling of heavenly bodies when the rotatory force predominates over the actual falling force1 or downward attraction20 and ,simplicius mentions that 8water in a phial is not spilt when the movement of rotation is more rapid than the downward movement of the water40 ,this is illustrated at the present day by rapidly whirling a pail half-filled with water without spilling a drop4 ,plato had a clearer idea than ,aristotle of the attractive force exercised by the earth's centre on all heavy bodies removed from it2 for he was acquainted with the acceleration of falling bodies1 although he did not correctly understand the cause4 ,john ,philoponus1 the ,alexandrian1 probably in the sixth century1 was the first who ascribed the movement of the heavenly bodies to a primitive impulse1 connecting with this idea that of the fall of bodies1 or the tendency of all substances1 whether heavy or light1 to reach the ground4 ,the idea conceived by ,copernicus1 and more clearly expressed by ,kepler1 who even applied it to the ebb and flow of the ocean1 received in #afff and #afgd a new impulse from ,robert ,hooke2 and next ,newton's theory of gravitation presented the grand means of converting the whole of physical astronomy into a true mechanism of the heavens4 ,the law of gravitation knows no exception2 it accounts accurately for the most complex motions of the members of our own system2 nay more1 the paths of double stars1 far removed from all appreciable effects of our portion of the universe1 are in perfect accordance with its theory4#h ,,height ,,of ,,falls4 ,the fancy of the ,greeks delighted itself in wild visions of the height of falls4 ,in ,hesiod's ,theogony it is said1 speaking of the fall of the ,titans into ,tartarus1 8if a brazen anvil were to fall from heaven nine days and nine nights long1 it would reach the earth on the tenth40 ,this descent of the anvil in #ggg1fjj seconds of time gives an equivalent in distance of #cji1dbd geographical miles 7allowance being made1 according to ,galle's calculation1 for the considerable diminution in force of attraction at planetary distances72 therefore #a times the distance of the moon from the earth4 ,but1 according to the ,iliad1 ,hephstus fell down to ,lemnos in one day2 8when but a little breath was still in him40--,note to ,humboldt's ,cosmos1 vol4 iii4 ,,rate ,,of ,,the ,,fall ,,of ,,bodies4 ,a body falls in gravity precisely #af-a_/af feet in a second1 and the velocity increases according to the squares of the time1 viz43 ,in 7quarter of a second7 a body falls #a foot4 7half a second7 #d feet4 #a second #af 0 #b ditto #fd 0 #c ditto #add 0 ,the power of gravity at two miles distance from the earth is four times less than at one mile2 at three miles nine times less1 and so on4 ,it goes on lessening1 but is never destroyed4--,notes in various ,sciences4 ,,varieties ,,of ,,speed4 ,a ,french scientific work states the ordinary rate to be3 per second4 ,of a man walking #d feet4 ,of a good horse in harness #ab 0 ,of a rein-deer in a sledge on the ice #bf 0 ,of an ,english race-horse #dc 0 ,of a hare #hh 0 ,of a good sailing ship #ai 0 ,of the wind #hb 0 ,of sound #ajch 0 ,of a #bd-pounder cannon-ball #acjj 0 ,,lifting ,,heavy ,,persons4 ,one of the most extraordinary pages in ,sir ,david ,brewster's ,letters on ,natural ,magic is the experiment in which a heavy man is raised with the greatest facility when he is lifted up the instant that his own lungs1 and those of the persons who raise him1 are inflated with air4 ,thus the heaviest person in the party lies down upon two chairs1 his legs being supported by the one and his back by the other4 ,four persons1 one at each leg1 and one at each shoulder1 then try to raise him--the person to be raised giving two signals1 by clapping his hands4 ,at the first signal1 he himself and the four lifters begin to draw a long and full breath2 and when the inhalation is completed1 or the lungs filled1 the second signal is given for raising the person from the chair4 ,to his own surprise1 and that of his bearers1 he rises with the greatest facility1 as if he were no heavier than a feather4 ,sir ,david ,brewster states that he has seen this inexplicable experiment performed more than once2 and he appealed for testimony to ,sir ,walter ,scott1 who had repeatedly seen the experiment1 and performed the part both of the load and of the bearer4 ,it was first shown in ,england by ,major ,h41 who saw it performed in a large party at ,venice1 under the direction of an officer of the ,american navy4#i ,sir ,david ,brewster 7in a letter to ,notes and ,queries1 ,no4 #adc7 further remarks1 that 8the inhalation of the lifters the moment the effort is made is doubtless essential1 and for this reason3 when we make a great effort1 either in pulling or lifting1 we always fill the chest with air previous to the effort2 and when the inhalation is completed1 we close the rima glottidis to keep the air in the lungs4 ,the chest being thus kept expanded1 the pulling or lifting muscles have received as it were a fulcrum round which their power is exerted2 and we can thus lift the greatest weight which the muscles are capable of doing4 ,when the chest collapses by the escape of the air1 the lifters lose their muscular power2 reinhalation of air by the liftee can certainly add nothing to the power of the lifters1 or diminish his own weight1 which is only increased by the weight of the air which he inhales40 8,,force ,,can ,,neither ,,be ,,created ,,nor ,,destroyed40 ,professor ,faraday1 in his able inquiry upon 8the ,conservation of ,force10 maintains that to admit that force may be destructible1 or can altogether disappear1 would be to admit that matter could be uncreated2 for we know matter only by its forces4 ,from his many illustrations we select the following3 ,the indestructibility of individual matter is a most important case of the ,conservation of ,chemical ,force4 ,a molecule has been endowed with powers which give rise in it to various qualities2 and those never change1 either in their nature or amount4 ,a particle of oxygen is ever a particle of oxygen2 nothing can in the least wear it4 ,if it enters into combination1 and disappears as oxygen2 if it pass through a thousand combinations--animal1 vegetable1 mineral2 if it lie hid for a thousand years1 and then be evolved1--it is oxygen with the first qualities1 neither more nor less4 ,it has all its original force1 and only that2 the amount of force which it disengaged when hiding itself1 has again to be employed in a reverse direction when it is set at liberty3 and if1 hereafter1 we should decompose oxygen1 and find it compounded of other particles1 we should only increase the strength of the proof of the conservation of force2 for we should have a right to say of these particles1 long as they have been hidden1 all that we could say of the oxygen itself4 ,in conclusion1 he adds3 ,let us not admit the destruction or creation of force without clear and constant proof4 ,just as the chemist owes all the perfection of his science to his dependence on the certainty of gravitation applied by the balance1 so may the physical philosopher expect to find the greatest security and the utmost aid in the principle of the conservation of force4 ,all that we have that is good and safe--as the steam-engine1 the electric telegraph1 c4--witness to that principle2 it would require a perpetual motion1 a fire without heat1 heat without a source1 action without reaction1 cause without effect1 or effect without cause1 to displace it from its rank as a law of nature4 ,,nothing ,,lost ,,in ,,the ,,material ,,world4 8,it is remarkable10 says ,kobell in his ,mineral ,kingdom1 8how a change of place1 a circulation as it were1 is appointed for the inanimate or naturally immovable things upon the earth2 and how new conditions1 new creations1 are continually developing themselves in this way4 ,i will not enter here into the evaporation of water1 for instance from the widely-spreading ocean2 how the clouds produced by this pass over into foreign lands and then fall again to the earth as rain1 and how this wandering water is1 partly at least1 carried along new journeys1 returning after various voyages to its original home3 the mere mechanical phenomena1 such as the transfer of seeds by the winds or by birds1 or the decomposition of the surface of the earth by the friction of the elements1 suffice to illustrate this40 ,,time ,,an ,,element ,,of ,,force4 ,professor ,faraday observes that ,time is growing up daily into importance as an element in the exercise of ,force1 which he thus strikingly illustrates3 ,the earth moves in its orbit of time2 the crust of the earth moves in time2 light moves in time2 an electro-magnet requires time for its charge by an electric current3 to inquire1 therefore1 whether power1 acting either at sensible or insensible distances1 always acts in time1 is not to be metaphysical2 if it acts in time and across space1 it must act by physical lines of force2 and our view of the nature of force may be affected to the extremest degree by the conclusions which experiment and observation on time may supply1 being perhaps finally determinable only by them4 ,to inquire after the possible time in which gravitating1 magnetic1 or electric force is exerted1 is no more metaphysical than to mark the times of the hands of a clock in their progress2 or that of the temple of ,serapis1 and its ascents and descents2 or the periods of the occultation of ,jupiter's satellites2 or that in which the light comes from them to the earth4 ,again1 in some of the known cases of the action of time something happens while the time is passing which did not happen before1 and does not continue after2 it is therefore not metaphysical to expect an effect in every case1 or to endeavour to discover its existence and determine its nature4 ,,calculation ,,of ,,heights ,,and ,,distances4 ,by the assistance of a seconds watch the following interesting calculations may be made3 ,if a traveller1 when on a precipice or on the top of a building1 wish to ascertain the height1 he should drop a stone1 or any other substance sufficiently heavy not to be impeded by the resistance of the atmosphere2 and the number of seconds which elapse before it reaches the bottom1 carefully noted on a seconds watch1 will give the height4 ,for the stone will fall through the space of #af-a_/h feet during the first second1 and will increase in rapidity as the square of the time employed in the fall3 if1 therefore1 #af-a_/h be multiplied by the number of seconds the stone has taken to fall1 this product also multiplied by the same number of seconds will give the height4 ,suppose the stone takes five seconds to reach the bottom3 #af-a_/h #e #hj-e_/h #e #djc-a_/h1 height of the precipice4 ,the ,count ,xavier de ,maistre1 in his ,expdition nocturne autour de ma ,chambre1 anxious to ascertain the exact height of his room from the ground on which ,turin is built1 tells us he proceeded as follows3 8,my heart beat quickly1 and ,i just counted three pulsations from the instant ,i dropped my slipper until ,i heard the sound as it fell in the street1 which1 according to the calculations made of the time taken by bodies in their accelerated fall1 and of that employed by the sonorous undulations of the air to arrive from the street to my ear1 gave the height of my apartment as #id feet #c inches #a tenth 7,french measure71 supposing that my heart1 agitated as it was1 beat #abj times in a minute40 ,a person travelling may ascertain his rate of walking by the aid of a slight string with a piece of lead at one end1 and the use of a seconds watch2 the string being knotted at distances of #dd feet1 the #abjth part of an ,english mile1 and bearing the same proportion to a mile that half a minute bears to an hour4 ,if the traveller1 when going at his usual rate1 drops the lead1 and suffers the string to slip through his hand1 the number of knots which pass in half a minute indicate the number of miles he walks in an hour4 ,this contrivance is similar to a log-line for ascertaining a ship's rate at sea3 the lead is enclosed in wood 7whence the name log71 that it may float1 and the divisions1 which are called knots1 are measured for nautical miles4 ,thus1 if ten knots are passed in half a minute1 they show that the vessel is sailing at the rate of ten knots1 or miles1 an hour3 a seconds watch would here be of great service1 but the half-minute sand-glass is in general use4 ,the rapidity of a river may be ascertained by throwing in a light floating substance1 which1 if not agitated by the wind1 will move with the same celerity as the water3 the distance it floats in a certain number of seconds will give the rapidity of the stream2 and this indicates the height of its source1 the nature of its bottom1 c4--,see ,sir ,howard ,douglas on ,bridges4 ,thomson's ,time and ,time-keepers4 ,,sand ,,in ,,the ,,hour-,,glass4 ,it is a noteworthy fact1 that the flow of ,sand in the ,hour-glass is perfectly equable1 whatever may be the quantity in the glass2 that is1 the sand runs no faster when the upper half of the glass is quite full than when it is nearly empty4 ,it would1 however1 be natural enough to conclude1 that when full of sand it would be more swiftly urged through the aperture than when the glass was only a quarter full1 and near the close of the hour4 ,the fact of the even flow of sand may be proved by a very simple experiment4 ,provide some silver sand1 dry it over or before the fire1 and pass it through a tolerably fine sieve4 ,then take a tube1 of any length or diameter1 closed at one end1 in which make a small hole1 say the eighth of an inch2 stop this with a peg1 and fill up the tube with the sifted sand4 ,hold the tube steadily1 or fix it to a wall or frame at any height from a table2 remove the peg1 and permit the sand to flow in any measure for any given time1 and note the quantity4 ,then let the tube be emptied1 and only half or a quarter filled with sand2 measure again for a like time1 and the same quantity of sand will flow3 even if you press the sand in the tube with a ruler or stick1 the flow of the sand through the hole will not be increased4 ,the above is explained by the fact1 that when the sand is poured into the tube1 it fills it with a succession of conical heaps2 and that all the weight which the bottom of the tube sustains is only that of the heap which first falls upon it1 as the succeeding heaps do not press downward1 but only against the sides or walls of the tube4 ,,figure ,,of ,,the ,,earth4 ,by means of a purely astronomical determination1 based upon the action which the earth exerts on the motion of the moon1 or1 in other words1 on the inequalities in lunar longitudes and latitudes1 ,laplace has shown in one single result the mean ,figure of the ,earth4 ,it is very remarkable that an astronomer1 without leaving his observatory1 may1 merely by comparing his observations with mean analytical results1 not only be enabled to determine with exactness the size and degree of ellipticity of the earth1 but also its distance from the sun and moon2 results that otherwise could only be arrived at by long and arduous expeditions to the most remote parts of both hemispheres4 ,the moon may therefore1 by the observation of its movements1 render appreciable to the higher departments of astronomy the ellipticity of the earth1 as it taught the early astronomers the rotundity of our earth by means of its eclipses4--,laplace's ,expos4 du ,syst4 du ,monde4 ,,how ,,to ,,ascertain ,,the ,,earth',s ,,magnitude4 ,sir ,john ,herschel gives the following means of approximation4 ,it appears by observation that two points1 each ten feet above the surface1 cease to be visible from each other over still water1 and1 in average atmospheric circumstances1 at a distance of about eight miles4 ,but #aj feet is the #ebhth part of a mile2 so that half their distance1 or four miles1 is to the height of each as #d #ebh1 or #baab3a1 and therefore in the same proportion to four miles is the length of the earth's diameter4 ,it must1 therefore1 be equal to #d #baab #hddh1 or in round numbers1 about #hjjj miles1 which is not very far from the truth4 ,the excess is1 however1 about #ajj miles1 or #a_/hjth part4 ,as convenient numbers to remember1 the reader may bear in mind1 that in our latitude there are just as many thousands of feet in a degree of the meridian as there are days in the year 7#cfe72 that1 speaking loosely1 a degree is about seventy ,british statute miles1 and a second about #ajj feet2 that the equatorial circumference of the earth is a little less than #be1jjj miles 7#bd1hii71 and the ellipticity or polar flattening amounts to #a_/cjjth part of the diameter4--,outlines of ,astronomy4 ,,mass ,,and ,,density ,,of ,,the ,,earth4 ,with regard to the determination of the ,mass and ,density of the ,earth by direct experiment1 we have1 in addition to the deviations of the pendulum produced by mountain masses1 the variation of the same instruments when placed in a mine #abjj feet in depth4 ,the most recent experiments were conducted by ,professor ,airy1 in the ,harton coal-pit1 near ,south ,shields3#aj the oscillations of the pendulum at the bottom of the pit were compared with those of a clock above2 the beats of the clock were transferred below for comparison by an electrio wire2 and it was thus determined that a pendulum vibrating seconds at the mouth of the pit would gain #b seconds per day at its bottom4 ,the final result of the calculations depending on this experiment1 which were published in the ,philosophical ,transactions of #ahef1 gives #fefe for the mean density of the earth4 ,the celebrated ,cavendish experiment1 by means of which the density of the earth was determined by observing the attraction of leaden balls on each other1 has been repeated in a manner exhibiting an astonishing amount of skill and patience by the late ,mr4 ,f4 ,baily4#aa ,the result of these experiments1 combined with those previously made1 gives as a mean result #edda as the earth's density1 when compared with water2 thus confirming one of ,newton's astonishing divinations1 that the mean density of the earth would be found to be between five and six times that of water4 ,humboldt is1 however1 of opinion that 8we know only the mass of the whole earth and its mean density by comparing it with the open strata1 which alone are accessible to us4 ,in the interior of the earth1 where all knowledge of its chemical and mineralogical character fails1 we are limited to as pure conjecture as in the remotest bodies that revolve round the sun4 ,we can determine nothing with certainty regarding the depth at which the geological strata must be supposed to be in a state of softening or of liquid fusion1 of the condition of fluids when heated under an enormous pressure1 or of the law of the increase of density from the upper surface to the centre of the earth40--,cosmos1 vol4 i4 ,in ,m4 ,foucault's beautiful experiment1 by means of the vibration of a long pendulum1 consisting of a heavy mass of metal suspended by a long wire from a strong fixed support1 is demonstrated to the eye the rotation of the earth4 ,the ,gyroscope of the same philosopher is regarded not as a mere philosophical toy2 but the principles of dynamics1 by means of which it is made to demonstrate the earth's rotation on its own axis1 are explained with the greatest clearness4 ,thus the ingenuity of ,m4 ,foucault1 combined with a profound knowledge of mechanics1 has obtained proofs of one of the most interesting problems of astronomy from an unsuspected source4 ,,the ,,earth ,,and ,,man ,,compared4 ,the ,earth--speaking roundly--is #hjjj miles in diameter2 the atmosphere is calculated to be fifty miles in altitude2 the loftiest mountain peak is estimated at five miles above the level of the sea1 for this height has never been visited by man2 the deepest mine that he has formed is #afej feet2 and his own stature does not average six feet4 ,therefore1 if it were possible for him to construct a globe #hjj feet--or twice the height of ,st4 ,paul's ,cathedral--in diameter1 and to place upon any one point of its surface an atom of #a_/dchjth of an inch in diameter1 and #a_/gbjth of an inch in height1 it would correctly denote the proportion that man bears to the earth upon which he moves4 ,when by measurements1 in which the evidence of the method advances equally with the precision of the results1 the volume of the earth is reduced to the millionth part of the volume of the sun2 when the sun himself1 transported to the region of the stars1 takes up a very modest place among the thousands of millions of those bodies that the telescope has revealed to us2 when the #ch1jjj1jjj of leagues which separate the earth from the sun have become1 by reason of their comparative smallness1 a base totally insufficient for ascertaining the dimensions of the visible universe2 when even the swiftness of the luminous rays 7#gg1jjj leagues per second7 barely suffices for the common valuations of science2 when1 in short1 by a chain of irresistible proofs1 certain stars have retired to distances that light could not traverse in less than a million of years2--we feel as if annihilated by such immensities4 ,in assigning to man and to the planet that he inhabits so small a position in the material world1 astronomy seems really to have made progress only to humble us4--,arago4 ,,mean ,,temperature ,,of ,,the ,,earth',s ,,surface4 ,professor ,dove has shown1 by taking at all seasons the mean of the temperature of points diametrically opposite to each other1 that the mean temperature of the whole earth's surface in ,june considerably exceeds that in ,december4 ,this result1 which is at variance with the greater proximity of the sun in ,december1 is1 however1 due to a totally different and very powerful cause1--the greater amount of land in that hemisphere which has its summer solstice in ,june 7i4 e4 the northern72 and the fact is so explained by him4 ,the effect of land under sunshine is to throw heat into the general atmosphere1 and to distribute it by the carrying power of the latter over the whole earth4 ,water is much less effective in this respect1 the heat penetrating its depths and being there absorbed2 so that the surface never acquires a very elevated temperature1 even under the equator4--,sir ,john ,herschel's ,outlines4 ,,temperature ,,of ,,the ,,earth ,,stationary4 ,although1 according to ,bessel1 #be1jjj cubic miles of water flow in every six hours from one quarter of the earth to another1 and the temperature is augmented by the ebb and flow of every tide1 all that we know with certainty is1 that the resultant effect of all the thermal agencies to which the earth is exposed has undergone no perceptible change within the historic period4 ,we owe this fine deduction to ,arago4 ,in order that the date palm should ripen its fruit1 the mean temperature of the place must exceed #gj deg4 ,fahr42 and1 on the other hand1 the vine cannot be cultivated successfully when the temperature is #gb deg4 or upwards4 ,hence the mean temperature of any place at which these two plants flourished and bore fruit must lie between these narrow limits1 i4 e4 could not differ from #ga deg4 ,fahr4 by more than a single degree4 ,now from the ,bible we learn that both plants were simultaneously cultivated in the central valleys of ,palestine in the time of ,moses2 and its then temperature is thus definitively determined4 ,it is the same at the present time2 so that the mean temperature of this portion of the globe has not sensibly altered in the course of thirty-three centuries4 ,,theory ,,of ,,crystallisation4 ,professor ,plcker has ascertained that certain crystals1 in particular the cyanite1 8point very well to the north by the magnetic power of the earth only4 ,it is a true compass-needle2 and more than that1 you may obtain its declination40 ,upon this ,mr4 ,hunt remarks3 8,we must remember that this crystal1 the cyanite1 is a compound of silica and alumina only4 ,this is the amount of experimental evidence which science has afforded in explanation of the conditions under which nature pursues her wondrous work of crystal formation4 ,we see just sufficient of the operation to be convinced that the luminous star which shines in the brightness of heaven1 and the cavern-secreted gem1 are equally the result of forces which are known to us in only a few of their modifications40--,poetry of ,science4 ,gay ,lussac first made the remark1 that a crystal of potash-alum1 transferred to a solution of ammonia-alum1 continued to increase without its form being modified1 and might thus be covered with alternate layers of the two alums1 preserving its regularity and proper crystalline figure4 ,m4 ,beudant afterwards observed that other bodies1 such as the sulphates of iron and copper1 might present themselves in crystals of the same form and angles1 although the form was not a simple one1 like that of alum4 ,but ,m4 ,mitscherlich first recognised this correspondence in a sufficient number of cases to prove that it was a general consequence of similarity of composition in different bodies4--,graham's ,elements of ,chemistry4 ,,immense ,,crystals4 ,crystals are found in the most microscopic character1 and of an exceedingly large size4 ,a crystal of quartz at ,milan is three feet and a quarter long1 and five feet and a half in circumference3 its weight is #hgj pounds4 ,beryls have been found in ,new ,hampshire measuring four feet in length4--,dana4 ,,visible ,,crystallisation4 ,professor ,tyndall1 in a lecture delivered by him at the ,royal ,institution1 ,london1 on the properties of ,ice1 gave the following interesting illustration of crystalline force4 ,by perfectly cleaning a piece of glass1 and placing on it a film of a solution of chloride of ammonium or sal ammoniac1 the action of crystallisation was shown to the whole audience4 ,the glass slide was placed in a microscope1 and the electric light passing through it was concentrated on a white disc4 ,the image of the crystals1 as they started into existence1 and shot across the disc in exquisite arborescent and symmetrical forms1 excited the admiration of every one4 ,the lecturer explained that the heat1 causing the film of moisture to evaporate1 brought the particles of salt sufficiently near to exercise the crystalline force1 the result being the beautiful structure built up with such marvellous rapidity4 ,,union ,,of ,,mineralogy ,,and ,,geometry4 ,it is a peculiar characteristic of minerals1 that while plants and animals differ in various regions of the earth1 mineral matter of the same character may be discovered in any part of the world1--at the ,equator or towards the ,poles2 at the summit of the loftiest mountains1 and in works far beneath the level of the sea4 ,the granite of ,australia does not necessarily differ from that of the ,british islands2 and ores of the same metals 7the proper geological conditions prevailing7 may be found of the same general character in all regions4 ,climate and geographical position have no influence on the composition of mineral substances4 ,this uniformity may1 in some measure1 have induced philosophers to seek its extension to the forms of crystallography4 ,about #agfj 7says ,mr4 ,buckle1 in his ,history of ,civilization71 ,rom de ,lisle set the first example of studying crystals1 according to a scheme so large as to include all the varieties of their primary forms1 and to account for their irregularities and the apparent caprice with which they were arranged4 ,in this investigation he was guided by the fundamental assumption1 that what is called an irregularity is in truth perfectly regular1 and that the operations of nature are invariable4 ,hay applied this great idea to the almost innumerable forms in which minerals crystallise4 ,he thus achieved a complete union between mineralogy and geometry2 and1 bringing the laws of space to bear on the molecular arrangements of matter1 he was able to penetrate into the intimate structure of crystals4 ,by this means he proved that the secondary forms of all crystals are derived from their primary forms by a regular process of decrement2 and that when a substance is passing from a liquid to a solid state1 its particles cohere1 according to a scheme which provides for every possible change1 since it includes even those subsequent layers which alter the ordinary type of the crystal1 by disturbing its natural symmetry4 ,to ascertain that such violations of symmetry are susceptible of mathematical calculation1 was to make a vast addition to our knowledge2 and1 by proving that even the most uncouth and singular forms are the natural results of their antecedents1 ,hay laid the foundation of what may be called the pathology of the inorganic world4 ,however paradoxical such a notion may appear1 it is certain that symmetry is to crystals what health is to animals2 so that an irregularity of shape in the first corresponds with an appearance of disease in the second4--,see ,hist4 ,civilization1 vol4 i4 ,,reproductive ,,crystallisation4 ,the general belief that only organic beings have the power of reproducing lost parts has been disproved by the experiments of ,jordan on crystals4 ,an octohedral crystal of alum was fractured2 it was then replaced in a solution1 and after a few days its injury was seen to be repaired4 ,the whole crystal had of course increased in size2 but the increase on the broken surface had been so much greater that a perfect octohedral form was regained4--,g4 ,h4 ,lewes4 ,this remarkable power possessed by crystals1 in common with animals1 of repairing their own injuries had1 however1 been thus previously referred to by ,paget1 in his ,pathology1 confirming the experiments of ,jordan on this curious subject3 8,the ability to repair the damages sustained by injury 444 is not an exclusive property of living beings2 for even crystals will repair themselves when1 after pieces have been broken from them1 they are placed in the same conditions in which they were first formed40 ,,glass ,,broken ,,by ,,sand4 ,in some glass-houses the workmen show glass which has been cooled in the open air2 on this they let fall leaden bullets without breaking the glass4 ,they afterwards desire you to let a few grains of sand fall upon the glass1 by which it is broken into a thousand pieces4 ,the reason of this is1 that the lead does not scratch the surface of the glass2 whereas the sand1 being sharp and angular1 scratches it sufficiently to produce the above effect4 ,sound and ,light4 ,,sounding ,,sand4 ,mr4 ,hugh ,miller1 the geologist1 when in the island of ,eigg1 in the ,hebrides1 observed that a musical sound was produced when he walked over the white dry sand of the beach4 ,at each step the sand was driven from his footprint1 and the noise was simultaneous with the scattering of the sand2 the cause being either the accumulated vibrations of the air when struck by the driven sand1 or the accumulated sounds occasioned by the mutual impact of the particles of sand against each other4 ,if a musket-ball passing through the air emits a whistling note1 each individual particle of sand must do the same1 however faint be the note which it yields2 and the accumulation of these infinitesimal vibrations must constitute an audible sound1 varying with the number and velocity of the moving particles4 ,in like manner1 if two plates of silex or quartz1 which are but crystals of sand1 give out a musical sound when mutually struck1 the impact or collision of two minute crystals or particles of sand must do the same1 in however inferior a degree2 and the union of all these sounds1 though singly imperceptible1 may constitute the musical notes of 8the ,mountain of the ,bell0 in ,arabia ,petra1 or the lesser sounds of the trodden sea-beach of ,eigg4--,north-,british ,review1 ,no4 #e4 ,,intensity ,,of ,,sound ,,in ,,rarefied ,,air4 ,the experiences during ascents of the highest mountains are contradictory4 ,saussure describes the sounds on the top of ,mont ,blanc as remarkably weak3 a pistol-shot made no more noise than an ordinary ,chinese cracker1 and the popping of a bottle of champagne was scarcely audible4 ,yet ,martius1 in the same situation1 was able to distinguish the voices of the guides at a distance of #acdj feet1 and to hear the tapping of a lead pencil upon a metallic surface at a distance of from #ge to #ajj feet4 ,,mm ,wertheim and ,breguet have propagated sound over the wire of an electric telegraph at the rate of #aa1ded feet per second4 ,,distance ,,at ,,which ,,the ,,human ,,voice ,,may ,,be ,,heard4 ,experience shows that the human voice1 under favourable circumstances1 is capable of filling a larger space than was ever probably enclosed within the walls of a single room4 ,lieutenant ,foster1 on ,parry's third ,arctic expedition1 found that he could converse with a man across the harbour of ,port ,bowen1 a distance of #ffif feet1 or about one mile and a quarter4 ,dr4 ,young records that at ,gibraltar the human voice has been heard at a distance of ten miles4 ,if sound be prevented from spreading and losing itself in the air1 either by a pipe or an extensive flat surface1 as a wall or still water1 it may be conveyed to a great distance4 ,biot heard a flute clearly through a tube of cast-iron 7the water-pipes of ,paris7 #cabj feet long3 the lowest whisper was distinctly heard2 indeed1 the only way not to be heard was not to speak at all4 ,,the ,,roar ,,of ,,niagara4 ,the very nature of the sound of running water pronounces its origin to be the bursting of bubbles3 the impact of water against water is a comparatively subordinate cause1 and could never of itself occasion the murmur of a brook2 whereas1 in streams which ,dr4 ,tyndall has examined1 he1 in all cases where a ripple was heard1 discovered bubbles caused by the broken column of water4 ,now1 were ,niagara continuous1 and without lateral vibration1 it would be as silent as a cataract of ice4 ,in all probability1 it has its 8contracted sections10 after passing which it is broken into detached masses1 which1 plunging successively upon the air-bladders formed by their precursors1 suddenly liberate their contents1 and thus create the thunder of the waterfall4 ,,figures ,,produced ,,by ,,sound4 ,stretch a sheet of wet paper over the mouth of a glass tumbler which has a footstalk1 and glue or paste the paper at the edges4 ,when the paper is dry1 strew dry sand thinly upon its surface4 ,place the tumbler on a table1 and hold immediately above it1 and parallel to the paper1 a plate of glass1 which you also strew with sand1 having previously rubbed the edges smooth with emery powder4 ,draw a violin-bow along any part of the edges2 and as the sand upon the glass is made to vibrate1 it will form various figures1 which will be accurately imitated by the sand upon the paper2 or if a violin or flute be played within a few inches of the paper1 they will cause the sand upon its surface to form regular lines and figures4 ,,the ,,tuning-,,fork ,a ,,flute-,,player4 ,take a common tuning-fork1 and on one of its branches fasten with sealing-wax a circular piece of card of the size of a small wafer1 or sufficient nearly to cover the aperture of a pipe1 as the sliding of the upper end of a flute with the mouth stopped3 it may be tuned in unison with the loaded tuning-fork by means of the movable stopper or card1 or the fork may be loaded till the unison is perfect4 ,then set the fork in vibration by a blow on the unloaded branch1 and hold the card closely over the mouth of the pipe1 as in the engraving1 when a note of surprising clearness and strength will be heard4 ,indeed a flute may be made to 8speak0 perfectly well1 by holding close to the opening a vibrating tuning-fork1 while the fingering proper to the note of the fork is at the same time performed4 ,,theory ,,of ,,the ,,jew',s ,,harp4 ,if you cause the tongue of this little instrument to vibrate1 it will produce a very low sound2 but if you place it before a cavity 7as the mouth7 containing a column of air1 which vibrates much faster1 but in the proportion of any simple multiple1 it will then produce other higher sounds1 dependent upon the reciprocation of that portion of the air4 ,now the bulk of air in the mouth can be altered in its form1 size1 and other circumstances1 so as to produce by reciprocation many different sounds2 and these are the sounds belonging to the ,jew's ,harp4 ,a proof of this fact has been given by ,mr4 ,eulenstein1 who fitted into a long metallic tube a piston1 which being moved1 could be made to lengthen or shorten the efficient column of air within at pleasure4 ,a ,jew's ,harp was then so fixed that it could be made to vibrate before the mouth of the tube1 and it was found that the column of air produced a series of sounds1 according as it was lengthened or shortened2 a sound being produced whenever the length of the column was such that its vibrations were a multiple of those of the ,jew's ,harp4 ,,solar ,,and ,,artificial ,,light ,,compared4 ,the most intensely ignited solid 7produced by the flame of ,lieutenant ,drummond's oxy-hydrogen lamp directed against a surface of chalk7 appears only as black spots on the disc of the sun1 when held between it and the eye2 or in other words1 ,drummond's light is to the light of the sun's disc as #a to #adf4 ,hence we are doubly struck by the felicity with which ,galileo1 as early as #afab1 by a series of conclusions on the smallness of the distance from the sun at which the disc of ,venus was no longer visible to the naked eye1 arrived at the result that the blackest nucleus of the sun's spots was more luminous than the brightest portions of the full moon4 7,see 8,the ,sun's ,light compared with ,terrestrial ,lights10 in ,things not generally ,known1 pp4 #d1 #e47 ,,source ,,of ,,light4 ,mr4 ,robert ,hunt1 in a lecture delivered by him at the ,russell ,institution1 8,on the ,physics of a ,sunbeam10 mentions some experiments by ,lord ,brougham on the sunbeam1 in which1 by placing the edge of a sharp knife just within the limit of the light1 the ray was inflected from its previous direction1 and coloured red2 and when another knife was placed on the opposite side1 it was deflected1 and the colour was blue4 ,these experiments 7says ,mr4 ,hunt7 seem to confirm ,sir ,isaac ,newton's theory1 that light is a fluid emitted from the sun4 ,,the ,,undulatory ,,scale ,,of ,,light4 ,the white light of the sun is well known to be composed of several coloured rays2 or rather1 according to the theory of undulations1 when the rate at which a ray vibrates is altered1 a different sensation is produced upon the optic nerve4 ,the analytical examination of this question shows that to produce a red colour the ray of light must give #cg1fdj undulations in an inch1 and #deh1jjj1jjj1jjj1jjj in a second4 ,yellow light requires #dd1jjj undulations in an inch1 and #ece1jjj1jjj1jjj1jjj in a second2 whilst the effect of blue results from #ea1aaj undulations within an inch1 and #fbb1jjj1jjj1jjj1jjj of waves in a second of time4--,hunt's ,poetry of ,science4 ,,visibility ,,of ,,objects4 ,in terrestrial objects1 the form1 no less than the modes of illumination1 determines the magnitude of the smallest angle of vision for the naked eye4 ,adams very correctly observed that a long and slender staff can be seen at a much greater distance than a square whose sides are equal to the diameter of the staff4 ,a stripe may be distinguished at a greater distance than a spot1 even when both are of the same diameter4 ,the minimum optical visual angle at which terrestrial objects can be recognised by the naked eye has been gradually estimated lower and lower1 from the time when ,robert ,hooke fixed it exactly at a full minute1 and ,tobias ,meyer required #cd to perceive a black speck on white paper1 to the period of ,leuwenhoeck's experiments with spiders' threads1 which are visible to ordinary sight at an angle of #dg4 ,in ,hueck's most accurate experiments on the problem of the movement of the crystalline lens1 white lines on a black ground were seen at an angle of #ab2 a spider's thread at #jf2 and a fine glistening wire at scarcely #jb4 ,humboldt1 when at ,chillo1 near ,quito1 where the crests of the volcano of ,pichincha lay at a horizontal distance of #ij1jjj feet1 was much struck by the circumstance that the ,indians standing near distinguished the figure of ,bonpland 7then on an expedition to the volcano71 as a white point moving on the black basaltic sides of the rock1 sooner than ,humboldt could discover him with a telescope4 ,bonpland was enveloped in a white cotton poncho3 assuming the breadth across the shoulders to vary from three to five feet1 according as the mantle clung to the figure or fluttered in the breeze1 and judging from the known distance1 the angle at which the moving object could be distinctly seen varied from #g to #ab4 ,white objects on a black ground are1 according to ,hueck1 distinguished at a greater distance than black objects on a white ground4 ,gauss's heliotrope light has been seen with the naked eye reflected from the ,brocken on ,hobenhagen at a distance of about #bbg1jjj feet1 or more than #db miles2 being frequently visible at points in which the apparent breadth of a three-inch mirror was only #jdc4 ,,the ,,smallest ,,bright ,,bodies4 ,ehrenberg has found from experiments on the dust of diamonds1 that a diamond superficies of #a_/ajjth of a line in diameter presents a much more vivid light to the naked eye than one of quicksilver of the same diameter4 ,on pressing small globules of quicksilver on a glass micrometer1 he easily obtained smaller globules of the #a_/ajjth to the #a_/bjjjth of a line in diameter4 ,in the sunshine he could only discern the reflection of light1 and the existence of such globules as were #a_/cjjth of a line in diameter1 with the naked eye4 ,smaller ones did not affect his eye2 but he remarked that the actual bright part of the globule did not amount to more than #a_/ijjth of a line in diameter4 ,spider threads of #a_/bjjjth in diameter were still discernible from their lustre4 ,ehrenberg concludes that there are in organic bodies magnitudes capable of direct proof which are in diameter #a_/ajjjjj of a line2 and others1 that can be indirectly proved1 which may be less than a six-millionth part of a ,parisian line in diameter4 ,,velocity ,,of ,,light4 ,it is scarcely possible so to strain the imagination as to conceive the ,velocity with which ,light travels4 8,what mere assertion will make any man believe10 asks ,sir ,john ,herschel1 8that in one second of time1 in one beat of the pendulum of a clock1 a ray of light travels over #aib1jjj miles2 and would therefore perform the tour of the world in about the same time that it requires to wink with our eyelids1 and in much less time than a swift runner occupies in taking a single stride80 ,were a cannon-ball shot directly towards the sun1 and were it to maintain its full speed1 it would be twenty years in reaching it2 and yet light travels through this space in seven or eight minutes4 ,the result given in the ,annuaire for #ahdb for the velocity of light in a second is #gg1jjj leagues1 which corresponds to #bae1hcd miles2 while that obtained at the ,pulkowa ,observatory is #ahi1gdf miles4 ,william ,richardson gives as the result of the passage of light from the sun to the earth #h #aibh1 from which we obtain a velocity of #bae1cib miles in a second4--,memoirs of the ,astronomical ,society1 vol4 iv4 ,in other words1 light travels a distance equal to eight times the circumference of the earth between two beats of a clock4 ,this is a prodigious velocity2 but the measure of it is very certain4--,professor ,airy4 ,the navigator who has measured the earth's circuit by his hourly progress1 or the astronomer who has paced a degree of the meridian1 can alone form a clear idea of velocity1 when we tell him that light moves through a space equal to the circumference of the earth in the eighth part of a second--in the twinkling of an eye4 ,could an observer1 placed in the centre of the earth1 see this moving light1 as it describes the earth's circumference1 it would appear a luminous ring2 that is1 the impression of the light at the commencement of its journey would continue on the retina till the light had completed its circuit4 ,nay1 since the impression of light continues longer than the fourth part of a second1 two luminous rings would be seen1 provided the light made two rounds of the earth1 and in paths not coincident4 ,,apparatus ,,for ,,the ,,measurement ,,of ,,light4 ,humboldt enumerates the following different methods adopted for the ,measurement of ,light3 a comparison of the shadows of artificial lights1 differing in numbers and distance2 diaphragms2 plane-glasses of different thickness and colour2 artificial stars formed by reflection on glass spheres2 the juxtaposition of two seven-feet telescopes1 separated by a distance which the observer could pass in about a second2 reflecting instruments in which two stars can be simultaneously seen and compared1 when the telescope has been so adjusted that the star gives two images of like intensity2 an apparatus having 7in front of the object-glass7 a mirror and diaphragms1 whose rotation is measured on a ring2 telescopes with divided object-glasses1 on either half of which the stellar light is received through a prism2 astrometers1 in which a prism reflects the image of the moon or ,jupiter1 and concentrates it through a lens at different distances into a star more or less bright4--,cosmos1 vol4 iii4 ,,how ,,fizeau ,,measured ,,the ,,velocity ,,of ,,light4 ,this distinguished physicist has submitted the ,velocity of ,light to terrestrial measurement by means of an ingeniously constructed apparatus1 in which artificial light 7resembling stellar light71 generated from oxygen and hydrogen1 is made to pass back1 by means of a mirror1 over a distance of #bh1cba feet to the same point from which it emanated4 ,a disc1 having #gbj teeth1 which made #abf rotations in a second1 alternately obscured the ray of light and allowed it to be seen between the teeth on the margin4 ,it was supposed1 from the marking of a counter1 that the artificial light traversed #ef1fdb feet1 or the distance to and from the stations1 in #a_/ahjjth part of a second1 whence we obtain a velocity of #aia1dfj miles in a second4#ab ,this result approximates most closely to ,delambre's 7which was #ahi1agc miles71 as obtained from ,jupiter's satellites4 ,the invention of the rotating mirror is due to ,wheatstone1 who made an experiment with it to determine the velocity of the propagation of the discharge of a ,leyden battery4 ,the most striking application of the idea was made by ,fizeau and ,foucault1 in #ahec1 in carrying out a proposition made by ,arago1 soon after the invention of the mirror3 we have here determined in a distance of twelve feet no less than the velocity with which light is propagated1 which is known to be nearly #bjj1jjj miles a second2 the distance mentioned corresponds therefore to the #gg-millionth part of a second4 ,the object of these measurements was to compare the velocity of light in air with its velocity in water2 which1 when the length is greater1 is not sufficiently transparent4 ,the most complete optical and mechanical aids are here necessary3 the mirror of ,foucault made from #fjj to #hjj revolutions in a second1 while that of ,fizeau performed #abjj to #aejj in the same time4--,prof4 ,helmholtz on the ,methods of ,measuring very small ,portions of ,time4 ,,what ,,is ,,done ,,by ,,polarisation ,,of ,,light4 ,malus1 in #ahjh1 was led by a casual observation of the light of the setting sun1 reflected from the windows of the ,palais de ,luxembourg1 at ,paris1 to investigate more thoroughly the phenomena of double refraction1 of ordinary and of chromatic polarisation1 of interference and of diffraction of light4 ,among his results may be reckoned the means of distinguishing between direct and reflected light2 the power of penetrating1 as it were1 into the constitution of the body of the sun and of its luminous envelopes2 of measuring the pressure of atmospheric strata1 and even the smallest amount of water they contain2 of ascertaining the depths of the ocean and its rocks by means of a tourmaline plate2 and in accordance with ,newton's prediction1 of comparing the chemical composition of several substances with their optical effects4 ,arago1 in a letter to ,humboldt1 states that by the aid of his polariscope1 he discovered1 before #ahbj1 that the light of all terrestrial objects in a state of incandescence1 whether they be solid or liquid1 is natural1 so long as it emanates from the object in perpendicular rays4 ,on the other hand1 if such light emanate at an acute angle1 it presents manifest proofs of polarisation4 ,this led ,m4 ,arago to the remarkable conclusion1 that light is not generated on the surface of bodies only1 but that some portion is actually engendered within the substance itself1 even in the case of platinum4 ,a ray of light which reaches our eyes after traversing many millions of miles1 from1 the remotest regions of heaven1 announces1 as it were of itself1 in the polariscope1 whether it is reflected or refracted1 whether it emanates from a solid or fluid or gaseous body2 it announces even the degree of its intensity4--,humboldt's ,cosmos1 vols4 i4 and ii4 ,,minuteness ,,of ,,light4 ,there is something wonderful1 says ,arago1 in the experiments which have led natural philosophers legitimately to talk of the different sides of a ray of light2 and to show that millions and millions of these rays can simultaneously pass through the eye of a needle without interfering with each other6 ,,the ,,importance ,,of ,,light4 ,light affects the respiration of animals just as it affects the respiration of plants4 ,this is novel doctrine1 but it is demonstrable4 ,in the day-time we expire more carbonic acid than during the night2 a fact known to physiologists1 who explain it as the effect of sleep3 but the difference is mainly owing to the presence or absence of sunlight2 for sleep1 as sleep1 increases1 instead of diminishing1 the amount of carbonic acid expired1 and a man sleeping will expire more carbonic acid than if he lies quietly awake under the same conditions of light and temperature2 so that if less is expired during the night than during the day1 the reason cannot be sleep1 but the absence of light4 ,now we understand why men are sickly and stunted who live in narrow streets1 alleys1 and cellars1 compared with those who1 under similar conditions of poverty and dirt1 live in the sunlight4--,blackwood's ,edinburgh ,magazine1 #aheh4 ,the influence of light on the colours of organised creation is well shown in the sea4 ,near the shores we find seaweeds of the most beautiful hues1 particularly on the rocks which are left dry by the tides2 and the rich tints of the actini which inhabit shallow water must often have been observed4 ,the fishes which swim near the surface are also distinguished by the variety of their colours1 whereas those which live at greater depths are gray1 brown1 or black4 ,it has been found that after a certain depth1 where the quantity of light is so reduced that a mere twilight prevails1 the inhabitants of the ocean become nearly colourless4--,hunt's ,poetry of ,science4 ,,action ,,of ,,light ,,on ,,muscular ,,fibres4 ,that light is capable of acting on muscular fibres1 independently of the influence of the nerves1 was mentioned by several of the old anatomists1 but repudiated by later authorities4 ,m4 ,brown ,squard has1 however1 proved to the ,royal ,society that some portions of muscular fibre--the iris of the eye1 for example--are affected by light independently of any reflex action of the nerves1 thereby confirming former experiences4 ,the effect is produced by the illuminating rays only1 the chemical and heat rays remaining neutral4 ,and not least remarkable is the fact1 that the iris of an eel showed itself susceptible of the excitement sixteen days after the eyes were removed from the creature's head4 ,so far as is yet known1 this muscle is the only one on which light thus takes effect4--,phil4 ,trans4 #aheg4 ,,light ,,nights4 ,it is not possible1 as well-attested facts prove1 perfectly to explain the operations at work in the much-contested upper boundaries of our atmosphere4 ,the extraordinary lightness of whole nights in the year #ahca1 during which small print might be read at midnight in the latitudes of ,italy and the north of ,germany1 is a fact directly at variance with all that we know1 according to the most recent and acute researches on the crepuscular theory and the height of the atmosphere4--,biot4 ,,phosphorescence ,,of ,,plants4 ,mr4 ,hunt recounts these striking instances4 ,the leaves of the nothera macrocarpa are said to exhibit phosphoric light when the air is highly charged with electricity4 ,the agarics of the olive-grounds of ,montpelier too have been observed to be luminous at night2 but they are said to exhibit no light1 even in darkness1 during the day4 ,the subterranean passages of the coal-mines near ,dresden are illuminated by the phosphorescent light of the rhizomorpha phosphoreus1 a peculiar fungus4 ,on the leaves of the ,pindoba palm grows a species of agaric which is exceedingly luminous at night2 and many varieties of the lichens1 creeping along the roofs of caverns1 lend to them an air of enchantment by the soft and clear light which they diffuse4 ,in a small cave near ,penryn1 a luminous moss is abundant2 it is also found in the mines of ,hesse4 ,according to ,heinzmann1 the rhizomorpha subterranea and aidul are also phosphorescent4--,see ,poetry of ,science4 ,,phosphorescence ,,of ,,the ,,sea4 ,by microscopic examination of the myriads of minute insects which cause this phenomenon1 no other fact has been elicited than that they contain a fluid which1 when squeezed out1 leaves a train of light upon the surface of the water4 ,the creatures appear almost invariably on the eve of some change of weather1 which would lead us to suppose that their luminous phenomena must be connected with electrical excitation2 and of this ,mr4 ,c4 ,peach of ,fowey has furnished the most satisfactory proofs yet obtained4#ac ,,light ,,from ,,the ,,juice ,,of ,a ,,plant4 ,in ,brazil has been observed a plant1 conjectured to be an ,euphorbium1 very remarkable for the light which it yields when cut4 ,it contains a milky juice1 which exudes as soon as the plant is wounded1 and appears luminous for several seconds4 ,,light ,,from ,,fungus4 ,phosphorescent funguses have been found in ,brazil by ,mr4 ,gardner1 growing on the decaying leaves of a dwarf palm4 ,they vary from one to two inches across1 and the whole plant gives out at night a bright phosphorescent light1 of a pale greenish hue1 similar to that emitted by fire-flies and phosphorescent marine animals4 ,the light given out by a few of these fungi in a dark room is sufficient to read by4 ,a very large phosphorescent species is occasionally found in the ,swan ,river colony4 ,,light ,,from ,,buttons4 ,upon highly polished gilt buttons no figure whatever can be seen by the most careful examination2 yet1 when they are made to reflect the light of the sun or of a candle upon a piece of paper held close to them1 they give a beautiful geometrical figure1 with ten rays issuing from the centre1 and terminating in a luminous rim4 ,,colours ,,of ,,scratches4 ,an extremely fine scratch on a well-polished surface may be regarded as having a concave1 cylindrical1 or at least a curved surface1 capable of reflecting light in all directions2 this is evident1 for it is visible in all directions4 ,hence a single scratch or furrow in a surface may produce colours by the interference of the rays reflected from its opposite edges4 ,examine a spider's thread in the sunshine1 and it will gleam with vivid colours4 ,these may arise from a similar cause2 or from the thread itself1 as spun by the animal1 consisting of several threads agglutinated together1 and thus presenting1 not a cylindrical1 but a furrowed surface4 ,,magic ,,bust4 ,sir ,david ,brewster has shown how the rigid features of a white bust may be made to move and vary their expression1 sometimes smiling and sometimes frowning1 by moving rapidly in front of the bust a bright light1 so as to make the lights and shadows take every possible direction and various degrees of intensity2 and if the bust be placed before a concave mirror1 its image may be made to do still more when it is cast upon wreaths of smoke4 ,,colours ,,hit ,,most ,,frequently ,,during ,,battle4 ,it would appear from numerous observations that soldiers are hit during battle according to the colour of their dress in the following order3 red is the most fatal colour2 the least fatal1 ,austrian gray4 ,the proportions are1 red1 #ab2 rifle-green1 #g2 brown1 #f2 ,austrian bluish-gray1 #e4--;,jameson's ,journal1 #ahec4 ,,transmutation ,,of ,,topaz4 ,yellow topazes may be converted into pink by heat2 but it is a mistake to suppose that in the process the yellow colour is changed into pink3 the fact is1 that one of the pencils being yellow and the other pink1 the yellow is discharged by heat1 thus leaving the pink unimpaired4 ,,colours ,,and ,,tints4 ,m4 ,chevreul1 the ,directeur des ,gobelins1 has presented to the ,french ,academy a plan for a universal chromatic scale1 and a methodical classification of all imaginable colours4 ,mayer1 a professor at ,gttingen1 calculated that the different combinations of primitive colours produced #hai different tints2 but ,m4 ,chevreul established not less than #ad1dbd1 all very distinct and easily recognised1--all of course proceeding from the three primitive simple colours of the solar spectrum1 red1 yellow1 and blue4 ,for example1 he states that in the violet there are twenty-eight colours1 and in the dahlia forty-two4 ,,objects ,,really ,,of ,,no ,,colour4 ,a body appears to be of the colour which it reflects2 as we see it only by reflected rays1 it can but appear of the colour of those rays4 ,thus grass is green because it absorbs all except the green rays4 ,flowers1 in the same manner1 reflect the various colours of which they appear to us3 the rose1 the red rays2 the violet1 the blue2 the daffodil1 the yellow1 c4 ,but these are not the permanent colours of the grass and flowers2 for wherever you see these colours1 the objects must be illuminated2 and light1 from whatever source it proceeds1 is of the same nature1 composed of the various coloured rays which paint the grass1 the flowers1 and every coloured object in nature4 ,objects in the dark have no colour1 or are black1 which is the same thing4 ,you can never see objects without light4 ,light is composed of colours1 therefore there can be no light without colours2 and though every object is black or without colour in the dark1 it becomes coloured as soon as it becomes visible4 ,,the ,,diorama--,,why ,,so ,,perfect ,,an ,,illusion4 ,because when an object is viewed at so great a distance that the optic axes of both eyes are sensibly parallel when directed towards it1 the perspective projections of it1 seen by each eye separately1 are similar2 and the appearance to the two eyes is precisely the same as when the object is seen by one eye only4 ,there is1 in such case1 no difference between the visual appearance of an object in relief and its perspective projection on a plane surface2 hence pictorial representations of distant objects1 when those circumstances which would prevent or disturb the illusion are carefully excluded1 may be rendered such perfect resemblances of the objects they are intended to represent as to be mistaken for them4 ,the ,diorama is an instance of this4--,professor ,wheatstone2 ,philosophical ,transactions1 #ahch4 ,,curious ,,optical ,,effects ,,at ,,the ,,cape4 ,sir ,john ,herschel1 in his observatory at ,feldhausen1 at the base of the ,table ,mountain1 witnessed several curious optical effects1 arising from peculiar conditions of the atmosphere incident to the climate of the ,cape4 ,in the hot season 8the nights are for the most part superb20 but occasionally1 during the excessive heat and dryness of the sandy plains1 8the optical tranquillity of the air0 is greatly disturbed4 ,in some cases1 the images of the stars are violently dilated into nebular balls or puffs of #ae in diameter2 on other occasions they form 8soft1 round1 quiet pellets of #c or #d diameter10 resembling planetary nebul4 ,in the cooler months the tranquillity of the image and the sharpness of vision are such1 that hardly any limit is set to magnifying power but that which arises from the aberration of the specula4 ,on occasions like these1 optical phenomena of extraordinary splendour are produced by viewing a bright star through a diaphragm of cardboard or zinc pierced in regular patterns of circular holes by machinery3 these phenomena surprise and delight every person that sees them4 ,when close double stars are viewed with the telescope1 with a diaphragm in the form of an equilateral triangle1 the discs of the two stars1 which are exact circles1 have a clearness and perfection almost incredible4 ,,the ,,telescope ,,and ,,the ,,microscope4 ,so singular is the position of the ,telescope and the ,microscope among the great inventions of the age1 that no other process but that which they embody could make the slightest approximation to the secrets which they disclose4 ,the steam-engine might have been imperfectly replaced by an air or an ether-engine2 and a highly elastic fluid might have been1 and may yet be1 found1 which shall impel the 8rapid car10 or drag the merchant-ship over the globe4 ,the electric telegraph1 now so perfect and unerring1 might have spoken to us in the rude 8language of chimes20 or sound1 in place of electricity1 might have passed along the metallic path1 and appealed to the ear in place of the eye4 ,for the printing-press and the typographic art might have been found a substitute1 however poor1 in the lithographic process2 and knowledge might have been widely diffused by the photographic printing powers of the sun1 or even artificial light4 ,but without the telescope and the microscope1 the human eye would have struggled in vain to study the worlds beyond our own1 and the elaborate structures of the organic and inorganic creation could never have been revealed4--,north-,british ,review1 ,no4 #ej4 ,,invention ,,of ,,the ,,microscope4 ,the earliest magnifying lens of which we have any knowledge was one rudely made of rock-crystal1 which ,mr4 ,layard found1 among a number of glass bowls1 in the north-west palace of ,nimroud2 but no similar lens has been found or described to induce us to believe that the microscope1 either single or compound1 was invented and used as an instrument previous to the commencement of the seventeenth century4 ,in the beginning of the first century1 however1 ,seneca alludes to the magnifying power of a glass globe filled with water2 but as he only states that it made small and indistinct letters appear larger and more distinct1 we cannot consider such a casual remark as the invention of the single microscope1 though it might have led the observer to try the effect of smaller globes1 and thus obtain magnifying powers sufficient to discover phenomena otherwise invisible4 ,lenses of glass were undoubtedly in existence at the time of ,pliny2 but at that period1 and for many centuries afterwards1 they appear to have been used only as burning or as reading glasses2 and no attempt seems to have been made to form them of so small a size as to entitle them to be regarded even as the precursors of the single microscope4--,north-,british ,review1 ,no4 #ej4 ,the rock-crystal lens found at ,nineveh was examined by ,sir ,david ,brewster4 ,it was not entirely circular in its aperture4 ,its general form was that of a plano-convex lens1 the plane side having been formed of one of the original faces of the six-sided crystal quartz1 as ,sir ,david ascertained by its action on polarised light3 this was badly polished and scratched4 ,the convex face of the lens had not been ground in a dish-shaped tool1 in the manner in which lenses are now formed1 but was shaped on a lapidary's wheel1 or in some such manner4 ,hence it was unequally thick2 but its extreme thickness was #b_/ajths of an inch1 its focal length being #d inches4 ,it had twelve remains of cavities1 which had originally contained liquids or condensed gases4 ,sir ,david has assigned reasons why this could not be looked upon as an ornament1 but a true optical lens4 ,in the same ruins were found some decomposed glass4 ,,how ,,to ,,make ,,the ,,fish-,,eye ,,microscope4 ,very good microscopes may be made with the crystalline lenses of fish1 birds1 and quadrupeds4 ,as the lens of fishes is spherical or spheroidal1 it is absolutely necessary1 previous to its use1 to determine its optical axis and the axis of vision of the eye from which it is taken1 and place the lens in such a manner that its axis is a continuation of the axis of our own eye4 ,in no other direction but this is the albumen of which the lens consists symmetrically disposed in lamin of equal density round a given line1 which is the axis of the lens2 and in no other direction does the gradation of density1 by which the spherical aberration is corrected1 preserve a proper relation to the axis of vision4 ,when the lens of any small fish1 such as a minnow1 a par1 or trout1 has been taken out1 along with the adhering vitreous humour1 from the eye-ball by cutting the sclerotic coat with a pair of scissors1 it should be placed upon a piece of fine silver-paper previously freed from its minute adhering fibres4 ,the absorbent nature of the paper will assist in removing all the vitreous humour from the lens2 and when this is carefully done1 by rolling it about with another piece of silver-paper1 there will still remain1 round or near the equator of the lens1 a black ridge1 consisting of the processes by which it was suspended in the eye-ball4 ,the black circle points out to us the true axis of the lens1 which is perpendicular to a plane passing through it4 ,when the small crystalline has been freed from all the adhering vitreous humour1 the capsule which contains it will have a surface as fine as a pellicle of fluid4 ,it is then to be dropped from the paper into a cavity formed by a brass rim1 and its position changed till the black circle is parallel to the circular rim1 in which case only the axis of the lens will be a continuation of the axis of the observer's eye4--,edin4 ,jour4 ,science1 vol4 ii4 ,,leuwenhoeck',s ,,microscopes4 ,leuwenhoeck1 the father of microscopical discovery1 communicated to the ,royal ,society1 in #afgc1 a description of the structure of a bee and a louse1 seen by aid of his improved microscopes2 and from this period until his decease in #agbc1 he regularly transmitted to the society his microscopical observations and discoveries1 so that #cge of his papers and letters are preserved in the society's archives1 extending over fifty years4 ,he further bequeathed to the ,royal ,society a cabinet of twenty-six microscopes1 which he had ground himself and set in silver1 mostly extracted by him from minerals2 these microscopes were exhibited to ,peter the ,great when he was at ,delft in #afih4 ,in acknowledging the bequest1 the council of the ,royal ,society1 in #agbd1 presented ,leuwenhoeck's daughter with a handsome silver bowl1 bearing the arms of the society4--,weld's ,history of the ,royal ,society1 vol4 i4 ,,diamond ,,lenses ,,for ,,microscopes4 ,in recommending the employment of ,diamond and other gems in the construction of ,microscopes1 ,sir ,david ,brewster has been met with the objection that they are too expensive for such a purpose2 and1 says ,sir ,david1 8they certainly are for instruments intended merely to instruct and amuse4 ,but if we desire to make great discoveries1 to unfold secrets yet hid in the cells of plants and animals1 we must not grudge even a diamond to reveal them4 ,if ,mr4 ,cooper and ,sir ,james ,south have given a couple of thousand pounds a piece for a refracting telescope1 in order to study what have been miscalled #8dots' and #8lumps' of light on the sky2 and if ,lord ,rosse has expended far greater sums on a reflecting telescope for analysing what has been called #8sparks of mud and vapour' encumbering the azure purity of the heavens1--why should not other philosophers open their purse1 if they have one1 and other noblemen sacrifice some of their household jewels1 to resolve the microscopic structures of our own real world1 and disclose secrets which the ,almighty must have intended that we should know80--,proceedings of the ,british ,association1 #aheg4 ,,the ,,eye ,,and ,,the ,,brain ,,seen ,,through ,a ,,microscope4 ,by a microscopic examination of the retina and optic nerve and the brain1 ,m4 ,bauer found them to consist of globules of #a_/bhjjth to #a_/djjjth an inch diameter1 united by a transparent viscid and coagulable gelatinous fluid4 ,,microscopical ,,examination ,,of ,,the ,,hair4 ,if a hair be drawn between the finger and thumb1 from the end to the root1 it will be distinctly felt to give a greater resistance and a different sensation to that which is experienced when drawn the opposite way3 in consequence1 if the hair be rubbed between the fingers1 it will only move one way 7travelling in the direction of a line drawn from its termination to its origin from the head or body71 so that each extremity may thus be easily distinguished1 even in the dark1 by the touch alone4 ,the mystery is resolved by the achromatic microscope4 ,a hair viewed on a dark ground as an opaque object with a high power1 not less than that of a lens of one-thirtieth of an inch focus1 and dully illuminated by a cup1 the hair is seen to be indented with teeth somewhat resembling those of a coarse round rasp1 but extremely irregular and rugged3 as these incline all in one direction1 like those of a common file1 viz4 from the origin of the hair towards its extremity1 it sufficiently explains the above singular property4 ,this is a singular proof of the acuteness of the sense of feeling1 for the said teeth may be felt much more easily than they can be seen4 ,we may thus understand why a razor will cut a hair in two much more easily when drawn against its teeth than in the opposite direction4--,dr4 ,goring4 ,,the ,,microscope ,,and ,,the ,,sea4 ,what myriads has the microscope revealed to us of the rich luxuriance of animal life in the ocean1 and conveyed to our astonished senses a consciousness of the universality of life6 ,in the oceanic depths every stratum of water is animated1 and swarms with countless hosts of small luminiferous animalcules1 mammaria1 crustacea1 peridinea1 and circling nereides1 which1 when attracted to the surface by peculiar meteorological conditions1 convert every wave into a foaming band of flashing light4 ,,use ,,of ,,the ,,microscope ,,to ,,mineralogists4 ,m4 ,dufour has shown that an imponderable quantity of a substance can be crystallised2 and that the crystals so obtained are quite characteristic of the substances1 as of sugar1 chloride of sodium1 arsenic1 and mercury4 ,this process may be extremely valuable to the mineralogist and toxicologist when the substance for examination is too small to be submitted to tests4 ,by aid of the microscope1 also1 shells are measured to the thousandth part of an inch4 ,,fine ,,down ,,of ,,quartz4 ,sir ,david ,brewster having broken in two a crystal of quartz of a smoky colour1 found both surfaces of the fracture absolutely black2 and the blackness appeared at first sight to be owing to a thin film of opaque matter which had insinuated itself into the crevice4 ,this opinion1 however1 was untenable1 as every part of the surface was black1 and the two halves of the crystals could not have stuck together had the crevice extended across the whole section4 ,upon further examination ,sir ,david found that the surface was perfectly transparent by transmitted light1 and that the blackness of the surfaces arose from their being entirely composed of a fine down of quartz1 or of short and slender filaments1 whose diameter was so exceedingly small that they were incapable of reflecting a single ray of the strongest light2 and they could not exceed the one third of the millionth part of an inch4 ,this curious specimen is in the cabinet of her grace the ,duchess of ,gordon4 ,,microscopic ,,writing4 ,professor ,kelland has shown1 in ,paris1 on a spot no larger than the head of a small pin1 by means of powerful microscopes1 several specimens of distinct and beautiful writing1 one of them containing the whole of the ,lord's ,prayer written within this minute compass4 ,in reference to this1 two remarkable facts in ,layard's latest work on ,nineveh show that the national records of ,assyria were written on square bricks1 in characters so small as scarcely to be legible without a microscope2 in fact1 a microscope1 as we have just shown1 was found in the ruins of ,nimroud4 ,,how ,,to ,,make ,a ,,magic ,,mirror4 ,draw a figure with weak gum-water upon the surface of a convex mirror4 ,the thin film of gum thus deposited on the outline or details of the figure will not be visible in dispersed daylight2 but when made to reflect the rays of the sun1 or those of a divergent pencil1 will be beautifully displayed by the lines and tints occasioned by the diffraction of light1 or the interference of the rays passing through the film with those which pass by it4 ,,sir ,,david ,,brewster',s ,,kaleidoscope4 ,the idea of this instrument1 constructed for the purpose of creating and exhibiting a variety of beautiful and perfectly symmetrical forms1 first occurred to ,sir ,david ,brewster in #ahad1 when he was engaged in experiments on the polarisation of light by successive reflections between plates of glass4 ,the reflectors were in some instances inclined to each other2 and he had occasion to remark the circular arrangement of the images of a candle round a centre1 or the multiplication of the sectors formed by the extremities of the glass plates4 ,in repeating at a subsequent period the experiments of ,m4 ,biot on the action of fluids upon light1 ,sir ,david ,brewster placed the fluids in a trough1 formed by two plates of glass cemented together at an angle2 and the eye being necessarily placed at one end1 some of the cement1 which had been pressed through between the plates1 appeared to be arranged into a regular figure4 ,the remarkable symmetry which it presented led to ,dr4 ,brewster's investigation of the cause of this phenomenon2 and in so doing he discovered the leading principles of the ,kaleidoscope4 ,by the advice of his friends1 ,dr4 ,brewster took out a patent for his invention2 in the specification of which he describes the kaleidoscope in two different forms4 ,the instrument1 however1 having been shown to several opticians in ,london1 became known before he could avail himself of his patent2 and being simple in principle1 it was at once largely manufactured4 ,it is calculated that not less than #bjj1jjj kaleidoscopes were sold in three months in ,london and ,paris2 though out of this number1 ,dr4 ,brewster says1 not perhaps #ajjj were constructed upon scientific principles1 or were capable of giving any thing like a correct idea of the power of his kaleidoscope4 ,,the ,,kaleidoscope ,,thought ,,to ,,be ,,anticipated4 ,in the seventh edition of a work on gardening and planting1 published in #agci1 by ,richard ,bradley1 ,f4,r4,s41 late ,professor of ,botany in the ,university of ,cambridge1 we find the following details of an invention1 8by which the best designers and draughtsmen may improve and help their fancies4 ,they must choose two pieces of looking-glass of equal bigness1 of the figure of a long square4 ,these must be covered on the back with paper or silk1 to prevent rubbing off the silver4 ,this covering must be so put on that nothing of it appears about the edges of the bright side4 ,the glasses being thus prepared1 must be laid face to face1 and hinged together so that they may be made to open and shut at pleasure like the leaves of a book40 ,after showing how various figures are to be looked at in these glasses under the same opening1 and how the same figure may be varied under the different openings1 the ingenious artist thus concludes3 8,if it should happen that the reader has any number of plans for parterres or wildernesses by him1 he may by this method alter them at his pleasure1 and produce such innumerable varieties as it is not possible the most able designer could ever have contrived40 ,,magic ,,of ,,photography4 ,professor ,moser of ,knigsberg has discovered that all bodies1 even in the dark1 throw out invisible rays2 and that these bodies1 when placed at a small distance from polished surfaces of all kinds1 depict themselves upon such surfaces in forms which remain invisible till they are developed by the human breath or by the vapours of mercury or iodine4 ,even if the sun's image is made to pass over a plate of glass1 the light tread of its rays will leave behind it an invisible track1 which the human breath will instantly reveal4 ,among the early attempts to take pictures by the rays of the sun was a very interesting and successful experiment made by ,dr4 ,thomas ,young4 ,in #ahjb1 when ,mr4 ,wedgewood was 8making profiles by the agency of light10 and ,sir ,humphry ,davy was 8copying on prepared paper the images of small objects produced by means of the solar microscope10 ,dr4 ,young was taking photographs upon paper dipped in a solution of nitrate of silver1 of the coloured rings observed by ,newton2 and his experiments clearly proved that the agent was not the luminous rays in the sun's light1 but the invisible or chemical rays beyond the violet4 ,this experiment is described in the ,bakerian ,lecture1 #ahjc4 ,niepce 7says ,mr4 ,hunt7 pursued a physical investigation of the curious change1 and found that all bodies were influenced by this principle radiated from the sun4 ,daguerre#ad produced effects from the solar pencil which no artist could approach2 and ,talbot and others extended the application4 ,herschel took up the inquiry2 and he1 with his usual power of inductive search and of philosophical deduction1 presented the world with a class of discoveries which showed how vast a field of investigation was opening for the younger races of mankind4 ,the first attempts in photography1 which were made at the instigation of ,m4 ,arago1 by order of the ,french ,government1 to copy the ,egyptian tombs and temples and the remains of the ,aztecs in ,central ,america1 were failures4 ,although the photographers employed succeeded to admiration1 in ,paris1 in producing pictures in a few minutes1 they found often that an exposure of an hour was insufficient under the bright and glowing illumination of a southern sky4 ,,the ,,best ,,sky ,,for ,,photography4 ,contrary to all preconceived ideas1 experience proves that the brighter the sky that shines above the camera the more tardy the action within it4 ,italy and ,malta do their work slower than ,paris4 ,under the brilliant light of a ,mexican sun1 half an hour is required to produce effects which in ,england would occupy but a minute4 ,in the burning atmosphere of ,india1 though photographical the year round1 the process is comparatively slow and difficult to manage2 while in the clear1 beautiful1 and moreover cool1 light of the higher ,alps of ,europe1 it has been proved that the production of a picture requires many more minutes1 even with the most sensitive preparations1 than in the murky atmosphere of ,london4 ,upon the whole1 the temperate skies of this country may be pronounced favourable to photographic action2 a fact for which the prevailing characteristic of our climate may partially account1 humidity being an indispensable condition for the working state both of paper and chemicals4--,quarterly ,review1 ,no4 #bjb4 ,,photographic ,,effects ,,of ,,lightning4 ,the following authenticated instances of this singular phenomenon have been communicated to the ,royal ,society by ,andrs ,poey1 ,director of the ,observatory at ,havana3 ,benjamin ,franklin1 in #aghf1 stated that about twenty years previous1 a man who was standing opposite a tree that had just been struck by 8a thunderbolt0 had on his breast an exact representation of that tree4 ,in the ,new-,york ,journal of ,commerce1 ,august #bfth1 #ahec1 it is related that 8a little girl was standing at a window1 before which was a young maple-tree2 after a brilliant flash of lightning1 a complete image of the tree was found imprinted on her body40 ,m4 ,raspail relates that1 in #ahee1 a boy having climbed a tree for the purpose of robbing a bird's nest1 the tree was struck1 and the boy thrown upon the ground2 on his breast the image of the tree1 with the bird and nest on one of its branches1 appeared very plainly4 ,m4 ,olioli1 a learned ,italian1 brought before the ,scientific ,congress at ,naples the following four instances3 #a4 ,in ,september #ahbe1 the foremast of a brigantine in the ,bay of ,st4 ,arniro was struck by lightning1 when a sailor sitting under the mast was struck dead1 and on his back was found an impression of a horse-shoe1 similar even in size to that fixed on the mast-head4 #b4 ,a sailor1 standing in a similar position1 was struck by lightning1 and had on his left breast the impression of the number #d #d1 with a dot between the two figures1 just as they appeared at the extremity of one of the masts4 #c4 ,on the #ith ,october #ahcf1 a young man was found struck by lightning2 he had on a girdle1 with some gold coins in it1 which were imprinted on his skin in the order they were placed in the girdle1--a series of circles1 with one point of contact1 being plainly visible4 #d4 ,in #ahdg1 ,mme4 ,morosa1 an ,italian lady of ,lugano1 was sitting near a window during a thunderstorm1 and perceived the commotion1 but felt no injury2 but a flower which happened to be in the path of the electric current was perfectly reproduced on one of her legs1 and there remained permanently4 ,m4 ,poey himself witnessed the following instance in ,cuba4 ,on ,july #bdth1 #aheb1 a poplar-tree in a coffee-plantation was struck by lightning1 and on one of the large dry leaves was found an exact representation of some pine-trees that lay #cfg yards distant4 ,m4 ,poey considers these lightning impressions to have been produced in the same manner as the electric images obtained by ,moser1 ,riess1 ,karster1 ,grove1 ,fox ,talbot1 and others1 either by statical or dynamical electricity of different intensities4 ,the fact that impressions are made through the garments is easily accounted for by their rough texture not preventing the lightning passing through them with the impression4 ,to corroborate this view1 ,m4 ,poey mentions an instance of lightning passing down a chimney into a trunk1 in which was found an inch depth of soot1 which must have passed through the wood itself4 ,,photographic ,,surveying4 ,during the summer of #ahed1 in the ,baltic1 the ,british steamers employed in examining the enemy's coasts and fortifications took photographic views for reference and minute examination4 ,with the steamer moving at the rate of fifteen knots an hour1 the most perfect definitions of coasts and batteries were obtained4 ,outlines of the coasts1 correct in height and distance1 have been faithfully transcribed2 and all details of the fortresses passed under this photographic review are accurately recorded4 ,it is curious to reflect that the aids to photographic development all date within the last half-century1 and are but little older than photography itself4 ,it was not until #ahaa that the chemical substance called iodine1 on which the foundations of all popular photography rest1 was discovered at all2 bromine1 the only other substance equally sensitive1 not till #ahbf4 ,the invention of the electro process was about simultaneous with that of photography itself4 ,gutta-percha only just preceded the substance of which collodion is made2 the ether and chloroform1 which are used in some methods1 that of collodion4 ,we say nothing of the optical improvements previously contrived or adapted for the purpose of the photograph3 the achromatic lenses1 which correct the discrepancy between the visual and chemical foci2 the double lenses1 which increase the force of the action2 the binocular lenses1 which do the work of the stereoscope2 nor of the innumerable other mechanical aids which have sprung up for its use4 ,,the ,,stereoscope ,,and ,,the ,,photograph4 ,when once the availability of one great primitive agent is worked out1 it is easy to foresee how extensively it will assist in unravelling other secrets in natural science4 ,the simple principle of the ,stereoscope1 for instance1 might have been discovered a century ago1 for the reasoning which led to it was independent of all the properties of light2 but it could never have been illustrated1 far less multiplied as it now is1 without ,photography4 ,a few diagrams1 of sufficient identity and difference to prove the truth of the principle1 might have been constructed by hand1 for the gratification of a few sages2 but no artist1 it is to be hoped1 could have been found possessing the requisite ability and stupidity to execute the two portraits1 or two groups1 or two interiors1 or two landscapes1 identical in every minutia of the most elaborate detail1 and yet differing in point of view by the inch between the two human eyes1 by which the principle is brought to the level of any capacity4 ,here1 therefore1 the accuracy and insensibility of a machine could alone avail2 and if in the order of things the cheap popular toy which the stereoscope now represents was necessary for the use of man1 the photograph was first necessary for the service of the stereoscope4--,quarterly ,review1 ,no4 #bjb4 ,,the ,,stereoscope ,,simplified4 ,when we look at any round object1 first with one eye1 and then with the other1 we discover that with the right eye we see most of the right-hand side of the object1 and with the left eye most of the left-hand side4 ,these two images are combined1 and we see an object which we know to be round4 ,this is illustrated by the ,stereoscope1 which consists of two mirrors placed each at an angle of #de deg41 or of two semi-lenses turned with their curved sides towards each other4 ,to view its phenomena two pictures are obtained by the camera on photographic paper of any object in two positions1 corresponding with the conditions of viewing it with the two eyes4 ,by the mirrors on the lenses these dissimilar pictures are combined within the eye1 and the vision of an actually solid object is produced from the pictures represented on a plane surface4 ,hence the name of the instrument1 which signifies ,solid ,i see4--,hunt's ,poetry of ,science4 ,,photo-,,galvanic ,,engraving4 ,that which was the chief aid of ,niepce in the humblest dawn of the art1 viz4 to transform the photographic plate into a surface capable of being printed1 is in the above process done by the coperation of ,electricity with ,photography4 ,this invention of ,m4 ,pretsch1 of ,vienna1 differs from all other attempts for the same purpose in not operating upon the photographic tablet itself1 and by discarding the usual means of varnishes and bitings-in4 ,the process is simply this3 ,a glass tablet is coated with gelatine diluted till it forms a jelly1 and containing bi-chromate of potash1 nitrate of silver1 and iodide of potassium4 ,upon this1 when dry1 is placed face downwards a paper positive1 through which the light1 being allowed to fall1 leaves upon the gelatine a representation of the print4 ,it is then soaked in water2 and while the parts acted upon by the light are comparatively unaffected by the fluid1 the remainder of the jelly swells1 and rising above the general surface1 gives a picture in relief1 resembling an ordinary engraving upon wood4 ,of this intaglio a cast is now taken in gutta-percha1 to which the electro process in copper being applied1 a plate or matrix is produced1 bearing on it an exact repetition of the original positive picture4 ,all that now remains to be done is to repeat the electro process2 and the result is a copper-plate in the necessary relievo1 of which it has been said nature furnished the materials and science the artist1 the inferior workman being only needed to roll it through the press4--,quarterly ,review1 ,no4 #bjb4 ,,science ,,of ,,the ,,soap-,,bubble4 ,few of the minor ingenuities of mankind have amused so many individuals as the blowing of bubbles with soap-lather from the bowl of a tobacco-pipe2 yet how few who in childhood's careless hours have thus amused themselves1 have in after-life become acquainted with the beautiful phenomena of light which the soap-bubble will enable us to illustrate6 ,usually the bubble is formed within the bowl of a tobacco-pipe1 and so inflated by blowing through the stem4 ,it is also produced by introducing a capillary tube under the surface of soapy water1 and so raising a bubble1 which may be inflated to any convenient size4 ,it is then guarded with a glass cover1 to prevent its bursting by currents of air1 evaporation1 and other causes4 ,when the bubble is first blown1 its form is elliptical1 into which it is drawn by its gravity being resisted2 but the instant it is detached from the pipe1 and allowed to float in air1 it becomes a perfect sphere1 since the air within presses equally in all directions4 ,there is also a strong cohesive attraction in the particles of soap and water1 after having been forcibly distended2 and as a sphere or globe possesses less surface than any other figure of equal capacity1 it is of all forms the best adapted to the closest approximation of the particles of soap and water1 which is another reason why the bubble is globular4 ,the film of which the bubble consists is inconceivably thin 7not exceeding the two-millionth part of an inch72 and by the evaporation from its surface1 the contraction and expansion of the air within1 and the tendency of the soap-lather to gravitate towards the lower part of the bubble1 and consequently to render the upper part still thinner1 it follows that the bubble lasts but a few seconds4 ,if1 however1 it were blown in a glass vessel1 and the latter immediately closed1 it might remain for some time2 ,dr4 ,paris thus preserved a bubble for a considerable period4 ,dr4 ,hooke1 by means of the coloured rings upon the soap-bubble1 studied the curious subject of the colours of thin plates1 and its application to explain the colours of natural bodies4 ,various phenomena were also discovered by ,newton1 who thus did not disdain to make a soap-bubble the object of his study4 ,the colours which are reflected from the upper surface of the bubble are caused by the decomposition of the light which falls upon it2 and the range of the phenomena is alike extensive and beautiful4#ae ,newton 7says ,sir ,d4 ,brewster71 having covered the soap-bubble with a glass shade1 saw its colours emerge in regular order1 like so many concentric rings encompassing the top of it4 ,as the bubble grew thinner by the continual subsidence of the water1 the rings dilated slowly1 and overspread the whole of it1 descending to the bottom1 where they vanished successively4 ,when the colours had all emerged from the top1 there arose in the centre of the rings a small round black spot1 dilating it to more than half an inch in breadth till the bubble burst4 ,upon examining the rings between the object-glasses1 ,newton found that when they were only eight or nine in number1 more than forty could be seen by viewing them through a prism2 and even when the plate of air seemed all over uniformly white1 multitudes of rings were disclosed by the prism4 ,by means of these observations ,newton was enabled to form his ,scale of ,colours1 of great value in all optical researches4 ,dr4 ,reade has thus produced a permanent soap-bubble3 ,put into a six-ounce phial two ounces of distilled water1 and set the phial in a vessel of water boiling on the fire4 ,the water in the phial will soon boil1 and steam will issue from its mouth1 expelling the whole of the atmospheric air from within4 ,then throw in a piece of soap about the size of a small pea1 cork the phial1 and at the same instant remove it and the vessel from the fire4 ,then press the cork farther into the neck of the phial1 and cover it thickly with sealing-wax2 and when the contents are cold1 a perfect vacuum will be formed within the bottle1--much better1 indeed1 than can be produced by the best-constructed air-pump4 ,to form a bubble1 hold the bottle horizontally in both hands1 and give it a sudden upward motion1 which will throw the liquid into a wave1 whose crest touching the upper interior surface of the phial1 the tenacity of the liquid will cause a film to be retained all round the phial4 ,next place the phial on its bottom2 when the film will form a section of the cylinder1 being nearly but never quite horizontal4 ,the film will be now colourless1 since it reflects all the light which falls upon it4 ,by remaining at rest for a minute or two1 minute currents of lather will descend by their gravitating force down the inclined plane formed by the film1 the upper part of which thus becomes drained to the necessary thinness2 and this is the part to be observed4 ,several concentric segments of coloured rings are produced2 the colours1 beginning from the top1 being as follows3 #ast order3 ,black1 white1 yellow1 orange1 red4 #b;d order3 ,purple1 blue1 white1 yellow1 red4 #c;d order3 ,purple1 blue1 green1 yellowish-green1 white1 red4 #dth order3 ,purple1 blue1 green1 white1 red4 #eth order3 ,greenish-blue1 very pale red4 #fth order3 ,greenish-blue1 pink4 #gth order3 ,greenish-blue1 pink4 ,as the segments advance they get broader1 while the film becomes thinner and thinner4 ,the several orders disappear upwards as the film becomes too thin to reflect their colours1 until the first order alone remains1 occupying the whole surface of the film4 ,of this order the red disappears first1 then the orange1 and lastly the yellow4 ,the film is now divided by a line into two nearly equal portions1 one black and the other white4 ,this remains for some time2 at length the film becomes too thin to hold together1 and then vanishes4 ,the colours are not faint and imperfect1 but well defined1 glowing with gorgeous hues1 or melting into tints so exquisite as to have no rival through the whole circle of the arts4 ,we quote these details from ,mr4 ,tomlinson's excellent ,student's ,manual of ,natural ,philosophy4 ,we find the following anecdote related of ,newton at the above period4 ,when ,sir ,isaac changed his residence1 and went to live in ,st4 ,martin's ,street1 ,leicester ,square1 his next-door neighbour was a widow lady1 who was much puzzled by the little she observed of the habits of the philosopher4 ,a ,fellow of the ,royal ,society called upon her one day1 when1 among her domestic news1 she mentioned that some one had come to reside in the adjoining house who1 she felt certain1 was a poor crazy gentleman1 8because10 she continued1 8he diverts himself in the oddest way imaginable4 ,every morning1 when the sun shines so brightly that we are obliged to draw the window-blinds1 he takes his seat on a little stool before a tub of soapsuds1 and occupies himself for hours blowing soap-bubbles through a common clay-pipe1 which bubbles he intently watches floating about till they burst4 ,he is doubtless10 she added1 8now at his favourite amusement1 for it is a fine day2 do come and look at him40 ,the gentleman smiled1 and they went upstairs2 when1 after looking through the staircase-window into the adjoining court-yard1 he turned and said3 8,my dear madam1 the person whom you suppose to be a poor lunatic is no other than the great ,sir ,isaac ,newton studying the refraction of light upon thin plates2 a phenomenon which is beautifully exhibited on the surface of a common soap-bubble40 ,,light ,,from ,,quartz4 ,among natural phenomena 7says ,sir ,david ,brewster7 illustrative of the colours of thin plates1 we find none more remarkable than one exhibited by the fracture of a large crystal of quartz of a smoky colour1 and about two and a quarter inches in diameter4 ,the surface of fracture1 in place of being a face or cleavage1 or irregularly conchoidal1 as we have sometimes seen it1 was filamentous1 like a surface of velvet1 and consisted of short fibres1 so small as to be incapable of reflecting light4 ,their size could not have been greater than the third of the millionth part of an inch1 or one-fourth of the thinnest part of the soap-bubble when it exhibits the black spot where it bursts4 ,,can ,,the ,,cat ,,see ,,in ,,the ,,dark8 ,no1 in all probability1 says the reader2 but the opposite popular belief is supported by eminent naturalists4 ,buffon says3 8,the eyes of the cat shine in the dark somewhat like diamonds1 which throw out during the night the light with which they were in a manner impregnated during the day40 ,valmont de ,bamare says3 8,the pupil of the cat is during the night still deeply imbued with the light of the day20 and again1 8the eyes of the cat are during the night so imbued with light that they then appear very shining and luminous40 ,spallanzani says3 8,the eyes of cats1 polecats1 and several other animals1 shine in the dark like two small tapers20 and he adds that this light is phosphoric4 ,treviranus says3 8,the eyes of the cat shine where no rays of light penetrate2 and the light must in many1 if not in all1 cases proceed from the eye itself40 ,now1 that the eyes of the cat do shine in the dark is to a certain extent true3 but we have to inquire whether by dark is meant the entire absence of light2 and it will be found that the solution of this question will dispose of several assertions and theories which have for centuries perplexed the subject4 ,dr4 ,karl ,ludwig ,esser has published in ,karsten's ,archives the results of an experimental inquiry on the luminous appearance of the eyes of the cat and other animals1 carefully distinguishing such as evolve light from those which only reflect it4 ,having brought a cat into a half-darkened room1 he observed from a certain direction that the cat's eyes1 when opposite the window1 sparkled brilliantly2 but in other positions the light suddenly vanished4 ,on causing the cat to be held so as to exhibit the light1 and then gradually darkening the room1 the light disappeared by the time the room was made quite dark4 ,in another experiment1 a cat was placed opposite the window in a darkened room4 ,a few rays were permitted to enter1 and by adjusting the light1 one or both of the cat's eyes were made to shine4 ,in proportion as the pupil was dilated1 the eyes were brilliant4 ,by suddenly admitting a strong glare of light into the room1 the pupil contracted2 and then suddenly darkening the room1 the eye exhibited a small round luminous point1 which enlarged as the pupil dilated4 ,the eyes of the cat sparkle most when the animal is in a lurking position1 or in a state of irritation4 ,indeed1 the eyes of all animals1 as well as of man1 appear brighter when in rage than in a quiescent state1 which ,collins has commemorated in his ,ode on the ,passions3 8,next ,anger rushed1 his eyes on fire40 ,this brilliancy is said to arise from an increased secretion of the lachrymal fluid on the surface of the eye1 by which the reflection of the light is increased4 ,dr4 ,esser1 in places absolutely dark1 never discovered the slightest trace of light in the eye of the cat2 and he has no doubt that in all cases where cats' eyes have been seen to shine in dark places1 such as a cellar1 light penetrated through some window or aperture1 and fell upon the eyes of the animal as it turned towards the opening1 while the observer was favourably situated to obtain a view of the reflection4 ,to prove more clearly that this light does not depend upon the will of the animal1 nor upon its angry passions1 experiments were made upon the head of a dead cat4 ,the sun's rays were admitted through a small aperture2 and falling immediately upon the eyes1 caused them to glow with a beautiful green light more vivid even than in the case of a living animal1 on account of the increased dilatation of the pupil4 ,it was also remarked that black and fox-coloured cats gave a brighter light than gray and white cats4 ,to ascertain the cause of this luminous appearance ,dr4 ,esser dissected the eyes of cats1 and exposed them to a small regulated amount of light after having removed different portions4 ,the light was not diminished by the removal of the cornea1 but only changed in colour4 ,the light still continued after the iris was displaced2 but on taking away the crystalline lens it greatly diminished both in intensity and colour4 ,dr4 ,esser then conjectured that the tapetum in the hinder part of the eye must form a spot which caused the reflection of the incident rays of light1 and thus produce the shining2 and this appeared more probable as the light of the eye now seemed to emanate from a single spot4 ,having taken away the vitreous humour1 ,dr4 ,esser observed that the entire want of the pigment in the hinder part of the choroid coat1 where the optic nerve enters1 formed a greenish1 silver-coloured1 changeable oblong spot1 which was not symmetrical1 but surrounded the optic nerve so that the greater part was above and only the smaller part below it2 wherefore the greater part lay beyond the axis of vision4 ,it is this spot1 therefore1 that produces the reflection of the incident rays of light1 and beyond all doubt1 according to its tint1 contributes to the different colouring of the light4 ,it may be as well to explain that the interior of the eye is coated with a black pigment1 which has the same effect as the black colour given to the inner surface of optical instruments3 it absorbs any rays of light that may be reflected within the eye1 and prevents them from being thrown again upon the retina so as to interfere with the distinctness of the images formed upon it4 ,the retina is very transparent2 and if the surface behind it1 instead of being of a dark colour1 were capable of reflecting light1 the luminous rays which had already acted on the retina would be reflected back again through it1 and not only dazzle from excess of light1 but also confuse and render indistinct the images formed on the retina4 ,now in the case of the cat this black pigment1 or a portion of it1 is wanting2 and those parts of the eye from which it is absent1 having either a white or a metallic lustre1 are called the tapetum4 ,the smallest portion of light entering from it is reflected as by a concave mirror2 and hence it is that the eyes of animals provided with this structure are luminous in a very faint light4 ,these experiments and observations show that the shining of the eyes of the cat does not arise from a phosphoric light1 but only from a reflected light2 that consequently it is not an effect of the will of the animal1 or of violent passions2 that their shining does not appear in absolute darkness2 and that it cannot enable the animal to move securely in the dark4 ,it has been proved by experiment that there exists a set of rays of light of far higher refrangibility than those seen in the ordinary ,newtonian spectrum4 ,mr4 ,hunt considers it probable that these highly refrangible rays1 although under ordinary circumstances invisible to the human eye1 may be adapted to produce the necessary degree of excitement upon which vision depends in the optic nerves of the night-roaming animals4 ,the bat1 the owl1 and the cat may see in the gloom of the night by the aid of rays which are invisible to1 or inactive on1 the eyes of man or those animals which require the light of day for perfect vision4 ,astronomy4 ,,the ,,great ,,truths ,,of ,,astronomy4 ,the difficulty of understanding these marvellous truths has been glanced at by an old divine 7see ,things not generally ,known1 p4 #a72 but the rarity of their full comprehension by those unskilled in mathematical science is more powerfully urged by ,lord ,brougham in these cogent terms3 ,satisfying himself of the laws which regulate the mutual actions of the planetary bodies1 the mathematician can convince himself of a truth yet more sublime than ,newton's discovery of gravitation1 though flowing from it2 and must yield his assent to the marvellous position1 that all the irregularities occasioned in the system of the universe by the mutual attraction of its members are periodical1 and subject to an eternal law1 which prevents them from ever exceeding a stated amount1 and secures through all time the balanced structure of a universe composed of bodies whose mighty bulk and prodigious swiftness of motion mock the utmost efforts of the human imagination4 ,all these truths are to the skilful mathematician as thoroughly known1 and their evidence is as clear1 as the simplest proposition of arithmetic to common understandings4 ,but how few are those who thus know and comprehend them6 ,of all the millions that thoroughly believe these truths1 certainly not a thousand individuals are capable of following even any considerable portion of the demonstrations upon which they rest2 and probably not a hundred now living have ever gone through the whole steps of these demonstrations4--,dissertations on ,subjects of ,science connected with ,natural ,theology1 vol4 ii4 ,sir ,david ,brewster thus impressively illustrates the same subject3 ,minds fitted and prepared for this species of inquiry are capable of appreciating the great variety of evidence by which the truths of the planetary system are established2 but thousands of individuals1 and many who are highly distinguished in other branches of knowledge1 are incapable of understanding such researches1 and view with a sceptical eye the great and irrefragable truths of astronomy4 ,that the sun is stationary in the centre of our system2 that the earth moves round the sun1 and round its own axis2 that the diameter of the earth is #hjjj miles1 and that of the sun one hundred and ten times as great2 that the earth's orbit is #aij1jjj1jjj of miles in breadth2 and that if this immense space were filled with light1 it would appear only like a luminous point at the nearest fixed star1--are positions absolutely unintelligible and incredible to all who have not carefully studied the subject4 ,to millions of our species1 then1 the great ,book of ,nature is absolutely sealed2 though it is in the power of all to unfold its pages1 and to peruse those glowing passages which proclaim the power and wisdom of its ,author4 ,,astronomy ,,and ,,dates ,,on ,,monuments4 ,astronomy is a useful aid in discovering the ,dates of ancient ,monuments4 ,thus1 on the ceiling of a portico among the ruins of ,tentyris are the twelve signs of the ,zodiac1 placed according to the apparent motion of the sun4 ,according to this ,zodiac1 the summer solstice is in ,leo2 from which it is easy to compute1 by the precession of the equinoxes of #eja annually1 that the ,zodiac of ,tentyris must have been made #djjj years ago4 ,mrs4 ,somerville relates that she once witnessed the ascertainment of the date of a ,papyrus by means of astronomy4 ,the manuscript was found in ,egypt1 in a mummy-case2 and its antiquity was determined by the configuration of the heavens at the time of its construction4 ,it proved to be a horoscope of the time of ,ptolemy4 8,,the ,,crystal ,,vault ,,of ,,heaven40 ,this poetic designation dates back as far as the early period of ,anaximenes2 but the first clearly defined signification of the idea on which the term is based occurs in ,empedocles4 ,this philosopher regarded the heaven of the fixed stars as a solid mass1 formed from the ether which had been rendered crystalline by the action of fire4 ,in the ,middle ,ages1 the fathers of the ,church believed the firmament to consist of from seven to ten glassy strata1 incasing each other like the different coatings of an onion4 ,this supposition still keeps its ground in some of the monasteries of southern ,europe1 where ,humboldt was greatly surprised to hear a venerable prelate express an opinion in reference to the fall of aerolites at ,aigle1 that the bodies we called meteoric stones with vitrified crusts were not portions of the fallen stone itself1 but simply fragments of the crystal vault shattered by it in its fall4 ,empedocles maintained that the fixed stars were riveted to the crystal heavens2 but that the planets were free and unconstrained4 ,it is difficult to conceive how1 according to ,plato in the ,timus1 the fixed stars1 riveted as they are to solid spheres1 could rotate independently4 ,among the ancient views1 it may be mentioned that the equal distance at which the stars remained1 while the whole vault of heaven seemed to move from east to west1 had led to the idea of a firmament and a solid crystal sphere1 in which ,anaximenes 7who was probably not much later than ,pythagoras7 had conjectured that the stars were riveted like nails4 ,,music ,,of ,,the ,,spheres4 ,the ,pythagoreans1 in applying their theory of numbers to the geometrical consideration of the five regular bodies1 to the musical intervals of tone which determine a word and form different kinds of sounds1 extended it even to the system of the universe itself2 supposing that the moving1 and1 as it were1 vibrating planets1 exciting sound-waves1 must produce a spheral music1 according to the harmonic relations of their intervals of space4 8,this music10 they add1 8would be perceived by the human ear1 if it was not rendered insensible by extreme familiarity1 as it is perpetual1 and men are accustomed to it from childhood40 ,the ,pythagoreans affirm1 in order to justify the reality of the tones produced by the revolution of the spheres1 that hearing takes place only where there is an alternation of sound and silence4 ,the inaudibility of the spheral music is also accounted for by its overpowering the senses4 ,aristotle himself calls the ,pythagorean tone-myth pleasing and ingenious1 but untrue4 ,plato attempted to illustrate the tones of the universe in an agreeable picture1 by attributing to each of the planetary spheres a syren1 who1 supported by the stern daughters of ,necessity1 the three ,fates1 maintain the eternal revolution of the world's axis4 ,mention is constantly made of the harmony of the spheres1 though generally reproachfully1 throughout the writings of ,christian antiquity and the ,middle ,ages1 from ,basil the ,great to ,thomas ,aquinas and ,petrus ,alliacus4 ,at the close of the sixteenth century1 ,kepler revived these musical ideas1 and sought to trace out the analogies between the relations of tone and the distances of the planets2 and ,tycho ,brahe was of opinion that the revolving conical bodies were capable of vibrating the celestial air 7what we now call 8resisting medium07 so as to produce tones4 ,yet ,kepler1 although he had talked of ,venus and the ,earth sounding sharp in aphelion and flat in perihelion1 and the highest tone of ,jupiter and that of ,venus coinciding in flat accord1 positively declared there to be 8no such things as sounds among the heavenly bodies1 nor is their motion so turbulent as to elicit noise from the attrition of the celestial air40 7,see ,things not generally ,known1 p4 #dd47 8,,more ,,worlds ,,than ,,one40 ,although this opinion was maintained incidentally by various writers both on astronomy#af and natural religion1 yet ,m4 ,fontenelle was the first individual who wrote a treatise on the ,plurality of ,worlds1 which appeared in #afhe1 the year before the publication of ,newton's ,principia4 ,fontenelle's work consists of five chapters3 #a4 ,the earth is a planet which turns round its axis1 and also round the sun4 #b4 ,the moon is a habitable world4 #c4 ,particulars concerning the world in the moon1 and that the other planets are also inhabited4 #d4 ,particulars of the worlds of ,venus1 ,mercury1 ,mars1 ,jupiter1 and ,saturn4 #e4 ,the fixed stars are as many suns1 each of which illuminates a world4 ,in a future edition1 #agai1 ,fontenelle added1 #f4 ,new thoughts which confirm those in the preceding conversations1 and the latest discoveries which have been made in the heavens4 ,the next work on the subject was the ,theory of the ,universe1 or ,conjectures concerning the ,celestial ,bodies and their ,inhabitants1 #afih1 by ,christian ,huygens1 the contemporary of ,newton4 ,the doctrine is maintained by almost all the distinguished astronomers and writers who have flourished since the true figure of the earth was determined4 ,giordano ,bruna of ,nola1 ,kepler1 and ,tycho ,brahe1 believed in it2 and ,cardinal ,cusa and ,bruno1 before the discovery of binary systems among the stars1 believed also that the stars were inhabited4 ,sir ,isaac ,newton likewise adopted the belief2 and ,dr4 ,bentley1 ,master of ,trinity ,college1 ,cambridge1 in his eighth sermon on the ,confutation of ,atheism from the origin and frame of the world1 has ably maintained the same doctrine4 ,in our own day we may number among its supporters the distinguished names of the ,marquis de la ,place1 ,sir ,william and ,sir ,john ,herschel1 ,dr4 ,chalmers1 ,isaac ,taylor1 and ,m4 ,arago4 ,dr4 ,chalmers maintains the doctrine in his ,astronomical ,discourses1 which one ,alexander ,maxwell 7who did not believe in the grand truths of astronomy7 attempted to controvert1 in #ahbj1 in a chapter of a volume entitled ,plurality of ,worlds4 ,next appeared ,of a ,plurality of ,worlds1 attributed to the ,rev4 ,dr4 ,whewell1 ,master of ,trinity ,college1 ,cambridge2 urging the theological not less than the scientific reasons for believing in the old tradition of a single world1 and maintaining that 8the earth is really the largest planetary body in the solar system1--its domestic hearth1 and the only world in the universe40 8,i do not pretend10 says ,dr4 ,whewell1 8to disprove the plurality of worlds2 but ,i ask in vain for any argument which makes the doctrine probable40 8,it is too remote from knowledge to be either proved or disproved40 ,sir ,david ,brewster has replied to ,dr4 ,whewell's ,essay1 in ,more ,worlds than ,one1 the ,creed of the ,philosopher and the ,hope of the ,christian1 emphatically maintaining that analogy strongly countenances the idea of all the solar planets1 if not all worlds in the universe1 being peopled with creatures not dissimilar in being and nature to the inhabitants of the earth4 ,this view is supported in ,scientific ,certainties of ,planetary ,life1 by ,t4 ,c4 ,simon1 who well treats one point of the argument--that mere distance of the planets from the central sun does not determine the condition as to light and heat1 but that the density of the ethereal medium enters largely into the calculation4 ,mr4 ,simon's general conclusion is1 that 8neither on account of deficient or excessive heat1 nor with regard to the density of the materials1 nor with regard to the force of gravity on the surface1 is there the slightest pretext for supposing that all the planets of our system are not inhabited by intellectual creatures with animal bodies like ourselves1--moral beings1 who know and love their great ,maker1 and who wait1 like the rest of ,his creation1 upon ,his providence and upon ,his care40 ,one of the leading points of ,dr4 ,whewell's ,essay is1 that we should not elevate the conjectures of analogy into the rank of scientific certainties2 and that 8the force of all the presumptions drawn from physical reasoning for the opinion of planets and stars being either inhabited or uninhabited is so small1 that the belief of all thoughtful persons on this subject will be determined by moral1 metaphysical1 and theological considerations40 ,,worlds ,,to ,,come--,,abodes ,,of ,,the ,,blest4 ,sir ,david ,brewster1 in his eloquent advocacy of the doctrine of 8more worlds than one10 thus argues for their peopling3 ,man1 in his future state of existence1 is to consist1 as at present1 of a spiritual nature residing in a corporeal frame4 ,he must live1 therefore1 upon a material planet1 subject to all the laws of matter1 and performing functions for which a material body is indispensable4 ,we must consequently find for the race of ,adam1 if not races that may have preceded him1 a material home upon which they may reside1 or by which they may travel1 by means unknown to us1 to other localities in the universe4 ,at the present hour1 the inhabitants of the earth are nearly a thousand millions2 and by whatever process we may compute the numbers that have existed before the present generation1 and estimate those that are yet to inherit the earth1 we shall obtain a population which the habitable parts of our globe could not possibly accommodate4 ,if there is not room1 then1 on our earth for the millions of millions of beings who have lived and died upon its surface1 and who may yet live and die during the period fixed for its occupation by man1 we can scarcely doubt that their future abode must be on some of the primary or secondary planets of the solar system1 whose inhabitants have ceased to exist like those on the earth1 or upon planets in our own or in other systems which have been in a state of preparation1 as our earth was1 for the advent of intellectual life4 8,,gauging ,,the ,,heavens40 ,sir ,william ,herschel1 in #aghe1 conceived the happy idea of counting the number of stars which passed at different heights and in various directions over the field of view1 of fifteen minutes in diameter1 of his twenty-feet reflecting telescope4 ,the field of view each time embraced only #a_/hccjjjth of the whole heavens2 and it would therefore require1 according to ,struve1 eighty-three years to gauge the whole sphere by a similar process4 ,,velocity ,,of ,,the ,,solar ,,system4 ,m4 ,f4 ,w4 ,g4 ,struve gives as the splendid result of the united studies of ,,mm4 ,argelander1 ,o4 ,struve1 and ,peters1 grounded on observations made at the three ,russian observatories of ,dorpat1 ,abo1 and ,pulkowa1 8that the velocity of the motion of the solar system in space is such that the sun1 with all the bodies which depend upon it1 advances annually towards the constellation ,hercules#ag #afbc times the radius of the earth's orbit1 or #cc1eej1jjj geographical miles4 ,the possible error of this last number amounts to #a1gcc1jjj geographical miles1 or to a seventh of the whole value4 ,we may1 then1 wager #djj1jjj to #a that the sun has a proper progressive motion1 and #a to #a that it is comprised between the limits of thirty-eight and twenty-nine millions of geographical miles40 ,that is1 taking #ie1jjj1jjj of ,english miles as the mean radius of the ,earth's orbit1 we have #ie #afbc #aedahe millions of miles2 and consequently1 ,english ,miles4 ,the velocity of the ,solar ,system #aed1ahe1jjj in the year4 0 0 #dbb1dbd in a day4 0 0 #ag1fja in an hour4 0 0 #bic in a minute4 0 0 #eg in a second4 ,the ,sun and all his planets1 primary and secondary1 are therefore now in rapid motion round an invisible focus4 ,to that now dark and mysterious centre1 from which no ray1 however feeble1 shines1 we may in another age point our telescopes1 detecting perchance the great luminary which controls our system and bounds its path3 into that vast orbit man1 during the whole cycle of his race1 may never be allowed to round4--,north-,british ,review1 ,no4 #af4 ,,nature ,,of ,,the ,,sun4 ,m4 ,arago has found1 by experiments with the polariscope1 that the light of gaseous bodies is natural light when it issues from the burning surface2 although this circumstance does not prevent its subsequent complete polarisation1 if subjected to suitable reflections or refractions4 ,hence we obtain a most simple method of discovering the nature of the sun at a distance of forty millions of leagues4 ,for if the light emanating from the margin of the sun1 and radiating from the solar substance at an acute angle1 reach us without having experienced any sensible reflections or refractions in its passage to the earth1 and if it offer traces of polarisation1 the sun must be a solid or a liquid body4 ,but if1 on the contrary1 the light emanating from the sun's margin give no indications of polarisation1 the incandescent portion of the sun must be gaseous4 ,it is by means of such a methodical sequence of observations that we may acquire exact ideas regarding the physical constitution of the sun4--,note to ,humboldt's ,cosmos1 vol4 iii4 ,,structure ,,of ,,the ,,luminous ,,disc ,,of ,,the ,,sun4 ,the extraordinary structure of the fully luminous ,disc of the ,sun1 as seen through ,sir ,james ,south's great achromatic1 in a drawing made by ,mr4 ,gwilt1 resembles compressed curd1 or white almond-soap1 or a mass of asbestos fibres1 lying in a quaquaversus direction1 and compressed into a solid mass4 ,there can be no illusion in this phenomenon2 it is seen by every person with good vision1 and on every part of the sun's luminous surface or envelope1 which is thus shown to be not a flame1 but a soft solid or thick fluid1 maintained in an incandescent state by subjacent heat1 capable of being disturbed by differences of temperature1 and broken up as we see it when the sun is covered with spots or openings in the luminous matter4--,north-,british ,review1 ,no4 #af4 ,copernicus named the sun the lantern of the world 7lucerna mundi72 and ,theon of ,smyrna called it the heart of the universe4 ,the mass of the sun is1 according to ,encke's calculation of ,sabine's pendulum formula1 #cei1eea times that of the earth1 or #cee1dii times that of the earth and moon together2 whence the density of the sun is only about 7or more accurately #jbeb7 that of the earth4 ,the volume of the sun is #fjj times greater1 and its mass1 according to ,galle1 #gch times greater1 than that of all the planets combined4 ,it may assist the mind in conceiving a sensuous image of the magnitude of the sun1 if we remember that if the solar sphere were entirely hollowed out1 and the earth placed in its centre1 there would still be room enough for the moon to describe its orbit1 even if the radius of the latter were increased #afj1jjj geographical miles4 ,a railway-engine1 moving at the rate of thirty miles an hour1 would require #cfj years to travel from the earth to the sun4 ,the diameter of the sun is rather more than one hundred and eleven times the diameter of the earth4 ,therefore the volume or bulk of the sun must be nearly one million four hundred thousand times that of the earth4 ,lastly1 if all the bodies composing the solar system were formed into one globe1 it would be only about the five-hundredth part of the size of the sun4 ,,great ,,size ,,of ,,the ,,sun ,,on ,,the ,,horizon ,,explained4 ,the dilated size 7generally7 of the ,sun or ,moon1 when seen near the horizon1 beyond what they appear to have when high up in the sky1 has nothing to do with refraction4 ,it is an illusion of the judgment1 arising from the terrestrial objects interposed1 or placed in close comparison with them4 ,in that situation we view and judge of them as we do of terrestrial objects--in detail1 and with an acquired attention to parts4 ,aloft we have no association to guide us1 and their insulation in the expanse of the sky leads us rather to undervalue than to over-rate their apparent magnitudes4 ,actual measurement with a proper instrument corrects our error1 without1 however1 dispelling our illusion4 ,by this we learn that the sun1 when just on the horizon1 subtends at our eyes almost exactly the same1 and the moon a materially less1 angle than when seen at a greater altitude in the sky1 owing to its greater distance from us in the former situation as compared with the latter4--,sir ,john ,herschel's ,outlines4 ,,translatory ,,motion ,,of ,,the ,,sun4 ,this phenomenon is the progressive motion of the centre of gravity of the whole solar system in universal space4 ,its velocity1 according to ,bessel1 is probably four millions of miles daily1 in a relative velocity to that of #fa ,cygni of at least #c1ccf1jjj miles1 or more than double the velocity of the revolution of the earth in her orbit round the sun4 ,this change of the entire solar system would remain unknown to us1 if the admirable exactness of our astronomical instruments of measurement1 and the advancement recently made in the art of observing1 did not cause our progress towards remote stars to be perceptible1 like an approximation to the objects of a distant shore in apparent motion4 ,the proper motion of the star #fa ,cygni1 for instance1 is so considerable1 that it has amounted to a whole degree in the course of #gjj years4--,humboldt's ,cosmos1 vol4 i4 ,,the ,,sun',s ,,light ,,compared ,,with ,,terrestrial ,,lights4 ,mr4 ,ponton has by means of a simple monochromatic photometer ascertained that a small surface1 illuminated by mean solar light1 is #ddd times brighter than when it is illuminated by a moderator lamp1 and #aefj times brighter than when it is illuminated by a wax-candle 7short six in the lb47--the artificial light being in both instances placed at two inches' distance from the illuminated surface4 ,and three electric lights1 each equal to #ebj wax-candles1 will render a small surface as bright as when it is illuminated by mean sunshine4 ,it is thence inferred1 that a stratum occupying the entire surface of the sphere of which the earth's distance from the sun is the radius1 and consisting of three layers of flame1 each #a_/ajjjth of an inch in thickness1 each possessing a brightness equal to that of such an electric light1 and all three embraced within a thickness of #a_/djth of an inch1 would give an amount of illumination equal in quantity and intensity to that of the sun at the distance of #ie millions of miles from his centre4 ,and were such a stratum transferred to the surface of the sun1 where it would occupy #df1bge times less area1 its thickness would be increased to #id feet1 and it would embrace #ach1hbe layers of flame1 equal in brightness to the electric light2 but the same effect might be produced by a stratum about nine miles in thickness1 embracing #gb millions of layers1 each having only a brightness equal to that of a wax-candle4#ah ,,actinic ,,power ,,of ,,the ,,sun4 ,mr4 ,j4 ,j4 ,waterston1 in #aheg1 made at ,bombay some experiments on the photographic power of the sun's direct light1 to obtain data in an inquiry as to the possibility of measuring the diameter of the sun to a very minute fraction of a second1 by combining photography with the principle of the electric telegraph2 the first to measure the element space1 the latter the element time4 ,the result is that about #a_/bjjjjth of a second is sufficient exposure to the direct light of the sun to obtain a distinct mark on a sensitive collodion plate1 when developed by the usual processes2 and the duration of the sun's full action on any one point is about #a_/ijjjth of a second4 ,m4 ,schatt1 a young painter of ,berlin1 after #aejj experiments1 succeeded in establishing a scale of all the shades of black which the action of the sun produces on photographic paper2 so that by comparing the shade obtained at any given moment on a certain paper with that indicated on the scale1 the exact force of the sun's light may be determined4 ,,heating ,,power ,,of ,,the ,,sun4 ,all moving power has its origin in the rays of the sun4 ,while ,stephenson's iron tubular railway-bridge over the ,menai ,straits1 #djj feet long1 bends but half an inch under the heaviest pressure of a train1 it will bend up an inch and a half from its usual horizontal line when the sun shines on it for some hours4 ,the ,bunker-,hill monument1 near ,boston1 ,u4,s41 is higher in the evening than in the morning of a sunny day2 the little sunbeams enter the pores of the stone like so many wedges1 lifting it up4 ,in winter1 the ,earth is nearer the ,sun by about #a_/cj than in summer2 but the rays strike the northern hemisphere more obliquely in winter than the other half year4 ,m4 ,pouillet has estimated1 with singular ingenuity1 from a series of observations made by himself1 that the whole quantity of heat which the ,earth receives annually from the ,sun is such as would be sufficient to melt a stratum of ice covering the entire globe forty-six feet deep4 ,by the action of the sun's rays upon the earth1 vegetables1 animals1 and man1 are in their turn supported2 the rays become likewise1 as it were1 a store of heat1 and 8the sources of those great deposits of dynamical efficiency which are laid up for human use in our coal strata0 7,herschel74 ,a remarkable instance of the power of the sun's rays is recorded at ,stonehouse ,point1 ,devon1 in the year #ahbh4 ,to lay the foundation of a sea-wall the workmen had to descend in a diving-bell1 which was fitted with convex glasses in the upper part1 by which1 on several occasions in clear weather1 the sun's rays were so concentrated as to burn the labourers' clothes when opposed to the focal point1 and this when the bell was twenty-five feet under the surface of the water6 ,,cause ,,of ,,dark ,,colour ,,of ,,the ,,skin4 ,darkness of complexion has been attributed to the sun's power from the age of ,solomon to this day1--8,look not upon me1 because ,i am black1 because the sun hath looked upon me30 and there cannot be a doubt that1 to a certain degree1 the opinion is well founded4 ,the invisible rays in the solar beams1 which change vegetable colour1 and have been employed with such remarkable effect in the daguerreotype1 act upon every substance on which they fall1 producing mysterious and wonderful changes in their molecular state1 man not excepted4--,mrs4 ,somerville4 ,,extreme ,,solar ,,heat4 ,the fluctuation in the sun's direct heating power amounts to #a_/aeth1 which is too considerable a fraction of the whole intensity not to aggravate in a serious degree the sufferings of those who are exposed to it in thirsty deserts without shelter4 ,the amount of these sufferings1 in the interior of ,australia for instance1 are of the most frightful kind1 and would seem far to exceed what have ever been undergone by travellers in the northern deserts of ,africa4 ,thus ,captain ,sturt1 in his account of his ,australian exploration1 says3 8,the ground was almost a molten surface2 and if a match accidentally fell upon it1 it immediately ignited40 ,sir ,john ,herschel has observed the temperature of the surface soil in ,south ,africa as high as #aei ,fahrenheit4 ,an ordinary lucifer-match does not ignite when simply pressed upon a smooth surface at #bab2 but in the act of withdrawing it it takes fire1 and the slightest friction upon such a surface of course ignites it4 ,,how ,,dr4 ,,wollaston ,,compared ,,the ,,light ,,of ,,the ,,sun ,,and ,,the ,,fixed ,,stars4 ,in order to compare the ,light of the ,sun with that of a ,star1 ,dr4 ,wollaston took as an intermediate object of comparison the light of a candle reflected from a bulb about a quarter of an inch in diameter1 filled with quicksilver2 and seen by one eye through a lens of two inches focus1 at the same time that the star on the sun's image1 placed at a proper distance1 was viewed by the other eye through a telescope4 ,the mean of various trials seemed to show that the light of ,sirius is equal to that of the sun seen in a glass bulb #a_/ajth of an inch in diameter1 at the distance of #baj feet2 or that they are in the proportion of one to ten thousand millions3 but as nearly one half of this light is lost by reflection1 the real proportion between the light from ,sirius and the sun is not greater than that of one to twenty thousand millions4 8,,the ,,sun ,,darkened40 ,humboldt selects the following example from historical records as to the occurrence of a sudden decrease in the light of the ,sun3 ,a4,d4 #cc1 the year of the ,crucifixion4 8,now from the sixth hour there was darkness over all the land till the ninth hour0 7,st4 ,matthew xxvii4 #de74 ,according to ,st4 ,luke 7xxiii4 #de71 8the sun was darkened40 ,in order to explain and corroborate these narrations1 ,eusebius brings forward an eclipse of the sun in the #bjb;d ,olympiad1 which had been noticed by the chronicler ,phlegon of ,tralles 7,ideler1 ,handbuch der ,mathem4 ,chronologie1 ,bd4 ii4 p4 #dag74 ,wurn1 however1 has shown that the eclipse which occurred during this ,olympiad1 and was visible over the whole of ,asia ,minor1 must have happened as early as the #bdth of ,november #bi ,a4,d4 ,the day of the ,crucifixion corresponded with the ,jewish ,passover 7,ideler1 ,bd4 i4 pp4 #eae-ebj71 on the #adth of the month ,nisan1 and the ,passover was always celebrated at the time of the full moon4 ,the sun cannot therefore have been darkened for three hours by the moon4 ,the ,jesuit ,scheiner thinks the decrease in the light might be ascribed to the occurrence of large sun-spots4 ,,the ,,sun ,,and ,,terrestrial ,,magnetism4 ,the important influence exerted by the ,sun's body1 as a mass1 upon ,terrestrial ,magnetism1 is confirmed by ,sabine in the ingenious observation1 that the period at which the intensity of the magnetic force is greatest1 and the direction of the needle most near to the vertical line1 falls in both hemispheres between the months of ,october and ,february2 that is to say1 precisely at the time when the earth is nearest to the sun1 and moves in its orbit with the greatest velocity4 ,,is ,,the ,,heat ,,of ,,the ,,sun ,,decreasing8 ,the ,heat of the ,sun is dissipated and lost by radiation1 and must be progressively diminished unless its thermal energy be supplied4 ,according to the measurements of ,m4 ,pouillet1 the quantity of heat given out by the sun in a year is equal to that which would be produced by the combustion of a stratum of coal seventeen miles in thickness2 and if the sun's capacity for heat be assumed equal to that of water1 and the heat be supposed drawn uniformly from its entire mass1 its temperature would thereby undergo a diminution of #bjd ,fahr4 annually4 ,on the other hand1 there is a vast store of force in our system capable of conversion into heat4 ,if1 as is indicated by the small density of the sun1 and by other circumstances1 that body has not yet reached the condition of incompressibility1 we have in the future approximation of its parts a fund of heat1 probably quite large enough to supply the wants of the human family to the end of its sojourn here4 ,it has been calculated that an amount of condensation which would diminish the diameter of the sun by only the ten-thousandth part1 would suffice to restore the heat emitted in #bjjj years4 ,,universal ,,sun-,,dial4 ,mr4 ,sharp1 of ,dublin1 exhibited to the ,british ,association in #ahdi a ,dial1 consisting of a cylinder set to the day of the month1 and then elevated to the latitude4 ,a thin plane of metal1 in the direction of its axis1 is then turned by a milled head below it till the shadow is a minimum1 when a dial on the top shows the hours by one hand1 and the minutes by another1 to the precision of about three minutes4 ,,length ,,of ,,days ,,at ,,the ,,poles4 ,during the summer1 in the northern hemisphere1 places near the ,north ,pole are in continual sunlight--the sun never sets to them2 while during that time places near the ,south ,pole never see the sun4 ,when it is summer in the southern hemisphere1 and the sun shines on the ,south ,pole without setting1 the ,north ,pole is entirely deprived of his light4 ,indeed1 at the ,poles there is but one day and one night2 for the sun shines for six months together on one ,pole1 and the other six months on the other ,pole4 ,,how ,,the ,,distance ,,of ,,the ,,sun ,,is ,,ascertained ,,by ,,the ,,yard-,,measure4 ,professor ,airy1 in his ,six ,lectures on ,astronomy1 gives a masterly analysis of a problem of considerable intricacy1 viz4 the determination of the parallax of the sun1 and consequently of his distance1 by observations of the transit of ,venus1 the connecting link between measures upon the earth's surface and the dimensions of our system4 ,the further step of investigating the parallax1 and consequently the distance of the fixed stars 7where that is practicable71 is also elucidated2 and the author1 with evident satisfaction1 thus sums up the several steps3 ,by means of a yard-measure1 a base-line in a survey was measured2 from this1 by the triangulations and computations of a survey1 an arc of meridian on the earth was measured2 from this1 with proper observations with the zenith sector1 the surveys being also repeated on different parts of the earth1 the earth's form and dimensions were ascertained2 from these1 and a previous independent knowledge of the proportions of the distances of the earth and other planets from the sun1 with observations of the transit of ,venus1 the sun's distance is determined2 and from this1 with observations leading to the parallax of the stars1 the distance of the stars is determined4 ,and every step in the process can be distinctly referred to its basis1 that is1 the yard-measure4 ,,how ,,the ,,tides ,,are ,,produced ,,by ,,the ,,sun ,,and ,,moon4 ,each of these bodies excites1 by its attraction upon the waters of the sea1 two gigantic waves1 which flow in the same direction round the world as the attracting bodies themselves apparently do4 ,the two waves of the moon1 on account of her greater nearness1 are about #c times as large as those excited by the sun4 ,one of these waves has its crest on the quarter of the earth's surface which is turned towards the moon2 the other is at the opposite side4 ,both these quarters possess the flow of the tide1 while the regions which lie between have the ebb4 ,although in the open sea the height of the tide amounts to only about three feet1 and only in certain narrow channels1 where the moving water is squeezed together1 rises to thirty feet1 the might of the phenomenon is nevertheless manifest from the calculation of ,bessel1 according to which a quarter of the earth covered by the sea possesses during the flow of the tide about #be1jjj cubic miles of water more than during the ebb2 and that1 therefore1 such a mass of water must in #f hours flow from one quarter of the earth to the other4--,professor ,helmholtz4 ,,spots ,,on ,,the ,,sun4 ,sir ,john ,herschel describes these phenomena1 when watched from day to day1 or even from hour to hour1 as appearing to enlarge or contract1 to change their forms1 and at length disappear altogether1 or to break out anew in parts of the surface where none were before4 ,occasionally they break up or divide into two or more4 ,the scale on which their movements takes place is immense4 ,a single second of angular measure1 as seen from the earth1 corresponds on the sun's disc to #dfa miles2 and a circle of this diameter 7containing therefore nearly #afg1jjj square miles7 is the least space which can be distinctly discerned on the sun as a visible area4 ,spots have been observed1 however1 whose linear diameter has been upwards of #de1jjj miles2 and even1 if some records are to be trusted1 of very much greater extent4 ,that such a spot should close up in six weeks time 7for they seldom last much longer71 its borders must approach at the rate of more than #ajjj miles a-day4 ,the same astronomer saw at the ,cape of ,good ,hope1 on the #bith ,march #ahcg1 a solar spot occupying an area of near five square minutes1 equal to #c1ghj1jjj1jjj square miles4 8,the black centre of the spot of ,may #beth1 #ahcg 7not the tenth part of the preceding one71 would have allowed the globe of our earth to drop through it1 leaving a thousand miles clear of contact on all sides of that tremendous gulf40 ,for such an amount of disturbance on the sun's atmosphere1 what reason can be assigned8 ,the ,rev4 ,mr4 ,dawes has invented a peculiar contrivance1 by means of which he has been enabled to scrutinise1 under high magnifying power1 minute portions of the solar disc4 ,he places a metallic screen1 pierced with a very small hole1 in the focus of the telescope1 where the image of the sun is formed4 ,a small portion only of the image is thus allowed to pass through1 so that it may be examined by the eye-piece without inconveniencing the observer by heat or glare4 ,by this arrangement1 ,mr4 ,dawes has observed peculiarities in the constitution of the sun's surface which are discernible in no other way4 ,before these observations1 the dark spots seen on the sun's surface were supposed to be portions of the solid body of the sun1 laid bare to our view by those immense fluctuations in the luminous regions of its atmosphere to which it appears to be subject4 ,it now appears that these dark portions are only an additional and inferior stratum of a very feebly luminous or illuminated portion of the sun's atmosphere4 ,this again in its turn ,mr4 ,dawes has frequently seen pierced with a smaller and usually much more rounded aperture1 which would seem at last to afford a view of the real solar surface of most intense blackness4 ,m4 ,schwabe1 of ,dessau1 has discovered that the abundance or paucity of spots displayed by the sun's surface is subject to a law of periodicity4 ,this has been confirmed by ,m4 ,wolf1 of ,berne1 who shows that the period of these changes1 from minimum to minimum1 is #aa years and #aa-;hundredths of a year1 being exactly at the rate of nine periods per century1 the last year of each century being a year of minimum4 ,it is strongly corroborative of the correctness both of ,m4 ,wolf's period and also of the periodicity itself1 that of all the instances of the appearance of spots on the sun recorded in history1 even before the invention of the telescope1 or of remarkable deficiencies in the sun's light1 of which there are great numbers1 only two are found to deviate as much as two years from ,m4 ,wolf's epochs4 ,sir ,william ,herschel observed that the presence or absence of spots had an influence on the temperature of the seasons2 his observations have been fully confirmed by ,m4 ,wolf4 ,and1 from an examination of the chronicles of ,zurich from ,a4,d4 #ajjj to ,a4,d4 #ahjj1 he has come to the conclusion 8that years rich in solar spots are in general drier and more fruitful than those of an opposite character2 while the latter are wetter and more stormy than the former40 ,the most extraordinary fact1 however1 in connection with the spots on the sun's surface1 is the singular coincidence of their periods with those great disturbances in the magnetic system of the earth to which the epithet of 8magnetic storms0 has been affixed4 ,these disturbances1 during which the magnetic needle is greatly and universally agitated 7not in a particular limited locality1 but at one and the same instant of time over whole continents1 or even over the whole earth71 are found1 so far as observation has hitherto extended1 to maintain a parallel1 both in respect of their frequency of occurrence and intensity in successive years1 with the abundance and magnitude of the spots in the same years1 too close to be regarded as fortuitous4 ,the coincidence of the epochs of maxima and minima in the two series of phenomena amounts1 indeed1 to identity2 a fact evidently of most important significance1 but which neither astronomical nor magnetic science is yet sufficiently advanced to interpret4--,herschel's ,outlines4 ,the signification and connection of the above varying phenomena 7,humboldt maintains7 can never be manifested in their entire importance until an uninterrupted series of representations of the sun's spots can be obtained by the aid of mechanical clock-work and photographic apparatus1 as the result of prolonged observations during the many months of serene weather enjoyed in a tropical climate4 ,m4 ,schwabe has thus distinguished himself as an indefatigable observer of the sun's spots1 for his researches received the ,royal ,astronomical ,society's ,medal in #aheg4 8,for thirty years10 said the ,president at the presentation1 8never has the sun exhibited his disc above the horizon of ,dessau without being confronted by ,schwabe's imperturbable telescope2 and that appears to have happened on an average about #cjj days a-year4 ,so1 supposing that he had observed but once a-day1 he has made #ijjj observations1 in the course of which he discovered about #dgjj groups4 ,this is1 ,i believe1 an instance of devoted persistence unsurpassed in the annals of astronomy4 ,the energy of one man has revealed a phenomenon that had eluded the suspicion of astronomers for #bjj years40 ,,has ,,the ,,moon ,,an ,,atmosphere8 ,the ,moon possesses neither ,sea nor ,atmosphere of appreciable extent4 ,still1 as a negative1 in such case1 is relative only to the capabilities of the instruments employed1 the search for the indications of a lunar atmosphere has been renewed with fresh augmentation of telescopic power4 ,of such indications1 the most delicate1 perhaps1 are those afforded by the occultation of a planet by the moon4 ,the occultation of ,jupiter1 which took place on ,january #b1 #aheg1 was observed with this reference1 and is said to have exhibited no hesitation1 or change of form or brightness1 such as would be produced by the refraction or absorption of an atmosphere4 ,as respects the sea1 if water existed on the moon's surface1 the sun's light reflected from it should be completely polarised at a certain elongation of the moon from the sun2 and no traces of such light have been observed4 ,,mm4 ,baer and ,maedler conclude that the moon is not entirely without an atmosphere1 but1 owing to the smallness of her mass1 she is incapacitated from holding an extensive covering of gas2 and they add1 8it is possible that this weak envelope may sometimes1 through local causes1 in some measure dim or condense itself40 ,but if any atmosphere exists on our satellite1 it must be1 as ,laplace says1 more attenuated than what is termed a vacuum in an air-pump4 ,mr4 ,hopkins thinks that if there be any lunar atmosphere1 it must be very rare in comparison with the terrestrial atmosphere1 and inappreciable to the kind of observation by which it has been tested2 yet the absence of any refraction of the light of the stars during occultation is a very refined test4 ,mr4 ,nasmyth observes that 8the sudden disappearance of the stars behind the moon1 without any change or diminution of her brilliancy1 is one of the most beautiful phenomena that can be witnessed40 ,sir ,john ,herschel observes3 ,the fact of the moon turning always the same face towards the earth is1 in all probability1 the result of an elongation of its figure in the direction of a line joining the centres of both the bodies1 acting conjointly with a non-coincidence of its centre of gravity with its centre of symmetry4 ,if to this we add the supposition that the substance of the moon is not homogeneous1 and that some considerable preponderance of weight is placed excentrically in it1 it will be easily apprehended that the portion of its surface nearer to that heavier portion of its solid content1 under all the circumstances of the moon's rotation1 will permanently occupy the situation most remote from the earth4 ,in what regards its assumption of a definite level1 air obeys precisely the same hydrostatical laws as water4 ,the lunar atmosphere would rest upon the lunar ocean1 and form in its basin a lake of air1 whose upper portions at an altitude such as we are now contemplating would be of excessive tenuity1 especially should the provision of air be less abundant in proportion than our own4 ,it by no means follows1 then1 from the absence of visible indications of water or air on this side of the moon1 that the other is equally destitute of them1 and equally unfitted for maintaining animal or vegetable life4 ,some slight approach to such a state of things actually obtains on the earth itself4 ,nearly all the land is collected in one of its hemispheres1 and much the larger portion of the sea in the opposite4 ,there is evidently an excess of heavy material vertically beneath the middle of the ,pacific2 while not very remote from the point of the globe diametrically opposite rises the great table-land of ,india and the ,himalaya chain1 on the summits of which the air has not more than a third of the density it has on the sea-level1 and from which animated existence is for ever excluded4--,herschel's ,outlines1 #eth edit4 ,,light ,,of ,,the ,,moon4 ,the actual illumination of the lunar surface is not much superior to that of weathered sandstone-rock in full sunshine4 ,sir ,john ,herschel has frequently compared the moon setting behind the gray perpendicular faade of the ,table ,mountain at the ,cape of ,good ,hope1 illuminated by the sun just risen from the opposite quarter of the horizon1 when it has been scarcely distinguishable in brightness from the rock in contact with it4 ,the sun and moon being nearly at equal altitudes1 and the atmosphere perfectly free from cloud or vapour1 its effect is alike on both luminaries4 ,,heat ,,of ,,moonlight4 ,m4 ,zantedeschi has proved1 by a long series of experiments in the ,botanic ,gardens at ,venice1 ,florence1 and ,padua1 that1 contrary to the general opinion1 the diffused rays of moonlight have an influence upon the organs of plants1 as the ,sensitive ,plant and the ,desmodium gyrans4 ,the influence was feeble compared with that of the sun2 but the action is left beyond further question4 ,melloni has proved that the rays of the ,moon give out a slight degree of ,heat 7see ,things not generally ,known1 p4 #g72 and ,professor ,piazzi ,smyth1 from a point of the ,peak of ,teneriffe #hhdj feet above the sea-level1 has found distinctly perceptible the heat radiated from the moon1 which has been so often sought for in vain in a lower region4 ,,scenery ,,of ,,the ,,moon4 ,by means of the telescope1 mountain-peaks are distinguished in the ash-gray light of the larger spots and isolated brightly-shining points of the moon1 even when the disc is already more than half illuminated4 ,lambert and ,schroter have shown that the extremely variable intensity of the ash-gray light of the moon depends upon the greater or less degree of reflection of the sunlight which falls upon the earth1 according as it is reflected from continuous continental masses1 full of sandy deserts1 grassy steppes1 tropical forests1 and barren rocky ground1 or from large ocean surfaces4 ,lambert made the remarkable observation 7#adth of ,february #aggd7 of a change of the ash-coloured moonlight into an olive-green colour bordering upon yellow4 8,the moon1 which then stood vertically over the ,atlantic ,ocean1 received upon its right side the green terrestrial light which is reflected towards her when the sky is clear by the forest districts of ,south ,america40 ,plutarch says distinctly1 in his remarkable work ,on the ,face in the ,moon1 that we may suppose the spots to be partly deep chasms and valleys1 partly mountain-peaks1 which cast long shadows1 like ,mount ,athos1 whose shadow reaches ,lemnos4 ,the spots cover about two-fifths of the whole disc4 ,in a clear atmosphere1 and under favourable circumstances in the position of the moon1 some of the spots are visible to the naked eye2 as the edge of the ,apennines1 the dark elevated plain ,grimaldus1 the enclosed ,mare ,crisium1 and ,tycho1 crowded round with numerous mountain ridges and craters4 ,professor ,alexander remarks1 that a map of the eastern hemisphere1 taken with the ,bay of ,bengal in the centre1 would bear a striking resemblance to the face of the moon presented to us4 ,the dark portions of the moon he considers to be continental elevations1 as shown by measuring the average height of mountains above the dark and the light portions of the moon4 ,the surface of the moon can be as distinctly seen by a good telescope magnifying #ajjj times1 as it would be if not more than #bej miles distant4 ,,life ,,in ,,the ,,moon4 ,a circle of one second in diameter1 as seen from the earth1 on the surface of the moon contains about a square mile4 ,telescopes1 therefore1 must be greatly improved before we could expect to see signs of inhabitants1 as manifested by edifices or changes on the surface of the soil4 ,it should1 however1 be observed1 that owing to the small density of the materials of the moon1 and the comparatively feeble gravitation of bodies on her surface1 muscular force would there go six times as far in overcoming the weight of materials as on the earth4 ,owing to the want of air1 however1 it seems impossible that any form of life analogous to those on earth can subsist there4 ,no appearance indicating vegetation1 or the slightest variation of surface which can in our opinion fairly be ascribed to change of season1 can any where be discerned4--,sir ,john ,herschel's ,outlines4 ,,the ,,moon ,,seen ,,through ,,lord ,,rosse',s ,,telescope4 ,in #ahdf1 the ,rev4 ,dr4 ,scoresby had the gratification of observing the ,moon through the stupendous telescope constructed by ,lord ,rosse at ,parsonstown4 ,it appeared like a globe of molten silver1 and every object to the extent of #ajj yards was quite visible4 ,edifices1 therefore1 of the size of ,york ,minster1 or even of the ruins of ,whitby ,abbey1 might be easily perceived1 if they had existed4 ,but there was no appearance of any thing of that nature2 neither was there any indication of the existence of water1 or of an atmosphere4 ,there were a great number of extinct volcanoes1 several miles in breadth2 through one of them there was a line of continuance about #aej miles in length1 which ran in a straight direction1 like a railway4 ,the general appearance1 however1 was like one vast ruin of nature2 and many of the pieces of rock driven out of the volcanoes appeared to lie at various distances4 ,,mountains ,,in ,,the ,,moon4 ,by the aid of telescopes1 we discern irregularities in the surface of the moon which can be no other than mountains and valleys1--for this plain reason1 that we see the shadows cast by the former in the exact proportion as to length which they ought to have when we take into account the inclinations of the sun's rays to that part of the moon's surface on which they stand4 ,from micrometrical measurements of the lengths of the shadows of the more conspicuous mountains1 ,messrs4 ,baer and ,maedler have given a list of heights for no less than #ajie lunar mountains1 among which occur all degrees of elevation up to #bb1hbc ,british feet1 or about #adjj feet higher than ,chimborazo in the ,andes4 ,if ,chimborazo were as high in proportion to the earth's diameter as a mountain in the moon known by the name of ,newton is to the moon's diameter1 its peak would be more than sixteen miles high4 ,arago calls to mind1 that with a #fjjj-;fold magnifying power1 which nevertheless could not be applied to the moon with proportionate results1 the mountains upon the moon would appear to us just as ,mont ,blanc does to the naked eye when seen from the ,lake of ,geneva4 ,we sometimes observe more than half the surface of the moon1 the eastern and northern edges being more visible at one time1 and the western or southern at another4 ,by means of this libration we are enabled to see the annular mountain ,malapert 7which occasionally conceals the moon's south pole71 the arctic landscape round the crater of ,gioja1 and the large gray plane near ,endymion1 which conceals in superficial extent the mare vaporum4 ,three-sevenths of the moon are entirely concealed from our observation2 and must always remain so1 unless some new and unexpected disturbing causes come into play4--,humboldt4 ,the first object to which ,galileo directed his telescope was the mountainous parts of the moon1 when he showed how their summits might be measured3 he found in the moon some circular districts surrounded on all sides by mountains similar to the form of ,bohemia4 ,the measurements of the mountains were made by the method of the tangents of the solar ray4 ,galileo1 as ,helvetius did still later1 measured the distance of the summit of the mountains from the boundary of the illuminated portion at the moment when the mountain summit was first struck by the solar ray4 ,humboldt found no observations of the lengths of the shadows of the mountains3 the summits were 8much higher than the mountains on our earth40 ,the comparison is remarkable1 since1 according to ,riccioli1 very exaggerated ideas of the height of our mountains were then entertained4 ,galileo like all other observers up to the close of the eighteenth century1 believed in the existence of many seas and of a lunar atmosphere4 ,,the ,,moon ,,and ,,the ,,weather4 ,the only influence of the ,moon on the ,weather of which we have any decisive evidence is the tendency to disappearance of clouds under the full moon1 which ,sir ,john ,herschel refers to its heat being much more readily absorbed in traversing transparent media than direct solar heat1 and being extinguished in the upper regions of our atmosphere1 never reaches the surface of the atmosphere at all4 ,,the ,,moon',s ,,attraction4 ,mr4 ,g4 ,p4 ,bond of ,cambridge1 by some investigations to ascertain whether the ,attraction of the ,moon has any effect upon the motion of a pendulum1 and consequently upon the rate of a clock1 has found the last to be changed to the amount of #i_/ajjj of a second daily4 ,at the equator the moon's attraction changes the weight of a body only #a_/gjjjjjj of the whole2 yet this force is sufficient to produce the vast phenomena of the tides6 ,it is no slight evidence of the importance of analysis1 that ,laplace's perfect theory of tides has enabled us in our astronomical ephemerides to predict the height of spring-tides at the periods of new and full moon1 and thus put the inhabitants of the sea on their guard against the increased danger attending the lunar revolutions4 ,,measuring ,,the ,,earth ,,by ,,the ,,moon4 ,as the form of the ,earth exerts a powerful influence on the motion of other cosmical bodies1 and especially on that of its neighbouring satellite1 a more perfect knowledge of the motion of the latter will enable us reciprocally to draw an inference regarding the figure of the earth4 ,thus1 as ,laplace ably remarks3 8an astronomer1 without leaving his observatory1 may1 by a comparison of lunar theory with true observations1 not only be enabled to determine the form and size of the earth1 but also its distance from the sun and moon2 results that otherwise could only be arrived at by long and arduous expeditions to the most remote parts of both hemispheres40 ,the compression which may be inferred from lunar inequalities affords an advantage not yielded by individual measurements of degrees or experiments with the pendulum1 since it gives a mean amount which is referable to the whole planet4--,humboldt's ,cosmos1 vol4 i4 ,the distance of the moon from the earth is about #bdj1jjj miles2 and if a railway-carriage were to travel at the rate of #ajjj miles a-day1 it would be eight months in reaching the moon4 ,but that is nothing compared with the length of time it would occupy a locomotive to reach the sun from the earth3 if travelling at the rate of #ajjj miles a-day1 it would require #bfj years to reach it4 ,,cause ,,of ,,eclipses4 ,as the ,moon is at a very moderate distance from us 7astronomically speaking71 and is in fact our nearest neighbour1 while the sun and stars are in comparison immensely beyond it1 it must of necessity happen that at one time or other it must pass over1 and occult or eclipse1 every star or planet within its zone1 and1 as seen from the surface of the earth1 even somewhat beyond it4 ,nor is the sun itself exempt from being thus hidden whenever any part of the moon's disc1 in this her tortuous course1 comes to overlap any part of the space occupied in the heavens by that luminary4 ,on these occasions is exhibited the most striking and impressive of all the occasional phenomena of astronomy1 an ,eclipse of the ,sun1 in which a greater or less portion1 or even in some conjunctures the whole of its disc1 is obscured1 and1 as it were1 obliterated1 by the superposition of that of the moon1 which appears upon it as a circularly-terminated black spot1 producing a temporary diminution of daylight1 or even nocturnal darkness1 so that the stars appear as if at midnight4--,sir ,john ,herschel's ,outlines4 ,,vast ,,numbers ,,in ,,the ,,universe4 ,the number of telescopic stars in the ,milky ,way uninterrupted by any nebul is estimated at #ah1jjj1jjj4 ,to compare this number with something analogous1 ,humboldt calls attention to the fact1 that there are not in the whole heavens more than about #hjjj stars1 between the first and the sixth magnitudes1 visible to the naked eye4 ,the barren astonishment excited by numbers and dimensions in space when not considered with reference to applications engaging the mental and perceptive powers of man1 is awakened in both extremes of the universe--in the celestial bodies as in the minutest animalcules4 ,a cubic inch of the polishing slate of ,bilin contains1 according to ,ehrenberg1 #dj1jjj millions of the siliceous shells of ,galionell4 ,,for ,,what ,,purpose ,,were ,,the ,,stars ,,created8 ,surely not 7says ,sir ,john ,herschel7 to illuminate our nights1 which an additional moon of the thousandth part of the size of our own would do much better2 nor to sparkle as a pageant void of meaning and reality1 and bewilder us among vain conjectures4 ,useful1 it is true1 they are to man as points of exact and permanent reference2 but he must have studied astronomy to little purpose1 who can suppose man to be the only object of his ,creator's care1 or who does not see in the vast and wonderful apparatus around us provision for other races of animated beings4 ,the planets derive their light from the sun2 but that cannot be the case with the stars4 ,these doubtless1 then1 are themselves suns2 and may perhaps1 each in its sphere1 be the presiding centre round which other planets1 or bodies of which we can form no conception from any analogy offered by our own system1 are circulating4#ai ,,number ,,of ,,stars4 ,various estimates have been hazarded on the ,number of ,stars throughout the whole heavens visible to us by the aid of our colossal telescopes4 ,struve assumes for ,herschel's #bj-;feet reflector1 that a magnifying power of #ahj would give #e1hjj1jjj for the number of stars lying within the zones extending #cj on either side of the equator1 and #bj1cgd1jjj for the whole heavens4 ,sir ,william ,herschel conjectured that #ah1jjj1jjj of stars in the ,milky ,way might be seen by his still more powerful #dj-;feet reflecting telescope4--,humboldt's ,cosmos1 vol4 iii4 ,the assumption that the extent of the starry firmament is literally infinite has been made by ,dr4 ,olbers the basis of a conclusion that the celestial spaces are in some slight degree deficient in transparency2 so that all beyond a certain distance is and must remain for ever unseen1 the geometrical progression of the extinction of light far outrunning the effect of any conceivable increase in the power of our telescopes4 ,were it not so1 it is argued that every part of the celestial concave ought to shine with the brightness of the solar disc1 since no visual ray could be so directed as not1 in some point or other of its infinite length1 to encounter such a disc4--,edinburgh ,review1 ,jan4 #ahdh4 ,,stars ,,that ,,have ,,disappeared4 ,notwithstanding the great accuracy of the catalogued positions of telescopic fixed stars and of modern star-maps1 the certainty of conviction that a star in the heavens has actually disappeared since a certain epoch can only be arrived at with great caution4 ,errors of actual observation1 of reduction1 and of the press1 often disfigure the very best catalogues4 ,the disappearance of a heavenly body from the place in which it had been before distinctly seen1 may be the result of its own motion as much as of any such diminution of its photometric process as would render the waves of light too weak to excite our organs of sight4 ,what we no longer see1 is not necessarily annihilated4 ,the idea of destruction or combustion1 as applied to disappearing stars1 belongs to the age of ,tycho ,brahe4 ,even ,pliny makes it a question4 ,the apparent eternal cosmical alternation of existence and destruction is not annihilation2 it is merely the transition of matter into new forms1 into combinations which are subject to new processes4 ,dark cosmical bodies may by a renewed process of light again become luminous4--,humboldt's ,cosmos1 vol4 iii4 ,,the ,,pole-,,star ,,four ,,thousand ,,years ,,ago4 ,sir ,john ,herschel1 in his ,outlines of ,astronomy1 thus shows the changes in the celestial pole in #djjj years3 ,at the date of the erection of the ,pyramid of ,gizeh1 which precedes the present epoch by nearly #djjj years1 the longitudes of all the stars were less by #ee #de than at present4 ,calculating from this datum the place of the pole of the heavens among the stars1 it will be found to fall near ,draconis2 its distance from that star being #c #dd #be4 ,this being the most conspicuous star in the immediate neighbourhood1 was therefore the ,pole ,star of that epoch4 ,the latitude of ,gizeh being just #cj north1 and consequently the altitude of the ,north ,pole there also #cj1 it follows that the star in question must have had at its lowest culmination at ,gizeh an altitude of #be #ae #ce4 ,now it is a remarkable fact1 that of the nine pyramids still existing at ,gizeh1 six 7including all the largest7 have the narrow passages by which alone they can be entered 7all which open out on the northern faces of their respective pyramids7 inclined to the horizon downwards at angles the mean of which is #bf #dg4 ,at the bottom of every one of these passages1 therefore1 the ,pole ,star must have been visible at its lower culmination2 a circumstance which can hardly be supposed to have been unintentional1 and was doubtless connected 7perhaps superstitiously7 with the astronomical observations of that star1 of whose proximity to the pole at the epoch of the erection of these wonderful structures we are thus furnished with a monumental record of the most imperishable nature4 ,,the ,,pleiades4 ,the ,pleiades prove that1 several thousand years ago even as now1 stars of the seventh magnitude were invisible to the naked eye of average visual power4 ,the group consists of seven stars1 of which six only1 of the third1 fourth1 and fifth magnitudes1 could be readily distinguished4 ,of these ,ovid says 7,fast4 iv4 #agj73 8,qu septem dici1 sex tamen esse solent40 ,aratus states there were only six stars visible in the ,pleiades4 ,one of the daughters of ,atlas1 ,merope1 the only one who was wedded to a mortal1 was said to have veiled herself for very shame and to have disappeared4 ,this is probably the star of the seventh magnitude1 which we call ,celne2 for ,hipparchus1 in his commentary on ,aratus1 observes that on clear moonless nights seven stars may actually be seen4 ,the ,pleiades were doubtless known to the rudest nations from the earliest times2 they are also called the mariner's stars4 ,the name is from 7plein71 #8to sail4' ,the navigation of the ,mediterranean lasted from ,may to the beginning of ,november1 from the early rising to the early setting of the ,pleiades4 ,in how many beautiful effusions of poetry and sentiment has 8the ,lost ,pleiad0 been deplored6--and1 to descend to more familiar illustration of this group1 the 8,seven ,stars10 the sailors' favourites1 and a frequent river-side public-house sign1 may be traced to the ,pleiades4 ,,change ,,of ,,colour ,,in ,,the ,,stars4 ,the scintillation or twinkling of the stars is accompanied by variations of colour1 which have been remarked from a very early age4 ,m4 ,arago states1 upon the authority of ,m4 ,babinet1 that the name of ,barakesch1 given by the ,arabians to ,sirius1 signifies the star of a thousand colours2 and ,tycho ,brahe1 ,kepler1 and others1 attest to similar change of colour in twinkling4 ,even soon after the invention of the telescope1 ,simon ,marius remarked that by removing the eye-piece of the telescope the images of the stars exhibited rapid fluctuations of brightness and colour4 ,in #ahad ,nicholson applied to the telescope a smart vibration1 which caused the image of the star to be transformed into a curved line of light returning into itself1 and diversified by several colours2 each colour occupied about a third of the whole length of the curve1 and by applying ten vibrations in a second1 the light of ,sirius in that time passed through thirty changes of colour4 ,hence the stars in general shine only by a portion of their light1 the effect of twinkling being to diminish their brightness4 ,this phenomenon ,m4 ,arago explains by the principle of the interference of light4 ,ptolemy is said to have noted ,sirius as a red star1 though it is now white4 ,sirius twinkles with red and blue light1 and ,ptolemy's eyes1 like those of several other persons1 may have been more sensitive to the red than to the blue rays4--,sir ,david ,brewster's ,more ,worlds than ,one1 p4 #bce4 ,some of the double stars are of very different and dissimilar colours2 and to the revolving planetary bodies which apparently circulate around them1 a day lightened by a red light is succeeded by1 not a night1 but a day equally brilliant1 though illuminated only by a green light4 ,,distance ,,of ,,the ,,nearest ,,fixed ,,star ,,from ,,the ,,earth4 ,sir ,john ,herschel wrote in #ahcc3 8,what is the distance of the nearest fixed star8 ,what is the scale on which our visible firmament is constructed8 ,and what proportion do its dimensions bear to those of our own immediate system8 ,to this1 however1 astronomy has hitherto proved unable to supply an answer4 ,all we know on this subject is negative40 ,to these questions1 however1 an answer can now be given4 ,slight changes of position of some of the stars1 called parallax1 have been distinctly observed and measured2 and among these stars ,no4 #fa ,cygni of ,flamstead's catalogue has a parallax of #e1 and that of ,centauri has a proper motion of #d per annum4 ,the same astronomer states that each second of parallax indicates a distance of #bj billions of miles1 or #c years' journey of light4 ,now the light sent to us by the sun1 as compared with that sent by ,sirius and ,centauri1 is about #bb thousand millions to #a4 8,hence1 from the parallax assigned above to that star1 it is easy to conclude that its intrinsic splendour1 as compared with that of our sun at equal distances1 is #bcbdg1 that of the sun being unity4 ,the light of ,sirius is four times that of ,centauri1 and its parallax only #jae4 ,this1 in effect1 ascribes to it an intrinsic splendour equal to #iffc times that of ,centauri1 and therefore #bbdg times that of our sun40 ,this is justly regarded as one of the most brilliant triumphs of astronomical science1 for the delicacy of the investigation is almost inconceivable2 yet the reasoning is as unimpeachable as the demonstration of a theorem of ,euclid4 ,,light ,,of ,a ,,star ,,sixteenfold ,,that ,,of ,,the ,,sun4 ,the bright star in the constellation of the ,lyre1 termed ,vega1 is the brightest in the northern hemisphere2 and the combined researches of ,struve1 father and son1 have found that the distance of this star from the earth is no less than #acj billions of miles6 ,light travelling at the rate of #aib thousand miles in a second consequently occupies twenty-one years in passing from this star to the earth4 ,now it has been found1 by comparing the light of ,vega with the light of the sun1 that if the latter were removed to the distance of #acj billions of miles1 his apparent brightness would not amount to more than the sixteenth part of the apparent brightness of ,vega4 ,we are therefore warranted in concluding that the light of ,vega is equal to that of sixteen suns4 ,,diversities ,,of ,,the ,,planets4 ,in illustration of the great diversity of the physical peculiarities and probable condition of the planets1 ,sir ,john ,herschel describes the intensity of solar radiation as nearly seven times greater on ,mercury than on the earth1 and on ,uranus #ccj times less2 the proportion between the two extremes being that of upwards of #bjjj to #a4 ,let any one figure to himself1 7adds ,sir ,john17 the condition of our globe were the sun to be septupled1 to say nothing of the greater ratio2 or were it diminished to a seventh1 or to a #cjjth of its actual power6 ,again1 the intensity of gravity1 or its efficacy in counteracting muscular power and repressing animal activity1 on ,jupiter is nearly two-and-a-half times that on the earth2 on ,mars not more than one-half2 on the moon one-sixth2 and on the smaller planets probably not more than one-twentieth2 giving a scale of which the extremes are in the proportion of sixty to one4 ,lastly1 the density of ,saturn hardly exceeds one-eighth of the mean density of the earth1 so that it must consist of materials not much heavier than cork4 ,jupiter is eleven times1 ,saturn ten times1 ,uranus five times1 and ,neptune nearly six times1 the diameter of our earth4 ,these four bodies revolve in space at such distances from the sun1 that if it were possible to start thence for each in succession1 and to travel at the railway speed of #cc miles per hour1 the traveller would reach ,jupiter in #agab years ,saturn #caac 0 ,uranus #fbbf 0 ,neptune #ifhe 0 ,if1 therefore1 a person had commenced his journey at the period of the ,christian era1 he would now have to travel nearly #acjj years before he would arrive at the planet ,saturn2 more than #dcjj years before he would reach ,uranus2 and no less than #ghjj years before he could reach the orbit of ,neptune4 ,yet the light which comes to us from these remote confines of the solar system first issued from the sun1 and is then reflected from the surface of the planet4 ,when the telescope is turned towards ,neptune1 the observer's eye sees the object by means of light that issued from the sun eight hours before1 and which since then has passed nearly twice through that vast space which railway speed would require almost a century of centuries to accomplish4--,bouvier's ,familiar ,astronomy4 ,,grand ,,results ,,of ,,the ,,discovery ,,of ,,jupiter',s ,,satellites4 ,this discovery1 one of the first fruits of the invention of the telescope1 and of ,galileo's early and happy idea of directing its newly-found powers to the examination of the heavens1 forms one of the most memorable epochs in the history of astronomy4 ,the first astronomical solution of the great problem of the longitude1 practically the most important for the interests of mankind which has ever been brought under the dominion of strict scientific principles1 dates immediately from this discovery4 ,the final and conclusive establishment of the ,copernican system of astronomy may also be considered as referable to the discovery and study of this exquisite miniature system1 in which the laws of the planetary motions1 as ascertained by ,kepler1 and specially that which connects their periods and distances1 were specially traced1 and found to be satisfactorily maintained4 ,and 7as if to accumulate historical interest on this point7 it is to the observation of the eclipses of ,jupiter's satellites that we owe the grand discovery of the aberration of light1 and the consequent determination of the enormous velocity of that wonderful element--#aib1jjj miles per second4 ,mr4 ,dawes1 in #ahdi1 first noticed the existence of round1 well-defined1 bright spots on the belts of ,jupiter4 ,they vary in situation and number1 as many as ten having been seen on one occasion4 ,as the belts of ,jupiter have been ascribed to the existence of currents analogous to our trade-winds1 causing the body of ,jupiter to be visible through his cloudy atmosphere1 ,sir ,john ,herschel conjectures that those bright spots may possibly be insulated masses of clouds of local origin1 similar to the cumuli which sometimes cap ascending columns of vapour in our atmosphere4 ,it would require nearly #acjj globes of the size of our earth to make one of the bulk of ,jupiter4 ,a railway-engine travelling at the rate of thirty-three miles an hour would travel round the earth in a month1 but would require more than eleven months to perform a journey round ,jupiter4 ,,was ,,saturn',s ,,ring ,,known ,,to ,,the ,,ancients8 ,in ,maurice's ,indian ,antiquities is an engraving of ,sani1 the ,saturn of the ,hindoos1 taken from an image in a very ancient pagoda1 which represents the deity encompassed by a ring formed of two serpents4 ,hence it is inferred that the ancients were acquainted with the existence of the ring of ,saturn4 ,arago mentions the remarkable fact of the ring and fourth satellite of ,saturn having been seen by ,sir ,w4 ,herschel with his smaller telescope by the naked eye1 without any eye-piece4 ,the first or innermost of ,saturn's satellites is nearer to the central body than any other of the secondary planets4 ,its distance from the centre of ,saturn is #hj1jhh miles2 from the surface of the planet #dg1dhj miles2 and from the outmost edge of the ring only #diaf miles4 ,the traveller may form to himself an estimate of the smallness of this amount by remembering the statement of the well-known navigator1 ,captain ,beechey1 that he had in three years passed over #gb1hjj miles4 ,according to very recent observations1 ,saturn's ring is divided into three separate rings1 which1 from the calculations of ,mr4 ,bond1 an ,american astronomer1 must be fluid4 ,he is of opinion that the number of rings is continually changing1 and that their maximum number1 in the normal condition of the mass1 does not exceed twenty4 ,mr4 ,bond likewise maintains that the power which sustains the centre of gravity of the ring is not in the planet itself1 but in its satellites2 and the satellites1 though constantly disturbing the ring1 actually sustain it in the very act of perturbation4 ,m4 ,otto ,struve and ,mr4 ,bond have lately studied with the great ,munich telescope1 at the observatory of ,pulkowa1 the third ring of ,saturn1 which ,mr4 ,lassell and ,mr4 ,bond discovered to be fluid4 ,they saw distinctly the dark interval between this fluid ring and the two old ones1 and even measured its dimensions2 and they perceived at its inner margin an edge feebly illuminated1 which they thought might be the commencement of a fourth ring4 ,these astronomers are of opinion1 that the fluid ring is not of very recent formation1 and that it is not subject to rapid change2 and they have come to the extraordinary conclusion1 that the inner border of the ring has1 since the time of ,huygens1 been gradually approaching to the body of ,saturn1 and that we may expect1 sooner or later1 perhaps in some dozen of years1 to see the rings united with the body of the planet4 ,but this theory is by other observers pronounced untenable4 ,,temperature ,,of ,,the ,,planet ,,mercury4 ,mercury being so much nearer to the ,sun than the ,earth1 he receives1 it is supposed1 seven times more heat than the earth4 ,mrs4 ,somerville says3 8,on ,mercury1 the mean heat arising from the intensity of the sun's rays must be above that of boiling quicksilver1 and water would boil even at the poles40 ,but he may be provided with an atmosphere so constituted as to absorb or reflect a great portion of the superabundant heat2 so that his inhabitants 7if he have any7 may enjoy a climate as temperate as any on our globe4 ,,speculations ,,on ,,vesta ,,and ,,pallas4 ,the most remarkable peculiarities of these ultra-zodiacal planets1 according to ,sir ,john ,herschel1 must lie in this condition of their state3 a man placed on one of them would spring with ease sixty feet high1 and sustain no greater shock in his descent than he does on the earth from leaping a yard4 ,on such planets1 giants might exist2 and those enormous animals which on the earth require the buoyant power of water to counteract their weight1 might there be denizens of the land4 ,but of such speculations there is no end4 ,,is ,,the ,,planet ,,mars ,,inhabited8 ,the opponents of the doctrine of the ,plurality of ,worlds allow that a greater probability exists of ,mars being inhabited than in the case of any other planet4 ,his diameter is #dajj miles2 and his surface exhibits spots of different hues1--the seas1 according to ,sir ,john ,herschel1 being green1 and the land red4 8,the variety in the spots10 says this astronomer1 8may arise from the planet not being destitute of atmosphere and cloud2 and what adds greatly to the probability of this1 is the appearance of brilliant white spots at its poles1 which have been conjectured1 with some probability1 to be snow1 as they disappear when they have been long exposed to the sun1 and are greatest when emerging from the long night of their polar winter1 the snow-line then extending to about six degrees from the pole40 8,the length of the day10 says ,sir ,david ,brewster1 8is almost exactly twenty-four hours1--the same as that of the earth4 ,continents and oceans and green savannahs have been observed upon ,mars1 and the snow of his polar regions has been seen to disappear with the heat of summer40 ,we actually see the clouds floating in the atmosphere of ,mars1 and there is the appearance of land and water on his disc4 ,in a sketch of this planet1 as seen in the pure atmosphere of ,calcutta by ,mr4 ,grant1 it appears1 to use his words1 8actually as a little world10 and as the earth would appear at a distance1 with its seas and continents of different shades4 ,as the diameter of ,mars is only about one half that of our earth1 the weight of bodies will be about one half what it would be if they were placed upon our globe4 ,,discovery ,,of ,,the ,,planet ,,neptune4 ,this noble discovery marked in a signal manner the maturity of astronomical science4 ,the proof1 or at least the urgent presumption1 of the existence of such a planet1 as a means of accounting 7by its attraction7 for certain small irregularities observed in the motions of ,uranus1 was afforded almost simultaneously by the independent researches of two geometers1 ,mr4 ,adams of ,cambridge1 and ,m4 ,leverrier of ,paris1 who were enabled from theory alone to calculate whereabouts it ought to appear in the heavens1 if visible1 the places thus independently calculated agreeing surprisingly4 ,within a single degree of the place assigned by ,m4 ,leverrier's calculations1 and by him communicated to ,dr4 ,galle of the ,royal ,observatory at ,berlin1 it was actually found by that astronomer on the very first night after the receipt of that communication1 on turning a telescope on the spot1 and comparing the stars in its immediate neighbourhood with those previously laid down in one of the zodiacal charts4 ,this remarkable verification of an indication so extraordinary took place on the #bc;d of ,september #ahdf4bj--,sir ,john ,herschel's ,outlines4 ,neptune revolves round the sun in about #agb years1 at a mean distance of thirty1--that of ,uranus being nineteen1 and that of the earth one3 and by its discovery the solar system has been extended one thousand millions of miles beyond its former limit4 ,neptune is suspected to have a ring1 but the suspicion has not been confirmed4 ,it has been demonstrated by the observations of ,mr4 ,lassell1 ,m4 ,otto ,struve1 and ,mr4 ,bond1 to be attended by at least one satellite4 ,one of the most curious facts brought to light by the discovery of ,neptune1 is the failure of ,bode's law to give an approximation to its distance from the sun2 a striking exemplification of the danger of trusting to the universal applicability of an empirical law4 ,after standing the severe test which led to the discovery of the asteroids1 it seemed almost contrary to the laws of probability that the discovery of another member of the planetary system should prove its failure as an universal rule4 ,,magnitude ,,of ,,comets4 ,although ,comets have a smaller mass than any other cosmical bodies--being1 according to our present knowledge1 probably not equal to #a_/ejjjth part of the earth's mass--yet they occupy the largest space1 as their tails in several instances extend over many millions of miles4 ,the cone of luminous vapour which radiates from them has been found in some cases 7as in #afhj and #ahaa7 equal to the length of the earth's distance from the sun1 forming a line that intersects both the orbits of ,venus and ,mercury4 ,it is even probable that the vapour of the tails of comets mingled with our atmosphere in the years #ahai and #ahbc4--;,humboldt's ,cosmos1 vol4 i4 ,,comets ,,visible ,,in ,,sunshine--,,the ,,great ,,comet ,,of #ahdc4 ,the phenomenon of the tail of a ,comet being visible in bright ,sunshine1 which is recorded of the comet of #adjb1 occurred again in the case of the large comet of #ahdc1 whose nucleus and tail were seen in ,north ,america on ,february #bhth 7according to the testimony of ,j4 ,g4 ,clarke1 of ,portland1 ,state of ,maine71 between one and three o'clock in the afternoon4 ,the distance of the very dense nucleus from the sun's light admitted of being measured with much exactness4 ,the nucleus and tail 7a darker space intervening7 appeared like a very pure white cloud4--,american ,journal of ,science1 vol4 xiv4 ,e4 ,c4 ,ott1 the translator of ,bohn's edition of ,humboldt's ,cosmos1 at ,new ,bedford1 ,massachusetts1 ,u4,s41 ,feb4 #bhth1 #ahdc1 distinctly saw the above comet between one and two in the afternoon4 ,the sky at the time was intensely blue1 and the sun shining with a dazzling brightness unknown in ,european climates4 ,this very remarkable ,comet1 seen in ,england on the #agth of ,march #ahdc1 had a nucleus with the appearance of a planetary disc1 and the brightness of a star of the first or second magnitude4 ,it had a double tail divided by a dark line4 ,at the ,cape of ,good ,hope it was seen in full daylight1 and in the immediate vicinity of the sea2 but the most remarkable fact in its history was its near approach to the sun1 its distance from his surface being only one-fourteenth of his diameter4 ,the heat to which it was exposed1 therefore1 was much greater than that which ,sir ,isaac ,newton ascribed to the comet of #afhj1 namely #bjj times that of red-hot iron4 ,sir ,john ,herschel has computed that it must have been #bd times greater than that which was produced in the focus of ,parker's burning lens1 #cb inches in diameter1 which melts crystals of quartz and agate4#ba ,,the ,,milky ,,way ,,unfathomable4 ,m4 ,struve of ,pulkowa has compared ,sir ,william ,herschel's opinion on this subject1 as maintained in #aghe1 with that to which he was subsequently led2 and arrives at the conclusion that1 according to ,sir ,w4 ,herschel himself1 the visible extent of the ,milky ,way increases with the penetrating power of the telescopes employed2 that it is impossible to discover by his instruments the termination of the ,milky ,way 7as an independent cluster of stars72 and that even his gigantic telescope of forty feet focal length does not enable him to extend our knowledge of the ,milky ,way1 which is incapable of being sounded4 ,sir ,william ,herschel's ,theory of the ,milky ,way was as follows3 ,he considered our solar system1 and all the stars which we can see with the eye1 as placed within1 and constituting a part of1 the nebula of the ,milky ,way1 a congeries of many millions of stars1 so that the projection of these stars must form a luminous track on the concavity of the sky2 and by estimating or counting the number of stars in different directions1 he was able to form a rude judgment of the probable form of the nebula1 and of the probable position of the solar system within it4 ,this remarkable belt has maintained from the earliest ages the same relative situation among the stars2 and1 when examined through powerful telescopes1 is found 7wonderful to relate67 to consist entirely of stars scattered by millions1 like glittering dust1 on the black ground of the general heavens4 ,,distances ,,of ,,nebul4 ,these are truly astounding4 ,sir ,william ,herschel estimated the distance of the annular nebula between ,beta and ,gamma ,lyr to be from our system #iej times that of ,sirius2 and a globular cluster about #e south-east of ,beta ,sir ,william computed to be one thousand three hundred billions of miles from our system4 ,again1 in ,scutum ,sobieski is one nebula in the shape of a horseshoe2 but which1 when viewed with high magnifying power1 presents a different appearance4 ,sir ,william ,herschel estimated this nebula to be #ijj times farther from us than ,sirius4 ,in some parts of its vicinity he observed #ehh stars in his telescope at one time2 and he counted #beh1jjj in a space #aj long and #b wide4 ,there is a globular cluster between the mouths of ,pegasus and ,equuleus1 which ,sir ,william ,herschel estimated to be #bdc times farther from us than ,sirius4 ,caroline ,herschel discovered in the right foot of ,andromeda a nebula of enormous dimensions1 placed at an inconceivable distance from us3 it consists probably of myriads of solar systems1 which1 taken together1 are but a point in the universe4 ,the nebula about #aj west of the principal star in ,triangulum is supposed by ,sir ,william ,herschel to be #cdd times the distance of ,sirius from the earth1 which would be the immense sum of nearly seventeen thousand billions of miles from our planet4 ,,infinite ,,space4 ,after the straining mind has exhausted all its resources in attempting to fathom the distance of the smallest telescopic star1 or the faintest nebula1 it has reached only the visible confines of the sidereal creation4 ,the universe of stars is but an atom in the universe of space2 above it1 and beneath it1 and around it1 there is still infinity4 ,,origin ,,of ,,our ,,planetary ,,system4 ,,the ,,nebular ,,hypothesis4#bb ,the commencement of our ,planetary ,system1 including the sun1 must1 according to ,kant and ,laplace1 be regarded as an immense nebulous mass filling the portion of space which is now occupied by our system far beyond the limits of ,neptune1 our most distant planet4 ,even now we perhaps see similar masses in the distant regions of the firmament1 as patches of nebul1 and nebulous stars2 within our system also1 comets1 the zodiacal light1 the corona of the sun during a total eclipse1 exhibit resemblances of a nebulous substance1 which is so thin that the light of the stars passes through it unenfeebled and unrefracted4 ,if we calculate the density of the mass of our planetary system1 according to the above assumption1 for the time when it was a nebulous sphere which reached to the path of the outmost planet1 we should find that it would require several cubic miles of such matter to weigh a single grain4--,professor ,helmholtz4 ,a quarter of a century ago1 ,sir ,john ,herschel expressed his opinion that those nebul which were not resolved into individual stars by the highest powers then used1 might be hereafter completely resolved by a further increase of optical power3 ,in fact1 this probability has almost been converted into a certainty by the magnificent reflecting telescope constructed by ,lord ,rosse1 of #f feet in aperture1 which has resolved1 or rendered resolvable1 multitudes of nebul which had resisted all inferior powers4 ,the sublimity of the spectacle afforded by that instrument of some of the larger globular and other clusters is declared by all who have witnessed it to be such as no words can express4#bc ,although1 therefore1 nebul do exist1 which even in this powerful telescope appear as nebul1 without any sign of resolution1 it may very reasonably be doubted whether there be really any essential physical distinction between nebul and clusters of stars1 at least in the nature of the matter of which they consist2 and whether the distinction between such nebul as are easily resolved1 barely resolvable with excellent telescopes1 and altogether irresolvable with the best1 be any thing else than one of degree1 arising merely from the excessive minuteness and multitude of the stars of which the latter1 as compared with the former1 consist4--,outlines of ,astronomy1 #eth edit4 #aheh4 ,it should be added1 that ,sir ,john ,herschel considers the 8nebular hypothesis0 and the above theory of sidereal aggregation to stand quite independent of each other4 ,,origin ,,of ,,heat ,,in ,,our ,,system4 ,professor ,helmholtz1 assuming that at the commencement the density of the nebulous matter was a vanishing quantity1 as compared with the present density of the sun and planets1 calculates how much work has been performed by the condensation2 how much of this work still exists in the form of mechanical force1 as attraction of the planets towards the sun1 and as vis viva of their motion2 and finds by this how much of the force has been converted into heat4 ,the result of this calculation is1 that only about the #deth part of the original mechanical force remains as such1 and that the remainder1 converted into heat1 would be sufficient to raise a mass of water equal to the sun and planets taken together1 not less than #bh1jjj1jjj of degrees of the centigrade scale4 ,for the sake of comparison1 ,professor ,helmholtz mentions that the highest temperature which we can produce by the oxy-hydrogen blowpipe1 which is sufficient to vaporise even platina1 and which but few bodies can endure1 is estimated at about #bjjj degrees4 ,of the action of a temperature of #bh1jjj1jjj of such degrees we can form no notion4 ,if the mass of our entire system were of pure coal1 by the combustion of the whole of it only the #cejth part of the above quantity would be generated4 ,the store of force at present possessed by our system is equivalent to immense quantities of heat4 ,if our earth were by a sudden shock brought to rest in her orbit--which is not to be feared in the existing arrangement of our system--by such a shock a quantity of heat would be generated equal to that produced by the combustion of fourteen such earths of solid coal4 ,making the most unfavourable assumption as to its capacity for heat1 that is1 placing it equal to that of water1 the mass of the earth would thereby be heated #aa1bjj2 it would therefore be quite fused1 and for the most part reduced to vapour4 ,if1 then1 the earth1 after having been thus brought to rest1 should fall into the sun1 which of course would be the case1 the quantity of heat developed by the shock would be #djj times greater4 ,,an ,,astronomer',s ,,dream ,,verified4 ,the most fertile region in astronomical discovery during the last quarter of a century has been the planetary members of the solar system4 ,in #ahcc1 ,sir ,john ,herschel enumerated ten planets as visible from the earth1 either by the unaided eye or by the telescope2 the number is now increased more than fivefold4 ,with the exception of ,neptune1 the discovery of new planets is confined to the class called ,asteroids4 ,these all revolve in elliptic orbits between those of ,jupiter and ,mars4 ,zitius of ,wittemberg discovered an empirical law1 which seemed to govern the distances of the planets from the sun2 but there was a remarkable interruption in the law1 according to which a planet ought to have been placed between ,mars and ,jupiter4 ,professor ,bode of ,berlin directed the attention of astronomers to the possibility of such a planet existing2 and in seven years' observations from the commencement of the present century1 not one but four planets were found1 differing widely from one another in the elements of their orbits1 but agreeing very nearly at their mean distances from the sun with that of the supposed planet4 ,this curious coincidence of the mean distances of these four asteroids with the planet according to ,bode's law1 as it is generally called1 led to the conjecture that these four planets were but fragments of the missing planet1 blown to atoms by some internal explosion1 and that many more fragments might exist1 and be possibly discovered by diligent search4 ,concerning this apparently wild hypothesis1 ,sir ,john ,herschel offered the following remarkable apology3 8,this may serve as a specimen of the dreams in which astronomers1 like other speculators1 occasionally and harmlessly indulge40 ,the dream1 wild as it appeared1 has been realised now4 ,sir ,john1 in the fifth edition of his ,outlines of ,astronomy1 published in #aheh1 tells us3 ,whatever may be thought of such a speculation as a physical hypothesis1 this conclusion has been verified to a considerable extent as a matter of fact by subsequent discovery1 the result of a careful and minute examination and mapping down of the smaller stars in and near the zodiac1 undertaken with that express object4 ,zodiacal charts of this kind1 the product of the zeal and industry of many astronomers1 have been constructed1 in which every star down to the ninth1 tenth1 or even lower magnitudes1 is inserted2 and these stars being compared with the actual stars of the heavens1 the intrusion of any stranger within their limits cannot fail to be noticed when the comparison is systematically conducted4 ,the discovery of ,astra and ,hebe by ,professor ,hencke1 in #ahde and #ahdg1 revived the flagging spirit of inquiry in this direction2 with what success1 the list of fifty-two asteroids1 with their names and the dates of their discovery1 will best show4 ,the labours of our indefatigable countryman1 ,mr4 ,hind1 have been rewarded by the discovery of no less than eight of them4 ,,fire-,,balls ,,and ,,shooting ,,stars4 ,humboldt relates1 that a friend at ,popayan1 at an elevation of #eehc feet above the sea-level1 at noon1 when the sun was shining brightly in a cloudless sky1 saw his room lighted up by a fire-ball3 he had his back towards the window at the time1 and on turning round1 perceived that great part of the path traversed by the fire-ball was still illuminated by the brightest radiance4 ,the ,germans call these phenomena star-snuff1 from the vulgar notion that the lights in the firmament undergo a process of snuffing1 or cleaning4 ,other nations call it a shot or fall of stars1 and the ,english star-shoot4 ,certain tribes of the ,orinoco term the pearly drops of dew which cover the beautiful leaves of the heliconia star-spit4 ,in the ,lithuanian mythology1 the nature and signification of falling stars are embodied under nobler and more graceful symbols4 ,the ,parc1 ,werpeja1 weave in heaven for the new-born child its thread of fate1 attaching each separate thread to a star4 ,when death approaches the person1 the thread is rent1 and the star wanes and sinks to the earth4--,jacob ,grimm4 ,,theory ,,and ,,experience4 ,in the perpetual vicissitude of theoretical views1 says the author of ,giordano ,bruno1 8most men see nothing in philosophy but a succession of passing meteors2 whilst even the grander forms in which she has revealed herself share the fate of comets1--bodies that do not rank in popular opinion amongst the external and permanent works of nature1 but are regarded as mere fugitive apparitions of igneous vapour40 ,,meteorites ,,from ,,the ,,moon4 ,the hypothesis of the selenic origin of meteoric stones depends upon a number of conditions1 the accidental coincidence of which could alone convert a possible to an actual fact4 ,the view of the original existence of small planetary masses in space is simpler1 and at the same time more analogous with those entertained concerning the formation of other portions of the solar system4 ,diogenes ,laertius thought aerolites came from the sun2 but ,pliny derides this theory4 ,the fall of aerolites in bright sunshine1 and when the moon's disc was invisible1 probably led to the idea of sun-stones4 ,moreover ,anaxagoras regarded the sun as 8a molten fiery mass20 and ,euripides1 in ,phaton1 terms the sun 8a golden mass10 that is to say1 a fire-coloured1 brightly-shining matter1 but not leading to the inference that aerolites are golden sun-stones4 ,the ,greek philosophers had four hypotheses as to their origin3 telluric1 from ascending exhalations2 masses of stone raised by hurricanes2 a solar origin2 and lastly1 an origin in the regions of space1 as heavenly bodies which had long remained invisible3 the last opinion entirely according with that of the present day4 ,chladni states that an ,italian physicist1 ,paolo ,maria ,terzago1 on the occasion of the fall of an aerolite at ,milan1 in #affj1 by which a ,franciscan monk was killed1 was the first who surmised that aerolites were of selenic origin4 ,without any previous knowledge of this conjecture1 ,olbers was led1 in #agie 7after the celebrated fall at ,siena1 ,june #afth1 #agid71 to investigate the amount of the initial tangential force that would be required to bring to the earth masses projected from the moon4 ,olbers1 ,brandes1 and ,chaldni thought that 8the velocity of #af to #cb miles1 with which fire-balls and shooting-stars entered our atmosphere10 furnished a refutation to the view of their selenic origin4 ,according to ,olbers1 it would require to reach the earth1 setting aside the resistance of the air1 an initial velocity of #hbib feet in the second2 according to ,laplace1 #ghfb2 to ,biot1 #hbhb2 and to ,poisson1 #geie4 ,laplace states that this velocity is only five or six times as great as that of a cannon-ball2 but ,olbers has shown that 8with such an initial velocity as #gejj or #hjjj feet in a second1 meteoric stones would arrive at the surface of our earth with a velocity of only #ce1jjj feet40 ,but the measured velocity of meteoric stones averages upwards of #aad1jjj feet to a second2 consequently the original velocity of projection from the moon must be almost #aaj1jjj feet1 and therefore #ad times greater than ,laplace asserted4 ,it must1 however1 be recollected1 that the opinion then so prevalent1 of the existence of active volcanoes in the moon1 where air and water are absent1 has since been abandoned4 ,laplace elsewhere states1 that in all probability aerolites 8come from the depths of space20 yet he in another passage inclines to the hypothesis of their lunar origin1 always1 however1 assuming that the stones projected from the moon 8become satellites of our earth1 describing around it more or less eccentric orbits1 and thus not reaching its atmosphere until several or even many revolutions have been accomplished40 ,in ,syria there is a popular belief that aerolites chiefly fall on clear moonlight nights4 ,the ancients 7,pliny tells us7 looked for their fall during lunar eclipses4--,abridged from ,humboldt's ,cosmos1 vol4 i4 7,bohn's edition74 ,dr4 ,laurence ,smith1 ,u4,s41 accepts the 8lunar theory10 and considers meteorites to be masses thrown off from the moon1 the attractive power of which is but one-sixth that of the earth2 so that bodies thrown from the surface of the moon experience but one sixth the retarding force they would have when thrown from the earth's surface4 ,look again 7says ,dr4 ,smith7 at the constitution of the meteorite1 made up principally of pure iron4 ,it came evidently from some place where there is little or no oxygen4 ,now the moon has no atmosphere1 and no water on its surface4 ,there is no oxygen there4 ,hurled from the moon1 these bodies1--these masses of almost pure iron1--would flame in the sun like polished steel1 and on reaching our atmosphere would burn in its oxygen until a black oxide cooled it2 and this we find to be the case with all meteorites1--the black colour is only an external covering4 ,sir ,humphry ,davy1 from facts contained in his researches on flame1 in #ahag1 conceives that the light of meteors depends1 not upon the ignition of inflammable gases1 but upon that of solid bodies2 that such is their velocity of motion1 as to excite sufficient heat for their ignition by the compression even of rare air2 and that the phenomena of falling stars may be explained by regarding them as small incombustible bodies moving round the earth in very eccentric orbits1 and becoming ignited only when they pass with immense rapidity through the upper regions of the atmosphere2 whilst those meteors which throw down stony bodies are1 similarly circumstanced1 combustible masses4 ,masses of iron and nickel1 having all the appearance of aerolites or meteoric stones1 have been discovered in ,siberia1 at a depth of ten metres below the surface of the earth4 ,from the fact1 however1 that no meteoric stones are found in the secondary and tertiary formations1 it would seem to follow that the phenomena of falling stones did not take place till the earth assumed its present conditions4 ,,vast ,,shower ,,of ,,meteors4 ,the most magnificent ,shower of ,meteors that has ever been known was that which fell during the night of ,november #abth1 #ahcc1 commencing at nine o'clock in the evening1 and continuing till the morning sun concealed the meteors from view4 ,this shower extended from ,canada to the northern boundary of ,south ,america1 and over a tract of nearly #cjjj miles in width4 ,,immense ,,meteorite4 ,mrs4 ,somerville mentions a ,meteorite which passed within twenty-five miles of our planet1 and was estimated to weigh #fjj1jjj tons1 and to move with a velocity of twenty miles in a second4 ,only a small fragment of this immense mass reached the earth4 ,four instances are recorded of persons being killed by their fall4 ,a block of stone fell at gos ,potamos1 ,b4,c4 #dfe1 as large as two millstones2 another at ,narni1 in #iba1 projected like a rock four feet above the surface of the river1 in which it was seen to fall4 ,the ,emperor ,jehangire had a sword forged from a mass of meteoric iron1 which fell in #afbj at ,jahlinder in the ,punjab4 ,sixteen instances of the fall of stones in the ,british ,isles are well authenticated to have occurred since #afbj1 one of them in ,london4 ,it is very remarkable that no new chemical element has been detected in any of the numerous meteorites which have been analysed4 ,,no ,,fossil ,,meteoric ,,stones4 ,it is 7says ,olbers7 a remarkable but hitherto unregarded fact1 that while shells are found in secondary and tertiary formations1 no ,fossil ,meteoric ,stones have as yet been discovered4 ,may we conclude from this circumstance1 that previous to the present and last modification of the earth's surface no meteoric stones fell on it1 though at the present time it appears probable1 from the researches of ,schreibers1 that #gjj fall annually8#bd ,,the ,,end ,,of ,,our ,,system4 ,while all the phenomena in the heavens indicate a law of progressive creation1 in which revolving matter is distributed into suns and planets1 there are indications in our own system that a period has been assigned for its duration1 which1 sooner or later1 it must reach4 ,the medium which fills universal space1 whether it be a luminiferous ether1 or arise from the indefinite expansion of planetary atmospheres1 must retard the bodies which move in it1 even were it #cfj1jjj millions of times more rare than atmospheric air2 and1 with its time of revolution gradually shortening1 the satellite must return to its planet1 the planet to its sun1 and the sun to its primeval nebula4 ,the fate of our system1 thus deduced from mechanical laws1 must be the fate of all others4 ,motion cannot be perpetuated in a resisting medium2 and where there exist disturbing forces1 there must be primarily derangement1 and ultimately ruin4 ,from the great central mass1 heat may again be summoned to exhale nebulous matter2 chemical forces may again produce motion1 and motion may again generate systems2 but1 as in the recurring catastrophes which have desolated our earth1 the great ,first ,cause must preside at the dawn of each cosmical cycle2 and1 as in the animal races which were successively reproduced1 new celestial creations of a nobler form of beauty and of a higher form of permanence may yet appear in the sidereal universe4 8,behold1 ,i create new heavens and a new earth1 and the former shall not be remembered40 8,the new heavens and the new earth shall remain before me40 8,let us look1 then1 according to this promise1 for the new heavens and the new earth1 wherein dwelleth righteousness40--,north-,british ,review1 ,no4 #c4 ,,benefits ,,of ,,glass ,,to ,,man4 ,cuvier eloquently says3 8,it could not be expected that those ,phnician sailors who saw the sand of the shores of ,btica transformed by fire into a transparent ,glass1 should have at once foreseen that this new substance would prolong the pleasures of sight to the old2 that it would one day assist the astronomer in penetrating the depths of the heavens1 and in numbering the stars of the ,milky ,way2 that it would lay open to the naturalist a miniature world1 as populous1 as rich in wonders as that which alone seemed to have been granted to his senses and his contemplation3 in fine1 that the most simple and direct use of it would enable the inhabitants of the coast of the ,baltic ,sea to build palaces more magnificent than those of ,tyre and ,memphis1 and to cultivate1 almost under the polar circle1 the most delicious fruit of the torrid zone40 ,,the ,,galilean ,,telescope4 ,galileo appears to be justly entitled to the honour of having invented that form of ,telescope which still bears his name2 while we must accord to ,john ,lippershey1 the spectacle-maker of ,middleburg1 the honour of having previously invented the astronomical telescope4 ,the interest excited at ,venice by ,galileo's invention amounted almost to frenzy4 ,on ascending the tower of ,st4 ,mark1 that he might use one of his telescopes without molestation1 ,galileo was recognised by a crowd in the street1 who took possession of the wondrous tube1 and detained the impatient philosopher for several hours1 till they had successively witnessed its effects4 ,these instruments were soon manufactured in great numbers2 but were purchased merely as philosophical toys1 and were carried by travellers into every corner of ,europe4 ,,what ,,galileo ,,first ,,saw ,,with ,,his ,,telescope4 ,the moon displayed to him her mountain-ranges and her glens1 her continents and her highlands1 now lying in darkness1 now brilliant with sunshine1 and undergoing all those variations of light and shadow which the surface of our own globe presents to the alpine traveller or to the aeronaut4 ,the four satellites of ,jupiter illuminating their planet1 and suffering eclipses in his shadow1 like our own moon2 the spots on the sun's disc1 proving his rotation round his axis in twenty-five days2 the crescent phases of ,venus1 and the triple form or the imperfectly developed ring of ,saturn1--were the other discoveries in the solar system which rewarded the diligence of ,galileo4 ,in the starry heavens1 too1 thousands of new worlds were discovered by his telescope2 and the ,pleiades alone1 which to the unassisted eye exhibit only seven stars1 displayed to ,galileo no fewer than forty4--,north-,british ,review1 ,no4 #c4 ,the first telescope 8the starry ,galileo0 constructed with a leaden tube a few inches long1 with a spectacle-glass1 one convex and one concave1 at each of its extremities4 ,it magnified three times4 ,telescopes were made in ,london in ,february #afaj1 a year after ,galileo had completed his own 7,rigaud1 ,on ,harriot's ,papers1 #ahcc74 ,they were at first called cylinders4 ,the telescopes which ,galileo constructed1 and others of which he made use for observing ,jupiter's satellites1 the phases of ,venus1 and the solar spots1 possessed the gradually-increasing powers of magnifying four1 seven1 and thirty-two linear diameters2 but they never had a higher power4--,arago1 in the ,annuaire for #ahdb4 ,clock-work is now applied to the equatorial telescope1 so as to allow the observer to follow the course of any star1 comet1 or planet he may wish to observe continuously1 without using his hands for the mechanical motion of the instrument4 ,,antiquity ,,of ,,telescopes4 ,long tubes were certainly employed by ,arabian astronomers1 and very probably also by the ,greeks and ,romans2 the exactness of their observations being in some degree attributable to their causing the object to be seen through diopters or slits4 ,abul ,hassan speaks very distinctly of tubes1 to the extremities of which ocular and object diopters were attached2 and instruments so constructed were used in the observatory founded by ,hulagu at ,meragha4 ,if stars be more easily discovered during twilight by means of tubes1 and if a star be sooner revealed to the naked eye through a tube than without it1 the reason lies1 as ,arago has truly observed1 in the circumstance that the tube conceals a great portion of the disturbing light diffused in the atmospheric strata between the star and the eye applied to the tube4 ,in like manner1 the tube prevents the lateral impression of the faint light which the particles of air receive at night from all the other stars in the firmament4 ,the intensity of the image and the size of the star are apparently augmented4--,humboldt's ,cosmos1 vol4 iii4 p4 #ec4 ,,newton',s ,,first ,,reflecting ,,telescope4 ,the year #affh may be regarded as the date of the invention of ,newton's ,reflecting ,telescope4 ,five years previously1 ,james ,gregory had described the manner of constructing a reflecting telescope with two concave specula2 but ,newton perceived the disadvantages to be so great1 that1 according to his statement1 he 8found it necessary1 before attempting any thing in the practice1 to alter the design1 and place the eye-glass at the side of the tube rather than at the middle40 ,on this improved principle ,newton constructed his telescope1 which was examined by ,charles ,,ii42 it was presented to the ,royal ,society near the end of #afga1 and is carefully preserved by that distinguished body1 with the inscription3 8,,the ,,first ,,reflecting ,,telescope2 ,,invented ,,by ,,sir ,,isaac ,,newton1 ,,and ,,made ,,with ,,his ,,own ,,hands40 ,sir ,david ,brewster describes this telescope as consisting of a concave metallic speculum1 the radius of curvature of which was #ab-b_/c or #ac inches1 so that 8it collected the sun's rays at the distance of #f-a_/c inches40 ,the rays reflected by the speculum were received upon a plane metallic speculum inclined #de to the axis of the tube1 so as to reflect them to the side of the tube in which there was an aperture to receive a small tube with a plano-convex eye-glass whose radius was one-twelfth of an inch1 by means of which the image formed by the speculum was magnified #ch times4 ,such was the first reflecting telescope applied to the heavens2 but ,sir ,david ,brewster describes this instrument as small and ill-made2 and fifty years elapsed before telescopes of the ,newtonian form became useful in astronomy4 ,,sir ,,william ,,herschel',s ,,great ,,telescope ,,at ,,slough4 ,the plan of this ,telescope was intimated by ,herschel1 through ,sir ,joseph ,banks1 to ,george ,,iii41 who offered to defray the whole expense of it2 a noble act of liberality1 which has never been imitated by any other ,british sovereign4 ,towards the close of #aghe1 accordingly1 ,herschel began to construct his reflecting telescope1 forty feet in length1 and having a speculum fully four feet in diameter4 ,the thickness of the speculum1 which was uniform in every part1 was #c inches1 and its weight nearly #baah pounds2 the metal being composed of #cb copper1 and #ajg of tin3 it was the third speculum cast1 the two previous attempts having failed4 ,the speculum1 when not in use1 was preserved from damp by a tin cover1 fitted upon a rim of close-grained cloth4 ,the tube of the telescope was #ci ft4 #d in4 long1 and its width #d ft4 #aj in42 it was made of iron1 and was #cjjj lbs4 lighter than if it had been made of wood4 ,the observer was seated in a suspended movable seat at the mouth of the tube1 and viewed the image of the object with a magnifying lens or eye-piece4 ,the focus of the speculum1 or place of the image1 was within four inches of the lower side of the mouth of the tube1 and came forward into the air1 so that there was space for part of the head above the eye1 to prevent it from intercepting many of the rays going from the object to the mirror4 ,the eye-piece moved in a tube carried by a slider directed to the centre of the speculum1 and fixed on an adjustible foundation at the mouth of the tube4 ,it was completed on the #bgth ,august #aghi2 and the very first moment it was directed to the heavens1 a new body was added to the solar system1 namely1 ,saturn and six of its satellites2 and in less than a month after1 the seventh satellite of ,saturn1 8an object10 says ,sir ,john ,herschel1 8of a far higher order of difficulty40--,abridged from the ,north-,british ,review1 ,no4 #c4 ,this magnificent instrument stood on the lawn in the rear of ,sir ,william ,herschel's house at ,slough2 and some of our readers1 like ourselves1 may remember its extraordinary aspect when seen from the ,bath coach-road1 and the road to ,windsor4 ,the difficulty of managing so large an instrument--requiring as it did two assistants in addition to the observer himself and the person employed to note the time--prevented its being much used4 ,sir ,john ,herschel1 in a letter to ,mr4 ,weld1 states the entire cost of its construction1 #djjjl41 was defrayed by ,george ,,iii4 ,in #ahci1 the woodwork of the telescope being decayed1 ,sir ,john ,herschel had it cleared away2 and piers were erected1 on which the tube was placed1 that being of iron1 and so well preserved that1 although not more than one-twentieth of an inch thick1 when in the horizontal position it contained within all ,sir ,john's family2 and next the two reflectors1 the polishing apparatus1 and portions of the machinery1 to the amount of a great many tons4 ,sir ,john attributes this great strength and resistance to the internal structure of the tube1 very similar to that patented under the name of corrugated iron-roping4 ,sir ,john ,herschel also thinks that system of triangular arrangement of the woodwork was upon the principle to which 8diagonal bracing0 owes its strength4 ,,the ,,earl ,,of ,,rosse',s ,,great ,,reflecting ,,telescope4 ,sir ,david ,brewster has remarked1 that 8the long interval of half a century seems to be the period of hybernation during which the telescopic mind rests from its labours in order to acquire strength for some great achievement4 ,fifty years elapsed between the dwarf telescope of ,newton and the large instruments of ,hadley2 other fifty years rolled on before ,sir ,william ,herschel constructed his magnificent telescope2 and fifty years more passed away before the ,earl of ,rosse produced that colossal instrument which has already achieved such brilliant discoveries40#be ,in the improvement of the ,reflecting ,telescope1 the first object has always been to increase the magnifying power and light by the construction of as large a mirror as possible2 and to this point ,lord ,rosse's attention was directed as early as #ahbh1 the field of operation being at his lordship's seat1 ,birr ,castle at ,parsonstown1 about fifty miles west of ,dublin4 ,for this high branch of scientific inquiry ,lord ,rosse was well fitted by a rare combination of 8talent to devise1 patience to bear disappointment1 perseverance1 profound mathematical knowledge1 mechanical skill1 and uninterrupted leisure from other pursuits20#bf all these1 however1 would not have been sufficient1 had not a great command of money been added2 the gigantic telescope we are about to describe having cost certainly not less than twelve thousand pounds4 ,lord ,rosse ground and polished specula fifteen inches1 two feet1 and three feet in diameter before he commenced the colossal instrument4 ,it is impossible here to detail the admirable contrivances and processes by which he prepared himself for this great work4 ,he first ascertained the most useful combination of metals for specula1 both in whiteness1 porosity1 and hardness1 to be copper and tin4 ,of this compound the reflector was cast in pieces1 which were fixed on a bed of zinc and copper1--a species of brass which expanded in the same degree by heat as the pieces of the speculum themselves4 ,they were ground as one body to a true surface1 and then polished by machinery moved by a steam-engine4 ,the peculiarities of this mechanism were entirely ,lord ,rosse's invention1 and the result of close calculation and observation3 they were chiefly1 placing the speculum with the face upward1 regulating the temperature by having it immersed in water1 usually at #ee ,fahr41 and regulating the pressure and velocity4 ,this was found to work a perfect spherical figure in large surfaces with a degree of precision unattainable by the hand2 the polisher1 by working above and upon the face of the speculum1 being enabled to examine the operation as it proceeded without removing the speculum1 which1 when a ton weight1 is no easy matter4 ,the contrivance for doing this is very beautiful4 ,the machine is placed in a room at the bottom of a high tower1 in the successive floors of which trap-doors can be opened4 ,a mast is elevated on the top of the tower1 so that its summit is about ninety feet above the speculum4 ,a dial-plate is attached to the top of the mast1 and a small plane speculum and eye-piece1 with proper adjustments1 are so placed that the combination becomes a ,newtonian telescope1 and the dial-plate the object4 ,the last and most important part of the process of working the speculum1 is to give it a true parabolic figure1 that is1 such a figure that each portion of it should reflect the incident ray to the same focus4 ,lord ,rosse's operations for this purpose consist--#ast1 of a stroke of the first eccentric1 which carries the polisher along one-third of the diameter of the speculum2 #b;d1 a transverse stroke twenty-one times slower1 and equal to #jbg of the same diameter1 measured on the edge of the tank1 or #ag beyond the centre of the polisher2 #c;d1 a rotation of the speculum performed in the same time as thirty-seven of the first strokes2 and #dth1 a rotation of the polisher in the same direction about sixteen times slower4 ,if these rules are attended to1 the machine will give the true parabolic figure to the speculum1 whether it be six inches or three feet in diameter4 ,in the three-feet speculum1 the figure is so true with the whole aperture1 that it is thrown out of focus by a motion of less than the thirtieth of an inch1 8and even with a single lens of one-eighth of an inch focus1 giving a power of #beib1 the dots on a watch-dial are still in some degree defined40 ,thus was executed the three-feet speculum for the twenty-six-feet telescope placed upon the lawn at ,parsonstown1 which1 in #ahdj1 showed with powers up to #ajjj and even #afjj2 and which resolved nebul into stars1 and destroyed that symmetry of form in globular nebul upon which was founded the hypothesis of the gradual condensation of nebulous matter into suns and planets4#bg ,scarcely was this instrument out of ,lord ,rosse's hands1 when he resolved to attempt by the same processes to construct another reflector1 with a speculum six feet in diameter and fifty feet long6 and this magnificent instrument was completed early in #ahde4 ,the focal length of the speculum is fifty-four feet4 ,it weighs four tons1 and1 with its supports1 is seven times as heavy as the four-feet speculum of ,sir ,william ,herschel4 ,the speculum is placed in one of the sides of a cubical wooden box1 about eight feet wide1 and to the opposite end of this box is fastened the tube1 which is made of deal staves an inch thick1 hooped with iron clamp-rings1 like a huge cask4 ,it carries at its upper end1 and in the axis of the tube1 a small oval speculum1 six inches in its lesser diameter4 ,the tube is about #ej feet long and #h feet in diameter in the middle1 and furnished with diaphragms #f feet in aperture4 ,the late ,dean of ,ely walked through the tube with an umbrella up4 ,the telescope is established between two lofty castellated piers #fj feet high1 and is raised to different altitudes by a strong chain-cable attached to the top of the tube4 ,this cable passes over a pulley on a frame down to a windlass on the ground1 which is wrought by two assistants4 ,to the frame are attached chain-guys fastened to the counterweights2 and the telescope is balanced by these counterweights suspended by chains1 which are fixed to the sides of the tube and pass over large iron pulleys4 ,the immense mass of matter weighs about twelve tons4 ,on the eastern pier is a strong semicircle of cast-iron1 with which the telescope is connected by a racked bar1 with friction-rollers attached to the tube by wheelwork1 so that by means of a handle near the eye-piece1 the observer can move the telescope along the bar on either side of the meridian1 to the distance of an hour for an equatorial star4 ,on the western pier are stairs and galleries4 ,the observing gallery is moved along a railway by means of wheels and a winch2 and the mechanism for raising the galleries to various altitudes is very ingenious4 ,sometimes the galleries1 filled with observers1 are suspended midway between the two piers1 over a chasm sixty feet deep4 ,an excellent description of this immense ,telescope at ,birr ,castle will be found in ,mr4 ,weld's volume of ,vacation ,rambles4 ,sir ,david ,brewster thus eloquently sketches the powers of the telescope at the close of his able description of the instrument1 which we have in part quoted from his ,life of ,sir ,isaac ,newton4 ,we have1 in the mornings1 walked again and again1 and ever with new delight1 along its mystic tube1 and at midnight1 with its distinguished architect1 pondered over the marvellous sights which it dis-closes1--the satellites and belts and rings of ,saturn1--the old and new ring1 which is advancing with its crest of waters to the body of the planet1--the rocks1 and mountains1 and valleys1 and extinct volcanoes of the moon1--the crescent of ,venus1 with its mountainous outline1--the systems of double and triple stars1--the nebul and starry clusters of every variety of shape1--and those spiral nebular formations which baffle human comprehension1 and constitute the greatest achievement in modern discovery4 ,the ,astronomer ,royal1 ,mr4 ,airy1 alludes to the impression made by the enormous light of the telescope1--partly by the modifications produced in the appearance of nebul already figured1 partly by the great number of stars seen at a distance from the ,milky ,way1 and partly from the prodigious brilliancy of ,saturn4 ,the account given by another astronomer of the appearance of ,jupiter was that it resembled a coach-lamp in the telescope2 and this well expresses the blaze of light which is seen in the instrument4 ,the ,rev4 ,dr4 ,scoresby thus records the results of his visits3 ,the range opened to us by the great telescope at ,birr ,castle is best1 perhaps1 apprehended by the now usual measurement--not of distances in miles1 or millions of miles1 or diameters of the earth's orbit1 but--of the progress of light in free space4 ,the determination within1 no doubt1 a small proportion of error of the parallax of a considerable number of the fixed stars yields1 according to ,mr4 ,peters1 a space betwixt us and the fixed stars of the smallest magnitude1 the sixth1 ordinarily visible to the naked eye1 of #acj years in the flight of light4 ,this information enables us1 on the principles of sounding the heavens1 suggested by ,sir ,w4 ,herschel1 with the photometrical researches on the stars of ,dr4 ,wollaston and others1 to carry the estimation of distances1 and that by no means on vague assumption1 to the limits of space opened out by the most effective telescopes4 ,and from the guidance thus afforded us as to the comparative power of the six feet speculum in the penetration of space as already elucidated1 we might fairly assume the fact1 that if any other telescope now in use could follow the sun if removed to the remotest visible position1 or till its light would require #aj1jjj years to reach us1 the grand instrument at ,parsonstown would follow it so far that from #bj1jjj to #be1jjj years would be spent in the transmission of its light to the earth4 ,but in the cases of clusters of stars1 and of nebul exhibiting a mere speck of misty luminosity1 from the combined light of perhaps hundreds of thousands of suns1 the penetration into space1 compared with the results of ordinary vision1 must be enormous2 so that it would not be difficult to show the probability that a million of years1 in flight of light1 would be requisite1 in regard to the most distant1 to trace the enormous interval4 ,,gigantic ,,telescopes ,,proposed4 ,hooke is said to have proposed the use of ,telescopes having a length of upwards of #aj1jjj feet 7or nearly two miles71 in order to see animals in the moon6 an extravagant expectation which ,auzout considered it necessary to refute4 ,the ,capuchin monk ,schyrle von ,rheita1 who was well versed in optics1 had already spoken of the speedy practicability of constructing telescopes that should magnify #djjj times1 by means of which the lunar mountains might be accurately laid down4 ,optical instruments of such enormous focal lengths remind us of the ,arabian contrivances of measurement3 quadrants with a radius of about #aij feet1 upon whose graduated limb the image of the sun was received as in the gnomon1 through a small round aperture4 ,such a quadrant was erected at ,samarcand1 probably constructed after the model of the older sextants of ,alchokandi1 which were about sixty feet in height4 ,,late ,,invention ,,of ,,optical ,,instruments4 ,a writer in the ,north-,british ,review1 ,no4 #ej1 considers it strange that a variety of facts which must have presented themselves to the most careless observer should not have led to the earlier construction of ,optical ,instruments4 ,the ancients1 doubtless1 must have formed metallic articles with concave surfaces1 in which the observer could not fail to see himself magnified2 and if the radius of the concavity exceeded twelve inches1 twice the focal distance of his eye1 he had in his hands an extempore reflecting telescope of the ,newtonian form1 in which the concave metal was the speculum1 and his eye the eye-glass1 and which would magnify and bring near him the image of objects nearly behind him4 ,through the spherical drops of water suspended before his eye1 an attentive observer might have seen magnified some minute body placed accidentally in its anterior focus2 and in the eyes of fishes and quadrupeds which he used for his food1 he might have seen1 and might have extracted1 the beautiful lenses which they contain1 and which he could not fail to regard as the principal agents in the vision of the animals to which they belonged4 ,curiosity might have prompted him to look through these remarkable lenses or spheres2 and had he placed the lens of the smallest minnow1 or that of the bird1 the sheep1 or the ox1 in or before a circular aperture1 he would have produced a microscope or microscopes of excellent quality and different magnifying powers4 ,no such observations seem1 however1 to have been made2 and even after the invention of glass1 and its conversion into globular vessels1 through which1 when filled with any fluid1 objects are magnified1 the microscope remained undiscovered4 ,a ,,triad ,,of ,,contemporary ,,astronomers4 ,it is a remarkable fact in the history of astronomy 7says ,sir ,david ,brewster71 that three of its most distinguished professors were contemporaries4 ,galileo was the contemporary of ,tycho during thirty-seven years1 and of ,kepler during the fifty-nine years of his life4 ,galileo was born seven years before ,kepler1 and survived him nearly the same time4 ,we have not learned that the intellectual triumvirate of the age enjoyed any opportunity for mutual congratulation4 ,what a privilege would it have been to have contrasted the aristocratic dignity of ,tycho with the reckless ease of ,kepler1 and the manly and impetuous mien of the ,italian sage6--,brewster's ,life of ,newton4 ,a ,,peasant ,,astronomer4 ,at about the same time that ,goodricke discovered the variation of the remarkable periodical star ,algol1 or ,persei1 one ,palitzch1 a farmer of ,prolitz1 near ,dresden1--a peasant by station1 an astronomer by nature1--from his familiar acquaintance with the aspect of the heavens1 was led to notice1 among so many thousand stars1 ,algol1 as distinguished from the rest by its variation1 and ascertained its period4 ,the same ,palitzch was also the first to re-discover the predicted comet of ,halley in #agei1 which he saw nearly a month before any of the astronomers1 who1 armed with their telescopes1 were anxiously watching its return4 ,these anecdotes carry us back to the era of the ,chaldean shepherds4--,sir ,john ,herschel's ,outlines4 ,,shirburn-,,castle ,,observatory4 ,lord ,macclesfield1 the eminent mathematician1 who was twelve years ,president of the ,royal ,society1 built at his seat1 ,shirburn ,castle in ,oxfordshire1 an ,observatory1 about #agci4 ,it stood #ajj yards south from the castle-gate1 and consisted of a bed-chamber1 a room for the transit1 and the third for a mural quadrant4 ,in the possession of the ,royal ,astronomical ,society is a curious print representing two of ,lord ,macclesfield's servants taking observations in the ,shirburn observatory2 they are ,thomas ,phelps1 aged #hb1 who1 from being a stable-boy to ,lord-,chancellor ,macclesfield1 rose by his merit and genius to be appointed observer4 ,his companion is ,john ,bartlett1 originally a shepherd1 in which station he1 by books and observation1 acquired such a knowledge in computation1 and of the heavenly bodies1 as to induce ,lord ,macclesfield to appoint him assistant-observer in his observatory4 ,phelps was the person who1 on ,december #bc;d1 #agdc1 discovered the great comet1 and made the first observation of it2 an account of which is entered in the ,philosophical ,transactions1 but not the name of the observer4 ,,lacaille',s ,,observatory4 ,lacaille1 who made more observations than all his contemporaries put together1 and whose researches will have the highest value as long as astronomy is cultivated1 had an observatory at the ,collge ,mazarin1 part of which is now the ,palace of the ,institute1 at ,paris4 ,for a long time it had been without observer or instruments2 under ,napoleon's reign it was demolished4 ,lacaille never used to illuminate the wires of his instruments4 ,the inner part of his observatory was painted black2 he admitted only the faintest light1 to enable him to see his pendulum and his paper3 his left eye was devoted to the service of looking to the pendulum1 whilst his right eye was kept shut4 ,the latter was only employed to look to the telescope1 and during the time of observation never opened but for this purpose4 ,thus the faintest light made him distinguish the wires1 and he very seldom felt the necessity of illuminating them4 ,part of these blackened walls were visible long after the demolition of the observatory1 which took place somewhat about #ahaa4--,professor ,mohl4 ,,nicety ,,required ,,in ,,astronomical ,,calculations4 ,in the ,edinburgh ,review1 #ahej1 we find the following illustrations of the enormous propagation of minute errors3 ,the rod used in measuring a base-line is commonly about ten feet long2 and the astronomer may be said truly to apply that very rod to mete the distance of the stars4 ,an error in placing a fine dot which fixes the length of the rod1 amounting to one-five-thousandth of an inch 7the thickness of a single silken fibre71 will amount to an error of #gj feet in the earth's diameter1 of #caf miles in the sun's distance1 and to #fe1bjj1jjj miles in that of the nearest fixed star4 ,secondly1 as the astronomer in his observatory has nothing further to do with ascertaining lengths or distances1 except by calculation1 his whole skill and artifice are exhausted in the measurement of angles2 for by these alone spaces inaccessible can be compared4 ,happily1 a ray of light is straight3 were it not so 7in celestial spaces at least71 there would be an end of our astronomy4 ,now an angle of a second 7#cfjj to a degree7 is a subtle thing4 ,it has an apparent breadth utterly invisible to the unassisted eye1 unless accompanied with so intense a splendour 7e4 g4 in the case of a fixed star7 as actually to raise by its effect on the nerve of sight a spurious image having a sensible breadth4 ,a silkworm's fibre1 such as we have mentioned above1 subtends an angle of a second at #c feet distance2 a cricket-ball1 #b inches diameter1 must be removed1 in order to subtend a second1 to #dc1jjj feet1 or about #h miles1 where it would be utterly invisible to the sharpest sight aided even by a telescope of some power4 ,yet it is on the measure of one single second that the ascertainment of a sensible parallax in any fixed star depends2 and an error of one-thousandth of that amount 7a quantity still unmeasurable by the most perfect of our instruments7 would place the star too far or too near by #bjj1jjj1jjj1jjj miles2 a space which light requires #aah days to travel4 ,,can ,,stars ,,be ,,seen ,,by ,,daylight8 ,aristotle maintains that ,stars may occasionally be seen in the ,daylight1 from caverns and cisterns1 as through tubes4 ,pliny alludes to the same circumstance1 and mentions that stars have been most distinctly recognised during solar eclipses4 ,sir ,john ,herschel has heard it stated by a celebrated optician1 that his attention was first drawn to astronomy by the regular appearance1 at a certain hour1 for several successive days1 of a considerable star through the shaft of a chimney4 ,the chimney-sweepers who have been questioned upon this subject agree tolerably well in stating that 8they have never seen stars by day1 but that when observed at night through deep shafts1 the sky appeared quite near1 and the stars larger40 ,saussure states that stars have been seen with the naked eye in broad daylight1 on the declivity of ,mont ,blanc1 at an elevation of #ab1geg feet1 as he was assured by several of the alpine guides4 ,the observer must be placed entirely in the shade1 and have a thick and massive shade above his head1 else the stronger light of the air will disperse the faint image of the stars2 these conditions resembling those presented by the cisterns of the ancients1 and the chimneys above referred to4 ,humboldt1 however1 questions the accuracy of these evidences1 adding that in the ,cordilleras of ,mexico1 ,quito1 and ,peru1 at elevations of #ae1jjj or #af1jjj feet above the sea-level1 he never could distinguish stars by daylight4 ,yet1 under the ethereally pure sky of ,cumana1 in the plains near the sea-shore1 ,humboldt has frequently been able1 after observing an eclipse of ,jupiter's satellites1 to find the planet again with the naked eye1 and has most distinctly seen it when the sun's disc was from #ah to #bj above the horizon4 ,,lost ,,heat ,,of ,,the ,,sun4 ,by the nature of our atmosphere1 we are protected from the influence of the full flood of solar heat4 ,the absorption of caloric by the air has been calculated at about one-fifth of the whole in passing through a column of #fjjj feet1 estimated near the earth's surface4 ,and we are enabled1 knowing the increasing rarity of the upper regions of our gaseous envelope1 in which the absorption is constantly diminishing1 to prove that about one-third of the solar heat is lost by vertical transmission through the whole extent of our atmosphere4--,j4 ,d4 ,forbes1 ,f4,r4,s42 ,bakerian ,lecture1 #ahdb4 ,,the ,,london ,,monument ,,used ,,as ,,an ,,observatory4 ,soon after the completion of the ,monument on ,fish ,street ,hill1 by ,wren1 in #afgg1 it was used by ,hooke and other members of the ,royal ,society for astronomical purposes1 but abandoned on account of the vibrations being too great for the nicety required in their observations4 ,hence arose the report that the ,monument was unsafe1 which has been revived in our time2 8but10 says ,elmes1 8its scientific construction may bid defiance to the attacks of all but earthquakes for centuries to come40 ,this vibration in lofty columns is not uncommon4 ,captain ,smythe1 in his ,cycle of ,celestial ,objects1 tells us1 that when taking observations on the summit of ,pompey's ,pillar1 near ,alexandria1 the mercury was sensibly affected by tremor1 although the pillar is a solid4 ,geology and ,paleontology4 ,,identity ,,of ,,astronomy ,,and ,,geology4 ,while the ,astronomer is studying the form and condition and structure of the planets1 in so far as the eye and the telescope can aid him1 the ,geologist is investigating the form and condition and structure of the planet to which he belongs2 and it is from the analogy of the earth's structure1 as thus ascertained1 that the astronomer is enabled to form any rational conjecture respecting the nature and constitution of the other planetary bodies4 ,astronomy and ,geology1 therefore1 constitute the same science--the science of material or inorganic nature4 ,when the astronomer first surveys the concavity of the celestial vault1 he finds it studded with luminous bodies differing in magnitude and lustre1 some moving to the east and others to the west2 while by far the greater number seem fixed in space2 and it is the business of astronomers to assign to each of them its proper place and sphere1 to determine their true distance from the earth1 and to arrange them in systems throughout the regions of sidereal space4 ,in like manner1 when the geologist surveys the convexity of his own globe1 he finds its solid covering composed of rocks and beds of all shapes and kinds1 lying at every possible angle1 occupying every possible position1 and all of them1 generally speaking1 at the same distance from the earth's centre4 ,every where we see what was deep brought into visible relation with what was superficial--what is old with what is new--what preceded life with what followed it4 ,thus displayed on the surface of his globe1 it becomes the business of the geologist to ascertain how these rocks came into their present places1 to determine their different ages1 and to fix the positions which they originally occupied1 and consequently their different distances from the centre or the circumference of the earth4 ,raised from their original bed1 the geologist must study the internal forces by which they were upheaved1 and the agencies by which they were indurated2 and when he finds that strata of every kind1 from the primitive granite to the recent tertiary marine mud1 have been thus brought within his reach1 and prepared for his analysis1 he reads their respective ages in the organic remains which they entomb2 he studies the manner in which they have perished1 and he counts the cycles of time and of life which they disclose4--,abridged from the ,north-,british ,review1 ,no4 #i4 ,,the ,,geology ,,of ,,england is more interesting than that of other countries1 because our island is in a great measure an epitome of the globe2 and the observer who is familiar with our strata1 and the fossil remains which they include1 has not only prepared himself for similar inquiries in other countries1 but is already1 as it were1 by anticipation1 acquainted with what he is to find there4--,transactions of the ,geological ,society4 ,,probable ,,origin ,,of ,,the ,,english ,,channel4 ,the proposed construction of a submarine tunnel across the ,straits of ,dover has led ,m4 ,bou1 ,for4 ,mem4 ,geol4 ,soc41 to point out the probability that the ,english ,channel has not been excavated by water-action only2 but owes its origin to one of the lines of disturbance which have fissured this portion of the earth's crust3 and taking this view of the case1 the fissure probably still exists1 being merely filled with comparatively loose material1 so as to prove a serious obstacle to any attempt made to drive through it a submarine tunnel4--,proceedings of the ,geological ,society4 ,,how ,,boulders ,,are ,,transported ,,to ,,great ,,heights4 ,sir ,roderick ,murchison has shown that in ,russia1 when the ,dwina is at its maximum height1 and penetrates into the chinks of its limestone banks1 when frozen and expanded it causes disruptions of the rock1 the entanglement of stony fragments in the ice4 ,in remarkable spring floods1 the stream so expands that in bursting it throws up its icy fragments to #ae or #bj feet above the stream2 and the waters subsiding1 these lateral ice-heaps melt away1 and leave upon the bank the rifled and angular blocks as evidence of the highest ice-mark4 ,in ,lapland1 ,m4 ,bhtlingk assures us that he has found large granitic boulders weighing several tons actually entangled and suspended1 like birds'-nests1 in the branches of pine-trees1 at heights of #cj or #dj feet above the summer level of the stream6#bh ,,why ,,sea-,,shells ,,are ,,found ,,at ,,great ,,heights4 ,the action of subterranean forces in breaking through and elevating strata of sedimentary rocks1--of which the coast of ,chili1 in consequence of a great earthquake1 furnishes an example1--leads to the assumption that the pelagic shells found by ,,mm4 ,bonpland and ,humboldt on the ridge of the ,andes1 at an elevation of more than #ae1jjj ,english feet1 may have been conveyed to so extraordinary a position1 not by a rising of the ocean1 but by the agency of volcanic forces capable of elevating into ridges the softened crust of the earth4 ,,sand ,,of ,,the ,,sea ,,and ,,desert4 ,that sand is an assemblage of small stones may be seen with the eye unarmed with art2 yet how few are equally aware of the synonymous nature of the sand of the sea and of the land6 ,quartz1 in the form of sand1 covers almost entirely the bottom of the sea4 ,it is spread over the banks of rivers1 and forms vast plains1 even at a very considerable elevation above the level of the sea1 as the desert of ,sahara in ,africa1 of ,kobi in ,asia1 and many others4 ,this quartz is produced1 at least in part1 from the disintegration of the primitive granite rocks4 ,the currents of water carry it along1 and when it is in very small1 light1 and rounded grains1 even the wind transports it from one place to another4 ,the hills are thus made to move like waves1 and a deluge of sand frequently inundates the neighbouring countries3 8,so where o'er wide ,numidian wastes extend1 ,sudden the impetuous hurricanes descend40--,addison's ,cato4 ,to illustrate the trite axiom1 that nothing is lost1 let us glance at the most important use of sand3 8,quartz in the form of sand10 observes ,maltebrun1 8furnishes1 by fusion1 one of the most useful substances we have1 namely glass1 which1 being less hard than the crystals of quartz1 can be made equally transparent1 and is equally serviceable to our wants and to our pleasures4 ,there it shines in walls of crystal in the palaces of the great1 reflecting the charms of a hundred assembled beauties2 there1 in the hand of the philosopher1 it discovers to us the worlds that revolve above us in the immensity of space1 and the no less astonishing wonders that we tread beneath our feet40 ,,pebbles4 ,the various heights and situations at which ,pebbles are found have led to many erroneous conclusions as to the period of changes of the earth's surface4 ,all the banks of rivers and lakes1 and the shores of the sea1 are covered with pebbles1 rounded by the waves which have rolled them against each other1 and which frequently seem to have brought them from a distance4 ,there are also similar masses of pebbles found at very great elevations1 to which the sea appears never to have been able to reach4 ,we find them in the ,alps at ,valorsina1 more than #fjjj feet above the level of the sea2 and on the mountain of ,bon ,homme1 which is more than #ajjj feet higher4 ,there are some places little elevated above the level of the sea1 which1 like the famous plain of ,crau1 in ,provence1 are entirely paved with pebbles2 while in ,norway1 near ,quedlia1 some mountains of considerable magnitude seem to be completely formed of them1 and in such a manner that the largest pebbles occupy the summit1 and their thickness and size diminish as you approach the base4 ,we may include in the number of these confused and irregular heaps most of the depositions of matter brought by the river or sea1 and left on the banks1 and perhaps even those immense beds of sand which cover the centre of ,asia and ,africa4 ,it is this circumstance which renders so uncertain the distinction1 which it is nevertheless necessary to establish1 between alluvial masses created before the commencement of history1 and those which we see still forming under our own eyes4 ,a charming monograph1 entitled 8,thoughts on a ,pebble10 full of playful sentiment and graceful fancy1 has been written by the amiable ,dr4 ,mantell1 the geologist4 ,,elevation ,,of ,,mountain-,,chains4 ,professor ,ansted1 in his ,ancient ,world1 thus characterises this phenomenon3 ,these movements1 described in a few words1 were doubtless going on for many thousands and tens of thousands of revolutions of our planet4 ,they were accompanied also by vast but slow changes of other kinds4 ,the expansive force employed in lifting up1 by mighty movements1 the northern portion of the continent of ,asia1 found partial vent2 and from partial subaqueous fissures there were poured out the tabular masses of basalt occurring in ,central ,india2 while an extensive area of depression in the ,indian ,ocean1 marked by the coral islands of the ,laccadives1 the ,maldives1 the great ,chagos bank1 and some others1 were in the course of depression by a counteracting movement4 ,hitherto the processes of denudation and of elevation have been so far balanced as to preserve a pretty steady proportion of sea and dry land during geological ages2 but if the internal temperature should be so far reduced as to be no longer capable of generating forces of expansion sufficient for this elevatory action1 while the denuding forces should continue to act with unabated energy1 the inevitable result would be1 that every mountain-top would be in time brought low4 ,no earthly barrier could declare to the ocean that there its proud waves should be stayed4 ,nothing would stop its ravages till all dry land should be laid prostrate1 to form the bed over which it would continue to roll an uninterrupted sea4 ,,the ,,chalk ,,formation4 ,mr4 ,horner1 ,f4,r4,s41 among other things in his researches in the ,delta1 considers it extremely probable that every particle of ,chalk in the world has at some period been circulating in the system of a living animal4 ,,wear ,,of ,,building-,,stones4 ,professor ,henry1 in an account of testing the marbles used in building the ,capitol at ,washington1 states that every flash of lightning produces an appreciable amount of nitric acid1 which1 diffused in rain-water1 acts on the carbonate of lime2 and from specimens subjected to actual freezing1 it was found that in ten thousand years one inch would be worn from the blocks by the action of frost4 ,in #ahci1 a report of the examination of ,sandstones1 ,limestones1 and ,oolites of ,britain was made to the ,government1 with a view to the selection of the best material for building the new ,houses of ,parliament4 ,for this purpose1 #ajc quarries were described1 #if buildings in ,england referred to1 many chemical analyses of the stones were given1 and a great number of experiments related1 showing1 among other points1 the cohesive power of each stone1 and the amount of disintegration apparent1 when subjected to ,brard's process4 ,the magnesian limestone1 or dolomite of ,bolsover ,moor1 was recommended1 and finally adopted for the ,houses2 but the selection does not appear to have been so successful as might have been expected from the skill and labour of the investigation4 ,it may be interesting to add1 that the publication of the above ,report 7for which see ,year-,book of ,facts1 #ahdj1 pp4 #gh-hj7 occasioned ,mr4 ,john ,mallcott to remark in the ,times journal1 8that all stone made use of in the immediate neighbourhood of its own quarries is more likely to endure that atmosphere than if it be removed therefrom1 though only thirty or forty miles30 and the lapse of comparatively few years has proved the soundness of this observation4#bi ,,phenomena ,,of ,,glaciers ,,illustrated4 ,professor ,tyndall1 being desirous of investigating some of the phenomena presented by the large masses of mountain-ice1--those frozen rivers called ,glaciers1--devised the plan of sending a destructive agent into the midst of a mass of ice1 so as to break down its structure in the interior1 in order to see if this method would reveal any thing of its internal constitution4 ,taking advantage of the bright weather of #aheg1 he concentrated a beam of sunlight by a condensing lens1 so as to form the focus of the sun's rays in the midst of a mass of ice4 ,a portion of the ice was melted1 but the surrounding parts shone out as brilliant stars1 produced by the reflection of the faces of the crystalline structure4 ,on examining these brilliant portions with a lens1 ,professor ,tyndall discovered that the structure of the ice had been broken down in symmetrical forms of great beauty1 presenting minute stars1 surrounded by six petals1 forming a beautiful flower1 the plane being always parallel to the plane of congelation of the ice4 ,he then prepared a piece of ice1 by making both its surfaces smooth and parallel to each other4 ,he concentrated in the centre of the ice the rays of heat from the electric light2 and then1 placing the piece of ice in the electric microscope1 the disc revealed these beautiful ice-flowers4 ,a mass of ice was crushed into fragments2 the small fragments were then placed in a cup of wood2 a hollow wooden die1 somewhat smaller than the cup1 was then pressed into the cup of ice-fragments by the pressure of a hydraulic press1 and the ice-fragments were immediately united into a compact cup of nearly transparent ice4 ,this pressure of fragments of ice into a solid mass explains the formation of the glaciers and their origin4 ,they are composed of particles of ice or snow2 as they descend the sides of the mountain1 the pressure of the snow becomes sufficiently great to compress the mass into solid ice1 until it becomes so great as to form the beautiful blue ice of the glaciers4 ,this compression1 however1 will not form the solid mass unless the temperature of the ice be near that of freezing water4 ,to prove this1 the lecturer cooled a mass of ice1 by wrapping it in a piece of tinfoil and exposing it for some time to a bath of the ethereal solution of solidified carbonic-acid gas1 the coldest freezing mixture known4 ,this cooled mass of ice was crushed to fragments1 and submitted to the same pressure which the other fragments had been exposed to without cohering in the slightest degree4--,lecture at the ,royal ,institution1 #aheh4 ,,antiquity ,,of ,,glaciers4 ,the importance of glacier agency in the past as well as the present condition of the earth1 is undoubtedly very great4 ,one of our most accomplished and ingenious geologists has1 indeed1 carried back the existence of ,glaciers to an epoch of dim antiquity1 even in the reckoning of that science whose chronology is counted in millions of years4 ,professor ,ramsay has shown ground for believing that in the fragments of rock that go to make up the conglomerates of the ,permian strata1 intermediate between the ,old and the ,new ,red ,sandstone1 there is still preserved a record of the action of ice1 either in glaciers or floating icebergs1 before those strata were consolidated4--,saturday ,review1 ,no4 #adb4 ,,flow ,,of ,,the ,,mer ,,de ,,glace4 ,michel ,devouasson of ,chamouni fell into a crevasse on the ,glacier of ,talefre1 a feeder of the ,mer de ,glace1 on the #bith of ,july #ahcf1 and after a severe struggle extricated himself1 leaving his knapsack below4 ,the identical knapsack reappeared in ,july #ahdf1 at a spot on the surface of the glacier four thousand three hundred feet from the place where it was lost1 as ascertained by ,professor ,forbes1 who himself collected the fragments2 thus indicating the rate of flow of the icy river in the intervening ten years4--,quarterly ,review1 ,no4 #bjb4 ,,the ,,alluvial ,,land ,,of ,,egypt3 ,,ancient ,,pottery4 ,mr4 ,l4 ,horner1 in his recent researches near ,cairo1 with the view of throwing light upon the geological history of the alluvial land of ,egypt1 obtained from the lowest part of the boring of the sediment at the colossal statue of ,rameses1 at a depth of thirty-nine feet1 this curious relic of the ancient world2 the boring instrument bringing up a fragment of pottery about an inch square and a quarter of an inch in thickness--the two surfaces being of a brick-red colour1 the interior dark gray4 ,according to ,mr4 ,horner's deductions1 this fragment1 having been found at a depth of #ci feet 7if there be no fallacy in his reasoning71 must be held to be a record of the existence of man #ac1cge years before ,a4,d4 #aheh1 reckoning by the calculated rate of increase of three inches and a half of alluvium in a century--#aa1eag years before the ,christian era1 and #gfbe before the beginning assigned by ,lepsius to the reign of ,menos1 the founder of ,memphis4 ,moreover it proves in his opinion1 that man had already reached a state of civilisation1 so far at least as to be able to fashion clay into vessels1 and to know how to harden it by the action of strong heat4 ,this calculation is supported by the ,chevalier ,bunsen1 who is of opinion that the first epochs of the history of the human race demand at the least a period of #bj1jjj years before our era as a fair starting-point in the earth's history4--,proceedings of ,royal ,soc41 #aheh4 ,upon this theory1 a ,correspondent1 8,an ,old ,indigo-,planter10 writes to the ,athenum1 ,no4 #aeji1 the following suggestive note3 8,having lived many years on the banks of the ,ganges1 ,i have seen the stream encroach on a village1 undermining the bank where it stood1 and deposit1 as a natural result1 bricks1 pottery1 c4 in the bottom of the stream4 ,on one occasion1 ,i am certain that the depth of the stream where the bank was breaking was above #dj feet2 yet in three years the current of the river drifted so much1 that a fresh deposit of soil took place over the dbris of the village1 and the earth was raised to a level with the old bank4 ,now had our traveller then obtained a bit of pottery from where it had lain for only three years1 could he reasonably draw the inference that it had been made #ac1jjj years before80 ,,successive ,,changes ,,of ,,the ,,temple ,,of ,,serapis4 ,the ,temple of ,serapis at ,puzzuoli1 near ,naples1 is perhaps1 of all the structures raised by the hands of man1 the one which affords most instruction to a geologist4 ,it has not only undergone a wonderful succession of changes in past time1 but is still undergoing changes of condition4 ,this edifice was exhumed in #agej from the eastern shore of the ,bay of ,bai1 consisting partly of strata containing marine shells with fragments of pottery and sculpture1 and partly of volcanic matter of sub-aerial origin4 ,various theories were proposed in the last century to explain the perforations and attached animals observed on the middle zone of the three erect marble columns until recently standing2 ,goethe1 among the rest1 suggesting that a lagoon had once existed in the vestibule of the temple1 filled during a temporary incursion of the sea with salt water1 and that marine mollusca and annelids flourished for years in this lagoon at twelve feet or more above the sea-level4 ,this hypothesis was advanced at a time when almost any amount of fluctuation in the level of the sea was thought more probable than the slightest alteration in the level of the solid land4 ,in #ahjg the architect ,niccolini observed that the pavement of the temple was dry1 except when a violent south wind was blowing2 whereas1 on revisiting the temple fifteen years later1 he found the pavement covered by salt water twice every day at high tide4 ,from measurements made from #ahbb to #ahch1 and thence to #ahde1 he inferred that the sea was gaining annually upon the floor of the temple at the rate of about one-third of an inch during the first period1 and about three-fourths of an inch during the second4 ,mr4 ,smith of ,jordan ,hill1 from his visits in #ahai and #ahde1 found an average rise of about an inch annually1 which was in accordance with visits made by ,mr4 ,babbage in #ahbh1 and ,professor ,james ,forbes in #ahbf and #ahdc4 ,in #aheb ,signor ,scaecchi1 at the request of ,sir ,charles ,lyell1 compared the depth of water on the pavement with its level taken by him in #ahci1 and found that it had gained only #d inches in thirteen years1 and was not so deep as when ,,mm4 ,niccolini and ,smith measured it in #ahde2 from which he inferred that after #ahde the downward movement of the land had ceased1 and before #aheb had been converted into an upward movement4 ,arago and others maintained that the surface on which the temple stands has been depressed1 has remained under the sea1 and has again been elevated4 ,russager1 however1 contends that there is nothing in the vicinity of the temple1 or in the temple itself1 to justify this bold hypothesis4 ,every thing leads to the belief that the temple has remained unchanged in the position in which it was originally built2 but that the sea rose1 surrounded it to a height of at least twelve feet1 and again retired2 but the elevated position of the sea continued sufficiently long to admit of the animals boring the pillars4 ,this view can even be proved historically2 for ,niccolini1 in a memoir published in #ahdj1 gives the heights of the level of the sea in the ,bay of ,naples for a period of #aijj years1 and has with much acuteness proved his assertions historically4 ,the correctness of ,russager's opinion1 he states1 can be demonstrated and reduced to figures by means of the dates collected by ,niccolini4--,see ,jameson's ,journal1 ,no4 #eh4 ,at the present time the floor is always covered with sea-water4 ,on the whole1 there is little doubt that the ground has sunk upwards of two feet during the last half-century4 ,this gradual subsidence confirms in a remarkable manner ,mr4 ,babbage's conclusions--drawn from the calcareous incrustations formed by the hot springs on the walls of the building and from the ancient lines of the water-level at the base of the three columns--that the original subsidence was not sudden1 but slow and by successive movements4 ,sir ,charles ,lyell 7who1 in his ,principles of ,geology1 has given a detailed account of the several upfillings of the temple7 considers that when the mosaic pavement was re-constructed1 the floor of the building must have stood about twelve feet above the level of #ahch 7or about #aa feet above the level of the sea71 and that it had sunk about nineteen feet below that level before it was elevated by the eruption of ,monte ,nuovo4 ,we regret to add1 that the columns of the temple are no longer in the position in which they served so many years as a species of self-registering hydrometer3 the materials have been newly arranged1 and thus has been torn as it were from history a page which can never be replaced4 ,,the ,,grotto ,,del ,,cane4 ,this 8,dog ,grotto0 has been so much cited for its stratum of carbonic-acid gas covering the floor1 that all geological travellers who visit ,naples feel an interest in seeing the wonder4 ,this cavern was known to ,pliny4 ,it is continually exhaling from its sides and floor volumes of steam mixed with carbonic-acid gas2 but the latter1 from its greater specific gravity1 accumulates at the bottom1 and flows over the step of the door4 ,the upper part of the cave1 therefore1 is free from the gas1 while the floor is completely covered by it4 ,addison1 on his visit1 made some interesting experiments4 ,he found that a pistol could not be fired at the bottom2 and that on laying a train of gunpowder and igniting it on the outside of the cavern1 the carbonic-acid gas 8could not intercept the train of fire when it once began flashing1 nor hinder it from running to the very end40 ,he found that a viper was nine minutes in dying on the first trial1 and ten minutes on the second2 this increased vitality being1 in his opinion1 attributable to the stock of air which it had inhaled after the first trial4 ,dr4 ,daubeny found that phosphorus would continue lighted at about two feet above the bottom2 that a sulphur-match went out in a few minutes above it1 and a wax-taper at a still higher level4 ,the keeper of the cavern has a dog1 upon which he shows the effects of the gas1 which1 however1 are quite as well1 if not better1 seen in a torch1 a lighted candle1 or a pistol4 8,unfortunately10 says ,professor ,silliman1 8like some other grottoes1 the enchantment of the #8,dog ,grotto' disappears on a near view40 ,it is a little hole dug artificially in the side of a hill facing ,lake ,agnano3 it is scarcely high enough for a person to stand upright in1 and the aperture is closed by a door4 ,into this narrow cell a poor little dog is very unwillingly dragged and placed in a depression of the floor1 where he is soon narcotised by the carbonic acid4 ,the earth is warm to the hand1 and the gas given out is very constant4 ,,the ,,waters ,,of ,,the ,,globe ,,gradually ,,decreasing4 ,this was maintained by ,m4 ,bory ,saint ,vincent1 because the vast deserts of sand1 mixed up with the salt and remains of marine animals1 of which the surface of the globe is partly composed1 were formerly inland seas1 which have insensibly become dry4 ,the ,caspian1 the ,dead ,sea1 the ,lake ,baikal1 c4 will become dry in their turn also1 when their beds will be sandy deserts4 ,the inland seas1 whether they have only one outlet1 as the ,mediterranean1 the ,red ,sea1 the ,baltic1 c41 or whether they have several1 as the ,gulf of ,mexico1 the seas of ,o',kotsk1 of ,japan1 ,china1 c41 will at some future time cease to communicate with the great basins of the ocean2 they will become inland seas1 true ,caspians1 and in due time will become likewise dry4 ,on all sides the waters of rivers are seen to carry forward in their course the soil of the continent4 ,alluvial lands1 deltas1 banks of sand1 form themselves near the coasts1 and in the directions of the currents2 madreporic animals lay the foundations of new lands2 and while the straits become closed1 while the depths of the sea fill up1 the level of the sea1 which it would seem natural should become higher1 is sensibly lower4 ,there is1 therefore1 an actual diminution of liquid matter4 ,,the ,,salt ,,lake ,,of ,,utah4 ,lieutenant ,gunnison1 who has surveyed the great basin of the ,salt ,lake1 states the water to be about one-third salt1 which it yields on boiling4 ,its density is considerably greater than that of the ,red ,sea4 ,one can hardly get the whole body below the surface3 in a sitting position the head and shoulders will remain above the water1 such is the strength of the brine2 and on coming to the shore the body is covered with an incrustation of salt in fine crystals4 ,during summer the lake throws on shore abundance of salt1 while in winter it throws up ,glauber salt plentifully4 8,the reason of this10 says ,lieutenant ,gunnison1 8is left for the scientific to judge1 and also what becomes of the enormous amount of fresh water poured into it by three or four large rivers1--,jordan1 ,bear1 and ,weber1--as there is no visible effect40 ,,force ,,of ,,running ,,water4 ,it has been proved by experiment that the rapidity at the bottom of a stream is every where less than in any other part of it1 and is greatest at the surface4 ,also1 that in the middle of the stream the particles at the top move swifter than those at the sides4 ,this slowness of the lowest and side currents is produced by friction2 and when the rapidity is sufficiently great1 the soil composing the sides and bottom gives way4 ,if the water flows at the rate of three inches per second1 it will tear up fine clay2 six inches per second1 fine sand2 twelve inches per second1 fine gravel2 and three feet per second1 stones the size of an egg4--,sir ,charles ,lyell4 ,,the ,,artesian ,,well ,,of ,,grenelle ,,at ,,paris4 ,m4 ,peligot has ascertained that the ,water of the ,artesian ,well of ,grenelle contains not the least trace of air4 ,subterranean waters ought therefore to be aerated before being used as aliment4 ,accordingly1 at ,grenelle1 has been constructed a tower1 from the top of which the water descends in innumerable threads1 so as to present as much surface as possible to the air4 ,the boring of this ,well by the ,messrs4 ,mulot occupied seven years1 one month1 twenty-six days1 to the depth of #agid ,english feet1 or #aid feet below the depth at which ,m4 ,elie de ,beaumont foretold that water would be found4 ,the sound1 or borer1 weighed #bj1jjj lb41 and was treble the height of that of the dome of the ,hpital des ,invalides at ,paris4 ,in ,may #ahcg1 when the bore had reached #abdf feet #h inches1 the great chisel and #bfb feet of rods fell to the bottom2 and although these weighed five tons1 ,m4 ,mulot tapped a screw on the head of the rods1 and thus1 connecting another length to them1 after fifteen months' labour1 drew up the chisel4 ,on another occasion1 this chisel having been raised with great force1 sank at one stroke #he feet #c inches into the chalk6 ,the depth of the ,grenelle ,well is nearly four times the height of ,strasburg ,cathedral2 more than six times the height of the ,hpital des ,invalides at ,paris2 more than four times the height of ,st4 ,peter's at ,rome2 nearly four times and a half the height of ,st4 ,paul's1 and nine times the height of the ,monument1 ,london4 ,lastly1 suppose all the above edifices to be piled one upon each other1 from the base-line of the ,well of ,grenelle1 and they would but reach within #aa feet of its surface4 ,,mm4 ,elie de ,beaumont and ,arago never for a moment doubted the final success of the work2 their confidence being based on analogy1 and on a complete acquaintance with the geological structure of the ,paris basin1 which is identical with that of the ,london basin beneath the ,london clay4 ,in the duchy of ,luxembourg is a well the depth of which surpasses all others of the kind4 ,it is upwards of #ajjj feet more than that of ,grenelle near ,paris4 ,,how ,,the ,,gulf-,,stream ,,regulates ,,the ,,temperature ,,of ,,london4 ,great ,britain is almost exactly under the same latitude as ,labrador1 a region of ice and snow4 ,apparently1 the chief cause of the remarkable difference between the two climates arises from the action of the great oceanic ,gulf-,stream1 whereby this country is kept constantly encircled with waters warmed by a ,west-,indian sun4 ,were it not for this unceasing current from tropical seas1 ,london1 instead of its present moderate average winter temperature of #f above the freezing-point1 might for many months annually be ice-bound by a settled cold of #aj to #cj below that point1 and have its pleasant summer months replaced by a season so short as not to allow corn to ripen1 or only an alpine vegetation to flourish4 ,nor are we without evidence afforded by animal life of a greater cold having prevailed in this country at a late geological period4 ,one case in particular occurs within eighty miles of ,london1 at the village of ,chillesford1 near ,woodbridge1 where1 in a bed of clayey sand of an age but little 7geologically speaking7 anterior to the ,london gravel1 ,mr4 ,prestwich has found a group of fossil shells in greater part identical with species now living in the seas of ,greenland and of similar latitudes1 and which must evidently1 from their perfect condition and natural position1 have existed in the place where they are now met with4--,lectures on the ,geology of ,clapham1 c4 by ,joseph ,prestwich1 ,a4,r4,s41 ,f4,g4,s4 ,,solvent ,,action ,,of ,,common ,,salt ,,at ,,high ,,temperatures4 ,forchhammer1 after a long series of experiments1 has come to the conclusion that ,common ,salt at high temperatures1 such as prevailed at earlier periods of the earth's history1 acted as a general solvent1 similarly to water at common temperatures4 ,the amount of common salt in the earth would suffice to cover its whole surface with a crust ten feet in thickness4 ,,freezing ,,cavern ,,in ,,russia4 ,this famous ,cavern1 at ,ithetz ,kaya-,zastchita1 in the ,steppes of the ,kirghis1 is employed by the inhabitants as a cellar4 ,it has the very remarkable property of being so intensely cold during the hottest summers as to be then filled with ice1 which disappearing with cold weather1 is entirely gone in winter1 when all the country is clad in snow4 ,the roof is hung with ever-dripping solid icicles1 and the floor may be called a stalagmite of ice and frozen earth4 8,if10 says ,sir ,r4 ,murchison1 8as we were assured1 the cold is greatest when the external air is hottest and driest1 that the fall of rain and a moist atmosphere produce some diminution of the cold in the cave1 and that upon the setting-in of winter the ice disappears entirely1--then indeed the problem is very curious40 ,the peasants assert that in winter they could sleep in the cave without their sheepskins4 ,,interior ,,temperature ,,of ,,the ,,earth3 ,,central ,,heat4 ,by the observed temperature of mines1 and that at the bottom of artesian wells1 it has been established that the rate at which such temperature increases as we descend varies considerably in different localities1 where the depths are comparatively small2 but where the depths are great1 we find a much nearer approximation to a common rate of increase1 which1 as determined by the best observation in the deepest mines1 shafts1 and artesian wells in ,western ,europe1 is very nearly #a ,f4 for an increase in depth of fifty feet4--,w4 ,hopkins1 ,m4,a41 ,f4,r4,s4 ,humboldt states that1 according to tolerably coincident experiments in artesian wells1 it has been shown that the heat increases on an average about #a for every #ede feet4 ,if this increase can be reduced to arithmetical relations1 it will follow that a stratum of granite would be in a state of fusion at a depth of nearly twenty-one geographical miles1 or between four and five times the elevation of the highest summit of the ,himalaya4 ,the following is the opinion of ,professor ,silliman3 ,that the whole interior portion of the earth1 or at least a great part of it1 is an ocean of melted rock1 agitated by violent winds1 though ,i dare not affirm it1 is still rendered highly probable by the phenomena of volcanoes4 ,the facts connected with their eruption have been ascertained and placed beyond a doubt4 ,how1 then1 are they to be accounted for8 ,the theory prevalent some years since1 that they are caused by the combustion of immense coal-beds1 is puerile and now entirely abandoned4 ,all the coal in the world could not afford fuel enough for one of the tremendous eruptions of ,vesuvius4 ,this observed increase of temperature in descending beneath the earth's surface suggested the notion of a central incandescent nucleus still remaining in a state of fluidity from its elevated temperature4 ,hence the theory that the whole mass of the earth was formerly a molten fluid mass1 the exterior portion of which1 to some unknown depth1 has assumed its present solidity by the radiation of heat into surrounding space1 and its consequent refrigeration4 ,the mathematical solution of this problem of ,central ,heat1 assuming such heat to exist1 tells us that though the central portion of the earth may consist of a mass of molten matter1 the temperature of its surface is not thereby increased by more than the small fraction of a degree4 ,poisson has calculated that it would require a thousand millions of centuries to reduce this fraction to a degree by half its present amount1 supposing always the external conditions to remain unaltered4 ,in such cases1 the superficial temperature of the earth may1 in fact1 be considered to have approximated so near to its ultimate limit that it can be subject to no further sensible change4 ,,disappearance ,,of ,,volcanic ,,islands4 ,many of the ,volcanic ,islands thrown up above the sea-level soon disappear1 because the lavas and conglomerates of which they are formed spread over flatter surfaces1 through the weight of the incumbent fluid2 and the constant levelling process goes on below the sea by the action of tides and currents4 ,such islands as have effectually resisted this action are found to possess a solid framework of lava1 supporting or defending the loose fragmentary materials4 ,among the most celebrated of these phenomena in our times may be mentioned the ,isle of ,sabrina1 which rose off the coast of ,st4 ,michael's in #ahaa1 attained a circumference of one mile and a height of #cjj feet1 and disappeared in less than eight months2 in the following year there were eighty fathoms of water in its place4 ,in ,july #ahca appeared ,graham's ,island off the coast of ,sicily1 which attained a mile in circumference and #aej or #afj feet in height2 its formation much resembled that of ,sabrina4 ,the line of ancient subterranean fire which we trace on the ,mediterranean coasts has had a strange attestation in ,graham's ,island1 which is also described as a volcano suddenly bursting forth in the mid sea between ,sicily and ,africa2 burning for several weeks1 and throwing up an isle1 or crater-cone of scori and ashes1 which had scarcely been named before it was again lost by subsidence beneath the sea1 leaving only a shoal-bank to attest this strange submarine breach in the earth's crust1 which thus mingled fire and water in one common action4 ,floating islands are not very rare3 in #ahbg1 one was seen twenty leagues to the east of the ,azores2 it was three leagues in width1 and covered with volcanic products1 sugar-canes1 straw1 and pieces of wood4 ,,perpetual ,,fire4 ,not far from the ,deliktash1 on the side of a mountain in ,lycia1 is the ,perpetual ,fire described some forty years since by ,captain ,beaufort4 ,it was found by ,lieutenant ,spratt and ,professor ,forbes1 thirty years later1 as brilliant as ever1 and somewhat increased2 for besides the large flame in the corner of the ruins described by ,beaufort1 there were small jets issuing from crevices in the side of the crater-like cavity five or six feet deep4 ,at the bottom was a shallow pool of sulphureous and turbid water1 regarded by the ,turks as a sovereign remedy for all skin complaints4 ,the soot deposited from the flames was held to be efficacious for sore eyelids1 and valued as a dye for the eyebrows4 ,this phenomenon is described by ,pliny as the flame of the ,lycian ,chimera4 ,,artesian ,,fire-,,springs ,,in ,,china4 ,according to the statement of the missionary ,imbert1 the ,fire-,springs1 8,ho-tsing0 of the ,chinese1 which are sunk to obtain a carburetted-hydrogen gas for salt-boiling1 far exceed our artesian springs in depth4 ,these springs are very commonly more than #bjjj feet deep2 and a spring of continued flow was found to be #caig feet deep4 ,this natural gas has been used in the ,chinese province ,tse-tschuan for several thousand years2 and 8portable gas0 7in bamboo-canes7 has for ages been used in the city of ,khiung-tscheu4 ,more recently1 in the village of ,fredonia1 in the ,united ,states1 such gas has been used both for cooking and for illumination4 ,,volcanic ,,action ,,the ,,great ,,agent ,,of ,,geological ,,change4 ,mr4 ,james ,nasmyth observes1 that 8the floods of molten lava which volcanoes eject are nothing less than remaining portions of what was once the condition of the entire globe when in the igneous state of its early physical history1--no one knows how many years ago6 8,when we behold the glow and feel the heat of molten lava1 how vastly does it add to the interest of the sight when we consider that the heat we feel and the light we see are the residue of the once universal condition of our entire globe1 on whose cooled surface we now live and have our being6 ,but so it is2 for if there be one great fact which geological research has established beyond all doubt1 it is that we reside on the cooled surface of what was once a molten globe1 and that all the phenomena which geology has brought to light can be most satisfactorily traced to the successive changes incidental to its gradual cooling and contraction4 8,that the influx of the sea into the yet hot and molten interior of the globe may occasionally occur1 and enhance and vary the violence of the phenomenon of volcanic action1 there can be little doubt2 but the action of water in such cases is only secondary4 ,but for the pre-existing high temperature of the interior of the earth1 the influx of water would produce no such discharges of molten lava as generally characterise volcanic eruptions4 ,molten lava is therefore a true vestige of the ,natural ,history of the ,creation40 ,,the ,,snow-,,capped ,,volcano4 ,it is but rarely that the elastic forces at work within the interior of our globe have succeeded in breaking through the spiral domes which1 resplendent in the brightness of eternal snow1 crown the summits of the ,cordilleras2 and even where these subterranean forces have opened a permanent communication with the atmosphere1 through circular craters or long fissures1 they rarely send forth currents of lava1 but merely eject ignited scori1 steam1 sulphuretted hydrogen gas1 and jets of carbonic acid4--,humboldt's ,cosmos1 vol4 i4 ,,travels ,,of ,,volcanic ,,dust4 ,on the #b;d of ,september #ahde1 a quantity of ,volcanic ,dust fell in the ,orkney ,islands1 which was supposed to have originated in an eruption of ,hecla1 in ,iceland4 ,it was subsequently ascertained that an eruption of that volcano took place on the morning of the above day 7,september #b71 so as to leave no doubt of the accuracy of the conclusion4 ,the dust had thus travelled about #fjj miles6 ,,great ,,eruptions ,,of ,,vesuvius4 ,in the great eruption of ,vesuvius1 in ,august #aggi1 which ,sir ,william ,hamilton witnessed from his villa at ,pausilippo in the bay of ,naples1 the volcano sent up white sulphureous smoke resembling bales of cotton1 exceeding the height and size of the mountain itself at least four times2 and in the midst of this vast pile of smoke1 stones1 scori1 and ashes were thrown up not less than #bjjj feet4 ,next day a fountain of fire shot up with such height and brilliancy that the smallest objects could be clearly distinguished at any place within six miles or more of ,vesuvius4 ,but on the following day a more stupendous column of fire rose three times the height of ,vesuvius 7#cgjj feet71 or more than two miles high4 ,among the huge fragments of lava thrown out during this eruption was a block #ajh feet in circumference and #ag feet high1 another block #ff feet in circumference and #ai feet high1 and another #af feet high and #ib feet in circumference1 besides thousands of smaller fragments4 ,sir ,william ,hamilton suggests that from a scene of the above kind the ancient poets took their ideas of the giants waging war with ,jupiter4 ,the eruption of ,june #agid1 which destroyed the greater part of the town of ,torre del ,greco1 was1 however1 the most violent that has been recorded after the two great eruptions of #gi and #afca4 ,,earth-,,waves4 ,the waves of an earthquake have been represented in their progress1 and their propagation1 through rocks of different density and elasticity2 and the causes of the rapidity of propagation1 and its diminution by the refraction1 reflection1 and interference of the oscillations have been mathematically investigated4 ,air1 water1 and earth waves follow the same laws which are recognised by the theory of motion1 at all events in space2 but the earth-waves are accompanied in their destructive action by discharges of elastic vapours1 and of gases1 and mixtures of pyroxene crystals1 carbon1 and infusorial animalcules with silicious shields4 ,the more terrific effects are1 however1 when the earth-waves are accompanied by cleavage2 and1 as in the earthquake of ,riobamba1 when fissures alternately opened and closed again1 so that men saved themselves by extending both arms1 in order to prevent their sinking4 ,as a remarkable example of the closing of a fissure1 ,humboldt mentions that1 during the celebrated earthquake in #ahea1 in the ,neapolitan province of ,basilicata1 a hen was found caught by both feet in the street-pavement of ,barile1 near ,melfi4 ,mr4 ,hopkins has very correctly shown theoretically that the fissures produced by earthquakes are very instructive as regards the formation of veins and the phenomenon of dislocation1 the more recent vein displacing the older formation4 ,,rumblings ,,of ,,earthquakes4 ,when the great earthquake of ,coseguina1 in ,nicaragua1 took place1 ,january #bc1 #ahce1 the subterranean noise--the sonorous waves in the earth--was heard at the same time on the island of ,jamaica and on the plateau of ,bogota1 #hgdj feet above the sea1 at a greater distance than from ,algiers to ,london4 ,in the eruptions of the volcano on the island of ,st4 ,vincent1 ,april #cj1 #ahab1 at #b ,a4,m41 a noise like the report of cannons was heard1 without any sensible concussion of the earth1 over a space of #afj1jjj geographical square miles4 ,there have also been heard subterranean thunderings for two years without earthquakes4 ,,how ,,to ,,measure ,,an ,,earthquake-,,shock4 ,a new instrument 7the ,seismometer7 invented for this purpose by ,m4 ,kreil1 of ,vienna1 consists of a pendulum oscillating in every direction1 but unable to turn round on its point of suspension2 and bearing at its extremity a cylinder1 which1 by means of mechanism within it1 turns on its vertical axis once in twenty-four hours4 ,next to the pendulum stands a rod bearing a narrow elastic arm1 which slightly presses the extremity of a lead-pencil against the surface of the cylinder4 ,as long as the pendulum is quiet1 the pencil traces an uninterrupted line on the surface of the cylinder2 but as soon as it oscillates1 this line becomes interrupted and irregular1 and these irregularities indicate the time of the commencement of an earthquake1 together with its duration and intensity4#cj ,elastic fluids are doubtless the cause of the slight and perfectly harmless trembling of the earth's surface1 which has often continued for several days4 ,the focus of this destructive agent1 the seat of the moving force1 lies far below the earth's surface2 but we know as little of the extent of this depth as we know of the chemical nature of these vapours that are so highly compressed4 ,at the edges of two craters1--,vesuvius and the towering rock which projects beyond the great abyss of ,pichincha1 near ,quito1--,humboldt has felt periodic and very regular shocks of earthquakes1 on each occasion from twenty to thirty seconds before the burning scori or gases were erupted4 ,the intensity of the shocks was increased in proportion to the time intervening between them1 and consequently to the length of time in which the vapours were accumulating4 ,this simple fact1 which has been attested by the evidence of so many travellers1 furnishes us with a general solution of the phenomenon1 in showing that active volcanoes are to be considered as safety-valves for the immediate neighbourhood4 ,there are instances in which the earth has been shaken for many successive days in the chain of the ,andes1 in ,south ,america4 ,in certain districts1 the inhabitants take no more notice of the number of earthquakes than we in ,europe take of showers of rain2 yet in such a district ,bonpland and ,humboldt were compelled to dismount1 from the restiveness of their mules1 because the earth shook in a forest for fifteen to eighteen minutes without intermission4 ,,earthquakes ,,and ,,the ,,moon4 ,from a careful discussion of several thousand earthquakes which have been recorded between #ahja and #ahej1 and a comparison of the periods at which they occurred with the position of the moon in relation to the earth1 ,m4 ,perry1 of ,dijon1 infers that earthquakes may possibly be the result of attraction exerted by that body on the supposed fluid centre of our globe1 somewhat similar to that which she exercises on the waters of the ocean2 and the ,committee of the ,institute of ,france have reported favourably upon this theory4 ,,the ,,great ,,earthquake ,,of ,,lisbon4 ,the eloquent ,humboldt remarks1 that the activity of an igneous mountain1 however terrific and picturesque the spectacle may be which it presents to our contemplation1 is always limited to a very small space4 ,it is far otherwise with earthquakes1 which1 although scarcely perceptible to the eye1 nevertheless simultaneously propagate their waves to a distance of many thousand miles4 ,the great earthquake which destroyed the city of ,lisbon1 ,november #ast1 #agee1 was felt in the ,alps1 on the coast of ,sweden1 into the ,antilles1 ,antigua1 ,barbadoes1 and ,martinique2 in the great ,canadian lakes1 in ,thuringia1 in the flat country of northern ,germany1 and in the small inland lakes on the shores of the ,baltic4 ,remote springs were interrupted in their flow1--a phenomenon attending earthquakes which had been noticed among the ancients by ,demetrius the ,callatian4 ,the hot springs of ,tplitz dried up and returned1 inundating every thing around1 and having their waters coloured with iron ochre4 ,at ,cadiz1 the sea rose to an elevation of sixty-four feet2 while in the ,antilles1 where the tide usually rises only from twenty-six to twenty-eight inches1 it suddenly rose about twenty feet1 the water being of an inky blackness4 ,it has been computed that1 on ,november #ast1 #agee1 a portion of the earth's surface four times greater than that of ,europe was simultaneously shaken4#ca ,as yet there is no manifestation of force known to us 7says the vivid denunciation of the philosopher71 including even the murderous invention of our own race1 by which a greater number of people have been killed in the short space of a few minutes3 #fj1jjj were destroyed in ,sicily in #afic1 from #cj1jjj to #dj1jjj in the earthquake of ,riobamba in #agig1 and probably five times as many in ,asia ,minor and ,syria under ,tiberius and ,justinian the elder1 about the years #ai and #ebf4 ,,geological ,,age ,,of ,,the ,,diamond4 ,the discovery of ,diamonds in ,russia1 far from the tropical zone1 has excited much interest among geologists4 ,in the detritus on the banks of the ,adolfskoi1 no fewer than forty diamonds have been found in the gold alluvium1 only twenty feet above the stratum in which the remains of mammoths and rhinoceroses are found4 ,hence ,humboldt has concluded that the formation of gold-veins1 and consequently of diamonds1 is comparatively of recent date1 and scarcely anterior to the destruction of the mammoths4 ,sir ,roderick ,murchison and ,m4 ,verneuil have been led to the same result by different arguments4#cb ,,what ,,was ,,adamant8 ,professor ,tennant replies1 that the ,adamant described by ,pliny was a sapphire1 as proved by its form1 and by the fact that when struck on an anvil by a hammer it would make an indentation in the metal4 ,a true diamond1 under such circumstances1 would fly into a thousand pieces4 ,,what ,,is ,,coal8 ,the whole evidence we possess as to the nature of ,coal proves it to have been originally a mass of vegetable matter4 ,its microscopical characters point to its having been formed on the spot in which we find it1 to its being composed of vegetable tissues of various kinds1 separated and changed by maceration1 pressure1 and chemical action1 and to the introduction of its earthy matter1 in a large number of instances1 in a state of solution or fine molecular subdivision4 ,dr4 ,redfern1 from whose communication to the ,british ,association we quote1 knows nothing to countenance the supposition that our coal-beds are mainly formed of coniferous wood1 because the structures found in mother-coal1 or the charcoal layer1 have not the character of the glandular tissue of such wood1 as has been asserted4 ,geological research has shown that the immense forests from which our coal is formed teemed with life4 ,a frog as large as an ox existed in the swamps1 and the existence of insects proves that the higher order of organic creation flourished at this epoch4 ,it has been calculated that the available coal-beds in ,lancashire amount in weight to the enormous sum of #h1djj1jjj1jjj tons4 ,the total annual consumption of this coal1 it has been estimated1 amounts to #c1djj1abj tons2 hence it is inferred that the coal-beds of ,lancashire1 at the present rate of consumption1 will last #bdgj years4 ,making similar calculations for the coal-fields of ,south ,wales1 the north of ,england1 and ,scotland1 it will readily be perceived how ridiculous were the forebodings which lecturing geologists delighted to indulge in a few years ago4 ,,torbane-,,hill ,,coal4 ,the coal of ,torbane ,hill1 ,scotland1 is so highly inflammable1 that it has been disputed at law whether it be true coal1 or only asphaltum1 or bitumen4 ,dr4 ,redfern describes it as laminated1 splitting with great ease horizontally1 like many cannel coals1 and like them it may be lighted at a candle4 ,in all parts of the bed stigmaria and other fossil plants occur in greater numbers than in most other coals2 their distinct vascular tissue may be easily recognised by a common pocket lens1 and #fe of the mass consists of carbon4 ,dr4 ,redfern considers that all our coals may be arranged in a scale having the ,torbane-,hill coal at the top and anthracite at the bottom4 ,anthracite is almost pure carbon2 ,torbane ,hill contains less fixed carbon than most other cannels3 anthracite is very difficult to ignite1 and gives out scarcely any gas2 ,torbane-,hill burns like a candle1 and yields #cjjj cubic feet of gas per ton1 more than any other known coal1 its gas being also of greatly superior illuminating power to any other4 ,the only differences which the ,torbane-,hill coal presents from others are differences of degree1 not of kind4 ,it differs from other coals in being the best gas-coal1 and from other cannels in being the best cannel4 ,,how ,,malachite ,,is ,,formed4 ,the rich copper-ore of the ,ural1 which occurs in veins or masses1 amid metamorphic strata associated with igneous rocks1 and even in the hollows between the eruptive rocks1 is worked in shafts4 ,at the bottom of one of these1 #bhj feet deep1 has been found an enormous irregularly-shaped botryoidal mass of ,malachite 7,greek malache1 mountain-green71 sending off strings of green copper-ore4 ,the upper surface of it is about #ah feet long and #i wide2 and it was estimated to contain #ae1jjj poods1 or half a million pounds1 of pure and compact malachite4 ,sir ,roderick ,murchison is of opinion that this wonderful subterraneous incrustation has been produced in the stalagmitic form1 during a series of ages1 by copper solutions emanating from the surrounding loose and sporous mass1 and trickling through it to the lowest cavity upon the subjacent solid rock4 ,malachite is brought chiefly from one mine in ,siberia2 its value as raw material is nearly one-fourth that of the same weight of pure silver1 or in a manufactured state three guineas per pound avoirdupois4#cc ,,lumps ,,of ,,gold ,,in ,,siberia4 ,the gold mines south of ,miask are chiefly remarkable for the large lumps or pepites of gold which are found around the ,zavod of ,zarevo-,alexandroisk4 ,previous to #ahda were discovered here lumps of native gold2 in that year a lump of twenty-four pounds was met with2 and in #ahdc a lump weighing about seventy-eight pounds ,english was found1 and is now deposited with others in the ,museum of the ,imperial ,school of ,mines at ,st4 ,petersburg4 ,,sir ,,isaac ,,newton ,,upon ,,burnet',s ,,theory ,,of ,,the ,,earth4 ,in #affh1 ,dr4 ,thomas ,burnet printed his ,theoria ,telluris ,sacra1 8an eloquent physico-theological romance10 says ,sir ,david ,brewster1 8which was to a certain extent adopted even by ,newton1 ,burnet's friend4 ,abandoning1 as some of the fathers had done1 the hexameron1 or six days of ,moses1 as a physical reality1 and having no knowledge of geological phenomena1 he gives loose reins to his imagination1 combining passages of ,scripture with those of ancient authors1 and presumptuously describing the future catastrophes to which the earth is to be exposed40 ,previous to its publication1 ,burnet presented a copy of his book to ,newton1 and requested his opinion of the theory which it propounded4 ,newton took 8exceptions to particular passages10 and a correspondence ensued4 ,in one of ,newton's letters he treats of the formation of the earth1 and the other planets1 out of a general chaos of the figure assumed by the earth1--of the length of the primitive days1--of the formation of hills and seas1 and of the creation of the two ruling lights as the result of the clearing up of the atmosphere4 ,he considers the account of the creation in ,genesis as adapted to the judgment of the vulgar4 8,had ,moses10 he says1 8described the processes of creation as distinctly as they were in themselves1 he would have made the narrative tedious and confused amongst the vulgar1 and become a philosopher more than a prophet40 ,after referring to several 8causes of meteors1 such as the breaking out of vapours from below1 before the earth was well hardened1 the settling and shrinking of the whole globe after the upper regions or surface began to be hard10 ,newton closes his letter with an apology for being tedious1 which1 he says1 8he has the more reason to do1 as he has not set down any thing he has well considered1 or will undertake to defend40--,see the ,letter in the ,appendix to ,sir ,d4 ,brewster's ,life of ,newton1 vol4 ii4 ,the primitive condition of the earth1 and its preparation for man1 was a subject of general speculation at the close of the seventeenth century4 ,leibnitz1 like his great rival 7,newton71 attempted to explain the formation of the earth1 and of the different substances which composed it2 and he had the advantage of possessing some knowledge of geological phenomena3 the earth he regarded as having been originally a burning mass1 whose temperature gradually diminished till the vapours were condensed into a universal ocean1 which covered the highest mountains1 and gradually flowed into vacuities and subterranean cavities produced by the consolidation of the earth's crust4 ,he regarded fossils as the real remains of plants and animals which had been buried in the strata2 and1 in speculating on the formation of mineral substances1 he speaks of crystals as the geometry of inanimate nature4--,brewster's ,life of ,newton1 vol4 ii4 p4 #ajj1 note4 7,see also 8,the ,age of the ,globe10 in ,things not generally ,known1 p4 #ac47 8,,the ,,father ,,of ,,english ,,geology40 ,in #agfi was born1 the son of a yeoman of ,oxfordshire1 ,william ,smith4 ,when a boy he delighted to wander in the fields1 collecting 8pound-stones0 7,echinites71 8pundibs0 7,terebratul71 and other stony curiosities2 and receiving little education beyond what he taught himself1 he learned nothing of classics but the name4 ,grown to be a man1 he became a land-surveyor and civil engineer1 and was much engaged in constructing canals4 ,while thus occupied1 he observed that all the rocky masses forming the substrata of the country were gently inclined to the east and south-east1--that the red sandstones and marls above the coal-measures passed below the beds provincially termed lias-clay and limestone--that these again passed underneath the sands1 yellow limestone1 and clays that form the table-land of the ,coteswold ,hills2 while they in turn plunged beneath the great escarpment of chalk that runs from the coast of ,dorsetshire northward to the ,yorkshire shores of the ,german ,ocean4 ,he further observed that each formation of clay1 sand1 or limestone1 held to a very great extent its own peculiar suite of fossils4 ,the 8snake-stones0 7,ammonites7 of the lias were different in form and ornament from those of the inferior oolite2 and the shells of the latter1 again1 differed from those of the ,oxford clay1 ,cornbrash1 and ,kimmeridge clay4 ,pondering much on these things1 he came to the then unheard-of conclusion that each formation had been in its turn a sea-bottom1 in the sediments of which lived and died marine animals now extinct1 many specially distinctive of their own epochs in time4 ,here indeed was a discovery1--made1 too1 by a man utterly unknown to the scientific world1 and having no pretension to scientific lore4 8,strata ,smith's0 find was unheeded for many a long year2 but at length the first geologists of the day learned from the land-surveyor that superposition of strata is inseparably connected with the succession of life in time4 ,hooke's grand vision was at length realised1 and it was indeed possible 8to build up a terrestrial chronology from rotten shells0 imbedded in the rocks4 ,meanwhile he had constructed the first geological map of ,england1 which has served as a basis for geological maps of all other parts of the world4 ,william ,smith was now presented by the ,geological ,society with the ,wollaston ,medal1 and hailed as 8the ,father of ,english ,geology40 ,he died in #ahdj4 ,till the manner as well as the fact of the first appearance of successive forms of life shall be solved1 it is not easy to surmise how any discovery can be made in geology equal in value to that which we owe to the genius of ,william ,smith4--,saturday ,review1 ,no4 #adj4 ,,dr4 ,,buckland's ,,geological ,,labours4 ,sir ,henry ,de la ,beche1 in his ,anniversary ,address to the ,geological ,society in #ahdh1 on presenting the ,wollaston ,medal to ,dr4 ,buckland1 felicitously observed3 ,it may not be generally known that1 while yet a child1 at your native town1 ,axminster in ,devonshire1 ammonites1 obtained by your father from the lime quarries in the neighbourhood1 were presented to your attention4 ,as a scholar at ,winchester1 the chalk1 with its flints1 was brought under your observation1 and there it was that your collections in natural history first began4 ,removed to ,oxford1 as a scholar of ,corpus ,christi ,college1 the future teacher of geology in that ,university was fortunate in meeting with congenial tastes in our colleague ,mr4 ,w4 ,j4 ,broderip1 then a student at ,oriel ,college4 ,it was during your walks together to ,shotover ,hill1 when his knowledge of conchology was so valuable to you1 enabling you to distinguish the shells of the ,oxford oolite1 that you laid the foundation for those field-lectures1 forming part of your course of geology at ,oxford1 which no one is likely to forget who has been so fortunate at any time as to have attended them4 ,the fruits of your walks with ,mr4 ,broderip formed the nucleus of that great collection1 more especially remarkable for the organic remains it contains1 which1 after the labours of forty years1 you have presented to the ,geological ,museum at ,oxford1 in grave recollection of the aid which the endowments of that ,university1 and the leisure of its vacations1 had afforded you for extensive travelling during a residence at ,oxford of nearly forty-five years4 ,,discoveries ,,of ,m4 ,,agassiz4#cd ,this great paleontologist1 in the course of his ichthyological researches1 was led to perceive that the arrangement by ,cuvier according to organs did not fulfil its purpose with regard to fossil fishes1 because in the lapse of ages the characteristics of their structures were destroyed4 ,he therefore adopted the only other remaining plan1 and studied the tissues1 which1 being less complex than the organs1 are oftener found intact4 ,the result was the very remarkable discovery1 that the tegumentary membrane of fishes is so intimately connected with their organisation1 that if the whole of the fish has perished except this membrane1 it is practicable1 by noting its characteristics1 to reconstruct the animal in its most essential parts4 ,of the value of this principle of harmony1 some idea may be formed from the circumstance1 that on it ,agassiz has based the whole of that celebrated classification of which he is the sole author1 and by which fossil ichthyology has for the first time assumed a precise and definite shape4 ,how essential its study is to the geologist appears from the remark of ,sir ,roderick ,murchison1 that 8fossil fishes have every where proved the most exact chronometer of the age of rocks40 ,,succession ,,of ,,life ,,in ,,time4 ,in the ,museum of ,economic ,geology1 in ,jermyn ,street1 may be seen ores1 metals1 rocks1 and whole suites of fossils stratigraphically arranged in such a manner that1 with an observant eye for form1 all may easily understand the more obvious scientific meanings of the ,succession of ,life in ,time1 and its bearing on geological economies4 ,it is perhaps scarcely an exaggeration to say1 that the greater number of so-called educated persons are still ignorant of the meaning of this great doctrine4 ,they would be ashamed not to know that there are many suns and material worlds besides our own2 but the science1 equally grand and comprehensible1 that aims at the discovery of the laws that regulated the creation1 extension1 decadence1 and utter extinction of many successive species1 genera1 and whole orders of life1 is ignored1 or1 if intruded on the attention1 is looked on as an uncertain and dangerous dream1--and this in a country which was almost the nursery of geology1 and which for half a century has boasted the first ,geological ,society in the world4--,saturday ,review1 ,no4 #adj4 ,,primitive ,,diversity ,,and ,,numbers ,,of ,,animals ,,in ,,geological ,,times4 ,professor ,agassiz considers that the very fact of certain stratified rocks1 even among the oldest formations1 being almost entirely made up of fragments of organised beings1 should long ago have satisfied the most sceptical that both animal and vegetable life were as active and profusely scattered upon the whole globe at all times1 and during all geological periods1 as they are now4 ,no coral reef in the ,pacific contains a larger amount of organic dbris than some of the limestone deposits of the tertiary1 of the cretaceous1 or of the oolitic1 nay even of the paleozoic period2 and the whole vegetable carpet covering the present surface of the globe1 even if we were to consider only the luxuriant vegetation of the tropics1 leaving entirely out of consideration the entire expanse of the ocean1 as well as those tracts of land where1 under less favourable circumstances1 the growth of plants is more reduced1--would not form one single seam of workable coal to be compared to the many thick beds contained in the rocks of the carboniferous period alone4 ,,england ,,in ,,the ,,eocene ,,period4 ,eocene is ,sir ,charles ,lyell's term for the lowest group of the ,tertiary system in which the dawn of recent life appears2 and any one who wishes to realise what was the aspect presented by this country during the ,eocene period1 need only go to ,sheerness4 ,if1 leaving that place behind him1 he walks down the ,thames1 keeping close to the edge of the water1 he will find whole bushels of pyritised pieces of twigs and fruits4 ,these fruits and twigs belong to plants nearly allied to the screw-pine and custard-apple1 and to various species of palms and spice-trees which now flourish in the ,eastern ,archipelago4 ,at the time they were washed down from some neighbouring land1 not only crocodilian reptiles1 but sharks and innumerable turtles1 inhabited a sea or estuary which now forms part of the ,london district2 and huge boa-constrictors glided amongst the trees which fringed the adjoining shores4 ,countless as are the ages which intervened between the ,eocene period and the time when the little jawbones of ,stonesfield were washed down to the place where they were to await the day when science should bring them again to light1 not one mammalian genus which now lives upon our plane has been discovered amongst ,eocene strata4 ,we have existing families1 but nothing more4--,professor ,owen4 ,,food ,,of ,,the ,,iguanodon4 ,dr4 ,mantell1 from the examination of the anterior part of the right side of the lower jaw of an ,iguanodon discovered in a quarry in ,tilgate ,forest1 ,sussex1 has detected an extraordinary deviation from all known types of reptilian organisation1 and which could not have been predicated2 namely1 that this colossal reptile1 which equalled in bulk the gigantic ,edentata of ,south ,america1 and like them was destined to obtain support from comminuted vegetable substances1 was also furnished with a large prehensile tongue and fleshy lips1 to serve as instruments for seizing and cropping the foliage and branches of trees2 while the arrangement of the teeth as in the ruminants1 and their internal structure1 which resembles that of the molars of the sloth tribe in the vascularity of the dentine1 indicate adaptations for the same purpose4 ,among the physiological phenomena revealed by paleontology1 there is not a more remarkable one than this modification of the type of organisation peculiar to the class of reptiles to meet the conditions required by the economy of a lizard placed under similar physical relations2 and destined to effect the same general purpose in the scheme of nature as the colossal ,edentata of former ages and the large herbivorous mammalia of our own times4 ,,the ,,pterodactyl--,,the ,,flying ,,dragon4 ,the ,tilgate beds of the ,wealden series1 just mentioned1 have yielded numerous fragments of the most remarkable reptilian fossils yet discovered1 and whose wonderful forms denote them to have thronged the shallow seas and bays and lagoons of the period4 ,in the grounds of the ,crystal ,palace at ,sydenham the reader will find restorations of these animals sufficiently perfect to illustrate this reptilian epoch4 ,they include the iguanodon1 an herbivorous lizard exceeding in size the largest elephant1 and accompanied by the equally gigantic and carnivorous megalosaurus 7great saurian71 and by the two yet more curious reptiles1 the pylosaurus 7forest1 or weald1 saurian7 and the pterodactyl 7from pteron1 #8wing1' and dactylus1 #8a finger'71 an enormous bat-like creature1 now running upon the ground like a bird2 its elevated body and long neck not covered with feathers1 but with skin1 naked1 or resplendent with glittering scales2 its head like that of a lizard or crocodile1 and of a size almost preposterous compared with that of the body1 with its long fore extremities stretched out1 and connected by a membrane with the body and hind legs4 ,suddenly this mailed creature rose in the air1 and realised or even surpassed in strangeness the flying dragon of fable3 its fore-arms and its elongated wing-finger furnished with claws2 hand and fingers extended1 and the interspace filled up by a tough membrane2 and its head and neck stretched out like that of the heron in its flight4 ,when stationary1 its wings were probably folded back like those of a bird2 though perhaps1 by the claws attached to its fingers1 it might suspend itself from the branches of trees4 ,,mammalia ,,in ,,secondary ,,rocks4 ,it was supposed till very lately that few if any ,mammalia were to be found below the ,tertiary rocks1 i4 e4 those above the chalk2 and this supposed fact was very comfortable to those who support the doctrine of 8progressive development10 and hold1 with the notorious ,vestiges of ,creation1 that a fish by mere length of time became a reptile1 a lemur an ape1 and finally an ape a man4 ,but here1 as in a hundred other cases1 facts1 when duly investigated1 are against their theory4 ,a mammal jaw had been already discovered by ,mr4 ,brodie on the shore at the back of ,swanage ,point1 in ,dorsetshire1 when ,mr4 ,beckles1 ,f4,g4,s41 traced the vein from which this jaw had been procured1 and found it to be a stratum about five inches thick1 at the base of the ,middle ,purbeck beds2 and after removing many thousand tons of rock1 and laying bare an area of nearly #gjjj square feet 7the largest cutting ever made for purely scientific purposes71 he found reptiles 7tortoises and lizards7 in hundreds2 but the most important discovery was that of the jaws of at least fourteen different species of mammalia4 ,some of these were herbivorous1 some carnivorous1 connected with our modern shrews1 moles1 hedgehogs1 c42 but all of them perfectly developed and highly-organised quadrupeds4 ,ten years ago1 no remains of quadrupeds were believed to exist in the ,secondary strata4 8,even in #ahed10 says ,sir ,charles ,lyell 7in a supplement to the fifth edition of his ,manual of ,elementary ,geology71 8only six species of mammals from rocks older than the ,tertiary were known in the whole world40 ,we now possess evidence of the existence of fourteen species1 belonging to eight or nine genera1 from the fresh-water strata of the ,middle ,purbeck ,oolite4 ,it would be rash now to fix a limit in past time to the existence of quadrupeds4--,the ,rev4 ,c4 ,kingsley4 ,,fossil ,,human ,,bones4 ,in the paleontological collection in the ,british ,museum is preserved a considerable portion of a human skeleton imbedded in a slab of rock1 brought from ,guadaloupe1 and often referred to in opposition to the statement that hitherto no fossil human hones have been found4 ,the presence of these bones1 however1 has been explained by the circumstance of a battle and the massacre of a tribe of ,galtibis by the ,caribs1 which took place near the spot in which the bones were found about #acj years ago2 for as the bodies of the slain were interred on the seashore1 their skeletons may have been subsequently covered by sand-drift1 which has since consolidated into limestone4 ,it will be seen by reference to the ,philosophical ,transactions1 that on the reading of the paper upon this discovery to the ,royal ,society1 in #ahad1 ,sir ,joseph ,banks1 the president1 considered the 8fossil0 to be of very modern formation1 and that probably1 from the contiguity of a volcano1 the temperature of the water may have been raised at some time1 and dissolving carbonate of lime readily1 may have deposited about the skeleton in a comparatively short period hard and solid stone4 ,every person may be convinced of the rapidity of the formation and of the hardness of such stone by inspecting the inside of tea-kettles in which hard water is boiled4 ,descriptions of petrifactions of human bodies appear to refer to the conversion of bodies into adipocere1 and not into stone4 ,all the supposed cases of petrifaction are probably of this nature4 ,the change occurs only when the coffin becomes filled with water4 ,the body1 converted into adipocere1 floats on the water4 ,the supposed cases of changes of position in the grave1 bursting open the coffin-lids1 turning over1 crossing of limbs1 c41 formerly attributed to the coming to life of persons buried who were not dead1 is now ascertained to be due to the same cause4 ,the chemical change into adipocere1 and the evolution of gases1 produce these movements of dead bodies4--,mr4 ,trail ,green4 ,,the ,,most ,,ancient ,,fishes4 ,among the important results of ,sir ,roderick ,murchison's establishment of the ,silurian system is the following3 ,that as the ,lower ,silurian group1 often of vast dimensions1 has never afforded the smallest vestige of a ,fish1 though it abounds in numerous species of the marine classes1--corals1 crinoidea1 mollusca1 and crustacea2 and as in ,scandinavia and ,russia1 where it is based on rocks void of fossils1 its lowest stratum contains fucoids only1--,sir ,r4 ,murchison has1 after fifteen years of laborious research steadily directed to this point1 arrived at the conclusion1 that a very long period elapsed after life was breathed into the waters before the lowest order of vertebrata was created2 the earliest fishes being those of the ,upper ,silurian rocks1 which he was the first to discover1 and which he described 8as the most ancient beings of their class which have yet been brought to light40 ,though the ,lower ,silurian rocks of various parts of the world have since been ransacked by multitudes of prying geologists1 who have exhumed from them myriads of marine fossils1 not a single ichthyolite has been found in any stratum of higher antiquity than the ,upper ,silurian group of ,murchison4 ,the most remarkable of all fossil fishes yet discovered have been found in the ,old ,red ,sandstone cliffs at ,dorpat1 where the remains are so gigantic 7one bone measuring two feet nine inches in length7 that they were at first supposed to belong to saurians4 ,sir ,roderick's examination of ,russia has1 in short1 proved that the ichthyolites and mollusks which1 in ,western ,europe1 are separately peculiar to smaller detached basins1 were here 7in the ,british ,isles7 cohabitants of many parts of the same great sea4 ,,extinct ,,carnivorous ,,animals ,,of ,,britain4 ,professor ,owen has thus forcibly illustrated the ,carnivorous ,animals which preyed upon and restrained the undue multiplication of the vegetable feeders4 ,first we have the bear family1 which is now represented in this country only by the badger4 ,we were once blest1 however1 with many bears4 ,one species seems to have been identical with the existing brown bear of the ,european continent4 ,far larger and more formidable was the gigantic cave-bear 7,ursus spelus71 which surpassed in size his grisly brother of ,north ,america4 ,the skull of the cave-bear differs very much in shape from that of its small brown relative just alluded to2 the forehead1 in particular1 is much higher1--to be accounted for by an arrangement of air-cells similar to those which we have already remarked in the elephant4 ,the cave-bear has left its remains in vast abundance in ,germany4 ,in our own caves1 the bones of hynas are found in greater quantities4 ,the marks which the teeth of the hyna make upon the bones which it gnaws are quite unmistakable4 ,our ,english hynas had the most undiscriminating appetite1 preying upon every creature1 their own species amongst others4 ,wolves1 not distinguishable from those which now exist in ,france and ,germany1 seem to have kept company with the hynas2 and the ,felis spela1 a sort of lion1 but larger than any which now exists1 ruled over all weaker brutes4 ,here1 says ,professor ,owen1 we have the original ,british ,lion4 ,a species of ,machairodus has left its remains at ,kent's ,hole1 near ,torquay4 ,in ,england we had also the beaver1 which still lingers on the ,danube and the ,rhone1 and a larger species1 which has been called ,trogontherium 7gnawing beast71 and a gigantic mole4 ,,the ,,great ,,cave ,,tiger ,,or ,,lion ,,of ,,britain4 ,remains of this remarkable animal of the drift or gravel period of this country have been found at ,brentford and elsewhere near ,london4 ,speaking of this animal1 ,professor ,owen observes1 that 8it is commonly supposed that the ,lion1 the ,tiger1 and the ,jaguar are animals peculiarly adapted to a tropical climate4 ,the genus ,felis 7to which these animals belong7 is1 however1 represented by specimens in high northern latitudes1 and in all the intermediate countries to the equator40 ,the chief condition necessary for the presence of such animals is an abundance of the vegetable-feeding animals4 ,it is thus that the ,indian tiger has been known to follow the herds of antelope and deer in the lofty mountains of the ,himalaya to the verge of perpetual snow1 and far into ,siberia4 8,it need not1 therefore10 continues ,professor ,owen1 8excite surprise that indications should have been discovered in the fossil relics of the ancient mammalian population of ,europe of a large feline animal1 the contemporary of the mammoth1 of the tichorrhine rhinoceros1 of the great gigantic cave-bear and hyna1 and the slayer of the oxen1 deer1 and equine quadrupeds that so abounded during the same epoch40 ,the dimensions of this extinct animal equal those of the largest ,african lion or ,bengal tiger2 and some bones have been found which seem to imply that it had even more powerful limbs and larger paws4 ,,the ,,mammoths ,,of ,,the ,,british ,,isles4 ,dr4 ,buckland has shown that for long ages many species of carnivorous animals now extinct inhabited the caves of the ,british islands4 ,in low tracts of ,yorkshire1 where tranquil lacustrine 7lake-like7 deposits have occurred1 bones 7even those of the lion7 have been found so perfectly unbroken and unworn1 in fine gravel 7as at ,market ,weighton71 that few persons would be disposed to deny that such feline and other animals once roamed over the ,british isles1 as well as other ,european countries4 ,why1 then1 is it improbable that large elephants1 with a peculiarly thick integument1 a close coating of wool1 and much long shaggy hair1 should have been the occupants of wide tracts of ,northern ,europe and ,asia8 ,this coating1 ,dr4 ,fleming has well remarked1 was probably as impenetrable to rain and cold as that of the monster ox of the polar circle4 ,such is the opinion of ,sir ,roderick ,murchison1 who thus accounts for the disappearance of the mammoths from ,britain3 ,when we turn from the great ,siberian continent1 which1 anterior to its elevation1 was the chief abode of the mammoths1 and look to the other parts of ,europe1 where their remains also occur1 how remarkable is it that we find the number of these creatures to be justly proportionate to the magnitude of the ancient masses of land which the labours of geologists have defined6 ,take the ,british isles1 for example1 and let all their low1 recently elevated districts be submerged2 let1 in short1 ,england be viewed as the comparatively small island she was when the ancient estuary of the ,thames1 including the plains of ,hyde ,park1 ,chelsea1 ,hounslow1 and ,uxbridge1 were under the water2 when the ,severn extended far into the heart of the kingdom1 and large eastern tracts of the island were submerged1--and there will then remain but moderately-sized feeding-grounds for the great quadrupeds whose bones are found in the gravel of the adjacent rivers and estuaries4 ,this limited area of subsistence could necessarily only keep up a small stock of such animals2 and1 just as we might expect1 the remains of ,british mammoths occur in very small numbers indeed1 when compared with those of the great charnel-houses of ,siberia1 into which their bones had been carried down through countless ages from the largest mass of surface which geological inquiries have yet shown to have been dry land during that epoch4 ,the remains of the mammoth1 says ,professor ,owen1 have been found in all1 or almost all1 the counties of ,england4 ,off the coast of ,norfolk they are met with in vast abundance4 ,the fishermen who go to catch turbot between the mouth of the ,thames and the ,dutch coast constantly get their nets entangled in the tusks of the mammoth4 ,a collection of tusks and other remains1 obtained in this way1 is to be seen at ,ramsgate4 ,in ,north ,america1 this gigantic extinct elephant must have been very common2 and a large portion of the ivory which supplies the markets of ,europe is derived from the vast mammoth graveyards of ,siberia4 ,the mammoth ranged at least as far north as #fj4 ,there is no doubt that1 at the present day1 many specimens of the musk-ox are annually becoming imbedded in the mud and ice of the ,north-,american rivers4 ,it is curious to observe1 that the mammoth teeth which are met with in caves generally belonged to young mammoths1 who probably resorted thither for shelter before increasing age and strength emboldened them to wander far afield4 ,,the ,,rhinoceros ,,and ,,hippopotamus ,,of ,,england4 ,the mammoth was not the only giant that inhabited ,england in the ,pliocene or ,upper ,tertiary period4 ,we had also here the ,rhinoceros tichorrhinus1 or 8strongly walled about the nose10 remains of which have been discovered in enormous quantities in the brickfields about ,london4 ,pallas describes an entire specimen of this creature1 which was found near ,yakutsk1 the coldest town on the globe4 ,another rhinoceros1 leptorrhinus 7fine nose71 dwelt with the elephant of ,southern ,europe4 ,in ,siberia has been discovered the ,elaimotherium1 forming a link between the rhinoceros and the horse4 ,in the days of the mammoth1 we had also in ,england a ,hippopotamus1 rather larger than the species which now inhabits the ,nile4 ,of our ,british hippopotamus some remains were dug up by the workmen in preparing the foundations of the ,new ,junior ,united ,service ,club-house1 in ,regent-street4 ,,the ,,elephant ,,and ,,tortoise4 ,the idea of an ,elephant standing on the back of a ,tortoise was often laughed at as an absurdity1 until ,captain ,cautley and ,dr4 ,falconer at length discovered in the hills of ,asia the remains of a tortoise in a fossil state of such a size that an elephant could easily have performed the above feat4 ,,coexistence ,,of ,,man ,,and ,,the ,,mastodon4 ,dr4 ,c4 ,f4 ,winslow has communicated to the ,boston ,society of ,natural ,history the discovery of the fragment of a human cranium #ahj feet below the surface of the ,table ,mountain1 ,california4 ,now the mastodon's bones being found in the same deposits1 points very clearly to the probability of the appearance of the human race on the western portions of ,north ,america at least before the extinction of those huge creatures4 ,fragments of mastodon and ,elephas primigenius have been taken ten and twenty feet below the surface in the above locality2 where this discovery of human and mastodon remains gives strength to the possible truth of an old ,indian tradition1--the contemporary existence of the mammoth and aboriginals in this region of the globe4 ,,habits ,,of ,,the ,,megatherium4 ,much uncertainty has been felt about the habits of the ,megatherium1 or ,great ,beast4 ,it has been asked whether it burrowed or climbed1 or what it did2 and difficulties have presented themselves on all sides of the question4 ,some have thought that it lived in trees as much larger than those which now exist as the ,megatherium itself is larger than the common sloth4#ce ,this1 however1 is now known to be a mistake4 ,it did not climb trees--it pulled them down2 and in order to do this the hinder parts of its skeleton were made enormously strong1 and its prehensile fore-legs formed so as to give it a tremendous power over any thing which it grasped4 ,dr4 ,buckland suggested that animals which got their living in this way had a very fair chance of having their heads broken4 ,while ,professor ,owen was still pondering over this difficulty1 the skull of a cognate animal1 the ,mylodon1 came into his hands4 ,great was his delight when he found that the mylodon not only had his head broken1 but broken in two different places1 at two different times2 and moreover so broken that the injury could only have been inflicted by some such agent as a fallen tree4 ,the creature had recovered from the first blow1 but had evidently died of the second4 ,this tribe had1 as it turns out1 two skulls1 an outer and an inner one--given them1 as it would appear1 expressly with a view to the very dangerous method in which they were intended to obtain their necessary food4 ,the dentition of the megatherium is curious4 ,the elephant gets teeth as he wants them4 ,nature provided for the comfort of the megatherium in another way4 ,it did not get new teeth1 but the old ones went on for ever growing as long as the animal lived2 so that as fast as one grinding surface became useless1 another supplied its place4 ,,the ,,dinotherium1 ,,or ,,terrible ,,beast4 ,the family of herbivorous ,cetaceans are connected with the ,pachydermata of the land by one of the most wonderful of all the extinct creatures with which geologists have made us acquainted4 ,this is the ,dinotherium1 or ,terrible ,beast4 ,the remains of this animal were found in ,miocene sands at ,eppelsheim1 about forty miles from ,darmstadt4 ,it must have been larger than the largest extinct or living elephant4 ,the most remarkable peculiarity of its structure is the enormous tusks1 curving downwards and terminating its lower jaw4 ,it appears to have lived in the water1 where the immense weight of these formidable appendages would not be so inconvenient as on land4 ,what these tusks were used for is a mystery2 but perhaps they acted as pickaxes in digging up trees and shrubs1 or as harrows in raking the bottom of the water4 ,dr4 ,buckland used to suggest that they were perhaps employed as anchors1 by means of which the monster might fasten itself to the bank of a stream and enjoy a comfortable nap4 ,the extreme length of the ,dinotherium was about eighteen feet4 ,professor ,kemp1 in his restoration of the animal1 has given it a trunk like that of the elephant1 but not so long1 and the general form of the tapir4--,professor ,owen4 ,,the ,,glyptodon4 ,there are few creatures which we should less have expected to find represented in fossil history by a race of gigantic brethren than the armadillo4 ,the creature is so small1 not only in size but in all its works and ways1 that we with difficulty associate it with the idea of magnitude4 ,yet ,sir ,woodbine ,parish has discovered evidences of enormous animals of this family having once dwelt in ,south ,america4 ,the huge loricated 7plated over7 creature whose relics were first sent has received the name of ,glyptodon1 from its sculptured teeth4 ,unlike the small armadillos1 it was unable to roll itself up into a ball2 though an enormous carnivore which lived in those days must have made it sometimes wish it had the power to do so4 ,when attacked1 it must have crouched down1 and endeavoured to make its huge shell as good a defence as possible4--,professor ,owen4 ,,inmates ,,of ,,an ,,australian ,,cavern4 ,from the fossil-bone caverns in ,wellington ,valley1 in #ahcj1 were sent to ,professor ,owen several bones which belonged1 as it turned out1 to gigantic kangaroos1 immensely larger than any existing species2 to a kind of wombat1 to formidable dasyures1 and several other genera4 ,it also appeared that the bones1 which were those of herbivores1 had evidently belonged to young animals1 while those of the carnivores were full-sized2 a fact which points to the relations between the two families having been any thing but agreeable to the herbivores4 ,,the ,,pouch-,,lion ,,of ,,australia4 ,the ,thylacoleo 7,pouch-,lion7 was a gigantic marsupial carnivore1 whose character and affinities ,professor ,owen has1 with exquisite scientific tact1 made out from very small indications4 ,this monster1 which had kangaroos with heads three feet long to feed on1 must have been one of the most extraordinary animals of the antique world4 ,,the ,,coney ,,of ,,scripture4 ,paleontologists have pointed out the curious fact that the ,hyrax1 called #8coney' in our authorised version of the ,bible1 is really only a diminutive and hornless rhinoceros4 ,remains have been found at ,eppelsheim which indicate an animal more like a gigantic ,hyrax than any of the existing rhinoceroses4 ,to this the name of ,acerotherium 7,hornless ,beast7 has been given4 ,a ,,three-,,hoofed ,,horse4 ,professor ,owen describes the ,hipparion1 or ,three-hoofed ,horse1 as the first representative of a family so useful to mankind4 ,this animal1 in addition to its true hoof1 appears to have had two additional elementary hoofs1 analogous to those which we see in the ox4 ,the object of these no doubt was to enable the ,hipparion to extricate his foot with greater ease than he otherwise could when it sank through the swampy ground on which he lived4 ,,two ,,monster ,,carnivores ,,of ,,france4 ,a huge carnivorous creature has been found in ,miocene strata in ,france1 in which country it preyed upon the gazelle and antelope4 ,it must have been as large as a grisly bear1 but in general appearance and teeth more like a gigantic dog4 ,hence the name of ,amphicyon 7,doubtful ,dog7 has been assigned to it4 ,this animal must have derived part of its support from vegetables4 ,not so the coeval monster which has been called ,machairodus 7,sabre-tooth74 ,it must have been somewhat akin to the tiger1 and is by far the most formidable animal which we have met with in our ascending progress through the extinct mammalia4--,professor ,owen4 ,,geology ,,of ,,the ,,sheep4 ,no unequivocal fossil remains of the sheep have yet been found in the bone-caves1 the drift1 or the more tranquil stratified newer ,pliocene deposits1 so associated with the fossil bones of oxen1 wild-boars1 wolves1 foxes1 otters1 c41 as to indicate the coevality of the sheep with those species1 or in such an altered state as to indicate them to have been of equal antiquity4 ,professor ,owen had his attention particularly directed to this point in collecting evidence for a history of ,british ,fossil ,mammalia4 ,no fossil core-horns of the sheep have yet been any where discovered2 and so far as this negative evidence goes1 we may infer that the sheep is not geologically more ancient than man2 that it is not a native of ,europe1 but has been introduced by the tribes who carried hither the germs of civilisation in their migrations westward from ,asia4 ,,the ,,trilobite4 ,among the earliest races we have those remarkable forms1 the ,trilobites1 inhabiting the ancient ocean4 ,these crustacea remotely resemble the common wood-louse1 and like that animal they had the power of rolling themselves into a ball when attacked by an enemy4 ,the eye of the trilobite is a most remarkable organ2 and in that of one species1 ,phacops caudatus1 not less than #bej lenses have been discovered4 ,this remarkable optical instrument indicates that these creatures lived under similar conditions to those which surround the crustacea of the present day4--,hunt's ,poetry of ,science4 ,,profitable ,,science4 ,in that strip of reddish colour which runs along the cliffs of ,suffolk1 and is called the ,redcrag1 immense quantities of cetacean remains have been found4 ,four different kinds of whales1 little inferior in size to the whalebone whale1 have left their bones in this vast charnel-house4 ,in #ahdj1 a singularly perplexing fossil was brought to ,professor ,owen from this ,redcrag4 ,no one could say what it was4 ,he determined it to be the tooth of a cetacean1 a unique specimen4 ,now the remains of cetaceans in the ,suffolk crag have been discovered in such enormous quantities1 that many thousands a-year are made by converting them into manure4 ,,extinct ,,gigantic ,,birds ,,of ,,new ,,zealand4 ,in the islands of ,new ,zealand have been found the bones of large extinct wingless ,birds1 belonging to the ,post ,tertiary or ,recent system1 which have been deposited by the action of rivers4 ,the bird is named ,moa by the natives1 and ,dinornis by naturalists3 some of the bones have been found in two caves in the ,north ,island1 and have been sold by the natives at an extraordinary price4 ,the caves occur in limestone rocks1 and the bones are found beneath earth and a soft deposit of carbonate of lime4 ,the largest of the birds is stated to have stood thirteen or fourteen feet1 or twice the height of the ostrich2 and its egg large enough to fill the hat of a man as a cup4 ,several statements have appeared of these birds being still in existence1 but there is every reason to believe the ,moa to be altogether extinct4 ,an extensive collection of remains of these great wingless birds has been collected in ,new ,zealand by ,mr4 ,walter ,mantell1 and deposited in the ,british ,museum4 ,among these bones ,professor ,owen has discovered a species which he regards as the most remarkable of the feathered class for its prodigious strength and massive proportions1 and which he names ,dinornis elephantopus1 or elephant-footed1 of which the ,professor has been able to construct an entire lower limb3 the length of the metatarsal bone is #i inches1 the breadth of the lower end being #e-a_/c inches4 ,the extraordinary proportions of the metatarsus of this wingless bird will1 however1 be still better understood by comparison with the same bone in the ostrich1 in which the metatarsus is #ai inches in length1 the breadth of its lower end being only #b inches4 ,from the materials accumulated by ,mr4 ,mantell1 the entire skeleton of the ,dinornis elephantopus has been reconstructed2 and now forms a worthy companion of the ,megatherium and ,mastodon in the gallery of fossil remains in the ,british ,museum4 ,this species of ,dinornis appears to have been restricted to the ,middle ,island of ,new ,zealand4#cf ,another specimen of the remains of the ,dinornis is preserved in the ,museum of the ,royal ,college of ,surgeons1 in ,lincoln's-,inn ,fields2 and the means by which the college obtained this valuable acquisition is thus graphically narrated by ,mr4 ,samuel ,warren1 ,f4,r4,s43 ,in the year #ahci1 ,professor ,owen was sitting alone in his study1 when a shabbily-dressed man made his appearance1 announcing that he had got a great curiosity1 which he had brought from ,new ,zealand1 and wished to dispose of to him4 ,it had the appearance of an old marrow-bone1 about six inches in length1 and rather more than two inches in thickness1 with both extremities broken off2 and ,professor ,owen considered that1 to whatever animal it might have belonged1 the fragment must have lain in the earth for centuries4 ,at first he considered this same marrow-bone to have belonged to an ox1 at all events to a quadruped2 for the wall or rim of the bone was six times as thick as the bone of any bird1 even of the ostrich4 ,he compared it with the bones in the skeleton of an ox1 a horse1 a camel1 a tapir1 and every quadruped apparently possessing a bone of that size and configuration2 but it corresponded with none4 ,on this he very narrowly examined the surface of the bony rim1 and at length became satisfied that this fragment must have belonged to a bird6--to one at least as large as an ostrich1 but of a totally different species2 and consequently one never before heard of1 as an ostrich was by far the biggest bird known4 ,from the difference in the strength of the bone1 the ostrich being unable to fly1 so must have been unable this unknown bird2 and so our anatomist came to the conclusion that this old shapeless bone indicated the former existence in ,new ,zealand of some huge bird1 at least as great as an ostrich1 but of a far heavier and more sluggish kind4 ,professor ,owen was confident of the validity of his conclusions1 but would communicate that confidence to no one else2 and notwithstanding attempts to dissuade him from committing his views to the public1 he printed his deductions in the ,transactions of the ,zoological ,society for #ahci1 where fortunately they remain on record as conclusive evidence of the fact of his having then made this guess1 so to speak1 in the dark4 ,he caused the bone1 however1 to be engraved2 and having sent a hundred copies of the engraving to ,new ,zealand1 in the hope of their being distributed and leading to interesting results1 he patiently waited for three years1--viz4 till the year #ahdb1--when he received intelligence from ,dr4 ,buckland1 at ,oxford1 that a great box1 just arrived from ,new ,zealand1 consigned to himself1 was on its way1 unopened1 to ,professor ,owen1 who found it filled with bones1 palpably of a bird1 one of which bones was three feet in length1 and much more than double the size of any bone in the ostrich6 ,and out of the contents of this box the ,professor was positively enabled to articulate almost the entire skeleton of a huge wingless bird between ,,ten and ,,eleven feet in height1 its bony structure in strict conformity with the fragment in question2 and that skeleton may at any time be seen at the ,museum of the ,college of ,surgeons1 towering over1 and nearly twice the height of1 the skeleton of an ostrich2 and at its feet lying the old bone from which alone consummate anatomical science had deduced such an astounding reality1--the existence of an enormous extinct creature of the bird kind1 in an island where previously no bird had been known to exist larger than a pheasant or a common fowl6--,lecture on the ,moral and ,intellectual ,development of the present ,age4#cg 8,,the ,,maestricht ,,saurian ,,fossil0 ,a ,,fraud4 ,in #agie1 there was stated to have been discovered in the stone quarries adjoining ,maestricht the remains of the gigantic ,mossaurus 7,saurian of the ,meuse71 an aquatic reptile about twenty-five feet long1 holding an intermediate place between the ,monitors and ,iguanas4 ,it appears to have had webbed feet1 and a tail of such construction as to have served for a powerful oar1 and enabled the animal to stem the waves of the ocean1 of which ,cuvier supposed it to have been an inhabitant4 ,it is thus referred to by ,dr4 ,mantell1 in his ,medals of ,creation3 8,a specimen1 with the jaws and bones of the palate1 now in the ,museum at ,paris1 has long been celebrated2 and is still the most precious relic of this extinct reptile hitherto discovered40 ,an admirable cast of this specimen is preserved in the ,british ,museum1 in a case near the bones of the ,iguanodon4 ,this is1 however1 useless1 as ,cuvier is proved to have been imposed upon in the matter4 ,m4 ,schlegel has reported to the ,french ,academy of ,sciences1 that he has ascertained beyond all doubt that the famous fossil saurian of the quarries of ,maestricht1 described as a wonderful curiosity by ,cuvier1 is nothing more than an impudent fraud4 ,some bold impostor1 it seems1 in order to make money1 placed a quantity of bones in the quarries in such a way as to give them the appearance of having been recently dug up1 and then passed them off as specimens of antediluvian creation4 ,being successful in this1 he went the length of arranging a number of bones so as to represent an entire skeleton2 and had thus deceived the learned ,cuvier4 ,in extenuation of ,cuvier's credulity1 it is stated that the bones were so skilfully coloured as to make them look of immense antiquity1 and he was not allowed to touch them lest they should crumble to pieces4 ,but when ,m4 ,schlegel subjected them to rude handling1 he found that they were comparatively modern1 and that they were placed one by the other without that profound knowledge of anatomy which was to have been expected from the man bold enough to execute such an audacious fraud4 8,,the ,,oldest ,,piece ,,of ,,wood ,,upon ,,earth40 ,the most remarkable vegetable relic which the ,lower ,old ,red ,sandstone has given us is a small fragment of a coniferous tree of the ,araucarian family1 which formed one of the chief ornaments of the late ,hugh ,miller's museum1 and to which he used to point as the oldest piece of wood upon earth4 ,he found it in one of the ichthyolite beds of ,cromarty1 and thus refers to it in his ,testimony of the ,rocks3 ,on what perished land of the early paleozoic ages did this venerably antique tree cast root and flourish1 when the extinct genera ,pterichthys and ,coccoeteus were enjoying life by millions in the surrounding seas1 long ere the flora or fauna of the coal measures had begun to be8 ,the same nodule which enclosed this lignite contained part of another fossil1 the well-marked scales of ,diplacanthus striatus1 an ichthyolite restricted to the ,lower ,old ,red ,sandstone exclusively4 ,if there be any value in paleontological evidence1 this ,cromarty lignite must have been deposited in a sea inhabited by the ,coccoeteus and ,diplacanthus4 ,it is demonstrable that1 while yet in a recent state1 a ,diplacanthus lay down and died beside it2 and the evidence in the case is unequivocally this1 that in the oldest portion of the oldest terrestrial flora yet known there occurs the fragment of a tree quite as high in the scale as the stately ,norfolk-,island pine or the noble cedar of ,lebanon4 ,,no ,,fossil ,,rose4 ,professor ,agassiz1 in a lecture upon the trees of ,america1 states a remarkable fact in regard to the family of the rose1--which includes among its varieties not only many of the most beautiful flowers1 but also the richest fruits1 as the apple1 pear1 peach1 plum1 apricot1 cherry1 strawberry1 raspberry1 c41--namely1 that no fossil plants belonging to this family have ever been discovered by geologists6 ,this ,m4 ,agassiz regards as conclusive evidence that the introduction of this family of plants upon the earth was coeval with1 or subsequent to1 the creation of man1 to whose comfort and happiness they seem especially designed by a wise ,providence to contribute4 ,,changes ,,on ,,the ,,earth',s ,,surface4 ,in the ,imperial ,library at ,paris is preserved a manuscript work by an ,arabian writer1 ,mohammed ,karurini1 who flourished in the seventh century of the ,hegira1 or at the close of the thirteenth century of our era4 ,herein we find several curious remarks on aerolites and earthquakes1 and the successive changes of position which the land and sea have undergone4 ,of the latter class is the following beautiful passage from the narrative of ,khidz1 an allegorical personage3 ,i passed one day by a very ancient and wonderfully populous city1 and asked one of its inhabitants how long it had been founded4 8,it is indeed a mighty city10 replied he2 8we know not how long it has existed1 and our ancestors were on this subject as ignorant as ourselves40 ,five centuries afterwards1 as ,i passed by the same place1 ,i could not perceive the slightest vestige of the city4 ,i demanded of a peasant who was gathering herbs upon its former site how long it had been destroyed4 8,in sooth1 a strange question10 replied he2 8the ground here has never been different from what you now behold it40 8,was there not of old10 said ,i1 8a splendid city here80 8,never10 answered he1 8so far as we have seen2 and never did our fathers speak to us of any such40 ,on my return there five hundred years afterwards1 ,i found the sea in the same place2 and on its shores were a party of fishermen1 of whom ,i inquired how long the land had been covered by the waters4 8,is this a question10 say they1 8for a man like you8 ,this spot has always been what it is now40 ,i again returned five hundred years afterwards2 the sea had disappeared3 ,i inquired of a man who stood alone upon the spot how long this change had taken place1 and he gave me the same answer as ,i had received before4 ,lastly1 on coming back again after an equal lapse of time1 ,i found there a flourishing city1 more populous and more rich in beautiful buildings than the city ,i had seen the first time2 and when ,i would fain have informed myself concerning its origin1 the inhabitants answered me1 8,its rise is lost in remote antiquity3 we are ignorant how long it has existed1 and our fathers were on this subject as ignorant as ourselves40 ,this striking passage was quoted in the ,examiner1 in #ahcd4 ,surely in this fragment of antiquity we trace the 8geological changes0 of modern science4 ,,geological ,,time4 ,many ingenious calculations have been made to approximate the dates of certain geological events2 but these1 it must be confessed1 are more amusing than instructive4 ,for example1 so many inches of silt are yearly laid down in the delta of the ,mississippi--how many centuries will it have taken to accumulate a thickness of #cj1 #fj1 or #ajj feet8 ,again1 the ledges of ,niagara are wasting at the rate of so many feet per century--how many years must the river have taken to cut its way back from ,queenstown to the present ,falls8 ,again1 lavas and melted basalts cool1 according to the size of the mass1 at the rate of so many degrees in a given time--how many millions of years must have elapsed1 supposing an original igneous condition of the earth1 before its crust had attained a state of solidity8 or further1 before its surface had cooled down to the present mean temperature8 ,for these and similar computations1 the student will at once perceive we want the necessary uniformity of factor2 and until we can bring elements of calculation as exact as those of astronomy to bear on geological chronology1 it will be better to regard our 8eras0 and 8epochs0 and 8systems0 as so many terms1 indefinite in their duration1 but sufficient for the magnitude of the operations embraced within their limits4--,advanced ,textbook of ,geology1 by ,david ,page1 ,f4,g4,s4 ,m4 ,rozet1 in #ahda1 called attention to the fact1 that the causes which have produced irregularities in the structure of the globe have not yet ceased to act1 as is proved by earthquakes1 volcanic eruptions1 slow and continuous movements of the crust of the earth in certain regions1 c4 ,we may1 therefore1 yet see repeated the great catastrophes which the surface of the earth has undergone anteriorly to the historical period4 ,at the meeting of the ,british ,association in #ahee1 ,mr4 ,hopkins excited much controversy by his startling speculation--that #ijjj years ago the site on which ,london now stands was in the torrid zone2 and that1 according to perpetual changes in progress1 the whole of ,england would in time arrive within the ,arctic circle4 ,,curious ,,cause ,,of ,,change ,,of ,,level4 ,professor ,hennessey1 in #aheg1 found the entire mass of rock and hill on which the ,armagh ,observatory is erected to be slightly1 but to an astronomer quite perceptibly1 tilted or canted1 at one season to the east1 at another to the west4 ,this he at first attributed to the varying power of the sun's radiation to heat and expand the rock throughout the year2 but he subsequently had reason to attribute it rather to the infiltration of water to the parts where the clay-slate and limestone rocks met1 the varying quantity of the water exerting a powerful hydrostatic energy by which the position of the rock is slightly varied4 ,now ,armagh and its observatory stand at the junction of the mountain limestone with the clay-slate1 having1 as it were1 one leg on the former and the other on the latter2 and both rocks probably reach downwards #ajjj or #bjjj feet4 ,when rain falls1 the one will absorb more water than the other2 both will gain an increase of conductive power2 but the one which has absorbed most water will have the greatest increase1 and being thus the better conductor1 will draw a greater portion of heat from the hot nucleus below to the surface--will become1 in fact1 temporarily hotter1 and1 as a consequence1 expand more than the other4 ,in a word1 both rocks will expand at the wet season2 but the best conductor1 or most absorbent rock1 will expand most1 and seem to tilt the hill to one side2 at the dry season it will subside most1 and the hill will seem to be tilted in the opposite direction4 ,the fact is curious1 and not less so are the results deducible from it4 ,first1 hills are higher at one season than another2 a fact we might have supposed1 but never could have ascertained by measurement4 ,secondly1 they are highest1 not1 as we should have supposed1 at the hottest season1 but at the wettest4 ,thirdly1 it is from the different rates of expansion of different rocks that this has been discovered4 ,fourthly1 it is by converse with the heavens that it has been made known to us4 ,a variation of probably half a second1 or less1 in the right ascension of three or four stars1 observed at different seasons1 no doubt revealed the fact to the sagacious astronomer of ,armagh1 and even enabled him to divine its cause4 ,professor ,hennessey observes in connection with this phenomenon1 that a very small change of ellipticity would suffice to lay bare or submerge extensive tracts of the globe4 ,if1 for example1 the mean ellipticity of the ocean increased from #a_/cjj to #a_/bii1 the level of the sea would be raised at the equator by about #bbh feet1 while under the parallel of #eb it would be depressed by #aif feet4 ,shallow seas and banks in the latitudes of the ,british isles1 and between them and the pole1 would thus be converted into dry land1 while low-lying plains and islands near the equator would be submerged4 ,if similar phenomena occurred during early periods of geological history1 they would manifestly influence the distribution of land and water during these periods2 and with such a direction of the forces as that referred to1 they would tend to increase the proportion of land in the polar and temperate regions of the earth1 as compared with the equatorial regions during successive geological epochs4 ,such maps as those published by ,sir ,charles ,lyell on the distribution of land and water in ,europe during the ,tertiary period1 and those of ,m4 ,elie de ,beaumont1 contained in ,beaudant's ,geology1 would1 if sufficiently extended1 assist in verifying or disproving these views4 ,,the ,,outlines ,,of ,,continents ,,not ,,fixed4 ,continents 7says ,m4 ,agassiz7 are only a patchwork formed by the emergence and subsidence of land4 ,these processes are still going on in various parts of the globe4 ,where the shores of the continent are abrupt and high1 the effect produced may be slight1 as in ,norway and ,sweden1 where a gradual elevation is going on without much alteration in their outlines4 ,but if the continent of ,north ,america were to be depressed #ajjj feet1 nothing would remain of it except a few islands1 and any elevation would add vast tracts to its shores4 ,the west of ,asia1 comprising ,palestine and the country about ,ararat and the ,caspian ,sea1 is below the level of the ocean1 and a rent in the mountain-chains by which it is surrounded would transform it into a vast gulf4 ,meteorological ,phenomena4 ,,the ,,atmosphere4 ,a philosopher of the ,east1 with a richness of imagery truly oriental1 describes the ,atmosphere as 8a spherical shell which surrounds our planet to a depth which is unknown to us1 by reason of its growing tenuity1 as it is released from the pressure of its own superincumbent mass4 ,its upper surface cannot be nearer to us than #ej1 and can scarcely be more remote than #ejj1 miles4 ,it surrounds us on all sides1 yet we see it not2 it presses on us with a load of fifteen pounds on every square inch of surface of our bodies1 or from seventy to one hundred tons on us in all1 yet we do not so much as feel its weight4 ,softer than the softest down1 more impalpable than the finest gossamer1 it leaves the cobweb undisturbed1 and scarcely stirs the lightest flower that feeds on the dew it supplies2 yet it bears the fleets of nations on its wings around the world1 and crushes the most refractory substances with its weight4 ,when in motion1 its force is sufficient to level the most stately forests and stable buildings with the earth--to raise the waters of the ocean into ridges like mountains1 and dash the strongest ships to pieces like toys4 ,it warms and cools by turns the earth and the living creatures that inhabit it4 ,it draws up vapours from the sea and land1 retains them dissolved in itself or suspended in cisterns of clouds1 and throws them down again as rain or dew when they are required4 ,it bends the rays of the sun from their path to give us the twilight of evening and of dawn2 it disperses and refracts their various tints to beautify the approach and the retreat of the orb of day4 ,but for the atmosphere sunshine would burst on us and fail us at once1 and at once remove us from midnight darkness to the blaze of noon4 ,we should have no twilight to soften and beautify the landscape2 no clouds to shade us from the searching heat2 but the bald earth1 as it revolved on its axis1 would turn its tanned and weakened front to the full and unmitigated rays of the lord of day4 ,it affords the gas which vivifies and warms our frames1 and receives into itself that which has been polluted by use and is thrown off as noxious4 ,it feeds the flames of life exactly as it does that of the fire--it is in both cases consumed and affords the food of consumption--in both cases it becomes combined with charcoal1 which requires it for combustion and is removed by it when this is over40 ,,universality ,,of ,,the ,,atmosphere4 ,it is only the girdling1 encircling air that flows above and around all that makes the whole world kin4 ,the carbonic acid with which to-day our breathing fills the air1 to-morrow makes its way round the world4 ,the date-trees that grow round the falls of the ,nile will drink it in by their leaves2 the cedars of ,lebanon will take of it to add to their stature2 the cocoa-nuts of ,tahiti will grow rapidly upon it2 and the palms and bananas of ,japan will change it into flowers4 ,the oxygen we are breathing was distilled for us some short time ago by the magnolias of the ,susquehanna2 the great trees that skirt the ,orinoco and the ,amazon1 the giant rhododendrons of the ,himalayas1 contributed to it1 and the roses and myrtles of ,cashmere1 the cinnamon-tree of ,ceylon1 and the forest1 older than the ,flood1 buried deep in the heart of ,africa1 far behind the ,mountains of the ,moon4 ,the rain we see descending was thawed for us out of the icebergs which have watched the polar star for ages2 and the lotus-lilies have soaked up from the ,nile1 and exhaled as vapour1 snows that rested on the summits of the ,alps4--,north-,british ,review4 ,,the ,,height ,,of ,,the ,,atmosphere4 ,the differences existing between that which appertains to the air of heaven 7the realms of universal space7 and that which belongs to the strata of our terrestrial atmosphere are very striking4 ,it is not possible1 as well-attested facts prove1 perfectly to explain the operations at work in the much-contested upper boundaries of our atmosphere4 ,the extraordinary lightness of whole nights in the year #ahca1 during which small print might be read at midnight in the latitudes of ,italy and the north of ,germany1 is a fact directly at variance with all we know according to the researches on the crepuscular theory and the height of the atmosphere4 ,the phenomena of light depend upon conditions still less understood2 and their variability at twilight1 as well as in the zodiacal light1 excite our astonishment4 ,yet the atmosphere which surrounds the earth is not thicker in proportion to the bulk of our globe than the line of a circle two inches in diameter when compared with the space which it encloses1 or the down on the skin of a peach in comparison with the fruit inside4 ,,colours ,,of ,,the ,,atmosphere4 ,pure air is blue1 because1 according to ,newton1 the molecules of the air have the thickness necessary to reflect blue rays4 ,when the sky is not perfectly pure1 and the atmosphere is blended with perceptible vapours1 the diffused light is mixed with a large proportion of white4 ,as the moon is yellow1 the blue of the air assumes somewhat of a greenish tinge1 or1 in other words1 becomes blended with yellow4--,letter from ,arago to ,humboldt2 ,cosmos1 vol4 iii4 ,,beauty ,,of ,,twilight4 ,this phenomenon is caused by the refraction of solar light enabling it to diffuse itself gradually over our hemisphere1 obscured by the shades of night1 long before the sun appears1 even when that luminary is eighteen degrees below our horizon4 ,it is towards the poles that this reflected splendour of the great luminary is longest visible1 often changing the whole of the night into a magic day1 of which the inhabitants of southern ,europe can form no adequate conception4 ,,how ,,pascal ,,weighed ,,the ,,atmosphere4 ,pascal's treatise on the weight of the whole mass of air forms the basis of the modern science of ,pneumatics4 ,in order to prove that the mass of air presses by its weight on all the bodies which it surrounds1 and also that it is elastic and compressible1 he carried a balloon1 half-filled with air1 to the top of the ,puy de ,dome1 a mountain about #ejj toises above ,clermont1 in ,auvergne4 ,it gradually inflated itself as it ascended1 and when it reached the summit it was quite full1 and swollen as if fresh air had been blown into it2 or1 what is the same thing1 it swelled in proportion as the weight of the column of air which pressed upon it was diminished4 ,when again brought down it became more and more flaccid1 and when it reached the bottom it resumed its original condition4 ,in the nine chapters of which the treatise consists1 ,pascal shows that all the phenomena and effects hitherto ascribed to the horror of a vacuum arise from the weight of the mass of air2 and after explaining the variable pressure of the atmosphere in different localities and in its different states1 and the rise of water in pumps1 he calculates that the whole mass of air round our globe weighs #h1ihc1hhi1ddj1jjj1jjj1jjj ,french pounds4--,north-,british ,review1 ,no4 #b4 ,it seems probable1 from many indications1 that the greatest height at which visible clouds ever exist does not exceed ten miles2 at which height the density of the air is about an eighth part of what it is at the level of the sea4--,sir ,john ,herschel4 ,,variations ,,of ,,climate4 ,history informs us that many of the countries of ,europe which now possess very mild winters1 at one time experienced severe cold during this season of the year4 ,the ,tiber1 at ,rome1 was often frozen over1 and snow at one time lay for forty days in that city4 ,the ,euxine ,sea was frozen over every winter during the time of ,ovid1 and the rivers ,rhine and ,rhone used to be frozen over so deep that the ice sustained loaded wagons4 ,the waters of the ,tiber1 ,rhine1 and ,rhone1 now flow freely every winter2 ice is unknown in ,rome1 and the waves of the ,euxine dash their wintry foam uncrystallised upon the rocks4 ,some have ascribed these climate changes to agriculture--the cutting down of dense forests1 the exposing of the unturned soil to the summer's sun1 and the draining of great marshes4 ,we do not believe that such great changes could be produced on the climate of any country by agriculture2 and we are certain that no such theory can account for the contrary change of climate--from warm to cold winters--which history tells us has taken place in other countries than those named4 ,greenland received its name from the emerald herbage which once clothed its valleys and mountains2 and its east coast1 which is now inaccessible on account of perpetual ice heaped upon its shores1 was in the eleventh century the seat of flourishing ,scandinavian colonies1 all trace of which is now lost4 ,cold ,labrador was named ,vinland by the ,northmen1 who visited it ,a4,d4 #ajjj1 and were charmed with its then mild climate4 ,the cause of these changes is an important inquiry4--,scientific ,american4 ,,average ,,climates4 ,when we consider the numerous and rapid changes which take place in our climate1 it is a remarkable fact1 that the mean temperature of a place remains nearly the same4 ,the winter may be unusually cold1 or the summer unusually hot1 while the mean temperature has varied even less than a degree4 ,a very warm summer is therefore likely to be accompanied with a cold winter2 and in general1 if we have any long period of cold weather1 we may expect a similar period at a higher temperature4 ,in general1 however1 in the same locality the relative distribution over summer and winter undergoes comparatively small variations2 therefore every point of the globe has an average climate1 though it is occasionally disturbed by different atmospheric changes4--,north-,british ,review1 ,no4 #di4 ,,the ,,finest ,,climate ,,in ,,the ,,world4 ,humboldt regards the climate of the ,caspian ,sea as the most salubrious in the world3 here he found the most delicious fruits that he saw during his travels2 and such was the purity of the air1 that polished steel would not tarnish even by night exposure4 ,,the ,,purest ,,atmospheres4 ,the cloudless purity and transparency of the atmosphere1 which last for eight months at ,santiago1 in ,chili1 are so great1 that ,lieutenant ,gilliss1 with the first telescope ever constructed in ,america1 having a diameter of seven inches1 was clearly able to recognise the sixth star in the trapezium of ,orion4 ,if we are to rely upon the statements of the ,rev4 ,mr4 ,stoddart1 an ,american missionary1 ,oroomiah1 in ,persia1 seems to be1 in so far as regards the transparency of the atmosphere1 the most suitable place in the world for an astronomical observatory4 ,writing to ,sir ,john ,herschel from that country1 he mentions that he has been enabled to distinguish with the naked eye the satellites of ,jupiter1 the crescent of ,venus1 the rings of ,saturn1 and the constituent members of several double stars4 ,,sea-,,breezes ,,and ,,land-,,breezes ,,illustrated4 ,when a fire is kindled on the hearth1 we may1 if we will observe the motes floating in the room1 see that those nearest the chimney are the first to feel the draught and to obey it1--they are drawn into the blaze4 ,the circle of inflowing air is gradually enlarged1 until it is scarcely perceived in the remote parts of the room4 ,now the land is the hearth1 the rays of the sun the fire1 and the sea1 with its cool and calm air1 the room2 and thus we have at our firesides the sea-breeze in miniature4 ,when the sun goes down1 the fire ceases2 then the dry land commences to give off its surplus heat by radiation1 so that by nine or ten o'clock it and the air above it are cooled below the sea temperature4 ,the atmosphere on the land thus becomes heavier than that on the sea1 and consequently there is a wind seaward1 which we call the land-breeze4--,maury4 ,,superior ,,salubrity ,,of ,,the ,,west4 ,all large cities and towns have their best districts in the ,west2#ch which choice the ,french savans1 ,pelouze1 ,pouillet1 ,boussingault1 and ,elie de ,beaumont1 attribute to the law of atmospheric pressure4 8,when10 say they1 8the barometric column rises1 smoke and pernicious emanations rapidly evaporate in space40 ,on the contrary1 smoke and noxious vapours remain in apartments1 and on the surface of the soil4 ,now1 of all winds1 that which causes the greatest ascension of the barometric column is the east2 and that which lowers it most is the west4 ,when the latter blows1 it carries with it to the eastern parts of the town all the deleterious gases from the west2 and thus the inhabitants of the east have to support their own smoke and miasma1 and those brought by western winds4 ,when1 on the contrary1 the east wind blows1 it purifies the air by causing to ascend the pernicious emanations which it cannot drive to the west4 ,consequently1 the inhabitants of the west receive pure air1 from whatever part of the horizon it may arrive2 and as the west winds are most prevalent1 they are the first to receive the air pure1 and as it arrives from the country4 ,,fertilisation ,,of ,,clouds4 ,as the navigator cruises in the ,pacific ,ocean among the islands of the trade-wind region1 he sees gorgeous piles of cumuli1 heaped up in fleecy masses1 not only capping the island hills1 but often overhanging the lowest islet of the tropics1 and even standing above coral patches and hidden reefs2 8a cloud by day40 to serve as a beacon to the lonely mariner out there at sea1 and to warn him of shoals and dangers which no lead nor seaman's eye has ever seen or sounded4 ,these clouds1 under favourable circumstances1 may be seen gathering above the low coral island1 preparing it for vegetation and fruitfulness in a very striking manner4 ,as they are condensed into showers1 one fancies that they are a sponge of the most exquisite and delicately elaborated material1 and that he can see1 as they 8drop down their fatness10 the invisible but bountiful hand aloft that is pressing and squeezing it out4--,maury4 ,,barometric ,,measurement4 ,we must not place too implicit a dependence on ,barometrical ,measurements4 ,ermann in ,siberia1 and ,ross in the ,antarctic ,seas1 have demonstrated the existence of localities on the earth's surface where a permanent depression of the barometer prevails to the astonishing extent of nearly an inch4 ,,gigantic ,,barometer4 ,in the ,great ,exhibition ,building of #ahea was a colossal ,barometer1 the tube and scale reaching from the floor of the gallery nearly to the top of the building1 and the rise and fall of the indicating fluid being marked by feet instead of by tenths of inches4 ,the column of mercury1 supported by the pressure of the atmosphere1 communicated with a perpendicular tube of smaller bore1 which contained a coloured fluid much lighter than mercury4 ,when a diminution of atmospheric pressure occurred1 the mercury in the large tube descended1 and by its fall forced up the coloured fluid in the smaller tube2 the fall of the one being indicated in a magnified ratio by the rise in the other4 ,,the ,,atmosphere ,,compared ,,to ,a ,,steam-,,engine4 ,in this comparison1 by ,lieut4 ,maury1 the ,south ,seas themselves1 in all their vast intertropical extent1 are the boiler for the engine1 and the northern hemisphere is its condenser4 ,the mechanical power exerted by the air and the sun in lifting water from the earth1 in transporting it from one place to another1 and in letting it down again1 is inconceivably great4 ,the utilitarian who compares the water-power that the ,falls of ,niagara would afford if applied to machinery is astonished at the number of figures which are required to express its equivalent in horse-power4 ,yet what is the horse-power of the ,niagara1 falling a few steps1 in comparison with the horse-power that is required to lift up as high as the clouds and let down again all the water that is discharged into the sea1 not only by this river1 but by all the other rivers in the world8 ,the calculation has been made by engineers2 and according to it1 the force of making and lifting vapour from each area of one acre that is included on the surface of the earth1 is equal to the power of thirty horses2 and for the whole of the earth1 it is #hjj times greater than all the water-power in ,europe4 ,,how ,,does ,,the ,,rain-,,making ,,vapour ,,get ,,from ,,the ,,southern ,,into ,,the ,,northern ,,hemisphere8 ,this comes with such regularity1 that our rivers never go dry1 and our springs fail not1 because of the exact compensation of the grand machine of the atmosphere4 ,it is exquisitely and wonderfully counterpoised4 ,late in the autumn of the north1 throughout its winter1 and in early spring1 the sun is pouring his rays with the greatest intensity down upon the seas of the southern hemisphere2 and this powerful engine1 which we are contemplating1 is pumping up the water there with the greatest activity2 at the same time1 the mean temperature of the entire southern hemisphere is about #aj higher than the northern4 ,the heat which this heavy evaporation absorbs becomes latent1 and with the moisture is carried through the upper regions of the atmosphere until it reaches our climates4 ,here the vapour is formed into clouds1 condensed and precipitated2 the heat which held their water in the state of vapour is set free1 and becomes sensible heat2 and it is that which contributes so much to temper our winter climate4 ,it clouds up in winter1 turns warm1 and we say we are going to have falling weather3 that is because the process of condensation has already commenced1 though no rain or snow may have fallen4 ,thus we feel this southern heat1 that has been collected by the rays of the sun by the sea1 been bottled away by the winds in the clouds of a southern summer1 and set free in the process of condensation in our northern winter4 ,thus the ,south ,seas should supply mainly the water for the engine just described1 while the northern hemisphere condenses it2 we should1 therefore1 have more rain in the northern hemisphere4 ,the rivers tell us that we have1 at least on the land2 for the great water-courses of the globe1 and half the fresh water in the world1 are found on the north side of the equator4 ,this fact is strongly corroborative of this hypothesis4 ,to evaporate water enough annually from the ocean to cover the earth1 on the average1 five feet deep with rain2 to transport it from one zone to another2 and to precipitate it in the right places at suitable times and in the proportions due1--is one of the offices of the grand atmospherical machine4 ,this water is evaporated principally from the torrid zone4 ,supposing it all to come thence1 we shall have encircling the earth a belt of ocean #cjjj miles in breadth1 from which this atmosphere evaporates a layer of water annually sixteen feet in depth4 ,and to hoist up as high as the clouds1 and lower down again1 all the water1 in a lake sixteen feet deep and #cjjj miles broad and #bd1jjj long1 is the yearly business of this invisible machinery4 ,what a powerful engine is the atmosphere6 and how nicely adjusted must be all the cogs and wheels and springs and compensations of this exquisite piece of machinery1 that it never wears out nor breaks down1 nor fails to do its work at the right time and in the right way6--,maury4 ,,the ,,philosophy ,,of ,,rain4 ,to understand the philosophy of this beautiful and often sublime phenomenon1 a few facts derived from observation and a long train of experiments must be remembered4 #a4 ,were the atmosphere every where at all times at a uniform temperature1 we should never have rain1 or hail1 or snow4 ,the water absorbed by it in evaporation from the sea and the earth's surface would descend in an imperceptible vapour1 or cease to be absorbed by the air when it was once fully saturated4 #b4 ,the absorbing power of the atmosphere1 and consequently its capability to retain humidity1 is proportionally greater in warm than in cold air4 #c4 ,the air near the surface of the earth is warmer than it is in the region of the clouds4 ,the higher we ascend from the earth1 the colder do we find the atmosphere4 ,hence the perpetual snow on very high mountains in the hottest climate4 ,now when1 from continued evaporation1 the air is highly saturated with vapour1 though it be invisible and the sky cloudless1 if its temperature is suddenly reduced by cold currents descending from above or rushing from a higher to a lower latitude1 its capacity to retain moisture is diminished1 clouds are formed1 and the result is rain4 ,air condenses as it cools1 and1 like a sponge filled with water and compressed1 pours out the water which its diminished capacity cannot hold4 ,what but ,omniscience could have devised such an admirable arrangement for watering the earth8 ,,inordinate ,,rainy ,,climate4 ,the climate of the ,khasia mountains1 which lie north-east from ,calcutta1 and are separated by the valley of the ,burrampooter ,river from the ,himalaya range1 is remarkable for the inordinate fall of rain--the greatest1 it is said1 which has ever been recorded4 ,mr4 ,yule1 an ,english gentleman1 established that in the single month of ,august #ahda there fell #bfd inches of rain1 or #bb feet1 of which #ab feet fell in the space of five consecutive days4 ,this astonishing fact is confirmed by two other ,english travellers1 who measured #cj inches of rain in twenty-four hours1 and during seven months above #ejj inches4 ,this great rain-fall is attributed to the abruptness of the mountains which face the ,bay of ,bengal1 and the intervening flat swamps #bjj miles in extent4 ,the district of the excessive rain is extremely limited2 and but a few degrees farther west1 rain is said to be almost unknown1 and the winter falls of snow to seldom exceed two inches4 ,,how ,,does ,,the ,,north ,,wind ,,drive ,,away ,,rain8 ,we may liken it to a wet sponge1 and the decrease of temperature to the hand that squeezes that sponge4 ,finally1 reaching the cold latitudes1 all the moisture that a dew-point of zero1 and even far below1 can extract1 is wrung from it2 and this air then commences 8to return according to his circuits0 as dry atmosphere4 ,and here we can quote ,scripture again3 8,the north wind driveth away rain40 ,this is a meteorological fact of high authority and great importance in the study of the circulation of the atmosphere4--,maury4 ,,size ,,of ,,rain-,,drops4 ,the ,drops of ,rain vary in their size1 perhaps from the #beth to the of an inch in diameter4 ,in parting from the clouds1 they precipitate their descent till the increasing resistance opposed by the air becomes equal to their weight1 when they continue to fall with uniform velocity4 ,this velocity is1 therefore1 in a certain ratio to the diameter of the drops2 hence thunder and other showers in which the drops are large pour down faster than a drizzling rain4 ,a drop of the #beth part of an inch1 in falling through the air1 would1 when it had arrived at its uniform velocity1 only acquire a celerity of #aa feet per second2 while one of of an inch would equal a velocity of #cc feet4--,leslie4 ,,rainless ,,districts4 ,in several parts of the world there is no rain at all4 ,in the ,old ,world there are two districts of this kind3 the desert of ,sahara in ,africa1 and in ,asia part of ,arabia1 ,syria1 and ,persia2 the other district lies between north latitude #cj and #ej1 and between #ge and #aah of east longitude1 including ,thibet1 ,gobiar ,shama1 and ,mongolia4 ,in the ,new ,world the rainless districts are of much less magnitude1 occupying two narrow strips on the shores of ,peru and ,bolivia1 and on the coast of ,mexico and ,guatemala1 with a small district between ,trinidad and ,panama on the coast of ,venezuela4 ,,all ,,the ,,rain ,,in ,,the ,,world4 ,the ,pacific ,ocean and the ,indian ,ocean may be considered as one sheet of water covering an area quite equal in extent to one half of that embraced by the whole surface of the earth2 and the total annual fall of rain on the earth's surface is #ahf1bdj cubic imperial miles4 ,not less than three-fourths of the vapour which makes this rain comes from this waste of waters2 but1 supposing that only half of this quantity1 that is #ic1abj cubic miles of rain1 falls upon this sea1 and that that much at least is taken up from it again as vapour1 this would give #bee cubic miles as the quantity of water which is daily lifted up and poured back again into this expanse4 ,it is taken up at one place1 and rained down at another2 and in this process1 therefore1 we have agencies for multitudes of partial and conflicting currents1 all1 in their set strength1 apparently as uncertain as the winds4 ,the better to appreciate the operation of such agencies in producing currents in the sea1 imagine a district of #bee square miles to be set apart in the midst of the ,pacific ,ocean as the scene of operations for one day2 then conceive a machine capable of pumping up in the twenty-four hours all the water to the depth of one mile in this district4 ,the machine must not only pump up and bear off this immense quantity of water1 but it must discharge it again into the sea on the same day1 but at some other place4 ,all the great rivers of ,america1 ,europe1 and ,asia are lifted up by the atmosphere1 and flow in invisible streams back through the air to their sources among the hills2 and through channels so regular1 certain1 and well defined1 that the quantity thus conveyed one year with the other is nearly the same3 for that is the quantity which we see running down to the ocean through these rivers2 and the quantity discharged annually by each river is1 as far as we can judge1 nearly a constant4--,maury4 ,,an ,,inch ,,of ,,rain ,,on ,,the ,,atlantic4 ,lieutenant ,maury thus computes the effect of a single ,inch of ,rain falling upon the ,atlantic ,ocean4 ,the ,atlantic includes an area of twenty-five millions of square miles4 ,suppose an inch of rain to fall upon only one-fifth of this vast expanse4 ,it would weigh1 says our author1 three hundred and sixty thousand millions of tons3 and the salt which1 as water1 it held in solution in the sea1 and which1 when that water was taken up as vapour1 was left behind to disturb equilibrium1 weighed sixteen millions more of tons1 or nearly twice as much as all the ships in the world could carry at a cargo each4 ,it might fall in an hour1 or it might fall in a day2 but1 occupy what time it might in falling1 this rain is calculated to exert so much force--which is inconceivably great--in disturbing the equilibrium of the ocean4 ,if all the water discharged by the ,mississippi river during the year were taken up in one mighty measure1 and cast into the ocean at one effort1 it would not make a greater disturbance in the equilibrium of the sea than would the fall of rain supposed4 ,and yet so gentle are the operations of nature1 that movements so vast are unperceived4 ,,the ,,equatorial ,,cloud-,,ring4 ,in crossing the ,equatorial ,doldrums1 the voyager passes a ring of clouds that encircles the earth1 and is stretched around our planet to regulate the quantity of precipitation in the rain-belt beneath it2 to preserve the due quantum of heat on the face of the earth2 to adjust the winds2 and send out for distribution to the four corners vapours in proper quantities1 to make up to each river-basin1 climate1 and season1 its quota of sunshine1 cloud1 and moisture4 ,like the balance-wheel of a well-constructed chronometer1 this cloud-ring affords the grand atmospherical machine the most exquisitely arranged self-compensation4 ,nature herself has hung a thermometer under this cloud-belt that is more perfect than any that man can construct1 and its indications are not to be mistaken4--,maury4 8,,the ,,equatorial ,,doldrums0 is another of these calm places4 ,besides being a region of calms and baffling winds1 it is a region noted for its rains and clouds1 which make it one of the most oppressive and disagreeable places at sea4 ,the emigrant ships from ,europe for ,australia have to cross it4 ,they are often baffled in it for two or three weeks2 then the children and the passengers who are of delicate health suffer most4 ,it is a frightful graveyard on the wayside to that golden land4 ,,beauty ,,of ,,the ,,dew-,,drop4 ,the ,dew-drop is familiar to every one from earliest infancy4 ,resting in luminous beads on the down of leaves1 or pendent from the finest blades of grass1 or threaded upon the floating lines of the gossamer1 its 8orient pearl0 varies in size from the diameter of a small pea to the most minute atom that can be imagined to exist4 ,each of these1 like the rain-drops1 has the properties of reflecting and refracting light2 hence1 from so many minute prisms1 the unfolded rays of the sun are sent up to the eye in colours of brilliancy similar to those of the rainbow4 ,when the sunbeams traverse horizontally a very thickly-bedewed grass-plot1 these colours arrange themselves so as to form an iris1 or dew-bow2 and if we select any one of these drops for observation1 and steadily regard it while we gradually change our position1 we shall find the prismatic colours follow each other in their regular order4--,wells4 ,,fall ,,of ,,dew ,,in ,,one ,,year4 ,the annual average quantity of ,dew deposited in this country is estimated at a depth of about five inches1 being about one-seventh of the mean quantity of moisture supposed to be received from the atmosphere all over ,great ,britain in the year2 or about #bb1afa1ccg1cee tons1 taking the ton at #beb imperial gallons4--,wells4 ,,graduated ,,supply ,,of ,,dew ,,to ,,vegetation4 ,each of the different grasses draws from the atmosphere during the night a supply of dew to recruit its energies dependent upon its form and peculiar radiating power4 ,every flower has a power of radiation of its own1 subject to changes during the day and night1 and the deposition of moisture on it is regulated by the peculiar law which this radiating power obeys2 and this power will be influenced by the aspect which the flower presents to the sky1 unfolding to the contemplative mind the most beautiful example of creative wisdom4#ci ,,warmth ,,of ,,snow ,,in ,,arctic ,,latitudes4 ,the first warm ,snows of ,august and ,september 7says ,dr4 ,kane71 falling on a thickly-bleached carpet of grasses1 heaths1 and willows1 enshrine the flowery growths which nestle round them in a non-conducting air chamber2 and as each successive snow increases the thickness of the cover1 we have1 before the intense cold of winter sets in1 a light cellular bed covered by drift1 seven1 eight1 or ten feet deep1 in which the plant retains its vitality4 ,dr4 ,kane has proved by experiments that the conducting power of the snow is proportioned to its compression by winds1 rains1 drifts1 and congelation4 ,the drifts that accumulate during nine months of the year are dispersed in well-defined layers of different density4 ,we have first the warm cellular snows of fall1 which surround the plant2 next the finely-impacted snow-dust of winter2 and above these the later humid deposits of spring4 ,in the earlier summer1 in the inclined slopes that face the sun1 as the upper snow is melted and sinks upon the more compact layer below it is to a great extent arrested1 and runs off like rain from a slope of clay4 ,the plant reposes thus in its cellular bed1 safe from the rush of waters1 and protected from the nightly frosts by the icy roof above it4 ,,impurity ,,of ,,snow4 ,it is believed that in ascending mountains difficult breathing is sooner felt upon snow than upon rock2 and ,m4 ,boussingault1 in his account of the ascent of ,chimborazo1 attributes this to the sensible deficiency of oxygen contained in the pores of the snow1 which is exhaled when it melts4 ,the fact that the air absorbed by snow is impure1 was ascertained by ,de ,saussure1 and has been confirmed by ,boussingault's experiments4--,quarterly ,review1 ,no4 #bjb4 ,,snow ,,phenomenon4 ,professor ,dove of ,berlin relates1 in illustration of the formation of clouds of ,snow over plains situated at a distance from the cooling summits of mountains1 that on one occasion a large company had gathered in a ballroom in ,sweden4 ,it was one of those icy starlight nights which in that country are so aptly called 8iron nights40 ,the weather was clear and cold1 and the ballroom was clear and warm2 and the heat was so great1 that several ladies fainted4 ,an officer present tried to open a window2 but it was frozen fast to the sill4 ,as a last resort1 he broke a pane of glass2 the cold air rushed in1 and it snowed in the room4 ,a minute before all was clear2 but the warm air of the room had sustained an amount of moisture in a transparent condition which it was not able to maintain when mixed with the colder air from without4 ,the vapour was first condensed1 and then frozen4 ,,absence ,,of ,,snow ,,in ,,siberia4 ,there is in ,siberia1 ,m4 ,ermann informs us1 an entire district in which during the winter the sky is constantly clear1 and where a single particle of snow never falls4--,arago4 ,,accuracy ,,of ,,the ,,chinese ,,as ,,observers4 ,the beautiful forms of snow-crystals have long since attracted ,chinese observers2 for from a remote period there has been met with in their conversation and books an axiomatic expression1 to the effect that 8snow-flakes are hexagonal10 showing the ,chinese to be accurate observers of nature4 ,,protection ,,against ,,hail ,,and ,,storms4 ,arago relates1 that when1 in #ahdg1 two small agricultural districts of ,bourgoyne had lost by ,hail crops to the value of a million and a half of francs1 certain of the proprietors went to consult him on the means of protecting them from like disasters4 ,resting on the hypothesis of the electric origin of hail1 ,arago suggested the discharge of the electricity of the clouds by means of balloons communicating by a metallic wire with the soil4 ,this project was not carried out2 but ,arago persisted in believing in the effectiveness of the method proposed4 ,arago1 in his ,meteorological ,essays1 inquires whether the firing of cannon can dissipate storms4 ,he cites several cases in its favour1 and others which seem to oppose it2 but he concludes by recommending it to his successors4 ,whilst ,arago was propounding these questions1 a person not conversant with science1 the poet ,mry1 was collecting facts supporting the view1 which he has published in his ,paris ,futur4 ,his attention was attracted to the firing of cannon to dissipate storms in #ahbh1 whilst an assistant in the 8,ecole de ,tir0 at ,vincennes4 ,having observed that there was never any rain in the morning of the exercise of firing1 he waited to examine military records1 and found there1 as he says1 facts which justified the expressions of 8,le soleil d',austerlitz10 8,le soleil de juillet10 upon the morning of the ,revolution of ,july2 and he concluded by proposing to construct around ,paris twelve towers of great height1 which he calls 8tours imbrifuges10 each carrying #ajj cannons1 which should be discharged into the air on the approach of a storm4 ,about this time an incident occurred which in nowise confirmed the truth of ,m4 ,mry's theory4 ,the #adth of ,august was a fine day4 ,on the #aeth1 the fte of the ,empire1 the sun shone out1 the cannon thundered all day long1 fireworks and illuminations were blazing from nine o'clock in the evening4 ,every thing conspired to verify the hypothesis of ,m4 ,mry1 and chase away storms for a long time4 ,but towards eleven in the evening a torrent of rain burst upon ,paris1 in spite of the pretended influence of the discharge of cannon1 and gave an occasion for the mobile ,gallic mind to turn its attention in other directions4 ,,terrific ,,hailstorm4 ,jansen describes1 from the log-book of the ,rhijin1 ,captain ,brandligt1 in the ,south-,indian ,ocean 7#be south latitude7 a ,hurricane1 accompanied by ,hail1 by which several of the crew were made blind1 others had their faces cut open1 and those who were in the rigging had their clothes torn off them4 ,the master of the ship compared the sea 8to a hilly landscape in winter covered with snow40 ,does it not appear as if the 8treasures of the hail0 were opened1 which were 8reserved against the time of trouble1 against the day of battle and war08 ,,how ,,waterspouts ,,are ,,formed ,,in ,,the ,,java ,,sea4 ,among the small groups of islands in this sea1 in the day and night thunderstorms1 the combat of the clouds appears to make them more thirsty than ever4 ,in tunnel form1 when they can no longer quench their thirst from the surrounding atmosphere1 they descend near the surface of the sea1 and appear to lap the water directly up with their black mouths4 ,they are not always accompanied by strong winds2 frequently more than one is seen at a time1 whereupon the clouds whence they proceed disperse1 and the ends of the ,waterspouts bending over finally causes them to break in the middle4 ,they seldom last longer than five minutes4 ,as they are going away1 the bulbous tube1 which is as palpable as that of a thermometer1 becomes broader at the base2 and little clouds1 like steam from the pipe of a locomotive1 are continually thrown off from the circumference of the spout1 and gradually the water is released1 and the cloud whence the spout came again closes its mouth4 ,,cold ,,in ,,hudson',s ,,bay4 ,mr4 ,r4 ,m4 ,ballantyne1 in his journal of six years' residence in the territories of the ,hudson's ,bay ,company1 tells us1 that for part of ,october there is sometimes a little warm1 or rather thawy1 weather2 but after that1 until the following ,april1 the thermometer seldom rises to the freezing point4 ,in the depth of winter1 the thermometer falls from #cj to #dj1 #de1 and even #di below zero of ,fahrenheit4 ,this intense cold is not1 however1 so much felt as one might suppose2 for during its continuance the air is perfectly calm4 ,were the slightest breath of wind to rise when the thermometer stands so low1 no man could show his face to it for a moment4 ,forty degrees below zero1 and quite calm1 is infinitely preferable to fifteen below1 or thereabout1 with a strong breeze of wind4 ,spirit of wine is1 of course1 the only thing that can be used in the thermometer2 as mercury1 were it exposed to such cold1 would remain frozen nearly half the winter4 ,spirit never froze in any cold ever experienced at ,york ,factory1 unless when very much adulterated with water2 and even then the spirit would remain liquid in the centre of the mass4 ,quicksilver easily freezes in this climate1 and it has frequently been run into a bullet-mould1 exposed to the cold air till frozen1 and in this state rammed down a gun-barrel1 and fired through a thick plank4 ,the average cold may be set down at about #ae or #af below zero1 or #dh of frost4 ,the houses at the ,bay are built of wood1 with double windows and doors4 ,they are heated by large iron stoves1 fed with wood2 yet so intense is the cold1 that when a stove has been in places red-hot1 a basin of water in the room has been frozen solid4 ,,purity ,,of ,,wenham-,,lake ,,ice4 ,professor ,faraday attributes the purity of ,wenham-,lake ,ice to its being free from air-bubbles and from salts4 ,the presence of the first makes it extremely difficult to succeed in making a lens of ,english ice which will concentrate the solar rays1 and readily fire gunpowder2 whereas nothing is easier than to perform this singular feat of igniting a combustible body by aid of a frozen mass if ,wenham-,lake ice be employed4 ,the absence of salts conduces greatly to the permanence of the ice2 for where water is so frozen that the salts expelled are still contained in air-cavities and cracks1 or form thin films between the layers of ice1 these entangled salts cause the ice to melt at a lower temperature than #cb1 and the liquefied portions give rise to streams and currents within the body of the ice which rapidly carry heat to the interior4 ,the mass then goes on thawing within as well as without1 and at temperatures below #cb2 whereas pure1 compact1 ,wenham-,lake ice can only thaw at #cb1 and only on the outside of the mass4--,sir ,charles ,lyell's ,second ,visit to the ,united ,states4 ,,arctic ,,temperatures4 ,dr4 ,kane1 in his ,second ,arctic ,expedition1 found the thermometers beginning to show unexampled temperature3 they ranged from #fj to #gj below zero1 and upon the taffrail of the brig #fe4 ,the reduced mean of the best spirit-standards gave #fg or #ii below the freezing point of water4 ,at these temperatures chloric ether became solid1 and chloroform exhibited a granular pellicle on its surface4 ,spirit of naphtha froze at #ed1 and the oil of turpentine was solid at #fc and #fe4 ,,dr4 ,,rae',s ,,arctic ,,explorations4 ,the gold medal of the ,royal ,geographical ,society was in #aheb most rightfully awarded to this indefatigable ,arctic explorer4 ,his survey of the inlet of ,boothia1 in #ahdh1 was unique in its kind4 ,in ,repulse ,bay he maintained his party on deer1 principally shot by himself2 and spent ten months of an ,arctic winter in a hut of stones1 with no other fuel than a kind of hay of the ,andromeda tetragona4 ,thus he preserved his men to execute surveying journeys of #ajjj miles in the spring4 ,later he travelled #cjj miles on snow-shoes4 ,in a spring journey over the ice1 with a pound of fat daily for fuel1 accompanied by two men only1 and trusting solely for shelter to snow-houses1 which he taught his men to build1 he accomplished #ajfj miles in thirty-nine days1 or twenty-seven miles per day1 including stoppages1--a feat never equalled in ,arctic travelling4 ,in the spring journey1 and that which followed in the summer in boats1 #agjj miles were traversed in eighty days4 ,dr4 ,rae's greatest sufferings1 he once remarked to ,sir ,george ,back1 arose from his being obliged to sleep upon his frozen mocassins in order to thaw them for the morning's use4 ,,phenomena ,,of ,,the ,,arctic ,,climate4 ,sir ,john ,richardson1 in his history of his ,expedition to these regions1 describes the power of the sun in a cloudless sky to have been so great1 that he was glad to take shelter in the water while the crews were engaged on the portages2 and he has never felt the direct rays of the sun so oppressive as on some occasions in the high latitudes4 ,sir ,john observes3 ,the rapid evaporation of both snow and ice in the winter and spring1 long before the action of the sun has produced the slightest thaw or appearance of moisture1 is evident by many facts of daily occurrence4 ,thus when a shirt1 after being washed1 is exposed in the open air to a temperature of from #dj to #ej below zero1 it is instantly rigidly frozen1 and may be broken if violently bent4 ,if agitated when in this condition by a strong wind1 it makes a rustling noise like theatrical thunder4 ,in consequence of the extreme dryness of the atmosphere in winter1 most articles of ,english manufacture brought to ,rupert's ,land are shrivelled1 bent1 and broken4 ,the handles of razors and knives1 combs1 ivory scales1 c41 kept in the warm room1 are changed in this way4 ,the human body also becomes vividly electric from the dryness of the skin4 ,one cold night ,i rose from my bed1 and was going out to observe the thermometer1 with no other clothing than my flannel night-dress1 when on my hand approaching the iron latch of the door1 a distinct spark was elicited4 ,friction of the skin at almost all times in winter produced the electric odour4 ,even at midwinter we had but three hours and a half of daylight4 ,on ,december #bjth ,i required a candle to write at the window at ten in the morning4 ,the sun was absent ten days1 and its place in the heavens at noon was denoted by rays of light shooting into the sky above the woods4 ,the moon in the long nights was a most beautiful object1 that satellite being constantly above the horizon for nearly a fortnight together4 ,venus also shone with a brilliancy which is never witnessed in a sky loaded with vapours2 and1 unless in snowy weather1 our nights were always enlivened by the beams of the aurora4 ,,intense ,,heat ,,and ,,cold ,,of ,,the ,,desert4 ,among crystalline bodies1 rock-crystal1 or silica1 is the best conductor of heat4 ,this fact accounts for the steadiness of temperature in one set district1 and the extremes of ,heat and ,cold presented by day and night on such sandy wastes as the ,sahara4 ,the sand1 which is for the most part silica1 drinks-in the noon-day heat1 and loses it by night just as speedily4 ,the influence of the hot winds from the ,sahara has been observed in vessels traversing the ,atlantic at a distance of upwards of #aajj geographical miles from the ,african shores1 by the coating of impalpable dust upon the sails4 ,,transporting ,,power ,,of ,,winds4 ,the greatest example of their power is the sand-flood of ,africa1 which1 moving gradually eastward1 has overwhelmed all the land capable of tillage west of the ,nile1 unless sheltered by high mountains1 and threatens ultimately to obliterate the rich plain of ,egypt4 ,,exhilaration ,,in ,,ascending ,,mountains4 ,at all elevations of from #fjjj to #aa1jjj feet1 and not unfrequently for even #bjjj feet more1 the pedestrian enjoys a pleasurable feeling1 imparted by the consciousness of existence1 similar to that which is described as so fascinating by those who have become familiar with the desert-life of the ,east4 ,the body seems lighter1 the nervous power greater1 the appetite is increased2 and fatigue1 though felt for a time1 is removed by the shortest repose4 ,some travellers have described the sensation by the impression that they do not actually press the ground1 but that the blade of a knife could be inserted between the sole of the foot and the mountain top4--,quarterly ,review1 ,no4 #bjb4 ,,to ,,tell ,,the ,,approach ,,of ,,storms4 ,the proximity of ,storms has been ascertained with accuracy by various indications of the electrical state of the atmosphere4 ,thus ,professor ,scott1 of ,sandhurst ,college1 observed in ,shetland that drinking-glasses1 placed in an inverted position upon a shelf in a cupboard on the ground-floor of ,belmont ,house1 occasionally emitted sounds as if they were tapped with a knife1 or raised a little and then let fall on the shelf4 ,these sounds preceded wind2 and when they occurred1 boats and vessels were immediately secured4 ,the strength of the sound is said to be proportioned to the tempest that follows4 ,,revolving ,,storms4 ,by the conjoint labours of ,mr4 ,redfield1 ,colonel ,reid1 and ,mr4 ,piddington1 on the origin and nature of hurricanes1 typhoons1 or revolving storms1 the following important results have been obtained4 ,their existence in moderate latitudes on both sides the equator2 their absence in the immediate neighbourhood of the equatorial regions2 and the fact1 that while in the northern latitudes these storms revolve in a direction contrary to the hands of a watch the face of which is placed upwards1 in the southern latitudes they rotate in the opposite direction1--are shown to be so many additions to the long chain of evidence by which the rotation of the earth as a physical fact is demonstrated4 ,,impetus ,,of ,a ,,storm4 ,captain ,sir ,s4 ,brown estimates1 from experiments made by him at the extremity of the ,brighton-,chain ,pier in a heavy south-west gale1 that the waves impinge on a cylindrical surface one foot high and one foot in diameter with a force equal to eighty pounds1 to which must be added that of the wind1 which in a violent storm exerts a pressure of forty pounds4 ,he computed the collective impetus of the waves on the lower part of a lighthouse proposed to be built on the ,wolf ,rock 7exposed to the most violent storms of the ,atlantic71 of the surf on the upper part1 and of the wind on the whole1 to be equal to #ajj tons4 ,,how ,,to ,,make ,a ,,storm-,,glass4 ,this instrument consists of a glass tube1 sealed at one end1 and furnished with a brass cap at the other end1 through which the air is admitted by a very small aperture4 ,nearly fill the tube with the following solution3 camphor1 #b drams2 nitrate of potash1 #ch grains2 muriate of ammonia1 #ch grains2 water1 #i drams2 rectified spirit1 #i drams4 ,dissolve with heat4 ,at the ordinary temperature of the atmosphere1 plumose crystals are formed4 ,on the approach of stormy weather1 these crystals appear compressed into a compact mass at the bottom of the tube2 while during fine weather they assume their plumose character1 and extend a considerable way up the glass4 ,these results depend upon the condition of the air1 but they are not considered to afford any reliable indication of approaching weather4 ,,splendour ,,of ,,the ,,aurora ,,borealis4 ,humboldt thus beautifully describes this phenomenon3 ,the intensity of this light is at times so great1 that ,lowenrn 7on ,june #bi1 #aghf7 recognised its coruscation in bright sunshine4 ,motion renders the phenomenon more visible4 ,round the point in the vault of heaven which corresponds to the direction of the inclination of the needle the beams unite together to form the so-called corona1 the crown of the ,northern ,light1 which encircles the summit of the heavenly canopy with a milder radiance and unflickering emanations of light4 ,it is only in rare instances that a perfect crown or circle is formed2 but on its completion1 the phenomenon has invariably reached its maximum1 and the radiations become less frequent1 shorter1 and more colourless4 ,the crown1 and the luminous arches break up2 and the whole vault of heaven becomes covered with irregularly scattered1 broad1 faint1 almost ashy-gray1 luminous1 immovable patches1 which in their turn disappear1 leaving nothing but a trace of a dark smoke-like segment on the horizon4 ,there often remains nothing of the whole spectacle but a white delicate cloud with feathery edges1 or divided at equal distances into small roundish groups like cirro-cumuli4--,cosmos1 vol4 i4 ,among many theories of this phenomenon is that of ,lieutenant ,hooper1 ,r4,n41 who has stated to the ,british ,association that he believes 8the ,aurora ,borealis to be no more nor less than the moisture in some shape 7whether dew or vapour1 liquid or frozen71 illuminated by the heavenly bodies1 either directly1 or reflecting their rays from the frozen masses around the ,pole1 or even from the immediately proximate snow-clad earth40 ,,varieties ,,of ,,lightning4 ,according to ,arago's investigations1 the evolution of ,lightning is of three kinds3 zigzag1 and sharply defined at the edges2 in sheets of light1 illuminating a whole cloud1 which seems to open and reveal the light within it2 and in the form of fire-balls4 ,the duration of the first two kinds scarcely continues the thousandth part of a second2 but the globular lightning moves much more slowly1 remaining visible for several seconds4 ,,what ,,is ,,sheet-,,lightning8 ,this electric phenomenon is unaccompanied by thunder1 or too distant to be heard3 when it appears1 the whole sky1 but particularly the horizon1 is suddenly illuminated with a flickering flash4 ,philosophers differ much as to its cause4 ,matteucci supposes it to be produced either during evaporation1 or evolved 7according to ,pouillet's theory7 in the process of vegetation2 or generated by chemical action in the great laboratory of nature1 the earth1 and accumulated in the lower strata of the air in consequence of the ground being an imperfect conductor4 ,arago and ,kamtz1 however1 consider sheet-lightning as reflections of distant thunderstorms4 ,saussure observed sheet-lightning in the direction of ,geneva1 from the ,hospice du ,grimsel1 on the #ajth and #aath of ,july #aghc2 while at the same time a terrific thunderstorm raged at ,geneva4 ,howard1 from ,tottenham1 near ,london1 on ,july #ca1 #ahac1 saw sheet-lightning towards the south-east1 while the sky was bespangled with stars1 not a cloud floating in the air2 at the same time a thunderstorm raged at ,hastings1 and in ,france from ,calais to ,dunkirk4 ,arago supports his opinion1 that the phenomenon is reflected lightning1 by the following illustration3 ,in #ahjc1 when observations were being made for determining the longitude1 ,m4 de ,zach1 on the ,brocken1 used a few ounces of gunpowder as a signal1 the flash of which was visible from the ,klenlenberg1 sixty leagues off1 although these mountains are invisible from each other4 ,,production ,,of ,,lightning ,,by ,,rain4 ,a sudden gust of rain is almost sure to succeed a violent detonation immediately overhead4 ,mr4 ,birt1 the meteorologist1 asks3 ,is this rain a cause or consequence of the electric discharge8 ,to this he replies3 ,in the sudden agglomeration of many minute and feebly electrified globules into one rain-drop1 the quantity of electricity is increased in a greater proportion than the surface over which 7according to the laws of electric distribution7 it is spread4 ,by tension1 therefore1 it is increased1 and may attain the point when it is capable of separating from the drop to seek the surface of the cloud1 or of the newly-formed descending body of rain1 which1 under such circumstances1 may be regarded as a conducting medium4 ,arrived at this surface1 the tension1 for the same reason1 becomes enormous1 and a flash escapes4 ,this theory ,mr4 ,birt has confirmed by observation of rain in thunderstorms4 ,,service ,,of ,,lightning-,,conductors4 ,sir ,david ,brewster relates a remarkable instance of a tree in ,clandeboye ,park1 in a thick mass of wood1 and not the tallest of the group1 being struck by lightning1 which passed down the trunk into the ground1 rending the tree asunder4 ,this shows that an object may be struck by lightning in a locality where there are numerous conducting points more elevated than itself2 and at the same time proves that lightning cannot be diverted from its course by lofty isolated conductors1 but that the protection of buildings from this species of meteor can only be effected by conductors stretching out in all directions4 ,professor ,silliman states1 that lightning-rods cannot be relied upon unless they reach the earth where it is permanently wet2 and that the best security is afforded by carrying the rod1 or some good metallic conductor duly connected with it1 to the water in the well1 or to some other water that never fails4 ,the professor's house1 it seems1 was struck2 but his lightning-rods were not more than two or three inches in the ground1 and were therefore virtually of no avail in protecting the building4 ,,ancient ,,lightning-,,conductor4 ,humboldt informs us1 that 8the most important ancient notice of the relations between lightning and conducting metals is that of ,ctesias1 in his ,indica1 cap4 iv4 p4 #aij4 ,he possessed two iron swords1 presents from the king ,artaxerxes ,mnemon and from his mother ,parasytis1 which1 when planted in the earth1 averted clouds1 hail1 and strokes of lightning4 ,he had himself seen the operation1 for the king had twice made the experiment before his eyes40--,cosmos1 vol4 ii4 ,,the ,,temple ,,of ,,jerusalem ,,protected ,,from ,,lightning4 ,we do not learn1 either from the ,bible or ,josephus1 that the ,temple at ,jerusalem was ever struck by ,lightning during an interval of more than a thousand years1 from the time of ,solomon to the year #gj2 although1 from its situation1 it was completely exposed to the violent thunderstorms of ,palestine4 ,by a fortuitous circumstance1 the ,temple was crowned with lightning-conductors similar to those which we now employ1 and which we owe to ,franklin's discovery4 ,the roof1 constructed in what we call the ,italian manner1 and covered with boards of cedar1 having a thick coating of gold1 was garnished from end to end with long pointed and gilt iron or steel lances1 which1 ,josephus says1 were intended to prevent birds from roosting on the roof and soiling it4 ,the walls were overlaid throughout with wood1 thickly gilt4 ,lastly1 there were in the courts of the ,temple cisterns1 into which the rain from the roof was conducted by metallic pipes4 ,we have here both the lightning-rods and a means of conduction so abundant1 that ,lichtenberg is quite right in saying that many of the present apparatuses are far from offering in their construction so satisfactory a combination of circumstances4--,abridged from ,arago's ,meteorological ,essays4 ,,how ,,st4 ,,paul',s ,,cathedral ,,is ,,protected ,,from ,,lightning4 ,in ,march #agfi1 the ,dean and ,chapter of ,st4 ,paul's addressed a letter to the ,royal ,society1 requesting their opinion as to the best and most effectual method of fixing electrical conductors on the cathedral4 ,a committee was formed for the purpose1 and ,benjamin ,franklin was one of the members2 their report was made1 and the conductors were fixed as follows3 ,the seven iron scrolls supporting the ball and cross are connected with other rods 7used merely as conductors71 which unite them with several large bars1 descending obliquely to the stone-work of the lantern1 and connected by an iron ring with four other iron bars to the lead covering of the great cupola1 a distance of forty-eight feet2 thence the communication is continued by the rain-water pipes to the lead-covered roof1 and thence by lead water-pipes which pass into the earth2 thus completing the entire communication from the cross to the ground1 partly through iron1 and partly through lead4 ,on the clock-tower a bar of iron connects the pine-apple at the top with the iron staircase1 and thence with the lead on the roof of the church4 ,the bell-tower is similarly protected4 ,by these means the metal used in the building is made available as conductors2 the metal employed merely for that purpose being exceedingly small in quantity4--,curiosities of ,london4 ,,various ,,effects ,,of ,,lightning4 ,dr4 ,hibbert tells us that upon the western coast of ,scotland and ,ireland1 ,lightning coperates with the violence of the storm in shattering solid rocks1 and heaping them in piles of enormous fragments1 both on dry land and beneath the water4 ,euler informs us1 in his ,letters to a ,german ,princess1 that he corresponded with a ,moravian priest named ,divisch1 who assured him that he had averted during a whole summer every thunderstorm which threatened his own habitation and the neighbourhood1 by means of a machine constructed upon the principles of electricity2 that the machinery sensibly attracted the clouds1 and constrained them to descend quietly in a distillation1 without any but a very distant thunderclap4 ,euler assures us that 8the fact is undoubted1 and confirmed by irresistible proof40 ,about the year #ahaa1 in the village of ,phillipsthal1 in ,eastern ,prussia1 an attempt was made to split an immense stone into a multitude of pieces by means of lightning4 ,a bar of iron1 in the form of a conductor1 was previously fixed to the stone2 and the experiment was attended with complete success2 for during the very first thunderstorm the lightning burst the stone without displacing it4 ,the celebrated ,duhamel du ,monceau says1 that lightning1 unaccompanied by thunder1 wind1 or rain1 has the property of breaking oat-stalks4 ,the farmers are acquainted with this effect1 and say that the lightning breaks down the oats4 ,this is a well-received opinion with the farmers in ,devonshire4 ,lightning has in some cases the property of reducing solid bodies to ashes1 or to pulverisation1--even the human body1--without there being any signs of heat4 ,the effects of lightning on paralysis are very remarkable1 in some cases curing1 in others causing1 that disease4 ,the returning stroke of lightning is well known to be due to the restoration of the natural electric state1 after it has been disturbed by induction4 ,a ,,thunderstorm ,,seen ,,from ,a ,,balloon4 ,mr4 ,john ,west1 the ,american aeronaut1 in his observations made during his numerous ascents1 describes a storm viewed from above the clouds to have the appearance of ebullition4 ,the bulging upper surface of the cloud resembles a vast sea of boiling and upheaving snow2 the noise of the falling rain is like that of a waterfall over a precipice2 the thunder above the cloud is not loud1 and the flashes of lightning appear like streaks of intensely white fire on a surface of white vapour4 ,he thus describes a side view of a storm which he witnessed ,june #c1 #aheb1 in his balloon excursion from ,portsmouth1 ,ohio3 ,although the sun was shining on me1 the rain and small hail were rattling on the balloon4 ,a rainbow1 or prismatically-coloured arch or horse-shoe1 was reflected against the sun2 and as the point of observation changed laterally and perpendicularly1 the perspective of this golden grotto changed its hues and forms4 ,above and behind this arch was going on the most terrific thunder2 but no zigzag lightning was perceptible1 only bright flashes1 like explosions of 8,roman candles0 in fireworks4 ,occasionally there was a zigzag explosion in the cloud immediately below1 the thunder sounding like a feu-de-joie of a rifle-corps4 ,then an orange-coloured wave of light seemed to fall from the upper to the lower cloud2 this was 8still-lightning40 ,meanwhile intense electrical action was going on in the balloon1 such as expansion1 tremulous tension1 lifting papers ten feet out of the car below the balloon and then dropping them1 c4 ,the close view of this ,ohio storm was truly sublime2 its rushing noise almost appalling4 ,ascending from the earth with a balloon1 in the rear of a storm1 and mounted up a thousand feet above it1 the balloon will soon override the storm1 and may descend in advance of it4 ,mr4 ,west has experienced this several times4 ,,remarkable ,,aeronautic ,,voyage4 ,mr4 ,sadler1 the celebrated aeronaut1 ascended on one occasion in a balloon from ,dublin1 and was wafted across the ,irish ,channel2 when1 on his approach to the ,welsh coast1 the balloon descended nearly to the surface of the sea4 ,by this time the sun was set1 and the shades of evening began to close in4 ,he threw out nearly all his ballast1 and suddenly sprang upward to a great height2 and by so doing brought his horizon to dip below the sun1 producing the whole phenomenon of a western sunrise4 ,subsequently descending in ,wales1 he of course witnessed a second sunset on the same evening4--,sir ,john ,herschel's ,outlines of ,astronomy4 ,physical ,geography of the ,sea4#dj ,,climates ,,of ,,the ,,sea4 ,the fauna and flora of the ,sea are as much the creatures of ,climate1 and are as dependent for their well-being upon temperature1 as are the fauna and flora of the dry land4 ,were it not so1 we should find the fish and the alg1 the marine insect and the coral1 distributed equally and alike in all parts of the ocean2 the polar whale would delight in the torrid zone2 and the habitat of the pearl oyster would be also under the iceberg1 or in frigid waters colder than the melting ice4 ,,the ,,circulation ,,of ,,the ,,sea4 ,the coral islands1 reefs1 and beds with which the ,pacific ,ocean is studded and garnished1 were built up of materials which a certain kind of insect quarried from the sea-water4 ,the currents of the sea ministered to this little insect2 they were its hod-carriers4 ,when fresh supplies of solid matter were wanted for the coral rock upon which the foundations of the ,polynesian ,islands were laid1 these hod-carriers brought them in unfailing streams of sea-water1 loaded with food and building-materials for the coralline3 the obedient currents thread the widest and the deepest sea4 ,now we know that its adaptations are suited to all the wants of every one of its inhabitants1--to the wants of the coral insect as well as those of the whale4 ,hence we know that the sea has its system of circulation3 for it transports materials for the coral rock from one part of the world to another2 its currents receive them from rivers1 and hand them over to the little mason for the structure of the most stupendous works of solid masonry that man has ever seen--the coral islands of the sea4 ,,temperature ,,of ,,the ,,sea4 ,between the hottest hour of the day and the coldest hour of the night there is frequently a change of four degrees in the ,temperature of the ,sea4 ,taking one-fifth of the ,atlantic ,ocean for the scene of operation1 and the difference of four degrees to extend only ten feet below the surface1 the total and absolute change made in such a mass of sea-water1 by altering its temperature two degrees1 is equivalent to a change in its volume of #cij1jjj1jjj cubic feet4 ,,transparency ,,of ,,the ,,ocean4 ,captain ,glynn1 ,u4,s4,n41 has made some interesting observations1 ranging over #bjj of latitude1 in different oceans1 in very high latitudes1 and near the equator4 ,his apparatus was simple3 a common white dinner-plate1 slung so as to lie in the water horizontally1 and sunk by an iron pot with a line4 ,numbering the fathoms at which the plate was visible below the surface1 ,captain ,glynn saw it on two occasions1 at the maximum1 twenty-five fathoms 7#aej feet7 deep2 the water was extraordinarily clear1 and to lie in the boat and look down was like looking down from the mast-head2 and the objects were clearly defined to a great depth4 ,,the ,,basin ,,of ,,the ,,atlantic4 ,in its entire length1 the basin of this sea is a long trough1 separating the ,old ,world from the ,new1 and extending probably from pole to pole4 ,this ocean-furrow was scored into the solid crust of our planet by the ,almighty hand1 that there the waters which 8he called seas0 might be gathered together so as to 8let the dry land appear10 and fit the earth for the habitation of man4 ,from the top of ,chimborazo to the bottom of the ,atlantic1 at the deepest place yet recognised by the plummet in the ,north ,atlantic1 the distance in a vertical line is nine miles4 ,could the waters of the ,atlantic be drawn off1 so as to expose to view this great sea-gash1 which separates continents1 and extends from the ,arctic to the ,antarctic1 it would present a scene the most grand1 rugged1 and imposing4 ,the very ribs of the solid earth1 with the foundations of the sea1 would be brought to light2 and we should have presented to us at one view1 in the empty cradle of the ocean1 8a thousand fearful wrecks10 with that dreadful array of dead men's skulls1 great anchors1 heaps of pearls and inestimable stones1 which1 in the dreamer's eye1 lie scattered on the bottom of the sea1 making it hideous with sights of ugly death4 ,,gales ,,of ,,the ,,atlantic4 ,lieutenant ,maury has1 in a series of charts of the ,north and ,south ,atlantic1 exhibited1 by means of colours1 the prevalence of ,gales over the more stormy parts of the oceans for each month in the year4 ,one colour shows the region in which there is a gale every six days2 another colour every six to ten days2 another every ten to fourteen days3 and there is a separate chart for each month and each ocean4 ,,solitude ,,at ,,sea4 ,between ,humboldt's ,current of ,peru and the great equatorial flow1 there is 8a desolate region10 rarely visited by the whale1 either sperm or right4 ,formerly this part of the ocean was seldom whitened by the sails of a ship1 or enlivened by the presence of man4 ,neither the industrial pursuits of the sea nor the highways of commerce called him into it4 ,now and then a roving cruiser or an enterprising whalesman passed that way2 but to all else it was an unfrequented part of the ocean1 and so remained until the gold-fields of ,australia and the guano islands of ,peru made it a thoroughfare4 ,all vessels bound from ,australia to ,south ,america now pass through it2 and in the journals of some of them it is described as a region almost void of the signs of life in both sea and air4 ,in the ,south-,pacific ,ocean especially1 where there is such a wide expanse of water1 sea-birds often exhibit a companionship with a vessel1 and will follow and keep company with it through storm and calm for weeks together4 ,even the albatross and ,cape pigeon1 that delight in the stormy regions of ,cape ,horn and the inhospitable climates of the ,antarctic regions1 not unfrequently accompany vessels into the perpetual summer of the tropics4 ,the sea-birds that join the ship as she clears ,australia will1 it is said1 follow her to this region1 and then disappear4 ,even the chirp of the stormy petrel ceases to be heard here1 and the sea itself is said to be singularly barren of 8moving creatures that have life40 ,,bottles ,,and ,,currents ,,at ,,sea4 ,seafaring people often throw a bottle overboard1 with a paper stating the time and place at which it is done4 ,in the absence of other information as to ,currents1 that afforded by these mute little navigators is of great value4 ,they leave no track behind them1 it is true1 and their routes cannot be ascertained2 but knowing where they are cast1 and seeing where they are found1 some idea may be formed as to their course4 ,straight lines may at least be drawn1 showing the shortest distance from the beginning to the end of their voyage1 with the time elapsed4 ,admiral ,beechey has prepared a chart1 representing1 in this way1 the tracks of more than #ajj bottles4 ,from this it appears that the waters from every quarter of the ,atlantic tend towards the ,gulf of ,mexico and its stream4 ,bottles cast into the sea midway between the ,old and the ,new ,worlds1 near the coasts of ,europe1 ,africa1 and ,america at the extreme north or farthest south1 have been found either in the ,west ,indies1 or the ,british ,isles1 or within the well-known range of ,gulf-,stream waters4 8,,the ,,horse ,,latitudes0 are the belts of calms and light airs which border the polar edge of the north-east trade-winds4 ,they are so called from the circumstance that vessels formerly bound from ,new ,england to the ,west ,indies1 with a deck-load of horses1 were often so delayed in this calm belt of ,cancer1 that1 from the want of water for their animals1 they were compelled to throw a portion of them overboard4 8,,white ,,water0 ,,and ,,luminous ,,animals ,,at ,,sea4 ,captain ,kingman1 of the ,american clipper-ship ,shooting ,star1 in lat4 #h #df ,s41 long4 #aje #cj ,e41 describes a patch of white water1 about twenty-three miles in length1 making the whole ocean appear like a plain covered with snow4 ,he filled a #fj-;gallon tub with the water1 and found it to contain small luminous particles seeming to be alive with worms and insects1 resembling a grand display of rockets and serpents seen at a great distance in a dark night2 some of the serpents appearing to be six inches in length1 and very luminous4 ,on being taken up1 they emitted light until brought within a few feet of a lamp1 when nothing was visible2 but by aid of a sextant's magnifier they could be plainly seen--a jelly-like substance1 without colour4 ,a specimen two inches long was visible to the naked eye2 it was about the size of a large hair1 and tapered at the ends4 ,by bringing one end within about one-fourth of an inch of a lighted lamp1 the flame was attracted towards it1 and burned with a red light2 the substance crisped in burning1 something like hair1 or appeared of a red heat before being consumed4 ,in a glass of the water there were several small round substances 7say #a_/afth of an inch in diameter7 which had the power of expanding and contracting2 when expanded1 the outer rim appeared like a circular saw1 the teeth turned inward4 ,the scene from the clipper's deck was one of awful grandeur3 the sea having turned to phosphorus1 and the heavens being hung in blackness1 and the stars going out1 seemed to indicate that all nature was preparing for that last grand conflagration which we are taught to believe will annihilate this material world4 ,,invention ,,of ,,the ,,log4 ,long before the introduction of the ,log1 hour-glasses were used to tell the distance in sailing4 ,columbus1 ,juan de la ,cosa1 ,sebastian ,cabot1 and ,vasco de ,gama1 were not acquainted with the ,log and its mode of application2 and they estimated the ship's speed merely by the eye1 while they found the distance they had made by the running-down of the sand in the ampotellas1 or hour-glasses4 ,the ,log for the measurement of the distance traversed is stated by writers on navigation not to have been invented until the end of the sixteenth or the beginning of the seventeenth century 7see ,encyclopdia ,britannica1 #gth edition1 #ahdb74 ,the precise date is not known2 but it is certain that ,pigafetta1 the companion of ,magellan1 speaks1 in #aeba1 of the ,log as a well-known means of finding the course passed over4 ,navarete places the use of the log-line in ,english ships in #aegg4 ,,life ,,of ,,the ,,sea-,,deeps4 ,the ocean teems with life1 we know4 ,of the four elements of the old philosophers1--fire1 earth1 air1 and water1--perhaps the sea most of all abounds with living creatures4 ,the space occupied on the surface of our planet by the different families of animals and their remains is inversely as the size of the individual2 the smaller the animal1 generally speaking1 the greater the space occupied by his remains4 ,take the elephant and his remains1 and a microscopic animal and his1 and compare them2 the contrast as to space occupied is as striking as that of the coral reef or island with the dimensions of the whale4 ,the graveyard that would hold the corallines1 is larger than the graveyard that would hold the elephants4 ,,depths ,,of ,,ocean ,,and ,,air ,,unknown4 ,at some few places under the tropics1 no bottom has been found with soundings of #bf1jjj feet1 or more than four miles2 whilst in the air1 if1 according to ,wollaston1 we may assume that it has a limit from which waves of sound may be reverberated1 the phenomenon of twilight would incline us to assume a height at least nine times as great4 ,the aerial ocean rests partly on the solid earth1 whose mountain-chains and elevated plateaus rise like green wooded shoals1 and partly on the sea1 whose surface forms a moving base1 on which rest the lower1 denser1 and more saturated strata of air4--,humboldt's ,cosmos1 vol4 i4 ,the old ,alexandrian mathematicians1 on the testimony of ,plutarch1 believed the depth of the sea to depend on the height of the mountains4 ,mr4 ,w4 ,darling has propounded to the ,british ,association the theory1 that as the sea covers three times the area of the land1 so it is reasonable to suppose that the depth of the ocean1 and that for a large portion1 is three times as great as the height of the highest mountain4 ,recent soundings show depths in the sea much greater than any elevations on the surface of the earth2 for a line has been veered to the extent of seven miles4--,dr4 ,scoresby4 ,,greatest ,,ascertained ,,depth ,,of ,,the ,,sea4 ,in the dynamical theory of the tides1 the ratio of the effects of the sun and moon depends1 not only on the masses1 distances1 and periodic times of the two luminaries1 but also on the ,depth of the ,sea2 and this1 accordingly1 may be computed when the other quantities are known4 ,in this manner ,professor ,haughton has deduced1 from the solar and lunar coefficients of the diurnal tide1 a mean depth of #eab miles2 a result which accords in a remarkable manner with that inferred from the ratio of the semi-diurnal co-efficients as obtained by ,laplace from the ,brest observations4 ,professor ,hennessey states1 that from what is now known regarding the depth of the ocean1 the continents would appear as plateaus elevated above the oceanic depressions to an amount which1 although small compared to the earth's radius1 would be considerable when compared to its outswelling at the equator and its flattening towards the poles2 and the surface thus presented would be the true surface of the earth4 ,the greatest depths at which the bottom of the sea has been reached with the plummet are in the ,north-,atlantic ,ocean2 and the places where it has been fathomed 7by the ,united-,states deep-sea sounding apparatus7 do not show it to be deeper than #be1jjj feet #d miles1 #abic yards1 #a foot4 ,the deepest place in this ocean is probably between the parallels of #ce and #dj north latitude1 and immediately to the southward of the ,grand ,banks of ,newfoundland4 ,it appears that1 with one exception1 the bottom of the ,north-,atlantic ,ocean1 as far as examined1 from the depth of about sixty fathoms to that of more than two miles 7#bjjj fathoms71 is literally nothing but a mass of microscopic shells4 ,not one of the animalcules from these shells has been found living in the surface-waters1 nor in shallow water along the shore4 ,hence arises the question1 ,do they live on the bottom1 at the immense depths where the shells are found2 or are they borne by submarine currents from their real habitat8 ,,relative ,,levels ,,of ,,the ,,red ,,sea ,,and ,,mediterranean4 ,the ,french engineers1 at the beginning of the present century1 came to the conclusion that the ,red ,sea was about thirty feet above the ,mediterranean3 but the observations of ,mr4 ,robert ,stephenson1 the ,english engineer1 at ,suez2 of ,m4 ,negretti1 the ,austrian1 at ,tineh1 near the ancient ,pelusium2 and the levellings of ,messrs4 ,talabat1 ,bourdaloue1 and their assistants between the two seas2--have proved that the low-water mark of ordinary tides at ,suez and ,tineh is very nearly on the same levels1 the difference being that at ,suez it is rather more than one inch lower4--,leonard ,horner2 ,proceedings of the ,royal ,society1 #ahee4 ,,the ,,depth ,,of ,,the ,,mediterranean4 ,soundings made in the ,mediterranean suffice to indicate depths equal to the average height of the mountains girding round this great basin2 and1 if one particular experiment may be credited1 reaching even to #ae1jjj feet--an equivalent to the elevation of the highest ,alps4 ,this sounding was made about ninety miles east of ,malta4 ,between ,cyprus and ,egypt1 #fjjj feet of line had been let down without reaching the bottom4 ,other deep soundings have been made in other places with similar results4 ,in the lines of sea between ,egypt and the ,archipelago1 it is stated that one sounding made by the ,tartarus between ,alexandria and ,rhodes reached bottom at the depth of #iijj feet2 another1 between ,alexandria and ,candia1 gave a depth of #cjj feet beyond this4 ,these single soundings1 indeed1 whether of ocean or sea1 are always open to the certainty that greater as well as lesser depths must exist1 to which no line has ever been sunk2 a case coming under that general law of probabilities so largely applicable in every part of physics4 ,in the ,mediterranean especially1 which has so many aspects of a sunken basin1 there may be abysses of depth here and there which no plummet is ever destined to reach4--,edinburgh ,review4 ,,colour ,,of ,,the ,,red ,,sea4 ,m4 ,ehrenberg1 while navigating the ,red ,sea1 observed that the red colour of its waters was owing to enormous quantities of a new animal1 which has received the name of oscillatoria rubescens1 and which seems to be the same with what ,haller has described as a purple conferva swimming in water2 yet ,dr4 ,bonar1 in his work entitled ,the ,desert of ,sinai1 records3 ,blue ,i have called the sea2 yet not strictly so1 save in the far distance4 ,it is neither a red nor a blue sea1 but emphatically green1--yes1 green1 of the most brilliant kind ,i ever saw4 ,this is produced by the immense tracts of shallow water1 with yellow sand beneath1 which always gives this green to the sea1 even in the absence of verdure on the shore or sea-weeds beneath4 ,the blue of the sky and the yellow of the sands meeting and intermingling in the water1 form the green of the sea2 the water being the medium in which the mixing or fusing of the colours takes place4 ,,what ,,is ,,sea-,,milk8 ,the phenomena with this name and that of 8,squid0 are occasioned by the presence of phosphorescent animalcules4 ,they are especially produced in the intertropical seas1 and they appear to be chiefly abundant in the ,gulf of ,guinea and in the ,arabian ,gulf4 ,in the latter1 the phenomenon was known to the ancients more than a century before the ,christian era1 as may be seen from a curious passage from the geography of ,agatharcides3 8,along this country 7the coast of ,arabia7 the sea has a white aspect like a river3 the cause of this phenomenon is a subject of astonishment to us40 ,m4 ,quatrefages has discovered that the ,noctiluc which produce this phenomenon do not always give out clear and brilliant sparks1 but that under certain circumstances this light is replaced by a steady clearness1 which gives in these animalcules a white colour4 ,the waters in which they have been observed do not change their place to any sensible degree4 ,,the ,,bottom ,,of ,,the ,,sea ,a ,,burial-,,place4 ,among the minute shells which have been fished up from the great telegraphic plateau at the bottom of the sea between ,newfoundland and ,ireland1 the microscope has failed to detect a single particle of sand or gravel2 and the inference is1 that there1 if any where1 the waters of the sea are at rest4 ,there is not motion enough there to abrade these very delicate organisms1 nor current enough to sweep them about and mix them up with a grain of the finest sand1 nor the smallest particle of gravel from the loose beds of dbris that here and there strew the bottom of the sea4 ,the animalcul probably do not live or die there4 ,they would have had no light there2 and1 if they lived there1 their frail textures would be subjected in their growth to a pressure upon them of a column of water #ab1jjj feet high1 equal to the weight of #djj atmospheres4 ,they probably live and sport near the surface1 where they can feel the genial influence of both light and heat1 and are buried in the lichen caves below after death4 ,it is now suggested1 that henceforward we should view the surface of the sea as a nursery teeming with nascent organisms1 and its depths as the cemetery for families of living creatures that outnumber the sands on the sea-shore for multitude4 ,where there is a nursery1 hard by there will be found also a graveyard1--such is the condition of the animal world4 ,but it never occurred to us before to consider the surface of the sea as one wide nursery1 its every ripple as a cradle1 and its bottom one vast burial-place4--,lieut4 ,maury4 ,,why ,,is ,,the ,,sea ,,salt8 ,it has been replied1 ,in order to preserve it in a state of purity2 which is1 however1 untenable1 mainly from the fact that organic impurities in a vast body of moving water1 whether fresh or salt1 become rapidly lost1 so as apparently to have called forth a special agency to arrest the total organised matter in its final oscillation between the organic and inorganic worlds4 ,thus countless hosts of microscopic creatures swarm in most waters1 their principal function being1 as ,professor ,owen surmises1 to feed upon and thus restore to the living chain the almost unorganised matter of various zones4 ,these creatures preying upon one another1 and being preyed upon by others in their turn1 the circulation of organic matter is kept up4 ,if we do not adopt this view1 we must at least look upon the ,infusoria and ,foraminifera as scavenger agents to prevent an undue accumulation of decaying matter2 and thus the salt condition of the sea is not a necessity4 ,nor is the amount of saline matter in the sea sufficient to arrest decomposition4 ,that the sea is salt to render it of greater density1 and by lowering its freezing point to preserve it from congelation to within a shorter distance of the poles1 though admissible1 scarcely meets the entire solution of the question4 ,the freezing point of sea-water1 for instance1 is only #c ,f4 lower than that of fresh water2 hence1 with the present distribution of land and sea--and still less1 probably1 with that which obtained in former geological epochs--no very important effects would have resulted had the ocean been fresh instead of salt4 ,now ,professor ,chapman1 of ,toronto1 suggests that the salt condition of the sea is mainly intended to regulate evaporation1 and to prevent an undue excess of that phenomenon2 saturated solutions evaporating more slowly than weak ones1 and these latter more slowly again than pure water4 ,here1 then1 we have a self-adjusting phenomenon and admirable contrivance in the balance of forces4 ,if from any temporary cause there be an unusual amount of saline matter in the sea1 evaporation goes on the more and more slowly2 and1 on the other hand1 if this proportion be reduced by the addition of fresh water in undue excess1 the evaporating power is the more and more increased--thus aiding time1 in either instance1 to restore the balance4 ,the perfect system of oceanic circulation may be ascribed1 in a great degree at least1 if not wholly1 to the effect produced by the salts of the sea upon the mobility and circulation of its waters4 ,now this is an office which the sea performs in the economy of the universe by virtue of its saltness1 and which it could not perform were its waters altogether fresh4 ,and thus philosophers have a clue placed in their hands which will probably guide to one of the many hidden reasons that are embraced in the true answer to the question1 8,why is the sea salt80 ,,how ,,to ,,ascertain ,,the ,,saltness ,,of ,,the ,,sea4 ,dry a towel in the sun1 weigh it carefully1 and note its weight4 ,then dip it into sea-water1 wring it sufficiently to prevent its dripping1 and weigh it again2 the increase of the weight being that of the water imbibed by the cloth4 ,it should then be thoroughly dried1 and once more weighed2 and the excess of this weight above the original weight of the cloth shows the quantity of the salt retained by it2 then1 by comparing the weight of this salt with that of the sea-water imbibed by the cloth1 we shall find what proportion of salt was contained in the water4 ,,all ,,the ,,salt ,,in ,,the ,,sea4 ,the amount of common ,salt in all the oceans is estimated by ,schafhutl at #c1jea1cdb cubic geographical miles4 ,this would be about five times more than the mass of the ,alps1 and only one-third less than that of the ,himalaya4 ,the sulphate of soda equals #fcc1fddcf cubic miles1 or is equal to the mass of the ,alps2 the chloride of magnesium1 #dda1haahj cubic miles2 the lime salts1 #aji1ccidd cubic miles4 ,the above supposes the mean depth to be but #cjj metres1 as estimated by ,humboldt4 ,admitting1 with ,laplace1 that the mean depth is #ajjj metres1 which is more probable1 the mass of marine salt will be more than double the mass of the ,himalaya4--,silliman's ,journal1 ,no4 #af4 ,taking the average depth of the ocean at two miles1 and its average saltness at #c per cent1 it appears that there is salt enough in the sea to cover to the thickness of one mile an area of #g1jjj1jjj of square miles4 ,admit a transfer of such a quantity of matter from an average of half a mile above to one mile below the sea-level1 and astronomers will show by calculation that it would alter the length of the day4 ,these #g1jjj1jjj of cubic miles of crystal salt have not made the sea any fuller4 ,,properties ,,of ,,sea-,,water4 ,the solid constituents of sea-water amount to about #c per cent of its weight1 or nearly half an ounce to the pound4 ,its saltness is caused as follows3 ,rivers which are constantly flowing into the ocean contain salts varying from #aj to #ej1 and even #ajj1 grains per gallon4 ,they are chiefly common salt1 sulphate and carbonate of lime1 magnesia1#da soda1 potash1 and iron2 and these are found to constitute the distinguishing characteristics of sea-water4 ,the water which evaporates from the sea is nearly pure1 containing but very minute traces of salts4 ,falling as rain upon the land1 it washes the soil1 percolates through the rocky layers1 and becomes charged with saline substances1 which are borne seaward by the returning currents4 ,the ocean1 therefore1 is the great depository of every thing that water can dissolve and carry down from the surface of the continents2 and as there is no channel for their escape1 they consequently accumulate 7,youmans' ,chemistry74 ,they would constantly accumulate1 as this very shrewd author remarks1 were it not for the shells and insects of the sea and other agents4 ,,scenery ,,and ,,life ,,of ,,the ,,arctic ,,regions4 ,the late ,dr4 ,scoresby1 from personal observations made in the course of twenty-one voyages to the ,arctic ,regions1 thus describes these striking characteristics3 ,the coast scenes of ,greenland are generally of an abrupt character1 the mountains frequently rising in triangular profile2 so much so1 that it is sometimes not possible to effect their ascent4 ,one of the most notable characteristics of the ,arctic lands is the deception to which travellers are liable in regard to distances4 ,the occasion of this is the quantity of light reflected from the snow1 contrasted with the dark colour of the rocks4 ,several persons of considerable experience have been deceived in this way1 imagining1 for example1 that they were close to the shore when in fact they were more than twenty miles off4 ,the trees of these lands are not more than three inches above ground4 ,many of the icebergs are five miles in extent1 and some are to be seen running along the shore measuring as much as thirteen miles4 ,dr4 ,scoresby has seen a cliff of ice supported on those floating masses #djb feet in height4 ,there is no place in the world where animal life is to be found in greater profusion than in ,greenland1 ,spitzbergen1 ,baffin's ,bay1 and other portions of the ,arctic regions4 ,this is to be accounted for by the abundance and richness of the food supplied by the sea4 ,the number of birds is especially remarkable4 ,on one occasion1 no less than a million of little hawks came in sight of ,dr4 ,scoresby's ship within a single hour4 ,the various phenomena of the ,greenland sea are very interesting4 ,the different colours of the sea-water--olive or bottle-green1 reddish-brown1 and mustard--have1 by the aid of the microscope1 been found to be owing to animalcul of these various colours3 in a single drop of mustard-coloured water have been counted #bf1dej animals4 ,another remarkable characteristic of the ,greenland sea-water is its warm temperature--one1 two1 and three degrees above the freezing-point even in the cold season4 ,this ,dr4 ,scoresby accounts for by supposing the flow in that direction of warm currents from the south4 ,the polar fields of ice are to be found from eight or nine to thirty or forty feet in thickness4 ,by fastening a hook twelve or twenty inches in these masses of ice1 a ship could ride out in safety the heaviest gales4 ,,iceberg ,,of ,,the ,,polar ,,seas4 ,the ice of this berg1 although opaque and vascular1 is true glacier ice1 having the fracture1 lustre1 and other external characters of a nearly homogeneous growth4 ,the iceberg is true ice1 and is always dreaded by ships4 ,indeed1 though modified by climate1 and especially by the alternation of day and night1 the polar glacier must be regarded as strictly atmospheric in its increments1 and not essentially differing from the glacier of the ,alps4 ,the general appearance of a berg may be compared to frosted silver2 but when its fractures are very extensive1 the exposed faces have a very brilliant lustre4 ,nothing can be more exquisite than a fresh1 cleanly fractured berg surface3 it reminds one of the recent cleavage of sulphate of strontian--a resemblance more striking from the slightly lazulitic tinge of each4--,u4 ,s4 ,grinnel ,expedition in ,search of ,sir ,j4 ,franklin4 ,,immensity ,,of ,,polar ,,ice4 ,the quantity of solid matter that is drifted out of the ,polar ,seas through one opening--,davis's ,straits--alone1 and during a part of the year only1 covers to the depth of seven feet an area of #cjj1jjj square miles1 and weighs not less than #ah1jjj1jjj1jjj tons4 ,the quantity of water required to float and drive out this solid matter is probably many times greater than this4 ,a quantity of water equal in weight to these two masses has to go in4 ,the basin to receive these inflowing waters1 i4 e4 the unexplored basin about the ,north ,pole1 includes an area of #a1ejj1jjj square miles2 and as the outflowing ice and water are at the surface1 the return current must be submarine4 ,these two currents1 therefore1 it may be perceived1 keep in motion between the temperate and polar regions of the earth a volume of water1 in comparison with which the mighty ,mississippi in its greatest floods sinks down to a mere rill4--,maury4 ,,open ,,sea ,,at ,,the ,,pole4 ,the following fact is striking3 ,in #affb-c1 ,mr4 ,oldenburg1 ,secretary to the ,royal ,society1 was ordered to register a paper entitled 8,several ,inquiries concerning ,greenland1 answered by ,mr4 ,gray1 who had visited those parts40 ,the nineteenth query was1 8,how near any one hath been known to approach the ,pole4 ,answer4 ,i once met upon the coast of ,greenland a ,hollander1 that swore he had been but half a degree from the ,pole1 showing me his journal1 which was also attested by his mate2 where they had seen no ice or land1 but all water40 ,boyle mentions a similar account1 which he received from an old ,greenland master1 on ,april #e1 #agfe4 ,,river-,,water ,,on ,,the ,,ocean4 ,captain ,sabine found discoloured water1 supposed to be that of the ,amazon1 #cjj miles distant in the ocean from the embouchure of that river4 ,it was about #abf feet deep4 ,its specific gravity was #ajbjd1 and the specific gravity of the sea-water #ajbfb4 ,this appears to be the greatest distance from land at which river-water has been detected on the surface of the ocean4 ,it was estimated to be moving at the rate of three miles an hour1 and had been turned aside by an ocean-current4 8,it is not a little curious to reflect10 says ,sir ,henry de la ,beche1 8that the agitation and resistance of its particles should be sufficient to keep finely comminuted solid matter mechanically suspended1 so that it would not be disposed freely to part with it except at its junction with the sea-water over which it flows1 and where1 from friction1 it is sufficiently retarded40 ,,the ,,thames ,,and ,,its ,,salt-,,water ,,bed4 ,the ,thames below ,woolwich1 in place of flowing upon a solid bottom1 really flows upon the liquid bottom formed by the water of the sea4 ,at the flow of the tide1 the fresh water is raised1 as it were1 in a single mass by the salt water which flows in1 and which ascends the bed of the river1 while the fresh water continues to flow towards the sea4--,mr4 ,stevenson1 in ,jameson's ,journal4 ,,fresh ,,springs ,,in ,,the ,,middle ,,of ,,the ,,ocean4 ,on the southern coast of the island of ,cuba1 at a few miles from land1 ,springs of ,fresh ,water gush from the bed of the ,ocean1 probably under the influence of hydrostatic pressure1 and rise through the midst of the salt water4 ,they issue forth with such force that boats are cautious in approaching this locality1 which has an ill repute on account of the high cross sea thus caused4 ,trading vessels sometimes visit these springs to take in a supply of fresh water1 which is thus obtained in the open sea4 ,the greater the depth from which the water is taken1 the fresher it is found to be4 8,,the ,,black ,,waters40 ,in the upper portion of the basin of the ,orinoco and its tributaries1 ,nature has several times repeated the enigmatical phenomenon of the so-called 8,black ,waters40 ,the ,atabapo1 whose banks are adorned with ,carolinias and arborescent ,melastomas1 is a river of a coffee-brown colour4 ,in the shade of the palm-groves this colour seems about to pass into ink-black4 ,when placed in transparent vessels1 the water appears of a golden yellow4 ,the image of the ,southern ,constellation is reflected with wonderful clearness in these black streams4 ,when their waters flow gently1 they afford to the observer1 when taking astronomical observations with reflecting instruments1 a most excellent artificial horizon4 ,these waters probably owe their peculiar colour to a solution of carburetted hydrogen1 to the luxuriance of the tropical vegetation1 and to the quantity of plants and herbs on the ground over which they flow4--,humboldt's ,aspects of ,nature1 vol4 i4 ,,great ,,cataract ,,in ,,india4 ,where the river ,shirhawti1 between ,bombay and ,cape ,comorin1 falls into the ,gulf of ,arabia1 it is about one-fourth of a mile in width1 and in the rainy season some thirty feet in depth4 ,this immense body of water rushes down a rocky slope #cjj feet1 at an angle of #de1 at the bottom of which it makes a perpendicular plunge of #hej feet into a black and dismal abyss1 with a noise like the loudest thunder4 ,the whole descent is therefore #aaej feet1 or several times that of ,niagara2 but the volume of water in the latter is somewhat larger than in the former4 ,,cause ,,of ,,waves4 ,the friction of the wind combines with the tide in agitating the surface of the ocean1 and1 according to the theory of undulations1 each produces its effect independently of the other4 ,wind1 however1 not only raises waves1 but causes a transfer of superficial water also4 ,attraction between the particles of air and water1 as well as the pressure of the atmosphere1 brings its lower stratum into adhesive contact with the surface of the sea4 ,if the motion of the wind be parallel to the surface1 there will still be friction1 but the water will be smooth as a mirror2 but if it be inclined1 in however small a degree1 a ripple will appear4 ,the friction raises a minute wave1 whose elevation protects the water beyond it from the wind1 which consequently impinges on the surface at a small angle3 thus each impulse1 combining with the other1 produces an undulation which continually advances4--,mrs4 ,somerville's ,physical ,geography4 ,,rate ,,at ,,which ,,waves ,,travel4 ,professor ,bache states1 as one of the effects of an earthquake at ,simoda1 on the island of ,niphon1 in ,japan1 that the harbour was first emptied of water1 and then came in an enormous wave1 which again receded and left the harbour dry4 ,this occurred several times4 ,the ,united-,states self-acting tide-gauge at ,san ,francisco1 which records the rise of the tide upon cylinders turned by clocks1 showed that at ,san ,francisco1 #dhjj miles from the scene of the earthquake1 the first wave arrived twelve hours and sixteen minutes after it had receded from the harbour of ,simoda4 ,it had travelled across the broad bosom of the ,pacific ,ocean at the rate of six miles and a half a minute1 and arrived on the shores of ,california3 the first wave being seven-tenths of a foot in height1 and lasting for about half an hour1 followed by seven lesser waves1 at intervals of half an hour each4 ,the velocity with which a wave travels depends on the depth of the ocean4 ,the latest calculations for the ,pacific ,ocean give a depth of from #ad1jjj to #ah1jjj fathoms4 ,it is remarkable how the estimates of the ocean's depth have grown less4 ,laplace assumed it at ten miles1 ,whewell at #ce1 while the above estimate brings it down to two miles4 ,mr4 ,findlay states1 that the dynamic force exerted by ,sea-,waves is greatest at the crest of the wave before it breaks2 and its power in raising itself is measured by various facts4 ,at ,wasburg1 in ,norway1 in #ahbj1 it rose #djj feet2 and on the coast of ,cornwall1 in #ahdc1 #cjj feet4 ,the author shows that waves have sometimes raised a column of water equivalent to a pressure of from three to five tons the square foot4 ,he also proves that the velocity of the waves depends on their length1 and that waves of from #cjj to #djj feet in length from crest to crest travel from twenty to twenty-seven and a half miles an hour4 ,waves travel great distances1 and are often raised by distant hurricanes1 having been felt simultaneously at ,st4 ,helena and ,ascension1 though #fjj miles apart2 and it is probable that ground-swells often originate at the ,cape of ,good ,hope1 #cjjj miles distant4 ,dr4 ,scoresby found the travelling rate of the ,atlantic waves to be #cbfg ,english statute miles per hour4 ,in the winter of #ahef1 a heavy ground-swell1 brought on by five hours' gale1 scoured away in fourteen hours #c1ijj1jjj tons of pebbles from the coast near ,dover2 but in three days1 without any shift of wind1 upwards of #c1jjj1jjj tons were thrown back again4 ,these figures are to a certain extent conjectural2 but the quantities have been derived from careful measurement of the profile of the beach4 ,,ocean-,,highways3 ,,how ,,sea-,,routes ,,have ,,been ,,shortened4 ,when one looks seaward from the shore1 and sees a ship disappear in the horizon as she gains an offing on a voyage to ,india1 or the ,antipodes perhaps1 the common idea is that she is bound over a trackless waste2 and the chances of another ship sailing with the same destination the next day1 or the next week1 coming up and speaking with her on the 8pathless ocean10 would to most minds seem slender indeed4 ,yet the truth is1 the winds and the currents are now becoming so well understood1 that the navigator1 like the backwoodsman in the wilderness1 is enabled literally to 8blaze his way0 across the ocean2 not1 indeed1 upon trees1 as in the wilderness1 but upon the wings of the wind4 ,the results of scientific inquiry have so taught him how to use these invisible couriers1 that they1 with the calm belts of the air1 serve as sign-boards to indicate to him the turnings and forks and crossings by the way4 ,let a ship sail from ,new ,york to ,california1 and the next week let a faster one follow2 they will cross each other's path many times1 and are almost sure to see each other by the way1 as in the voyage of two fine clipper-ships from ,new ,york to ,california4 ,on the ninth day after the ,archer had sailed1 the ,flying ,cloud put to sea4 ,both ships were running against time1 but without reference to each other4 ,the ,archer1 with wind and current charts in hand1 went blazing her way across the calms of ,cancer1 and along the new route down through the north-east trades to the equator2 the ,cloud followed1 crossing the equator upon the trail of ,thomas of the ,archer4 ,off ,cape ,horn she came up with him1 spoke him1 and handed him the latest ,new ,york dates4 ,the ,flying ,cloud finally ranged ahead1 made her adieus1 and disappeared among the clouds that lowered upon the western horizon1 being destined to reach her port a week or more in advance of her ,cape ,horn consort4 ,though sighting no land from the time of their separation until they gained the offing of ,san ,francisco1--some six or eight thousand miles off1--the tracks of the two vessels were so nearly the same1 that being projected upon the chart1 they appear almost as one4 ,this is the great course of the ocean3 it is #ae1jjj miles in length4 ,some of the most glorious trials of speed and of prowess that the world ever witnessed among ships that 8walk the waters0 have taken place over it4 ,here the modern clipper-ship--the noblest work that has ever come from the hands of man--has been sent1 guided by the lights of science1 to contend with the elements1 to outstrip steam1 and astonish the world4--,maury4 ,,error ,,upon ,,error4 ,the great inducement to ,mr4 ,babbage1 some years since1 to attempt the construction of a machine by which astronomical tables could be calculated and even printed by mechanical means1 and with entire accuracy1 was the errors in the requisite tables4 ,nineteen such errors1 in point of fact1 were discovered in an edition of ,taylor's ,logarithms printed in #agif2 some of which might have led to the most dangerous results in calculating a ship's place4 ,these nineteen errors 7of which one only was an error of the press7 were pointed out in the ,nautical ,almanac for #ahcb4 ,in one of these errata1 the seat of the error was stated to be in cosine of #ad #ah #c4 ,subsequent examination showed that there was an error of one second in this correction1 and accordingly1 in the ,nautical ,almanac of the next year a new correction was necessary4 ,but in making the new correction of one second1 a new error was committed of ten degrees1 making it still necessary1 in some future edition of the ,nautical ,almanac1 to insert an erratum in an erratum of the errata in ,taylor's ,logarithms4--,edinburgh ,review1 vol4 #ei4 ,phenomena of ,heat4 ,,the ,,length ,,of ,,the ,,day ,,and ,,the ,,heat ,,of ,,the ,,earth4 ,as we may judge of the uniformity of temperature from the unaltered time of vibration of a pendulum1 so we may also learn from the unaltered rotatory velocity of the earth the amount of stability in the mean temperature of our globe4 ,this is the result of one of the most brilliant applications of the knowledge we had long possessed of the movement of the heavens to the thermic condition of our planet4 ,the rotatory velocity of the earth depends on its volume2 and since1 by the gradual cooling of the mass by radiation1 the axis of rotation would become shorter1 the rotatory velocity would necessarily increase1 and the length of the day diminish with a decrease of the temperature4 ,from the comparison of the secular inequalities in the motions of the moon with the eclipses observed in former ages1 it follows that1 since the time of ,hipparchus1--that is1 for full #bjjj years1--the length of the day has certainly not diminished by the hundredth part of a second4 ,the decrease of the mean heat of the globe during a period of #bjjj years has not therefore1 taking the extremest limits1 diminished as much as #a_/cjfth of a degree of ,fahrenheit4#db--;,humboldt's ,cosmos1 vol4 i4 ,,nice ,,measurement ,,of ,,heat4 ,a delicate thermometer1 placed on the ground1 will be affected by the passage of a single cloud across a clear sky2 and if a succession of clouds pass over1 with intervals of clear sky between them1 such an instrument has been observed to fluctuate accordingly1 rising with each passing mass of vapour1 and falling again when the radiation becomes unrestrained4 ,,expenditure ,,of ,,heat ,,by ,,the ,,sun4 ,sir ,john ,herschel estimates the total ,expenditure of ,heat by the ,sun in a given time1 by supposing a cylinder of ice #de miles in diameter to be continually darted into the sun with the velocity of light1 and that the water produced by its fusion were continually carried off3 the heat now given off constantly by radiation would then be wholly expended in its liquefaction1 on the one hand1 so as to leave no radiant surplus2 while1 on the other1 the actual temperature at its surface would undergo no diminution4 ,the great mystery1 however1 is to conceive how so enormous a conflagration 7if such it be7 can be kept up4 ,every discovery in chemical science here leaves us completely at a loss1 or rather seems to remove further the prospect of probable explanation4 ,if conjecture might be hazarded1 we should look rather to the known possibility of an indefinite generation of heat by friction1 or to its excitement by the electric discharge1 than to any combustion of ponderable fuel1 whether solid or gaseous1 for the origin of the solar radiation4--,outlines4#dc ,,distinctions ,,of ,,heat4 ,among the curious laws of modern science are those which regulate the transmission of radiant heat through transparent bodies4 ,the heat of our fires is intercepted and detained by screens of glass1 and1 being so detained1 warms them2 while solar heat passes freely through and produces no such effect4 8,the more recent researches of ,delaroche10 says ,sir ,john ,herschel1 8however1 have shown that this detention is complete only when the temperature of the source of heat is low2 but that as the temperature gets higher a portion of the heat radiated acquires a power of penetrating glass1 and that the quantity which does so bears continually a larger and larger proportion to the whole1 as the heat of the radiant body is more intense4 ,this discovery is very important1 as it establishes a community of nature between solar and terrestrial heat2 while at the same time it leads us to regard the actual temperature of the sun as far exceeding that of any earthly flame40 ,,latent ,,heat4 ,this extraordinary principle exists in all bodies1 and may be pressed out of them4 ,the blacksmith hammers a nail until it becomes red hot1 and from it he lights the match with which he kindles the fire of his forge4 ,the iron has by this process become more dense1 and percussion will not again produce incandescence until the bar has been exposed in fire to a red heat1 when it absorbs heat1 the particles are restored to their former state1 and we can again by hammering develop both heat and light4--,r4 ,hunt1 ,f4,r4,s4 ,,heat ,,and ,,evaporation4 ,in a communication made to the ,french ,academy1 ,m4 ,daubre calculates that the ,evaporation of the ,water on the surface of the globe employs a quantity of heat about equal to one-third of what is received from the sun2 or1 in other words1 equal to the melting of a bed of ice nearly thirty-five feet in thickness if spread over the globe4 ,,heat ,,and ,,mechanical ,,power4 ,it has been found that ,heat and ,mechanical ,power are mutually convertible2 and that the relation between them is definite1 #ggb foot-pounds of motive power being equivalent to a unit of heat1 that is1 to the amount of heat requisite to raise a pound of water through one degree of ,fahrenheit4 ,,heat ,,of ,,mines4 ,one cause of the great ,heat of many of our deep ,mines1 which appears to have been entirely lost sight of1 is the chemical action going on upon large masses of pyritic matter in their vicinity4 ,the heat1 which is so oppressive in the ,united ,mines in ,cornwall that the miners work nearly naked1 and bathe in water at #hj to cool themselves1 is without doubt due to the decomposition of immense quantities of the sulphurets of iron and copper known to be in this condition at a short distance from these mineral works4--,r4 ,hunt1 ,f4,r4,s4 ,,vibration ,,of ,,heated ,,metals4 ,mr4 ,arthur ,trevelyan discovered accidentally that a bar of iron1 when heated and placed with one end on a solid block of lead1 in cooling vibrates considerably1 and produces sounds similar to those of an olian harp4 ,the same effect is produced by bars of copper1 zinc1 brass1 and bell-metal1 when heated and placed on blocks of lead1 tin1 or pewter4 ,the bars were four inches long1 one inch and a half wide1 and three-eighths of an inch thick4 ,the conditions essential to these experiments are1 ,that two different metals must be employed--the one soft and possessed of moderate conducting powers1 viz4 lead or tin1 the other hard2 and it matters not whether soft metal be employed for the bar or block1 provided the soft metal be cold and the hard metal heated4 ,that the surface of the block shall be uneven1 for when rendered quite smooth the vibration does not take place2 but the bar cannot be too smooth4 ,that no matter be interposed1 else it will prevent vibration1 with the exception of a burnish of gold leaf1 the thickness of which cannot amount to the two-hundred-thousandth part of an inch4--,transactions of the ,royal ,society of ,edinburgh4 ,,expansion ,,of ,,spirits4 ,spirits expand and become lighter by means of heat in a greater proportion than water1 wherefore they are heaviest in winter4 ,a cubic inch of brandy has been found by many experiments to weigh ten grains more in winter than in summer1 the difference being between four drams thirty-two grains and four drams forty-two grains4 ,liquor-merchants take advantage of this circumstance1 and make their purchases in winter rather than in summer1 because they get in reality rather a larger quantity in the same bulk1 buying by measure4--,notes in ,various ,sciences4 ,,heat ,,passing ,,through ,,glass4 ,the following experiment is by ,mr4 ,fox ,talbot3 ,heat a poker bright-red hot1 and having opened a window1 apply the poker quickly very near to the outside of a pane1 and the hand to the inside2 a strong heat will be felt at the instant1 which will cease as soon as the poker is withdrawn1 and may be again renewed and made to cease as quickly as before4 ,now it is well known1 that if a piece of glass is so much warmed as to convey the impression of heat to the hand1 it will retain some part of that heat for a minute or more2 but in this experiment the heat will vanish in a moment3 it will not1 therefore1 be the heated pane of glass that we shall feel1 but heat which has come through the glass in a free or radiant state4 ,,heat ,,from ,,gas-,,lighting4 ,in the winter of #ahce1 ,mr4 ,w4 ,h4 ,white ascertained the temperature in the ,city to be #c higher than three miles south of ,london ,bridge2 and after the gas had been lighted in the ,city four or five hours the temperature increased full #c1 thus making #f difference in the three miles4 ,,heat ,,by ,,friction4 ,friction as a source of ,heat is well known3 we rub our hands to warm them1 and we grease the axles of carriage-wheels to prevent their setting fire to the wood4 ,count ,rumford has established the extraordinary fact1 that an unlimited supply of heat may be derived from friction by the same materials3 he made great quantities of water boil by causing a blunt borer to rub against a mass of metal immersed in the water4 ,savages light their fires by rubbing two pieces of wood3 the modus operandi1 as practised by the ,kaffirs of ,south ,africa1 is thus described by ,captain ,drayton3 ,two dry sticks1 one being of hard and the other of soft wood1 were the materials used4 ,the soft stick was laid on the ground1 and held firmly down by one ,kaffir1 whilst another employed himself in scooping out a little hole in the centre of it with the point of his assagy3 into this little hollow the end of the hard wood was placed1 and held vertically4 ,these two men sat face to face1 one taking the vertical stick between the palms of his hands1 and making it twist about very quickly1 while the other ,kaffir held the lower stick firmly in its place2 the friction caused by the end of one piece of wood revolving upon the other soon made the two pieces smoke4 ,when the ,kaffir who twisted became tired1 the respective duties were exchanged4 ,these operations having continued about a couple of minutes1 sparks began to appear1 and when they became numerous1 were gathered into some dry grass1 which was then swung round at arm's length until a blaze was established2 and a roaring fire was gladdening the hearts of the ,kaffirs with the anticipation of a glorious feast in about ten minutes from the time that the operation was first commenced4 ,,heat ,,by ,,friction ,,from ,,ice4 ,when ,sir ,humphry ,davy was studying medicine at ,penzance1 one of his constant associates was ,mr4 ,tom ,harvey1 a druggist in the above town4 ,they constantly experimented together2 and one severe winter's day1 after a discussion on the nature of heat1 the young philosophers were induced to go to ,larigan river1 where ,davy succeeded in developing heat by rubbing two pieces of ice together so as to melt each other2#dd an experiment which he repeated with much clat many years after1 in the zenith of his celebrity1 at the ,royal ,institution4 ,the pieces of ice for this experiment are fastened to the ends of two sticks1 and rubbed together in air below the temperature of #cb3 this ,davy readily accomplished on the day of severe cold at the ,larigan river2 but when the experiment was repeated at the ,royal ,institution1 it was in the vacuum of an air-pump1 when the temperature of the apparatus and of the surrounding air was below #cb4 ,it was remarked1 that when the surface of the rubbing pieces was rough1 only half as much heat was evolved as when it was smooth4 ,when the pressure of the rubbing piece was increased four times1 the proportion of heat evolved was increased sevenfold4 ,,warming ,,with ,,ice4 ,in common language1 any thing is understood to be cooled or warmed when the temperature thereof is made higher or lower1 whatever may have been the temperature when the change was commenced4 ,thus it is said that melted iron is cooled down to a sub-red heat1 or mercury is cooled from the freezing point to zero1 or far below4 ,by the same rule1 solid mercury1 say #ej below zero1 may1 in any climate or temperature of the atmosphere1 be immediately warmed and melted by being imbedded in a cake of ice4--,scientific ,american4 ,,repulsion ,,by ,,heat4 ,if water is poured upon an iron sieve1 the wires of which are made red-hot1 it will not run through2 but on cooling1 it will pass through rapidly4 ,m4 ,boutigny1 pursuing this curious inquiry1 has proved that the moisture upon the skin is sufficient to protect it from disorganisation if the arm is plunged into baths of melted metal4 ,the resistance of the surfaces is so great that little elevation of temperature is experienced4 ,professor ,plcker has stated1 that by washing the arm with ether previously to plunging it into melted metal1 the sensation produced while in the molten mass is that of freezing coldness4--,r4 ,hunt1 ,f4,r4,s4 ,,protection ,,from ,,intense ,,heat4 ,the singular power which the body possesses of resisting great heats1 and of breathing air of high temperatures1 has at various times excited popular wonder4 ,in the last century some curious experiments were made on this subject4 ,sir ,joseph ,banks1 ,dr4 ,solander1 and ,sir ,charles ,blagden1 entered a room in which the air had a temperature of #aih ,fahr41 and remained ten minutes4 ,subsequently they entered the room separately1 when ,dr4 ,solander found the heat #baj1 and ,sir ,joseph #baa1 whilst their bodies preserved their natural degree of heat4 ,whenever they breathed upon a thermometer1 it sank several degrees2 every inspiration gave coolness to their nostrils1 and their breath cooled their fingers when it reached them4 ,sir ,charles ,blagden entered an apartment when the heat was #a or #b above #bfj1 and remained eight minutes1 mostly on the coolest spot1 where the heat was above #bdj4 ,though very hot1 ,sir ,charles felt no pain3 during seven minutes his breathing was good2 but he then felt an oppression in his lungs1 and his pulse was #add1 double its ordinary quickness4 ,to prove the heat of the room1 eggs and a beefsteak were placed upon a tin frame near the thermometer1 when in twenty minutes the eggs were roasted hard1 and in forty-seven minutes the steak was dressed dry2 and when the air was put in motion by a pair of bellows upon another steak1 part of it was well done in thirteen minutes4 ,it is remarkable1 that in these experiments the same person who experienced no inconvenience from air heated to #baa1 could just bear rectified spirits of wine at #acj1 cooling oil at #abi1 cooling water at #abc1 and cooling quicksilver at #aag4 ,sir ,francis ,chantrey1 the sculptor1 however1 exposed himself to a temperature still higher than any yet mentioned1 as described by ,sir ,david ,brewster3 ,the furnace which he employs for drying his moulds is about fourteen feet long1 twelve feet high1 and twelve feet broad4 ,when it is raised to its highest temperature1 with the doors closed1 the thermometer stands at #cej1 and the iron floor is red-hot4 ,the workmen often enter it at a temperature of #cdj1 walking over the iron floor with wooden clogs1 which are of course charred on the surface4 ,on one occasion1 ,mr4 ,chantrey1 accompanied by five or six of his friends1 entered the furnace2 and after remaining two minutes they brought out a thermometer which stood at #cbj4 ,some of the party experienced sharp pains in the tips of their ears and in the septum of the nose1 while others felt a pain in their eyes4--,natural ,magic1 #ahcc4 ,in some cases the clothing worn by the experimenters conducts away the heat4 ,thus1 in #ahbh1 a ,spaniard entered a heated oven1 at the ,new ,tivoli1 near ,paris2 he sang a song while a fowl was roasted by his side1 he then ate the fowl and drank a bottle of wine1 and on coming out his pulse beat #agf1 and the thermometer was at #aaj ,reaumur4 ,he then stretched himself upon a plank in the oven surrounded by lighted candles1 when the mouth of the oven was closed2 he remained there five minutes1 and on being taken out1 all the candles were extinguished and melted1 and the ,spaniard's pulse beat #bjj4 ,now much of the surprise ceases when it is added that he wore wide woollen pantaloons1 a loose mantle of wool1 and a great quilted cap2 the several materials of this clothing being bad conductors of heat4 ,in #ahbi ,m4 ,chabert1 the 8,fire-,king10 exhibited similar feats at the ,argyll ,rooms in ,regent ,street4 ,he first swallowed forty grains of phosphorus1 then two spoonfuls of oil at #ccj1 and next held his head over the fumes of sulphuric acid4 ,he had previously provided himself with an antidote for the poison of the phosphorus4 ,dressed in a loose woollen coat1 he then entered a heated oven1 and in five minutes cooked two steaks2 he then came out of the oven1 when the thermometer stood at #chj4 ,upon another occasion1 at ,white ,conduit ,house1 some of his feats were detected4 ,the scientific secret is as follows3 ,muscular tissue is an extremely bad conductor2 and to this in a great measure the constancy of the temperature of the human body in various zones is to be attributed4 ,to this fact also ,sir ,charles ,blagden and ,chantrey owed their safety in exposing their bodies to a high temperature2 from the almost impervious character of the tissues of the body1 the irritation produced was confined to the surface4 ,magnetism and ,electricity4 ,,magnetic ,,hypotheses4 ,as an instance of the obstacles which erroneous hypotheses throw in the way of scientific discovery1 ,professor ,faraday adduces the unsuccessful attempts that had been made in ,england to educe ,magnetism from ,electricity until ,oersted showed the simple way4 ,faraday relates1 that when he came to the ,royal ,institution as an assistant in the laboratory1 he saw ,davy1 ,wollaston1 and ,young trying1 by every way that suggested itself to them1 to produce magnetic effects from an electric current2 but having their minds diverted from the true course by their existing hypotheses1 it did not occur to them to try the effect of holding a wire through which an electric current was passing over a suspended magnetic needle4 ,had they done so1 as ,oersted afterwards did1 the immediate deflection of the needle would have proved the magnetic property of an electric current4 ,faraday has shown that the magnetism of a steel bar is caused by the accumulated action of all the particles of which it is composed3 this he proves by first magnetising a small steel bar1 and then breaking it successively into smaller and smaller pieces1 each one of which possesses a separate pole2 and the same operation may be continued until the particles become so small as not to be distinguishable without a microscope4 ,we quote the above from a late ,number of the ,philosophical ,magazine1 wherein also we find the following noble tribute to the genius and public and private worth of ,faraday3 ,the public never can know and appreciate the national value of such a man as ,faraday4 ,he does not work to please the public1 nor to win its guineas2 and the said public1 if asked its opinion as to the practical value of his researches1 can see no possible practical issue there4 ,the public does not know that we need prophets more than mechanics in science1--inspired men1 who1 by patient self-denial and the exercise of the high intellectual gifts of the ,creator1 bring us intelligence of ,his doings in ,nature4 ,to them their pursuits are good in themselves4 ,their chief reward is the delight of being admitted into communion with ,nature1 the pleasure of tracing out and proclaiming her laws1 wholly forgetful whether those laws will ever augment our banker's account or improve our knowledge of cookery4 ,such men1 though not honoured by the title of 8practical10 are they which make practical men possible4 ,they bring us the tamed forces of ,nature1 and leave it to others to contrive the machinery to which they may be yoked4 ,if we are rightly informed1 it was ,faradaic electricity which shot the glad tidings of the fall of ,sebastopol from ,balaklava to ,varna4 ,had this man converted his talent to commercial purposes1 as so many do1 we should not like to set a limit to his professional income4 ,the quality of his services cannot be expressed by pounds2 but that brave body1 which for forty years has been the instrument of that great soul1 is a fit object for a nation's care1 as the achievements of the man are1 or will one day be1 the object of a nation's pride and gratitude4 ,,the ,,chinese ,,and ,,the ,,magnetic ,,needle4 ,more than a thousand years before our era1 a people living in the extremest eastern portions of ,asia had magnetic carriages1 on which the movable arm of the figure of a man continually pointed to the south1 as a guide by which to find the way across the boundless grass-plains of ,tartary2 nay1 even in the third century of our era1 therefore at least #gjj years before the use of the mariner's compass in ,european seas1 ,chinese vessels navigated the ,indian ,ocean under the direction of ,magnetic ,needles pointing to the south4 ,now the ,western nations1 the ,greeks and the ,romans1 knew that magnetism could be communicated to iron1 and that that metal would retain it for a length of time4 ,the great discovery of the terrestrial directive force depended1 therefore1 alone on this--that no one in the ,west had happened to observe an elongated fragment of magnetic iron-stone1 or a magnetic iron rod1 floating by the aid of a piece of wood in water1 or suspended in the air by a thread1 in such a position as to admit of free motion4--,humboldt's ,cosmos1 vol4 i4 ,,kircher',s 8,,magnetism40 ,more than two centuries since1 ,athanasius ,kircher published his strange book on ,magnetism1 in which he anticipated the supposed virtue of magnetic traction in the curative art1 and advocated the magnetism of the sun and moon1 of the divining-rod1 and showed his firm belief in animal magnetism4 8,in speaking of the vegetable world10 says ,mr4 ,hunt1 8and the remarkable processes by which the leaf1 the flower1 and the fruit are produced1 this sage brings forward the fact of the diamagnetic 7repelled by the magnet7 character of the plant which was in #aheb rediscovered2 and he refers the motions of the sunflower1 the closing of the convolvulus1 and the directions of the spiral formed by the twining plants1 to this particular influence40#de ,nor were ,kircher's anticipations random guesses1 but the result of deductions from experiment and observation2 and the universality of magnetism is now almost recognised by philosophers4 ,,minute ,,measurement ,,of ,,time4 ,by observing the magnet in the highly-convenient and delicate manner introduced by ,gauss and ,weber1 which consists in attaching a mirror to the magnet and determining the constant factor necessary to convert the differences of oscillation into differences of time1 ,professor ,helmholtz has been able1 with comparatively simple apparatus1 to make accurate determinations up to the #a_/ajjjjth part of a second4 ,,power ,,of ,a ,,magnet4 ,the ,power of a ,magnet is estimated by the weight its poles are able to carry4 ,each pole singly is able to support a smaller weight than when they both act together by means of a keeper1 for which reason horse-shoe magnets are superior to bar magnets of similar dimensions and character4 ,it has further been ascertained that small magnets have a much greater relative force than large ones4 ,when magnetism is excited in a piece of steel in the ordinary mode1 by friction with a magnet1 it would seem that its inductive power is able to overcome the coercive power of the steel only to a certain depth below the surface2 hence we see why small pieces of steel1 especially if not very hard1 are able to carry greater relative weights than large magnets4 ,sir ,isaac ,newton wore in a ring a magnet weighing only #c grains1 which would lift #gfj grains1 i4 e4 #bej times its own weight4 ,bar-magnets are seldom found capable of carrying more than their own weight2 but horse-shoe magnets of similar steel will bear considerably more4 ,small ones of from half an ounce to #a ounce in weight will carry from #cj to #dj times their own weight2 while such as weigh from #a to #b lbs4 will rarely carry more than from #aj to #ae times their weight4 ,the writer found a #a lb4 horse-shoe magnet that he impregnated by means of the feeder able to bear #bf times its own weight2 and ,fischer1 having adopted the like mode of magnetising the steel1 which he also carefully heated1 has made magnets of from #a to #c lbs4 weight that would carry #cj times1 and others of from #d to #f lbs4 weight that would carry #bj times1 their own weight4--,professor ,peschel4 ,,how ,,artificial ,,magnets ,,are ,,made4 ,in #agej1 ,mr4 ,canton1 ,f4,r4,s41 8one of the most successful experimenters in the golden age of electricity10#df communicated to the ,royal ,society his 8,method of making ,artificial ,magnets without the use of natural ones40 ,this he effected by using a poker and tongs to communicate magnetism to steel bars4 ,he derived his first hint from observing them one evening1 as he was sitting by the fire1 to be nearly in the same direction with the earth as the dipping needle4 ,he thence concluded that they must1 from their position and the frequent blows they receive1 have acquired some magnetic virtue1 which on trial he found to be the case2 and therefore he employed them to impregnate his bars1 instead of having recourse to the natural loadstone4 ,upon the reading of the above paper1 ,canton exhibited to the ,royal ,society his experiments1 for which the ,copley ,medal was awarded to him in #agea4 ,canton had1 as early as #agdg1 turned his attention1 with complete success1 to the production of powerful artificial magnets1 principally in consequence of the expense of procuring those made by ,dr4 ,gowan ,knight1 who kept his process secret4 ,canton for several years abstained from communicating his method even to his most intimate friends1 lest it might be injurious to ,dr4 ,knight1 who procured considerable pecuniary advantages by touching needles for the mariner's compass4 ,at length ,dr4 ,knight's method of making artificial magnets was communicated to the world by ,mr4 ,wilson1 in a paper published in the #fith volume of the ,philosophical ,transactions4 ,he provided himself with a large quantity of clean iron-filings1 which he put into a capacious tub about half full of clear water2 he then agitated the tub to and fro for several hours1 until the filings were reduced by attrition to an almost impalpable powder4 ,this powder was then dried1 and formed into paste by admixture with linseed-oil4 ,the paste was then moulded into convenient shapes1 which were exposed to a moderate heat until they had attained a sufficient degree of hardness4 ,after allowing them to remain for some time in this state1 ,dr4 ,knight gave them their magnetic virtue in any direction he pleased1 by placing them between the extreme ends of his large magazine of artificial magnets for a second or more1 as he saw occasion4 ,by this method the virtue they acquired was such1 that when any one of these pieces was held between two of his best ten-guinea bars1 with its poles purposely inverted1 it immediately of itself turned about to recover its natural direction1 which the force of those very powerful bars was not sufficient to counteract4 ,dr4 ,knight's powerful battery of magnets above mentioned is in the possession of the ,royal ,society1 having been presented by ,dr4 ,john ,fothergill in #aggf4 ,,power ,,of ,,the ,,sun',s ,,rays ,,in ,,increasing ,,the ,,strength ,,of ,,magnets4 ,professor ,barlocci found that an armed natural loadstone1 which would carry #a ,roman pounds1 had its power nearly doubled by twenty-four hours' exposure to the strong light of the sun4 ,m4 ,zantedeschi found that an artificial horse-shoe loadstone1 which carried #ac oz41 carried #c more by three days' exposure1 and at last arrived to #ca oz4 by continuing it in the sun's light4 ,he found that while the strength increased in oxidated magnets1 it diminished in those which were not oxidated1 the diminution becoming insensible when the loadstone was highly polished4 ,he now concentrated the solar rays upon the loadstone by means of a lens2 and he found that1 both in oxidated and polished magnets1 they acquire strength when their north pole is exposed to the sun's rays1 and lose strength when the south pole is exposed4--,sir ,david ,brewster4 ,,colour ,,of ,a ,,body ,,and ,,its ,,magnetic ,,properties4 ,solar rays bleach dead vegetable matter with rapidity1 while in living parts of plants their action is frequently to strengthen the colour4 ,their power is perhaps best seen on the sides of peaches1 apples1 c41 which1 exposed to a midsummer's sun1 become highly coloured4 ,in the open winter of #ahej1 ,mr4 ,adie1 of ,liverpool1 found in a wallflower plant proof of a like effect3 in the dark months there was a slow succession of one or two flowers1 of uniform pale yellow hue2 in ,march streaks of a darker colour appeared on the flowers1 and continued to slowly increase till in ,april they were variegated brown and yellow1 of rich strong colours4 ,on the supposition that these changes are referable to magnetic properties1 may hereafter be explained ,mrs4 ,somerville's experiments on steel needles exposed to the sun's rays under envelopes of silk of various colours2 the magnetisation of steel needles has failed in the coloured rays of the spectrum1 but ,mr4 ,adie considers that under dyed silk the effect will hinge on the chemical change wrought in the silk and its dye by the solar rays4 ,,the ,,onion ,,and ,,magnetism4 ,a popular notion has long been current1 more especially on the shores of the ,mediterranean1 that if a magnetic rod be rubbed with an onion1 or brought in contact with the emanations of the plant1 the directive force will be diminished1 while a compass thus treated will mislead the steersman4 ,it is difficult to conceive what could have given rise to so singular a popular error4#dg--;,humboldt's ,cosmos1 vol4 v4 ,,declination ,,of ,,the ,,needle--,,the ,,earth ,a ,,magnet4 ,the ,inclination or ,dip of the ,needle was first recorded by ,robert ,norman1 in a scarce book published in #aegf entitled ,the ,new ,attractive2 containing a short ,discourse of the ,magnet or ,loadstone1 c4 ,columbus has not only the merit of being the first to discover a line without magnetic variation1 but also of having first excited a taste for the study of terrestrial magnetism in ,europe1 by means of his observations on the progressive increase of western declination in receding from that line4 ,the first chart showing the variation of the compass1#dh or the declination of the needle1 based on the idea of employing curves drawn through points of equal declination1 is due to ,halley1 who is justly entitled the father and founder of terrestrial magnetism4 ,and it is curious to find that in ,no4 #aie of the ,philosophical ,transactions1 in #afhc1 ,halley had previously expressed his belief that he has put it past doubt that the globe of the earth is one great magnet1 having four magnetical poles or points of attraction1 near each pole of the equator two2 and that in those parts of the world which lie near adjacent to any one of those magnetical poles1 the needle is chiefly governed thereby1 the nearest pole being always predominant over the more remote4 8,to ,halley0 7says ,sir ,john ,herschel7 8we owe the first appreciation of the real complexity of the subject of magnetism4 ,it is wonderful indeed1 and a striking proof of the penetration and sagacity of this extraordinary man1 that with his means of information he should have been able to draw such conclusions1 and to take so large and comprehensive a view of the subject as he appears to have done40 ,and1 in our time1 8the earth is a great magnet10 says ,faraday3 8its power1 according to ,gauss1 being equal to that which would be conferred if every cubic yard of it contained six one-pound magnets2 the sum of the force is therefore equal to #h1dfd1jjj1jjj1jjj1jjj1jjj1jjj such magnets40 ,,the ,,aurora ,,borealis4 ,halley1 upon his return from his voyage to verify his theory of the variation of the compass1 in #agjj1 hazarded the conjecture that the ,aurora ,borealis is a magnetic phenomenon4 ,and ,faraday's brilliant discovery of the evolution of light by magnetism has raised ,halley's hypothesis1 enounced in #agad1 to the rank of an experimental certainty4 ,,effect ,,of ,,light ,,on ,,the ,,magnet4 ,in #ahed1 ,sir ,john ,ross stated to the ,british ,association1 in proof of the effect of every description of light on the magnet1 that during his last voyage in the ,felix1 when frozen in about one hundred miles north of the magnetic pole1 he concentrated the rays of the full moon on the magnetic needle1 when he found it was five degrees attracted by it4 ,,magneto-,,electricity4 ,in #ahbj1 the ,copley ,medal was adjudicated to ,m4 ,oersted of ,copenhagen1 8when10 says ,dr4 ,whewell1 8the philosopher announced that the conducting-wire of a voltaic circuit acts upon a magnetic needle2 and thus recalled into activity that endeavour to connect magnetism with electricity which1 though apparently on many accounts so hopeful1 had hitherto been attended with no success4 ,oersted found that the needle has a tendency to place itself at right angles to the wire2 a kind of action altogether different from any which had been suspected40 ,,electro-,,magnets ,,of ,,the ,,horse-,,shoe ,,form were discovered by ,sturgeon in #ahbe4 ,of two ,magnets made by a process devised by ,m4 ,elias1 and manufactured by ,m4 ,logemeur at ,haerlem1 one1 a single horse-shoe magnet weighing about #a lb41 lifts #bh lbs42 the other1 a triple horse-shoe magnet of about #aj lbs4 weight1 is capable of lifting about #aej lbs4 ,similar magnets are made by the same person capable of supporting #e cwt4 ,in the process of making them1 a helix of copper and a galvanic battery are used4 ,the smaller magnet has twice the power expressed by ,haecker's formula for the best artificial steel magnet4 ,subsequently ,henry and ,ten ,eyk1 in ,america1 constructed some electro-magnets on a large scale4 ,one horse-shoe magnet made by them1 weighing #fj lbs41 would support more than #bjjj lbs4 ,in ,september #aheh1 there were constructed for the ,atlantic-telegraph cable at ,valentia two permanent magnets1 from which the electric induction is obtained3 each is composed of #cj horse-shoe magnets1 #b feet long and from #d to #e inches broad2 the induction coils attached to these each contain six miles of wire1 and a shock from them1 if passed through the human body1 would be sufficient to destroy life4 ,,rotation-,,magnetism4 ,the unexpected discovery of ,rotation-,magnetism by ,arago1 in #ahbe1 has shown practically that every kind of matter is susceptible of magnetism2 and the recent investigations of ,faraday on diamagnetic substances have1 under special conditions of meridian or equatorial direction1 and of solid1 fluid1 or gaseous inactive conditions of the bodies1 confirmed this important result4 ,,influence ,,of ,,pendulums ,,on ,,each ,,other4 ,about a century since it became known1 that when two clocks are in action upon the same shelf1 they will disturb each other3 that the pendulum of the one will stop that of the other2 and that the pendulum that was stopped will after a while resume its vibrations1 and in its turn stop that of the other clock4 ,when two clocks are placed near one another in cases very slightly fixed1 or when they stand on the boards of a floor1 they will affect a little each other's pendulum4 ,mr4 ,ellicote observed that two clocks resting against the same rail1 which agreed to a second for several days1 varied one minute thirty-six seconds in twenty-four hours when separated4 ,the slower1 having a longer pendulum1 set the other in motion in #af-a_/c minutes1 and stopped itself in #cf-b_/c minutes4 ,,weight ,,of ,,the ,,earth ,,ascertained ,,by ,,the ,,pendulum4 ,by a series of comparisons with ,pendulums placed at the surface and the interior of the ,earth1 the ,astronomer-,royal has ascertained the variation of gravity in descending to the bottom of a deep mine1 as the ,harton coal-pit1 near ,south ,shields4 ,by calculations from these experiments1 he has found the mean density of the earth to be #feff1 the specific gravity of water being represented by unity4 ,in other words1 it has been ascertained by these experiments that if the earth's mass possessed every where its average density1 it would weigh1 bulk for bulk1 #feff times as much as water4 ,it is curious to note the different values of the earth's mean density which have been obtained by different methods4 ,the ,schehallien experiment indicated a mean density equal to about #d2 the ,cavendish apparatus1 repeated by ,baily and ,reich1 about #e2 and ,professor ,airy's pendulum experiment furnishes a value amounting to about #f4 ,the immediate result of the computations of the ,astronomer-,royal is3 supposing a clock adjusted to go true time at the top of the mine1 it would gain #b seconds per day at the bottom4 ,or it may be stated thus3 that gravity is greater at the bottom of a mine than at the top by #a_/aiaijth part4--,letter to ,james ,mather1 ,esq41 ,south ,shields4 ,see also ,professor ,airy's ,lecture1 #ahed4 ,,origin ,,of ,,terrestrial ,,magnetism4 ,the earliest view of ,terrestrial ,magnetism supposed the existence of a magnet at the earth's centre4 ,as this does not accord with the observations on declination1 inclination1 and intensity1 ,tobias ,meyer gave this fictitious magnet an eccentric position1 placing it one-seventh part of the earth's radius from the centre4 ,hansteen imagined that there were two such magnets1 different in position and intensity4 ,ampre set aside these unsatisfactory hypotheses by the view1 derived from his discovery1 that the earth itself is an electro-magnet1 magnetised by an electric current circulating about it from east to west perpendicularly to the plane of the magnetic meridian1 to which the same currents give direction as well as magnetise the ores of iron3 the currents being thermo-electric currents1 excited by the action of the sun's heat successively on the different parts of the earth's surface as it revolves towards the east4 ,william ,gilbert1#di who wrote an able work on magnetic and electric forces in the year #afjj1 regarded terrestrial magnetism and electricity as two emanations of a single fundamental source pervading all matter1 and he therefore treated of both at once4 ,according to ,gilbert's idea1 the earth itself is a magnet2 whilst he considered that the inflections of the lines of equal declination and inclination depend upon the distribution of mass1 the configuration of continents1 or the form and extent of the deep intervening oceanic basins4 ,till within the last eighty years1 it appears to have been the received opinion that the intensity of terrestrial magnetism was the same at all parts of the earth's surface4 ,in the instructions drawn up by the ,french ,academy for the expedition under ,la ,prouse1 the first intimation is given of a contrary opinion4 ,it is recommended that the time of vibration of a dipping-needle should be observed at stations widely remote1 as a test of the equality or difference of the magnetic intensity2 suggesting also that such observations should particularly be made at those parts of the earth where the dip was greatest and where it was least4 ,the experiments1 whatever their results may have been1 which1 in compliance with this recommendation1 were made in the expedition of ,la ,prouse1 perished in its general catastrophe2 but the instructions survived4 ,in #ahaa1 ,hansteen took up the subject1 and in #ahai published his celebrated work1 clearly demonstrating the fluctuations which this element has undergone during the last two centuries2 confirming in great detail the position of ,halley1 that 8the whole magnetic system is in motion1 that the moving force is very great as extending its effects from pole to pole1 and that its motion is not per saltum1 but a gradual and regular motion40 ,,the ,,north ,,and ,,south ,,magnetic ,,poles4 ,the knowledge of the geographical position of both ,magnetic ,poles is due to the scientific energy of the same navigator1 ,sir ,james ,ross4 ,his observations of the ,northern ,magnetic ,pole were made during the second expedition of his uncle1 ,sir ,john ,ross 7#ahbi-ahcc72 and of the ,southern during the ,antarctic expedition under his own command 7#ahci-ahdc74 ,the ,northern ,magnetic ,pole1 in #gj #e lat41 #if #dc ,w4 long41 is #e of latitude farther from the ordinary pole of the earth than the ,southern ,magnetic ,pole1 #ge #ce lat41 #aed #aj ,e4 long42 whilst it is also situated farther west from ,greenwich than the ,northern ,magnetic ,pole4 ,the latter belongs to the great island of ,boothia ,felix1 which is situated very near the ,american continent1 and is a portion of the district which ,captain ,parry had previously named ,north ,somerset4 ,it is not far distant from the western coast of ,boothia ,felix1 near the promontory of ,adelaide1 which extends into ,king ,william's ,sound and ,victoria ,strait4 ,the ,southern ,magnetic ,pole has been directly reached in the same manner as the ,northern ,pole4 ,on #agth ,february #ahda1 the ,erebus penetrated as far as #gf #ab ,s4 lat41 and #afd ,e4 long4 ,as the inclination was here only #hh #dj1 it was assumed that the ,southern ,magnetic ,pole was about #afj nautical miles distant4 ,many accurate observations of declination1 determining the intersection of the magnetic meridian1 render it very probable that the ,south ,magnetic ,pole is situated in the interior of the great ,antarctic region of ,south ,victoria ,land1 west of the ,prince ,albert mountains1 which approach the ,south ,pole and are connected with the active volcano of ,erebus1 which is #ab1djj feet in height4--,humboldt's ,cosmos1 vol4 v4 ,,magnetic ,,storms4 ,the mysterious course of the magnetic needle is equally affected by time and space1 by the sun's course1 and by changes of place on the earth's surface4 ,between the tropics the hour of the day may be known by the direction of the needle as well as by the oscillations of the barometer4 ,it is affected instantly1 but transiently1 by the northern light4 ,when the uniform horary motion of the needle is disturbed by a magnetic storm1 the perturbation manifests itself simultaneously1 in the strictest sense of the word1 over hundreds and thousands of miles of sea and land1 or propagates itself by degrees in short intervals every where over the earth's surface4 ,among numerous examples of perturbations occurring simultaneously and extending over wide portions of the earth's surface1 one of the most remarkable is that of ,september #beth1 #ahda1 which was observed at ,toronto in ,canada1 at the ,cape of ,good ,hope1 at ,prague1 and partially in ,van ,diemen's ,land4 ,sabine adds1 8,the ,english ,sunday1 on which it is deemed sinful1 after midnight on ,saturday1 to register an observation1 and to follow out the great phenomena of creation in their perfect development1 interrupted the observation in ,van ,diemen's ,land1 where1 in consequence of the difference of the longitude1 the magnetic storm fell on ,sunday40 ,it is but justice to add1 that to the direct instrumentality of the ,british ,association we are indebted for this system of observation1 which would not have been possible without some such machinery for concerted action4 ,it being known that the magnetic needle is subject to oscillations1 the nature1 the periods1 and the laws of which were unascertained1 under the direction of a committee of the ,association magnetic observatories were established in various places for investigating these strange disturbances4 ,as might have been anticipated1 regularly recurring perturbations were noted1 depending on the hour of the day and the season of the year4 ,magnetic storms were observed to sweep simultaneously over the whole face of the earth1 and these too have now been ascertained to follow certain periodic laws4 ,but the most startling result of the combined magnetic observations is the discovery of marked perturbations recurring at intervals of ten years2 a period which seemed to have no analogy to any thing in the universe1 but which ,m4 ,schwabe has found to correspond with the variation of the spots on the sun1 both attaining their maximum and minimum developments at the same time4 ,here1 for the present1 the discovery stops2 but that which is now an unexplained coincidence may hereafter supply the key to the nature and source of ,terrestrial ,magnetism3 or1 as ,dr4 ,lloyd observes1 this system of magnetic observation has gone beyond our globe1 and opened a new range for inquiry1 by showing us that this wondrous agent has power in other parts of the solar system4 ,,familiar ,,galvanic ,,effects4 ,by means of the galvanic agency a variety of surprising effects have been produced4 ,gunpowder1 cotton1 and other inflammable substances have been set on fire2 charcoal has been made to burn with a brilliant white flame2 water has been decomposed into its elementary parts2 metals have been melted and set on fire2 fragments of diamond1 charcoal1 and plumbago have been dispersed as if evaporated2 platina1 the hardest and the heaviest of the metals1 has been melted as readily as wax in the flame of a candle2 the sapphire1 quartz1 magnesia1 lime1 and the firmest compounds in nature1 have been fused4 ,its effects on the animal system are no less surprising4 ,the agency of galvanism explains why porter has a different and more pleasant taste when drunk out of a pewter-pot than out of glass or earthenware2 why works of metal which are soldered together soon tarnish in the place where the metals are joined2 and why the copper sheathing of ships1 when fastened with iron nails1 is soon corroded about the place of contact4 ,in all these cases a galvanic circle is formed which produces the effects4 ,,the ,,siamese ,,twins ,,galvanised4 ,it will be recollected that the ,siamese twins1 brought to ,england in the year #ahbi1 were united by a jointed cartilaginous band4 ,a silver tea spoon being placed on the tongue of one of the twins and a disc of zinc on the tongue of the other1 the moment the two metals were brought into contact both the boys exclaimed1 8,sour1 sour20 thus proving that the galvanic influence passed from the one to the other through the connecting band4 ,,minute ,,and ,,vast ,,batteries4 ,dr4 ,wollaston made a simple apparatus out of a silver thimble1 with its top cut off4 ,it was then partially flattened1 and a small plate of zinc being introduced into it1 the apparatus was immersed in a weak solution of sulphuric acid4 ,with this minute battery1 ,dr4 ,wollaston was able to fuse a wire of platinum #a_/cjjjth of an inch in diameter--a degree of tenuity to which no one had ever succeeded in drawing it4 ,upon the same principle 7that of introducing a plate of zinc between two plates of other metals7 ,mr4 ,children constructed his immense battery1 the zinc plates of which measured six feet by two feet eight inches2 each plate of zinc being placed between two of copper1 and each triad of plates being enclosed in a separate cell4 ,with this powerful apparatus a wire of platinum1 #a_/ajth of an inch in diameter and upwards of five feet long1 was raised to a red heat1 visible even in the broad glare of daylight4 ,the great battery at the ,royal ,institution1 with which ,sir ,humphry ,davy discovered the composition of the fixed alkalies1 was of immense power4 ,it consisted of #bjj separate parts1 each composed of ten double plates1 and each plate containing thirty-two square inches2 the number of double plates being #bjjj1 and the whole surface #abh1jjj square inches4 ,mr4 ,highton1 ,c4,e41 has made a battery which exposes a surface of only #a_/ajjth part of an inch3 it consists of but one cell2 it is less than #a_/ajjjjth part of a cubic inch1 and yet it produces electricity more than enough to overcome all the resistance in the inventor's brother's patent ,gold-leaf ,telegraph1 and works the same powerfully4 ,it is1 in short1 a battery which1 although it will go through the eye of a needle1 will yet work a telegraph well4 ,mr4 ,highton had previously constructed a battery in size less than #a_/djth of a cubic inch3 this battery1 he found1 would for a month together ring a telegraph-bell ten miles off4 ,,electric ,,incandescence ,,of ,,charcoal ,,points4 ,the most splendid phenomenon of this kind is the combustion of charcoal points4 ,pointed pieces of the residuum obtained from gas retorts will answer best1 or ,bunsen's composition may be used for this purpose4 ,put two such charcoal points in immediate contact with the wires of your battery2 bring the points together1 and they will begin to burn with a dazzling white light4 ,the charcoal points of the large apparatus belonging to the ,royal ,institution became incandescent at a distance of #a_/cjth of an inch2 when the distance was gradually increased till they were four inches asunder1 they continued to burn with great intensity1 and a permanent stream of light played between them4 ,professor ,bunsen obtained a similar flame from a battery of four pairs of plates1 its carbon surface containing #bi feet4 ,the heat of this flame is so intense1 that stout platinum wire1 sapphire1 quartz1 talc1 and lime are reduced by it to the liquid form4 ,it is worthy of remark1 that no combustion1 properly so called1 takes place in the charcoal itself1 which sustains only an extremely minute loss in its weight and becomes rather denser at the points4 ,the phenomenon is attended with a still more vivid brightness if the charcoal points are placed in a vacuum1 or in any of those gases which are not supporters of combustion4 ,instead of two charcoal points1 one only need be used if the following arrangement is adopted3 lay the piece of charcoal on some quicksilver that is connected with one pole of the battery1 and complete the circuit from the other pole by means of a strip of platinum4 ,when ,professor ,peschel used a piece of well-burnt coke in the manner just described1 he obtained a light which was almost intolerable to the eyes4 ,,voltaic ,,electricity4 ,on ,january #ca1 #agic1 ,volta announced to the ,royal ,society his discovery of the development of electricity in metallic bodies4 ,galvani had given the name of ,animal ,electricity to the power which caused spontaneous convulsions in the limbs of frogs when the divided nerves were connected by a metallic wire4 ,volta1 however1 saw the true cause of the phenomena described by ,galvani4 ,observing that the effects were far greater when the connecting medium consisted of two different kinds of metal1 he inferred that the principle of excitation existed in the metals1 and not in the nerves of the animal2 and he assumed that the exciting fluid was ordinary electricity1 produced by the contact of the two metals2 the convulsions of the frog consequently arose from the electricity thus developed passing along its nerves and muscles4 ,in #ahjj ,volta invented what is now called the ,voltaic ,pile1 or compound ,galvanic circle4 ,the term ,animal ,electricity 7says ,dr4 ,whewell7 has been superseded by others1 of which ,galvanism is the most familiar2 but ,i think that ,volta's office in this discovery is of a much higher and more philosophical kind than that of ,galvani2 and it would on this account be more fitting to employ the term ,voltaic ,electricity1 which1 indeed1 is very commonly used1 especially by our most recent and comprehensive writers4 ,the ,voltaic pile was a more important step in the history of electricity than the ,leyden jar had been--,hist4 ,ind4 ,sciences1 vol4 iii4 ,no one who wishes to judge impartially of the scientific history of these times and of its leaders1 will consider ,galvani and ,volta as equals1 or deny the vast superiority of the latter over all his opponents or fellow-workers1 more especially over those of the ,bologna school4 ,we shall scarcely again find in one man gifts so rich and so calculated for research as were combined in ,volta4 ,he possessed that 8incomprehensible talent10 as ,dove has called it1 for separating the essential from the immaterial in complicated phenomena2 that boldness of invention which must precede experiment1 controlled by the most strict and cautious mode of manipulation2 that unremitting attention which allows no circumstance to pass unnoticed2 lastly1 with so much acuteness1 so much simplicity1 so much grandeur of conception1 combined with such depth of thought1 he had a hand which was the hand of a workman4--,jameson's ,journal1 ,no4 #ajf4 ,,the ,,voltaic ,,battery ,,and ,,the ,,gymnotus4 8,we boast of our ,voltaic ,batteries10 says ,mr4 ,smee4 8,i should hardly be believed if ,i were to say that ,i did not feel pride in having constructed my own1 especially when ,i consider the extensive operations which it has conducted4 ,but when ,i compare my battery with the battery which nature has given to the electrical eel and the torpedo1 how insignificant are human operations compared with those of the ,architect of living beings6 ,the stupendous electric eel in the ,polytechnic ,institution1 when he seeks to kill his prey1 encloses him in a circle2 then1 by volition1 causes the voltaic force to be produced1 and the hapless creature is instantly killed4 ,it would probably require ten thousand of my artificial batteries to effect the same object1 as the creature is killed instanter on receiving the shock4 ,as much1 however1 as my battery is inferior to that of the electric fish1 so is man superior to the same animal4 ,man is endowed with a power of mind competent to appreciate the force of matter1 and is thus enabled to make the battery4 ,the eel can but use the specific apparatus which nature has bestowed upon it40 ,some observations upon the electric current around the gymnotus1 and notes of experiments with this and other electric fish1 will be found in ,things not generally ,known1 p4 #aii4 ,,voltaic ,,currents ,,in ,,mines4 ,many years ago1 ,mr4 ,r4 ,w4 ,fox1 from theory entertaining a belief that a connection existed between voltaic action in the interior of the earth and the arrangement of metalliferous veins1 and also the progressive increase of temperature in the strata as we descend from the surface1 endeavoured to verify the same from experiment in the mine of ,huel ,jewel1 in ,cornwall4 ,his apparatus consisted of small plates of sheet-copper1 which were fixed in contact with a plate in the veins with copper nails1 or else wedged closely against them with wooden props stretched across the galleries4 ,between two of these plates1 at different stations1 a communication was made by means of a copper wire #a_/bjth of an inch in diameter1 which included a galvanometer in its circuit4 ,in some instances #cjj fathoms of copper wire were employed4 ,it was then found that the intensity of the voltaic current was generally greater in proportion to the greater abundance of copper ore in the veins1 and in some degree to the depth of the stations4 ,hence ,mr4 ,fox's discovery promised to be of practical utility to the miner in discovering the relative quantity of ore in the veins1 and the directions in which it most abounds4 ,the result of extended experiments1 mostly made by ,mr4 ,robert ,hunt1 has not1 however1 confirmed ,mr4 ,fox's views4 ,it has been found that the voltaic currents detected in the lodes are due to the chemical decomposition going on there2 and the more completely this process of decomposition is established1 the more powerful are the voltaic currents4 ,meanwhile these have nothing whatever to do with the increase of temperature with depth4 ,recent observations1 made in the deep mines of ,cornwall under the direction of ,mr4 ,fox1 do not appear consistent with the law of thermic increase as formerly established1 the shallow mines giving a higher ratio of increase than the deeper ones4 ,,germs ,,of ,,electric ,,knowledge4 ,two centuries and a half ago1 ,gilbert recognised that the property of attracting light substances when rubbed1 be their nature what it may1 is not peculiar to amber1 which is a condensed earthy juice cast up by the waves of the sea1 and in which flying insects1 ants1 and worms lie entombed as in eternal sepulchres4 ,the force of attraction 7,gilbert continues7 belongs to a whole class of very different substances1 as glass1 sulphur1 sealing-wax1 and all resinous substances--rock crystal and all precious stones1 alum and rock-salt4 ,gilbert measured the strength of the excited electricity by means of a small needle--not made of iron--which moved freely on a pivot1 and perfectly similar to the apparatus used by ,hay and ,brewster in testing the electricity excited in minerals by heat and friction4 8,friction10 says ,gilbert further1 8is productive of a stronger effect in dry than in humid air2 and rubbing with silk cloths is most advantageous40 ,otto von ,guerike1 the inventor of the air-pump1 was the first who observed any thing more than mere phenomena of attraction4 ,in his experiments with a rubbed piece of sulphur he recognised the phenomena of repulsion1 which subsequently led to the establishment of the laws of the sphere of action and of the distribution of electricity4 ,he heard the first sound1 and saw the first light1 in artificially-produced electricity4 ,in an experiment instituted by ,newton in #afge1 the first traces of an electric charge in a rubbed plate of glass were seen4 ,,temperature ,,and ,,electricity4 ,professor ,tyndall has shown that all variations of temperature1 in metals at least1 excite electricity4 ,when the wires of a galvanometer are brought in contact with the two ends of a heated poker1 the prompt deflection of the galvanometer-needle indicates that a current of electricity has been sent through the instrument4 ,even the two ends of a spoon1 one of which has been dipped in hot water1 serve to develop an electric current2 and in cutting a hot beefsteak with a steel knife and a silver fork there is an excitement of electricity4 ,the mere heat of the finger is sufficient to cause the deflection of the galvanometer2 and when ice is applied to the part that has been previously warmed1 the galvanometer-needle is deflected in the contrary direction4 ,a small instrument invented by ,melloni is so extremely sensitive of the action of heat1 that electricity is excited when the hand is held six inches from it4 ,,vast ,,arrangement ,,of ,,electricity4 ,professor ,faraday has shown that the ,electricity which decomposes1 and that which is evolved in the decomposition of1 a certain quantity of matter1 are alike4 ,what an enormous quantity of electricity1 therefore1 is required for the decomposition of a single grain of water6 ,it must be in quantity sufficient to sustain a platinum wire #a_/ajdth of an inch in thickness red-hot in contact with the air for three minutes and three-quarters4 ,it would appear that #hjj1jjj charges of a ,leyden battery1 charged by thirty turns of a very large and powerful plate-machine in full action1 are necessary to supply electricity sufficient to decompose a single grain of water1 or to equal the quantity of electricity which is naturally associated with the elements of that grain of water1 endowing them with their mutual chemical affinity4 ,now the above quantity of electricity1 if passed at once through the head of a rat or a cat1 would kill it as by a flash of lightning4 ,the quantity is1 indeed1 equal to that which is developed from a charged thunder-cloud4 ,,decomposition ,,of ,,water ,,by ,,electricity4 ,professor ,andrews1 by an ingenious arrangement1 is enabled to show that water is decomposed by the common machine2 and by using an electrical kite1 he was able1 in fine weather1 to produce decomposition1 although so slowly that only #a_/gjjjjjth of a grain of water was decomposed per hour4 ,faraday has proved that the decomposition of one single grain of water produces more electricity than is contained in the most powerful flash of lightning4 ,,electricity ,,in ,,brewing4 ,mr4 ,black1 a practical writer upon ,brewing1 has found that by the practice of imbedding the fermentation-vats in the earth1 and connecting them by means of metallic pipes1 an electrical current passes through the beer and causes it to turn sour4 ,as a preventive1 he proposed to place the vats upon wooden blocks1 or on any other non-conductors1 so that they may be insulated4 ,it has likewise been ascertained that several brewers who had brewed excellent ale on the south side of the street1 on removing to the north have failed to produce good ale4 ,,electric ,,paper4 ,professor ,schonbein has prepared paper1 as transparent as glass and impermeable to water1 which develops a very energetic electric force4 ,by placing some sheets on each other1 and simply rubbing them once or twice with the hand1 it becomes difficult to separate them4 ,if this experiment is performed in the dark1 a great number of distinct flashes may be perceived between the separated surfaces4 ,the disc of the electrophorus1 placed on a sheet that has been rubbed1 produces sparks of some inches in length4 ,a thin and very dry sheet of paper1 placed against the wall1 will adhere strongly to it for several hours if the hand be passed only once over it4 ,if the same sheet be passed between the thumb and fore-finger in the dark1 a luminous band will be visible4 ,hence with this paper may be made powerful and cheap electrical machines4 ,,duration ,,of ,,the ,,electric ,,spark4 ,by means of ,professor ,wheatstone's apparatus1 the ,duration of the ,electric ,spark has been ascertained not to exceed the twenty-five-thousandth part of a second4 ,a cannon-ball1 if illumined in its flight by a flash of lightning1 would1 in consequence of the momentary duration of the light1 appear to be stationary1 and even the wings of an insect1 that move ten thousand times in a second1 would seem at rest4 ,,velocity ,,of ,,electric ,,light4 ,on comparing the velocities of solar1 stellar1 and terrestrial light1 which are all equally refracted in the prism1 with the velocity of the light of frictional electricity1 we are disposed1 in accordance with ,wheatstone's ingeniously-conducted experiments1 to regard the lowest ratio in which the latter excels the former as #c3b4 ,according to the lowest results of ,wheatstone's apparatus1 electric light traverses #bhh1jjj miles in a second4 ,if we reckon #ahi1ich miles for stellar light1 according to ,struve1 we obtain the difference of #ie1ggf miles as the greater velocity of electricity in one second4 ,from the experiment described in ,wheatstone's paper 7,philosophical ,transactions for #ahcd71 it would appear that the human eye is capable of perceiving phenomena of light whose duration is limited to the millionth part of a second4 ,in ,professor ,airy's experiments with the electric telegraph to determine the difference of longitude between ,greenwich and ,brussels1 the time spent by the electric current in passing from one observatory to the other 7#bgj miles7 was found to be #jaji or rather more than the ninth part of a second2 and this determination rests on #bfaf observations3 a speed which would 8girdle the globe0 in ten seconds4 ,,identity ,,of ,,electric ,,and ,,magnetic ,,attraction4 ,this vague presentiment of the ancients has been verified in our own times4 8,when electrum 7amber710 says ,pliny1 8is animated by friction and heat1 it will attract bark and dry leaves precisely as the loadstone attracts iron40 ,the same words may be found in the literature of an ,asiatic nation1 and occur in a eulogium on the loadstone by the ,chinese physicist ,knopho1 in the fourth century3 8,the magnet attracts iron as amber does the smallest grain of mustard-seed4 ,it is like a breath of wind1 which mysteriously penetrates through both1 and communicates itself with the rapidity of an arrow40 ,humboldt observed with astonishment 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 races4 ,children may be seen to rub the dry1 flat1 and shining seeds or husks of a trailing plant until they are able to attract threads of cotton and pieces of bamboo-cane4 ,what a chasm divides the electric pastime of these naked copper-coloured ,indians from the discovery of a metallic conductor discharging its electric shocks1 or a pile formed of many chemically-decomposing substances1 or a light-engendering magnetic apparatus6 ,in such a chasm lie buried thousands of years1 that compose the history of the intellectual development of mankind4--,humboldt's ,cosmos1 vol4 i4 ,,theory ,,of ,,the ,,electro-,,magnetic ,,engine4 ,several years ago a speculative ,american set the industrial world of ,europe in excitement by this proposition4 ,the ,magneto-,electric ,machines often made use of in the case of rheumatic disorders are well known4 ,by imparting a swift rotation to the magnet of such a machine1 we obtain powerful currents of electricity4 ,if these be conducted through water1 the latter will be reduced to its two components1 oxygen and hydrogen4 ,by the combustion of hydrogen water is again generated4 ,if this combustion takes place1 not in atmospheric air1 in which oxygen only constitutes a fifth part1 but in pure oxygen1 and if a bit of chalk be placed in the flame1 the chalk will be raised to a white heat1 and give us the sun-like ,drummond light3 at the same time the flame develops a considerable quantity of heat4 ,now the ,american inventor proposed to utilise in this way the gases obtained from electrolytic decomposition2 and asserted that by the combustion a sufficient amount of heat was generated to keep a small steam-engine in action1 which again drove his magneto-electric machine1 decomposed the water1 and thus continually prepared its own fuel4 ,this would certainly have been the most splendid of all discoveries1--a perpetual motion which1 besides the force that kept it going1 generated light like the sun1 and warmed all around it4 ,the affair1 however1 failed1 as was predicted by those acquainted with the physical investigations which bear upon the subject4--,professor ,helmholtz4 ,,magnetic ,,clock ,,and ,,watch4 ,in the ,museum of the ,royal ,society are two curiosities of the seventeenth century which are objects of much interest in association with the electric discoveries of our day4 ,these are a ,clock1 described by the ,count ,malagatti 7who accompanied ,cosmo ,,iii41 ,grand ,duke of ,tuscany1 to inspect the ,museum in #affi7 as more worthy of observation than all the other objects in the cabinet4 ,its 8movements are derived from the vicinity of a loadstone1 and it is so adjusted as to discover the distance of countries at sea by the longitude40 ,the analogy between this clock and the electric clock of the present day is very remarkable4 ,of kindred interest is 8,hook's ,magnetic ,watch10 often alluded to in the ,royal ,society's ,journal-book of #affi as 8going slower or faster according to the greater or less distance of the loadstone1 and so moving regularly in any posture40 ,,wheatstone',s ,,electro-,,magnetic ,,clock4 ,in this ingenious invention1 the object of ,professor ,wheatstone was to enable a simple clock to indicate exactly the same time in as many different places1 distant from each other1 as may be required4 ,a standard clock in an observatory1 for example1 would thus keep in order another clock in each apartment1 and that too with such accuracy1 that all of them1 however numerous1 will beat dead seconds audibly with as great precision as the standard astronomical time-piece with which they are connected4 ,but1 besides this1 the subordinate time-pieces thus regulated require none of the mechanism for maintaining or regulating the power4 ,they consist simply of a face1 with its second1 minute1 and hour hands1 and a train of wheels which communicate motion from the action of the second-hand to that of the hour-hand1 in the same manner as an ordinary clock-train4 ,nor is this invention confined to observatories and large establishments4 ,the great horologe of ,st4 ,paul's might1 by a suitable network of wires1 or even by the existing metallic pipes of the metropolis1 be made to command and regulate all the other steeple-clocks in the city1 and even every clock within the precincts of its metallic bounds4 ,as railways and telegraphs extend from ,london nearly to the remotest cities and villages1 the sensation of time may be transmitted along with the elements of language2 and the great cerebellum of the metropolis may thus constrain by its sympathies1 and regulate by its power1 the whole nervous system of the empire4 ,,how ,,to ,,make ,a ,,common ,,clock ,,electric4 ,m4 ,kammerer of ,belgium effects this by an addition to any clock whereby it is brought into contact with the two poles of a galvanic battery1 the wires from which communicate with a drum moved by the clockwork2 and every fifteen seconds the current is changed1 the positive and the negative being transmitted alternately4 ,a wire is continued from the drum to the electric clock1 the movement of which1 through the plate-glass dial1 is seen to be two pairs of small straight electro-magnets1 each pair having their ends opposite to the other pair1 with about half an inch space between4 ,within this space there hangs a vertical steel bar1 suspended from a spindle at the top4 ,the rod has two slight projections on each side parallel to the ends of the wire-coiled magnets4 ,when the electric current comes on the wire from the positive end of the battery 7through the drum of the regulator-clock7 the positive magnets attract the bar to it1 the distance being perhaps the sixteenth of an inch4 ,when1 at the end of fifteen seconds1 the negative pole operates1 repulsion takes effect1 and the bar moves to the opposite side4 ,this oscillating bar gives motion to a wheel which turns the minute and hour hands4 ,m4 ,kammerer states1 that if the galvanic battery be attached to any particular standard clock1 any number of clocks1 wherever placed1 in a city or kingdom1 and communicating with this by a wire1 will indicate precisely the same time4 ,such is the precision1 that the sounds of three clocks thus beating simultaneously have been mistaken as proceeding from one clock4 ,,dr4 ,,franklin',s ,,electrical ,,kite4 ,several philosophers had observed that lightning and electricity possessed many common properties2 and the light which accompanied the explosion1 the crackling noise made by the flame1 and other phenomena1 made them suspect that lightning might be electricity in a highly powerful state4 ,but this connection was merely the subject of conjecture until1 in the year #agej1 ,dr4 ,franklin suggested an experiment to determine the question4 ,while he was waiting for the building of a spire at ,philadelphia1 to which he intended to attach his wire1 the experiment was successfully made at ,marly-la-,ville1 in ,france1 in the year #ageb2 when lightning was actually drawn from the clouds by means of a pointed wire1 and it was proved to be really the electric fluid4 ,almost every early electrical discovery of importance was made by ,fellows of the ,royal ,society1 and is to be found recorded in the ,philosophical ,transactions4 ,in the forty-fifth volume occurs the first mention of ,dr4 ,franklin's name1 and his theory of positive and negative electricity4 ,in #agef he was elected into the ,society1 8without any fee or other payment40 ,his previous communications to the ,transactions1 particularly the account of his electrical kite1 had excited great interest4 7,weld's ,history of the ,royal ,society47 ,it is thus described by him in a letter dated ,philadelphia1 ,october #a1 #ageb3 8,as frequent mention is made in the public papers from ,europe of the success of the ,marly-la-,ville experiment for drawing the electric fire from clouds by means of pointed rods of iron erected on high buildings1 c41 it may be agreeable to the curious to be informed that the same experiment has succeeded in ,philadelphia1 though made in a different and more easy manner1 which any one may try1 as follows3 ,make a small cross of two light strips of cedar1 the arms so long as to reach to the four corners of a large thin silk handkerchief when extended4 ,tie the comers of the handkerchief to the extremities of the cross2 so you have the body of a kite1 which1 being properly accommodated with a tail1 loop1 and string1 will rise in the air like a kite made of paper2 but this1 being of silk1 is fitter to bear the wet and wind of a thunder-gust without tearing4 ,to the top of the upright stick of the cross is to be fixed a very sharp-pointed wire1 rising a foot or more above the wood4 ,to the end of the twine1 next the band1 is to be tied a silk ribbon2 and where the twine and silk join a key may be fastened4 ,the kite is to be raised when a thunder-gust appears to be coming on1 and the person who holds the string must stand within a door or window1 or under some cover1 so that the silk ribbon may not be wet2 and care must be taken that the twine does not touch the frame of the door or window4 ,as soon as any of the thunder-clouds come over the kite1 the pointed wire will draw the electric fire from them2 and the kite1 with all the twine1 will be electrified2 and the loose filaments of the twine will stand out every way1 and be attracted by an approaching finger4 ,when the rain has wet the kite and twine1 so that it can conduct the electric fire freely1 you will find it stream out plentifully from the key on the approach of your knuckle4 ,at this key the phial may be charged2 and from electric fire thus obtained spirits may be kindled1 and all the other electrical experiments be performed which are usually done by the help of a rubbed-glass globe or tube2 and thus the sameness of the electric matter with that of lightning is completely demonstrated40--,philosophical ,transactions4 ,of all this great man's 7,franklin's7 scientific excellencies1 the most remarkable is the smallness1 the simplicity1 the apparent inadequacy of the means which he employed in his experimental researches4 ,his discoveries were all made with hardly any apparatus at all2 and if at any time he had been led to employ instruments of a somewhat less ordinary description1 he never rested satisfied until he had1 as it were1 afterwards translated the process by resolving the problem with such simple machinery that you might say he had done it wholly unaided by apparatus4 ,the experiments by which the identity of lightning and electricity was demonstrated were made with a sheet of brown paper1 a bit of twine or silk thread1 and an iron key6--,lord ,brougham4#ej ,,fatal ,,experiment ,,with ,,lightning4 ,these experiments are not without danger2 and a flash of lightning has been found to be a very unmanageable instrument4 ,in #agec1 ,m4 ,richman1 at ,st4 ,petersburg1 was making an experiment of this kind by drawing lightning into his room1 when1 incautiously bringing his head too near the wire1 he was struck dead by the flash1 which issued from it like a globe of blue fire1 accompanied by a dreadful explosion4 ,,faraday',s ,,electrical ,,illustrations4 ,the following are selected from the very able series of lectures delivered by ,professor ,faraday at the ,royal ,institution3 ,the ,two ,electricities4--,after having shown by various experiments the attractions and repulsions of light substances from excited glass and from an excited tube of gutta-percha1 ,professor ,faraday proceeds to point out the difference in the character of the electricity produced by the friction of the two substances4 ,the opposite characters of the electricity evolved by the friction of glass and of that excited by the friction of gutta-percha and shellac are exhibited by several experiments1 in which the attraction of the positive and negative electricities to each other and the neutralisation of electrical action on the combination of the two forces are distinctly observable4 ,though adopting the terms 8positive0 and 8negative0 in distinguishing the electricity excited by glass from that excited by gutta-percha and resinous bodies1 ,professor ,faraday is strongly opposed to the ,franklinian theory from which these terms are derived4 ,according to ,franklin's view of the nature of electrical excitement1 it arises from the disturbance1 by friction or other means1 of the natural quantity of one electric fluid which is possessed by all bodies2 an excited piece of glass having more than its natural share1 which has been taken from the rubber1 the latter being consequently in a minus or negative state4 ,this theory ,professor ,faraday considers to be opposed to the distinct characteristic actions of the two forces2 and1 in his opinion1 it is impossible to deprive any body of electricity1 and reduce it to the minus state of ,franklin's hypothesis4 ,taking a ,zamboni's pile1 he applies its two ends separately to an electrometer1 to show that each end produces opposite kinds of electricity1 and that the zero1 or absence of electrical excitement1 only exists in the centre of the pile4 ,to prove how completely the two electricities neutralise each other1 an excited rod of gutta-percha and the piece of flannel with which it has been rubbed are laid on the top of the electrometer without any sign of electricity whilst they are together2 but when either is removed1 the gold leaves diverge with positive and negative electricity alternately4 ,the ,professor dwells strongly on the peculiarity of the dual force of electricity1 which1 in respect of its duality1 is unlike any other force in nature4 ,he then contrasts its phenomena of instantaneous conduction with those of the somewhat analogous force of heat2 and he illustrates by several striking experiments the peculiar property which static electricity possesses of being spread only over the surfaces of bodies4 ,a metal ice-pail is placed on an insulated stand and electrified1 and a metal ball suspended by a string is introduced1 and touches the bottom and sides without having any electricity imparted to it1 but on touching the outside it becomes strongly electrical4 ,the experiment is repeated with a wooden tub with the same result2 and ,professor ,faraday mentions the still more remarkable manner in which he has proved the surface distribution of electricity by having a small chamber constructed and covered with tinfoil1 which can be insulated2 and whilst torrents of electricity are being evolved from the external surface1 he enters it with a galvanometer1 and cannot perceive the slightest manifestation of electricity within4 ,the ,two ,threads4--,a curious experiment is made with two kinds of thread used as the conducting force4 ,from the electric machine on the table a silk thread is first carried to the indicator a yard or two off1 and is shown to be a non-conductor when the glass tube is rubbed and applied to the machine 7although the silk1 when wetted1 conducted72 while a metallic thread of the same thickness1 when treated in the same way1 conducts the force so much as to vehemently agitate the gold leaves within the indicator4 ,non-conducting ,bodies4--,the action that occurs in bodies which cannot conduct is the most important part of electrical science4 ,the principle is illustrated by the attraction and repulsion of an electrified ball of gilt paper by a glass tube1 between which and the ball a sheet of shellac is suspended4 ,the nearer a ball of another description--an unelectrical insulated body--is brought to the ,leyden jar when charged1 the greater influence it is seen to possess over the gold leaf within the indicator1 by induction1 not by conduction4 ,the questions1 how electricities attract each other1 what kind of electricity is drawn from the machine to the hand1 how the hand was electric1 are thus illustrated4 ,to show the divers operations of this wonderful force1 a tub 7a bad conductor7 is placed by the electric machine4 ,when the latter is charged1 a ball1 having been electrified from it1 is held in the tub1 and rattles against its sides and bottom4 ,on the application of the ball to the indicator1 the gold leaf is shown not to move1 whereas it is agitated manifestly when the same process is gone through with the exception that the ball is made to touch the outside only of the tub4 ,similar experiments with a ball in an ice-pail and a vessel of wire-gauze1 into the latter of which is introduced a mouse1 which is shown to receive no shock1 and not to be frightened at all2 while from the outside of the vessel electric sparks are rapidly produced4 ,this latter demonstration proves that1 as the mouse1 so men and women1 might be safe inside a building with proper conductors while lightning played about the exterior4 ,the wire-gauze being turned inside out1 the principle is shown to be irreversible in spite of the change--what has been the unelectrical inside of the vessel being now1 when made the outside portion1 capable of receiving and transmitting the power1 while the original outside is now unelectrical4 ,repulsion of ,bodies4--,a remarkable and playful experiment1 by which the repulsion of bodies similarly electrified is illustrated1 consists in placing a basket containing a heap of small pieces of paper on an insulated stand1 and connecting it with the prime conductor of the electrical machine2 when the pieces of paper rise rapidly after each other into the air1 and descend on the lecture-table like a fall of snow4 ,the effect is greatly increased when a metal disc is substituted for the basket4 ,,origin ,,of ,,the ,,leyden ,,jar4 ,muschenbroek and ,linnus had made various experiments of a strong kind with water and wire4 ,the former1 as appears from a letter of his to ,raumur1 filled a small bottle with water1 and having corked it up1 passed a wire through the cork into the bottle4 ,having rubbed the vessel on the outside and suspended it to the electric machine1 he was surprised to find that on trying to pull the wire out he was subjected to an awfully severe shock in his joints and his whole body1 such as he declared he would not suffer again for any experiment4 ,hence the ,leyden jar1 which owes its name to the ,university of ,leyden1 with which1 we believe1 ,muschenbroek was connected4--,faraday4 ,,danger ,,to ,,gunpowder ,,magazines4 ,by the illustration of a gas globule1 which is ignited from a spark by induction1 ,mr4 ,faraday has proved in a most interesting manner that the corrugated-iron roofs of some gunpowder-magazines1--on the subject of which he had often been consulted by the builders1 with a view to the greater safety of these manufactories1--are absolutely dangerous by the laws of induction2 as1 by the return of induction1 while a storm was discharging itself a mile or two off1 a secondary spark might ignite the building4 ,,artificial ,,crystals ,,and ,,minerals4--8,,the ,,crosse ,,mite40 ,among the experimenters on ,electricity in our time who have largely contributed to the 8,curiosities of ,science10 ,andrew ,crosse is entitled to special notice4 ,in his school-days he became greatly attached to the study of electricity2 and on settling on his paternal estate1 ,fyne ,court1 on the ,quantock ,hills in ,somersetshire1 he there devoted himself to chemistry1 mineralogy1 and electricity1 pursuing his experiments wholly independently of theories1 and searching only for facts4 ,in ,holwell ,cavern1 near his residence1 he observed the sides and the roof covered with ,arragonite crystallisations1 when his observations led him to conclude that the crystallisations were the effects1 at least to some extent1 of electricity4 ,this induced him to make the attempt to form artificial crystals by the same means1 which he began in #ahjg4 ,he took some water from the cave1 filled a tumbler1 and exposed it to the action of a voltaic battery excited by water alone1 letting the platinum-wires of the battery fall on opposite sides of the tumbler from the opposite poles of the battery4 ,after ten days' constant action1 he produced crystals of carbonate of lime2 and on repeating the experiment in the dark1 he produced them in six days4 ,thus ,mr4 ,crosse simulated in his laboratory one of the hitherto most mysterious processes of nature4 ,he pursued this line of research for nearly thirty years at ,fyne ,court1 where his electrical-room and laboratory were on an enormous scale3 the apparatus had cost some thousands of pounds1 and the house was nearly full of furnaces4 ,he carried an insulated wire above the tops of the trees around his house to the length of a mile and a quarter1 afterwards shortened to #ahjj feet4 ,by this wire1 which was brought into connection with the apparatus in a chamber1 he was enabled to see continually the changes in the state of the atmosphere1 and could use the fluid so collected for a variety of purposes4 ,in #ahaf1 at a meeting of country gentlemen1 he prophesied that1 8by means of electrical agency1 we shall be able to communicate our thoughts simultaneously with the uttermost ends of the earth40 ,still1 though he foresaw the powers of the medium1 he did not make any experiments in that direction1 but confined himself to the endeavour to produce crystals of various kinds4 ,he ultimately obtained forty-one mineral crystals1 or minerals uncrystallised1 in the form in which they are produced by nature1 including one sub-sulphate of copper--an entirely new mineral1 neither found in nature nor formed by art previously4 ,his belief was that even diamonds might be produced in this way4 ,mr4 ,crosse worked alone in his retreat until #ahcf1 when1 attending the meeting of the ,british ,association at ,bristol1 he was induced to explain his experiments1 for which he was highly complimented by ,dr4 ,buckland1 ,dr4 ,dalton1 ,professor ,sedgwick1 and others4#ea ,shortly after ,mr4 ,crosse's return to ,fyne ,court1 while pursuing his experiments for forming crystals from a highly caustic solution out of contact with atmospheric air1 he was greatly surprised by the appearance of an insect4 ,black flint1 burnt to redness and reduced to powder1 was mixed with carbonate of potash1 and exposed to a strong heat for fifteen minutes2 and the mixture was poured into a black-lead crucible in an air furnace4 ,it was reduced to powder while warm1 mixed with boiling water1 kept boiling for some minutes1 and then hydrochloric acid was added to supersaturation4 ,after being exposed to voltaic action for twenty-six days1 a perfect insect of the ,acari tribe made its appearance1 and in the course of a few weeks about a hundred more4 ,the experiment was repeated in other chemical fluids with the like results2 and ,mr4 ,weeks of ,sandwich afterwards produced the ,acari inferrocyanerret of potassium4 ,the ,acarus of ,mr4 ,crosse was found to contribute a new species of that genus1 nearly approaching the ,acari found in cheese and flour1 or more nearly1 ,hermann's ,acarus dimidiatus4 ,this discovery occasioned great excitement4 ,the possibility was denied1 though ,mr4 ,faraday is said to have stated in the same year that he had seen similar appearances in his own electrical experiments4 ,mr4 ,crosse was now accused of impiety and aiming at creation1 to which attacks he thus replied3 ,as to the appearance of the acari under long-continued electrical action1 ,i have never in thought1 word1 or deed given any one a right to suppose that ,i considered them as a creation1 or even as a formation1 from inorganic matter4 ,to create is to form a something out of a nothing4 ,to annihilate is to reduce that something to a nothing4 ,both of these1 of course1 can only be the attributes of the ,almighty4 ,in fact1 ,i can assure you most sacredly that ,i have never dreamed of any theory sufficient to account for their appearance4 ,i confess that ,i was not a little surprised1 and am so still1 and quite as much as ,i was when the acari made their first appearance4 ,again1 ,i have never claimed any merit as attached to these experiments4 ,it was a matter of chance2 ,i was looking for silicious formations1 and animal matter appeared instead4 ,these ,acari1 if removed from their birthplace1 lived and propagated2 but uniformly died on the first recurrence of frost1 and were entirely destroyed if they fell back into the fluid whence they arose4 ,one of ,mr4 ,crosse's visitors thus describes the vast electrical room at ,fyne ,court3 ,here was an immense number of jars and gallipots1 containing fluids on which electricity was operating for the production of crystals4 ,but you are startled in the midst of your observations by the smart crackling sound that attends the passage of the electrical spark2 you hear also the rumbling of distant thunder4 ,the rain is already plashing in great drops against the glass1 and the sound of the passing sparks continues to startle your ear2 you see at the window a huge brass conductor1 with a discharging rod near it passing into the floor1 and from the one knob to the other sparks are leaping with increasing rapidity and noise1 every one of which would kill twenty men at one blow1 if they were linked together hand in hand and the spark sent through the circle4 ,from this conductor wires pass off without the window1 and the electric fluid is conducted harmlessly away4 ,mr4 ,crosse approached the instrument as boldly as if the flowing stream of fire were a harmless spark4 ,armed with his insulated rod1 he sent it into his batteries3 having charged them1 he showed how wire was melted1 dissipated in a moment1 by its passage2 how metals--silver1 gold1 and tin--were inflamed and burnt like paper1 only with most brilliant hues4 ,he showed you a mimic aurora and a falling-star1 and so proved to you the cause of those beautiful phenomena4 ,mr4 ,crosse appears to have produced in all 8about #bjj varieties of minerals1 exactly resembling in all respects similar ones found in nature40 ,he tried also a new plan of extracting gold from its ores by an electrical process1 which succeeded1 but was too expensive for common use4 ,he was in the habit of saying that he could1 like ,archimedes1 move the world 8if he were able to construct a battery at once cheap1 powerful1 and durable40 ,his process of extracting metals from their ores has been patented4 ,among his other useful applications of electricity are the purifying by its means of brackish or sea-water1 and the improving bad wine and brandy4 ,he agreed with ,mr4 ,quekett in thinking that it is by electrical action that silica and other mineral substances are carried into and assimilated by plants4 ,negative electricity ,mr4 ,crosse found favourable to no plants except fungi2 and positive electricity he ascertained to be injurious to fungi1 but favourable to every thing else4 ,mr4 ,crosse died in #ahee4 ,his widow has published a very interesting volume of ,memorials of the ingenious experimenter1 from which we select the following3 ,on one occasion ,mr4 ,crosse kept a pair of soles under the electric action for three months2 and at the end of that time they were sent to a friend1 whose domestics knew nothing of the experiment4 ,before the cook dressed them1 her master asked her whether she thought they were fresh1 as he had some doubts4 ,she replied that she was sure they were fresh2 indeed1 she said she could swear that they were alive yesterday6 ,when served at table they appeared like ordinary fish2 but when the family attempted to eat them1 they were found to be perfectly tasteless--the electric action had taken away all the essential oil1 leaving the fish unfit for food4 ,however1 the process is exceedingly useful for keeping fish1 meat1 c4 fresh and good for ten days or a fortnight4 ,i have never heard a satisfactory explanation of the cause of the antiseptic power communicated to water by the passage of the electric current4 ,whether ozone has not something to do with it1 may be a question4 ,the same effect is produced whichever two dissimilar metals are used4 ,the ,electric ,telegraph4 ,,anticipations ,,of ,,the ,,electric ,,telegraph4 ,the great secret of ubiquity1 or at least of instantaneous transmission1 has ever exercised the ingenuity of mankind in various romantic myths2 and the discovery of certain properties of the loadstone gave a new direction to these fancies4 ,the earliest anticipation of the ,electric ,telegraph of this purely fabulous character forms the subject of one of the ,prolusiones ,academic of the learned ,italian ,jesuit ,strada1 first published at ,rome in the year #afag4 ,of this poem a free translation appeared in #agej4 ,strada's fancy was this3 8,there is10 he supposes1 8a species of loadstone which possesses such virtue1 that if two needles be touched with it1 and then balanced on separate pivots1 and the one be turned in a particular direction1 the other will sympathetically move parallel to it4 ,he then directs each of these needles to be poised and mounted parallel on a dial having the letters of the alphabet arranged round it4 ,accordingly1 if one person has one of the dials1 and another the other1 by a little pre-arrangement as to details a correspondence can be maintained between them at any distance by simply pointing the needles to the letters of the required words4 ,strada1 in his poetical reverie1 dreamt that some such sympathy might one day be found to hold up the ,magnesian ,stone40 ,strada's conceit seems to have made a profound impression on the master-minds of the day4 ,his poem is quoted in many works of the seventeenth and eighteenth centuries2 and ,bishop ,wilkins1 in his book on ,cryptology1 is strangely afraid lest his readers should mistake ,strada's fancy for fact4 ,wilkins writes3 8,this invention is altogether imaginary1 having no foundation in any real experiment4 ,you may see it frequently confuted in those that treat concerning magnetical virtues40 ,again1 ,addison1 in the #bdast ,no4 of the ,spectator1 #agab1 describes ,strada's 8,chimerical correspondence10 and adds that1 8if ever this invention should be revived or put in practice10 he 8would propose that upon the lover's dial-plate there should be written not only the four-and-twenty letters1 but several entire words which have always a place in passionate epistles1 as flames1 darts1 die1 language1 absence1 ,cupid1 heart1 eyes1 being1 drown1 and the like4 ,this would very much abridge the lover's pains in this way of writing a letter1 as it would enable him to express the most useful and significant words with a single touch of the needle40 ,after ,strada and his commentators comes ,henry ,van ,etten1 who shows how 8,claude1 being at ,paris1 and ,john at ,rome1 might converse together1 if each had a needle touched by a stone of such virtue that as one moved itself at ,paris the other should be moved at ,rome30 he adds1 8it is a fine invention1 but ,i do not think there is a magnet in the world which has such virtue2 besides1 it is inexpedient1 for treasons would be too frequent and too much protected4 7,recrations ,mathmatiques3 see #eth edition1 ,paris1 #affj1 p4 #aeh47 ,sir ,thomas ,browne refers to this 8conceit0 as 8excellent1 and1 if the effect would follow1 somewhat divine20 but he tried the two needles touched with the same loadstone1 and placed in two circles of letters1 8one friend keeping one and another the other1 and agreeing upon an hour when they will communicate10 and found the tradition a failure that1 8at what distance of place soever1 when one needle shall be removed unto any letter1 the other1 by a wonderful sympathy1 will move unto the same40 7,see ,vulgar ,errors1 book ii4 ch4 iii47 ,glanvill's ,vanity of ,dogmatizing1 a work published in #affa1 however1 contains the most remarkable allusion to the prevailing telegraphic fancy4 ,glanvill was an enthusiast1 and he clearly predicts the discovery and general adoption of the electric telegraph4 8,to confer10 he says1 8at the distance of the ,indies by sympathetic conveyance may be as usual to future times as to us in a literary correspondence40 ,by the word 8sympathetic0 he evidently intended to convey magnetic agency2 for he subsequently treats of 8conference at a distance by impregnated needles10 and describes the device substantially as it is given by ,sir ,thomas ,browne1 adding1 that though it did not then answer1 8by some other such way of magnetic efficiency it may hereafter with success be attempted1 when magical history shall be enlarged by riper inspection2 and 'tis not unlikely but that present discoveries might be improved to the performance40 ,this may be said to close the most speculative or mythical period in reference to the subject of electro-telegraphy4 ,electricians now began to be sedulous in their experiments upon the new force by friction1 then the only known method of generating electricity4 ,in #agbi1 ,stephen ,gray1 a pensioner of the ,charter-house1 contrived a method of making electrical signals through a wire #gfe feet long2 yet this most important experiment did not excite much attention4 ,next ,dr4 ,watson1 of the ,royal ,society1 experimented on the possibility of transmitting electricity through a large circuit from the simple fact of ,le ,monnier's account of his feeling the stroke of the electrified fires through two of the basins of the ,tuileries 7which occupy nearly an acre71 by means of an iron chain lying upon the ground and stretched round half their circumference4 ,in #agde1 ,dr4 ,watson1 assisted by several members of the ,royal ,society1 made a series of experiments to ascertain how far electricity could be conveyed by means of conductors4 8,they caused the shock to pass across the ,thames at ,westminster ,bridge1 the circuit being completed by making use of the river for one part of the chain of communication4 ,one end of the wire communicated with the coating of a charged phial1 the other being held by the observer1 who in his other hand held an iron rod which he dipped into the river4 ,on the opposite side of the river stood a gentleman1 who likewise dipped an iron rod in the river with one hand1 and in the other held a wire the extremity of which might be brought into contact with the wire of the phial4 ,upon making the discharge1 the shock was felt simultaneously by both the observers40 7,priestley's ,history of ,electricity47 ,subsequently the same parties made experiments near ,shooter's ,hill1 when the wires formed a circuit of four miles1 and conveyed the shock with equal facility1--8a distance which without trial10 they observed1 8was too great to be credited40#eb ,these experiments in #agdg established two great principles3 #a1 that the electric current is transmissible along nearly two miles and a half of iron wire2 #b1 that the electric current may be completed by burying the poles in the earth at the above distance4 ,in the following year1 #agdh1 ,benjamin ,franklin performed his celebrated experiments on the banks of the ,schuylkill1 near ,philadelphia2 which being interrupted by the hot weather1 they were concluded by a picnic1 when spirits were fired by an electric spark sent through a wire in the river1 and a turkey was killed by the electric shock1 and roasted by the electric jack before a fire kindled by the electrified bottle4 ,in the year #agec1 there appeared in the ,scots' ,magazine1 vol4 xv41 definite proposals for the construction of an electric telegraph1 requiring as many conducting wires as there are letters in the alphabet2 it was also proposed to converse by chimes1 by substituting bells for the balls4 ,a similar system of telegraphing was next invented by ,joseph ,bozolus1 a ,jesuit1 at ,rome2 and next by the great ,italian electrician ,tiberius ,cavallo1 in his treatise on ,electricity4 ,in #aghg1 ,arthur ,young1 when travelling in ,france1 saw a model working telegraph by ,m4 ,lomond3 8,you write two or three words on a paper10 says ,young2 8he takes it with him into a room1 and turns a machine enclosed in a cylindrical case1 at the top of which is an electrometer--a small fine pith-ball2 a wire connects with a similar cylinder and electrometer in a distant apartment2 and his wife1 by remarking the corresponding motions of the ball1 writes down the words they indicate3 from which it appears that he has formed an alphabet of motions4 ,as the length of the wire makes no difference in the effect1 a correspondence might be carried on at any distance4 ,whatever the use may be1 the invention is beautiful40 ,we now reach a new epoch in the scientific period--the discovery of the ,voltaic ,pile4 ,in #agid1 according to ,voigt's ,magazine1 ,reizen made use of the electric spark for the telegraph2 and in #agih ,dr4 ,salva of ,madrid constructed a similar telegraph1 which the ,prince of ,peace subsequently exhibited to the ,king of ,spain with great success4 ,in #ahji1 ,soemmering exhibited a telegraphic apparatus worked by galvanism before the ,academy of ,sciences at ,munich1 in which the mode of signalling consisted in the development of gas-bubbles from the decomposition of water placed in a series of glass tubes1 each of which denoted a letter of the alphabet4 ,in #ahac1 ,mr4 ,sharpe1 of ,doe ,hill near ,alfreton1 devised a voltaic-electric telegraph1 which he exhibited to the ,lords of the ,admiralty1 who spoke approvingly of it1 but declined to carry it into effect4 ,in the following year1 ,soemmering exhibited a voltaic-electric telegraph of his own construction1 which1 however1 was open to the objection of there being as many wires as signs or letters of the alphabet4 ,the next invention is of much greater importance4 ,upon the suggestion of ,cavallo1 already referred to1 ,francis ,ronalds constructed a perfect electric telegraph1 employing frictional electricity notwithstanding ,volta's discoveries had been known in ,england for sixteen years4 ,this telegraph was exhibited at ,hammersmith in #ahaf3ec it consisted of a single insulated wire1 the indication being by pith-balls in front of a dial4 ,when the wire was charged1 the balls were divergent1 but collapsed when the wire was discharged2 at the same time were employed two clocks1 with lettered discs for the signals4 8,if1 as ,paley asserts 7and ,coleridge denies71 #8he alone discovers who proves1' ,ronalds is entitled to the appellation of the first discoverer of an efficient electric telegraph40 7,saturday ,review1 ,no4 #adged7 ,nevertheless the ,government of the day refused to avail itself of this admirable contrivance4 ,in #ahai1 ,oersted made his great discovery of the deflection1 by a current of electricity1 of a magnetic needle at right angles to such current4 ,dr4 ,hamel of ,st4 ,petersburg states that ,baron ,schilling was the first to apply ,oersted's discovery to telegraphy2 ,ampre had previously suggested it1 but his plan was very complicated1 and ,dr4 ,hamel maintains that ,schilling first realised the idea by actually producing an electro-magnetic telegraph simpler in construction than that which ,ampre had imagined4 ,in #ahcf1 ,professor ,muncke of ,heidelberg1 who had inspected ,schilling's telegraphic apparatus1 explained the same to ,william ,fothergill ,cooke1 who in the following year returned to ,england1 and subsequently1 with ,professor ,wheatstone1 laboured simultaneously for the introduction of the electro-magnetic telegraph upon the ,english railways2 the first patent for which was taken out in the joint names of these two gentlemen4 ,in #ahdd1 ,professor ,wheatstone1 with one of his telegraphs1 formed a communication between ,king's ,college and the lofty shot-tower on the opposite bank of the ,thames3 the wire was laid along the parapets of the terrace of ,somerset ,house and ,waterloo ,bridge1 and thence to the top of the tower1 about #aej feet high1 where a telegraph was placed2 the wire then descended1 and a plate of zinc attached to its extremity was plunged into the mud of the river1 whilst a similar plate attached to the extremity at the north side was immersed in the water4 ,the circuit was thus completed by the entire breadth of the ,thames1 and the telegraph acted as well as if the circuit were entirely metallic4 ,shortly after this experiment1 ,professor ,wheatstone and ,mr4 ,cooke laid down the first working electric telegraph on the ,great ,western ,railway1 from ,paddington to ,slough4 ,,electric ,,girdle ,,for ,,the ,,earth4 ,one of our most profound electricians is reported to have exclaimed3 8,give me but an unlimited length of wire1 with a small battery1 and ,i will girdle the universe with a sentence in forty minutes40 ,yet this is no vain boast2 for so rapid is the transition of the electric current along the line of the telegraph wire1 that1 supposing it were possible to carry the wires eight times round the earth1 the transit would occupy but one second of time6 ,,consumption ,,of ,,the ,,electric ,,telegraph4 ,it is singular to see how this telegraphic agency is measured by the chemical consumption of zinc and acid4 ,mr4 ,jones 7who has written a work upon the ,electric ,telegraphs of ,america7 estimates that to work #ab1jjj miles of telegraph about #cjjj zinc cups are used to hold the acid3 these weigh about #ijjj lbs41 and they undergo decomposition by the galvanic action in about six months1 so that #ah1jjj lbs4 of zinc are consumed in a year4 ,there are also about #cfjj porcelain cups to contain nitric acid2 it requires #dej lbs4 of acid to charge them once1 and the charge is renewed every fortnight1 making about #ab1jjj lbs4 of nitric acid in a year4 ,,time ,,lost ,,in ,,electric ,,messages4 ,although it may require an hour1 or two or three hours1 to transmit a telegraphic message to a distant city1 yet it is the mechanical adjustment by the sender and receiver which really absorbs this time2 the actual transit is practically instantaneous1 and so it would be from here to the antipodes1 so far as the current itself is concerned4 ,,the ,,electric ,,telegraph ,,in ,,astronomy ,,and ,,the ,,determination ,,of ,,longitude4 ,the ,electric ,telegraph has become an instrument in the hands of the astronomer for determining the difference of longitude between two observatories4 ,thus in #ahed the difference of longitude between ,london and ,paris was determined within a limit of error which amounted barely to a quarter of a second4 ,the sudden disturbances of the magnetic needle1 when freely suspended1 which seem to take place simultaneously over whole continents1 if not over the whole globe1 from some unexplained cause1 are pointed out as means by which the differences of longitude between the magnetic observatories may possibly be determined with greater precision than by any yet known method4 ,so long ago as #ahci ,professor ,morse suggested some experiments for the determination of ,longitudes2 and in ,june #ahdd the difference of longitude between ,washington and ,baltimore was determined by electric means under his direction4 ,two persons were stationed at these two towns1 with clocks carefully adjusted to the respective spots2 and a telegraphic signal gave the means of comparing the two clocks at a given instant4 ,in #ahdg the relative longitudes of ,new ,york1 ,philadelphia1 and ,washington were determined by means of the electric telegraph by ,messrs4 ,keith1 ,walker1 and ,loomis4 ,,non-,,interference ,,of ,,galvanic ,,waves ,,on ,,the ,,same ,,wire4 ,one of the most remarkable facts in the economy of the telegraph is1 that the line1 when connected with a battery in action1 propagates the hydro-galvanic waves in either direction without interference4 ,as several successive syllables of sound may set out in succession from the same place1 and be on their way at the same time1 to a listener at a distance1 so also1 where the telegraph-line is long enough1 several waves may be on their way from the signal station before the first one reaches the receiving station2 two persons at a distance may pronounce several syllables at the same time1 and each hear those emitted by the other4 ,so1 on a telegraph-line of two or three thousand miles in length in the air1 and the same in the ground1 two operators may at the same instant commence a series of several dots and lines1 and each receive the other's writings1 though the waves have crossed each other on the way4 ,,effect ,,of ,,lightning ,,upon ,,the ,,electric ,,telegraph4 ,in the storm of ,sunday ,april #b1 #ahdh1 the lightning had a very considerable effect on the wires of the electric telegraph1 particularly on the line of railway eastward from ,manchester to ,normanton4 ,not only were the needles greatly deflected1 and their power of answering to the handles considerably weakened1 but those at the ,normanton station were found to have had their poles reversed by some action of the electric fluid in the atmosphere4 ,the damage1 however1 was soon repaired1 and the needles again put in good working order4 ,,electro-,,telegraphic ,,message ,,to ,,the ,,stars4 ,the electric fluid travels at the mean rate of #bj1jjj miles in a second under ordinary circumstances2 therefore1 if it were possible to establish a telegraphic communication with the star #fa ,cygni1 it would require ninety years to send a message there4 ,professor ,henderson and ,mr4 ,maclear have fully confirmed the annual parallax of ,centauri to amount to a second of arc1 which gives about twenty billions of miles as its distance from our system2 a ray of light would arrive from ,centauri to us in little more than three years1 and a telegraphic despatch would arrive there in thirty years4 ,,the ,,atlantic ,,telegraph4 ,the telegraphic communication between ,england and the ,united ,states is so grand a conception1 that it would be impossible to detail its scientific and mechanical relations within the limits of the present work4 ,all that we shall attempt1 therefore1 will be to glance at a few of the leading operations4 ,in the experiments made before the ,atlantic ,telegraph was finally decided on1 #bjjj miles of subterranean and submarine telegraphic wires1 ramifying through ,england and ,ireland and under the waters of the ,irish ,sea1 were specially connected for the purpose2 and through this distance of #bjjj miles #bej distinct signals were recorded and printed in one minute4 ,first1 as to the ,cable4 ,in the ordinary wires by the side of a railway the electric current travels on with the speed of lightning--uninterrupted by the speed of lightning2 but when a wire is encased in gutta-percha1 or any similar covering1 for submersion in the sea1 new forces come into play4 ,the electric excitement of the wire acts by induction1 through the envelope1 upon the particles of water in contact with that envelope1 and calls up an electric force of an opposite kind4 ,there are two forces1 in fact1 pulling against each other through the gutta-percha as a neutral medium1--that is1 the electricity in the wire1 and the opposite electricity in the film of water immediately surrounding the cable2 and to that extent the power of the current in the enclosed wire is weakened4 ,a submarine cable1 when in the water1 is virtually a lengthened-out ,leyden jar2 it transmits signals while being charged and discharged1 instead of merely allowing a stream to flow evenly along it3 it is a bottle for holding electricity rather than a pipe for carrying it2 and this has to be filled for every time of using4 ,the wire being carried underground1 or through the water1 the speed becomes quite measurable1 say a thousand miles in a second1 instead of two hundred thousand1 owing to the retardation by induced or retrograde currents4 ,the energy of the currents and the quality of the wire also affect the speed4 ,until lately it was supposed that the wire acts only as a conductor of electricity1 and that a long wire must produce a weaker effect than a short one1 on account of the consequent attenuation of the electrical influence2 but it is now known that1 the cable being a reservoir as well as a conductor1 its electrical supply is increased in proportion to its length4 ,the electro-magnetic current is employed1 since it possesses a treble velocity of transmission1 and realises consequently a threefold working speed as compared with simple voltaic electricity4 ,mr4 ,wildman ,whitehouse has determined by his ingenious apparatus that the speed of the voltaic current might be raised under special circumstances to #ahjj miles per second2 but that of the induced current1 or the electro-magnetic1 might be augmented to #fjjj miles per second4 ,next as to a ,quantity ,battery employed in these investigations4 ,to effect a charge1 and transmit a current through some thousand miles of the ,atlantic ,cable1 ,mr4 ,whitehouse had a piece of apparatus prepared consisting of twenty-five pairs of zinc and silver plates about the #bjth part of a square inch large1 and the pairs so arranged that they would hold a drop of acidulated water or brine between them4 ,on charging this ,lilliputian battery by dipping the plates in salt and water1 messages were sent from it through a thousand miles of cable with the utmost ease2 and not only so1--pair after pair was dropped out from the series1 the messages being still sent on with equal facility1 until at last only a single pair1 charged by one single drop of liquid1 was used4 ,strange to say1 with this single pair and single drop distinct signals were effected through the thousand miles of the cable6 ,each signal was registered at the end of the cable in less than three seconds of time4 ,the entire length of wire1 iron and copper1 spun into the cable amounts to #ccb1ejj miles1 a length sufficient to engirdle the earth thirteen times4 ,the cable weighs from #ai cwt4 to a ton per mile1 and will bear a strain of #e tons4 ,the ,perpetual ,maintenance ,battery1 for working the cable at the bottom of the sea1 consists of large plates of platinated silver and amalgamated zinc1 mounted in cells of gutta-percha4 ,the zinc plates in each cell rest upon a longitudinal bar at the bottom1 and the silver plates hang upon a similar bar at the top of the cell2 so that there is virtually but a single stretch of silver and a single stretch of zinc in operation4 ,each of the ten cells contains #bjjj square inches of acting surface2 and the combination is so powerful1 that when the broad strips of copper-plate which form the polar extensions are brought into contact or separated1 brilliant flashes are produced1 accompanied by a loud crackling sound4 ,the points of large pliers are made red-hot in five seconds when placed between them1 and even screws burn with vivid scintillation4 ,the cost of maintaining this magnificent ten-celled ,titan battery at work does not exceed a shilling per hour4 ,the voltaic current generated in this battery is not1 however1 the electric stream to be sent across the ,atlantic1 but is only the primary power used to call up and stimulate the energy of a more speedy traveller by a complicated apparatus of 8,double ,induction ,coils40 ,nor is the transmission-current generated in the inner wire of the double induction coil1--and which becomes weakened when it has passed through #ahjj or #aijj miles1--set to work to print or record the signals transmitted4 ,this weakened current merely opens and closes the outlet of a fresh battery1 which is to do the printing labour4 ,this relay-instrument 7as it is called71 which consists of a temporary and permanent magnet1 is so sensitive an apparatus1 that it may be put in action by a fragment of zinc and a sixpence pressed against the tongue4 ,the attempts to lay the cable in ,august #aheg failed through stretching it so tightly that it snapped and went to the bottom1 at a depth of #ab1jjj feet1 forty times the height of ,st4 ,paul's4 ,this great work was resumed in ,august #aheh2 and on the #eth the first signals were received through two thousand and fifty miles of the ,atlantic ,cable4 ,and it is worthy of remark1 that just #aaa years previously1 on the #eth of ,august #agdg1 ,dr4 ,watson astonished the scientific world by practically proving that the electric current could be transmitted through a wire hardly two miles and a half long4#ee ,miscellanea4 ,,how ,,marine ,,chronometers ,,are ,,rated ,,at ,,the ,,royal ,,observatory1 ,,greenwich4 ,the determination of the ,longitude at ,sea requires simply accurate instruments for the measurement of the positions of the heavenly bodies1 and one or other of the two following1--either perfectly correct watches--or chronometers1 as they are now called--or perfectly accurate tables of the lunar motions4 ,so early as #afif a report was spread among the members of the ,royal ,society that ,sir ,isaac ,newton was occupied with the problem of finding the longitude at sea2 but the rumour having no foundation1 he requested ,halley to acquaint the members 8that he was not about it40#ef 7,sir ,david ,brewster's ,life of ,newton47 ,in #agad the legislature of ,queen ,anne passed an ,act offering a reward of #bj1jjjl4 for the discovery of the longitude1 the problem being then very inaccurately solved for want of good watches or lunar tables4 ,about the year #agdi1 the attention of the ,royal ,society was directed to the improvements effected in the construction of watches by ,john ,harrison1 who received for his inventions the ,copley ,medal4 ,thus encouraged1 ,harrison continued his labours with unwearied diligence1 and produced in #ageh a timekeeper which was sent for trial on a voyage to ,jamaica4 ,after #afa days the error of the instrument was only #am #es1 and the maker received from the nation #ejjjl4 ,the ,commissioners of the ,board of ,longitude subsequently required ,harrison to construct under their inspection chronometers of a similar nature1 which were subjected to trial in a voyage to ,barbadoes1 and performed with such accuracy1 that1 after having fully explained the principle of their construction to the commissioners1 they awarded him #aj1jjjl4 more2 at the same time ,euler of ,berlin and the heirs of ,mayer of ,gttingen received each #cjjjl4 for their lunar tables4 ,the account of the trial of ,harrison's watch is very interesting4 ,in ,april #agff1 by desire of the ,commissioners of the ,board1 the ,lords of the ,admiralty delivered the watch into the custody of the ,astronomer-,royal1 the ,rev4 ,dr4 ,nevil ,maskelyne4 ,it was then placed at the ,royal ,observatory at ,greenwich1 in a box having two different locks1 fixed to the floor or wainscot1 with a plate of glass in the lid of the box1 so that it might be compared as often as convenient with the regulator and the variation set down4 ,the form observed by ,mr4 ,harrison in winding up the watch was exactly followed2 and an officer of ,greenwich ,hospital attended every day1 at a stated hour1 to see the watch wound up1 and its comparison with the regulator entered4 ,a key to one of the locks was kept at the ,hospital for the use of the officer1 and the other remained at the ,observatory for the use of the ,astronomer-,royal or his assistant4 ,the watch was then tried in various positions till the beginning of ,july2 and from thence to the end of ,february following in a horizontal position with its face upwards4 ,the variation of the watch was then noted down1 and a register was kept of the barometer and thermometer2 and the time of comparing the same with the regulator was regularly kept1 and attested by the ,astronomer-,royal or his assistant and such of the officers as witnessed the winding-up and comparison of the watch4 ,under these conditions ,harrison's watch was received by the ,astronomer-,royal at the ,admiralty on ,may #e1 #agff1 in the presence of ,philip ,stephens1 ,esq41 ,secretary of the ,admiralty2 ,captain ,baillie1 of the ,royal ,hospital1 ,greenwich2 and ,mr4 ,kendal the watchmaker1 who accompanied the ,astronomer-,royal to ,greenwich1 and saw the watch started and locked up in the box provided for it4 ,the watch was then compared with the transit clock daily1 and wound up in the presence of the officer of ,greenwich ,hospital4 ,from ,may #e to ,may #ag the watch was kept in a horizontal position with its face upwards2 from ,may #ah to ,july #f it was tried--first inclined at an angle of #bj to the horizon1 with the face upwards1 and the hours #ab1 #f1 #c1 and #i1 highest successively2 then in a vertical position1 with the same hours highest in order2 lastly1 in a horizontal position with the face downwards4 ,from ,july #af1 #agff1 to ,march #d1 #agfg1 it was always kept in a horizontal position with its face upwards1 lying upon the same cushion1 and in the same box in which ,mr4 ,harrison had kept it in the voyage to ,barbadoes4 ,from the observed transits of the sun over the meridian1 according to the time of the regulator of the ,observatory1 together with the attested comparisons of ,mr4 ,harrison's watch with the transit clock1 the watch was found too fast on several days as follows3 h4 m4 s4 #agff4 ,may #f too fast #j #j #afb ,may #ag 0 #j #c #eah ,july #f 0 #j #ad #adj ,aug4 #f 0 #j #bc #ehd ,sept4 #ag 0 #j #cb #aef ,oct4 #bi 0 #j #db #bji ,dec4 #aj 0 #j #ed #dfh #agfg4 ,jan4 #ba 0 #a #j #bhf ,march #d 0 #a #aa #bcj ,from ,may #f1 which was the day after the watch arrived at the ,royal ,observatory1 to ,march #d1 #agfg1 there were six periods of six weeks each in which the watch was tried in a horizontal position2 when the gaining in these several periods was as follows3 ,during the first #f weeks it gained #acm #bjs1 answering to #c #bj of longitude4 ,in the #b;d period of #f weeks 7from ,aug4 #f to 0 #h #ag 0 #b #d ,sept4 #ag7 ,in the #c;d period 7from 0 #aj #e 0 #b #ca ,sept4 #ag to ,oct4 #bi7 ,in the #dth period 7from 0 #ab #bf 0 #c #f ,oct4 #bi to ,dec4 #bj7 ,in the #eth period 7from 0 #e #db 0 #a #be ,dec4 #bj to ,jan4 #ba7 ,in the #fth period 7from 0 #aj #ed 0 #b #dc ,jan4 #ba to ,mar4 #d7 ,it was thence concluded that ,mr4 ,harrison's watch could not be depended upon to keep the longitude within a ,west-,india voyage of six weeks1 nor to keep the longitude within half a degree for more than a fortnight2 and that it must be kept in a place where the temperature was always some degrees above freezing4#eg 7,however1 ,harrison's watch1 which was made by ,mr4 ,kendal subsequently1 succeeded so completely1 that after it had been round the world with ,captain ,cook1 in the years #aggb-agge1 the second #aj1jjjl4 was given to ,harrison47 ,in the ,act of #abth ,queen ,anne1 the comparison of chronometers was not mentioned in reference to the ,observatory duties2 but after this time they became a serious charge upon the ,observatory1 which1 it must be admitted1 is by far the best place to try chronometers3 the excellence of the instruments1 and the frequent observations of the heavenly bodies over the meridian1 will always render the rate of going of the ,observatory clock better known than can be expected of the clock in most other places4 ,after ,mr4 ,harrison's watch was tried1 some watches by ,earnshaw1 ,mudge1 and others1 were rated and examined by the ,astronomer-,royal4 ,at the ,royal ,observatory1 ,greenwich1 there are frequently above #ajj chronometers being rated1 and there have been as many as #agj at one time4 ,they are rated daily by two observers1 the process being as follows4 ,at a certain time every day two assistants in charge repair to the chronometer-room1 where is a time-piece set to true time2 one winds up each with its own key1 and the second follows after some little time and verifies the fact that each is wound4 ,one assistant then looks at each watch in succession1 counting the beats of the clock whilst he compares the chronometer by the eye2 and in the course of a few seconds he calls out the second shown by the chronometer when the clock is at a whole minute4 ,this number is entered in a book by the other assistant1 and so on till all the chronometers are compared4 ,then the assistants change places1 the second comparing and the first writing down4 ,from these daily comparisons the daily rates are deduced1 by which the goodness of the watch is determined4 ,the errors are of two classes--that of general bad workmanship1 and that of over or under correction for temperature4 ,in the room is an apparatus in which the watch may be continually kept at temperatures exceeding #ajj by artificial heat2 and outside the window of the room is an iron cage1 in which they are subjected to low temperatures4 ,the very great care taken with all chronometers sent to the ,royal ,observatory1 as well as the perfect impartiality of the examination which each receives1 afford encouragement to their manufacture1 and are of the utmost importance to the safety and perfection of navigation4 ,we have before us now the ,report of the ,astronomer-,royal on the ,rates of ,chronometers in the year #ahed1 in which the following are the successive weekly sums of the daily rates of the first there mentioned3 ,week ending secs4 ,jan4 #ba1 loss in the week #bb 0 #bh 0 #dj ,feb4 #d 0 #aa 0 #aa 0 #ej 0 #ah 0 #di 0 #be 0 #ee ,mar4 #d 0 #fj 0 #aa 0 #fj 0 #ah 0 #ae 0 #be 0 #de ,apr4 #a 0 #dj 0 #h 0 #ae 0 #ae1 gain in the week #jd ,apr4 #bb1 0 #bf 0 #bi1 loss in the week #ad ,may #f 0 #ba 0 #ac 0 #cj 0 #bj 0 #ea 0 #bg 0 #cc ,june #c 0 #bh 0 #aj 0 #ah 0 #ag 0 #bj 0 #bd 0 #cj ,july #a 0 #be 0 #h 0 #ab ,till ,february #d the watch was exposed to the external air outside a north window2 from ,february #e to ,march #d it was placed in the chamber of a stove heated by gas to a moderate temperature2 and from ,april #bi to ,may #bj it was placed in the chamber when heated to a high temperature4 ,the advance in making chronometers since ,harrison's celebrated watch was tried at the ,royal ,observatory1 more than ninety years since1 may be judged by comparing its rates with those above4 ,,geometry ,,of ,,shells4 ,there is a mechanical uniformity observable in the description of shells of the same species which at once suggests the probability that the generating figure of each increases1 and that the spiral chamber of each expands itself1 according to some simple geometrical law common to all4 ,to the determination of this law the operculum lends itself1 in certain classes of shells1 with remarkable facility4 ,continually enlarged by the animal1 as the construction of its shell advances so as to fill up its mouth1 the operculum measures the progressive widening of the spiral chamber by the progressive stages of its growth4 99 99 99 99 99 ,the animal1 as he advances in the construction of his shell1 increases continually his operculum1 so as to adjust it to his mouth4 ,he increases it1 however1 not by additions made at the same time all round its margin1 but by additions made only on one side of it at once4 ,one edge of the operculum thus remains unaltered as it is advanced into each new position1 and placed in a newly-formed section of the chamber similar to the last but greater than it4 ,that the same edge which fitted a portion of the first less section should be capable of adjustment so as to fit a portion of the next similar but greater section1 supposes a geometrical provision in the curved form of the chamber of great complication and difficulty4 ,but ,god hath bestowed upon this humble architect the practical skill of the learned geometrician2 and he makes this provision with admirable precision in that curvature of the logarithmic spiral which he gives to the section of the shell4 ,this curvature obtaining1 he has only to turn his operculum slightly round in its own place1 as he advances it into each newly-formed portion of his chamber1 to adapt one margin of it to a new and larger surface and a different curvature1 leaving the space to be filled up by increasing the operculum wholly on the outer margin4 99 99 99 99 99 ,why the ,mollusks1 who inhabit turbinated and discoid shells1 should1 in the progressive increase of their spiral dwellings1 affect the peculiar law of the logarithmic spiral1 is easily to be understood4 ,providence has subjected the instinct which shapes out each to a rigid uniformity of operation4--,professor ,mosely3 ,philos4 ,trans4 #ahch4 ,,hydraulic ,,theory ,,of ,,shells4 ,how beautifully is the wisdom of ,god developed in shaping out and moulding shells6 and especially in the particular value of the constant angle which the spiral of each species of shell affects1--a value connected by a necessary relation with the economy of the material of each1 and with its stability and the conditions of its buoyancy4 ,thus the shell of the ,nautilus ,pompilius has1 hydrostatically1 an ,a-statical surface4 ,if placed with any portion of its surface upon the water1 it will immediately turn over towards its smaller end1 and rest only on its mouth4 ,those conversant with the theory of floating bodies will recognise in this an interesting property4--,ibid4 ,,services ,,of ,,sea-,,shells ,,and ,,animalcules4 ,dr4 ,maury is disposed to regard these beings as having much to do in maintaining the harmonies of creation1 and the principles of the most admirable compensation in the system of oceanic circulation4 8,we may even regard them as regulators1 to some extent1 of climates in parts of the earth far removed from their presence4 ,there is something suggestive both of the grand and the beautiful in the idea that while the insects of the sea are building up their coral islands in the perpetual summer of the tropics1 they are also engaged in dispensing warmth to distant parts of the earth1 and in mitigating the severe cold of the polar winter40 ,,depth ,,of ,,the ,,primeval ,,seas4 ,professor ,forbes1 in a communication to the ,royal ,society1 states that not only the colour of the shells of existing mollusks ceases to be strongly marked at considerable depths1 but also that well-defined patterns are1 with very few and slight exceptions1 presented only by testacea inhabiting the littoral1 circumlittoral1 and median zones4 ,in the ,mediterranean1 only one in eighteen of the shells taken from below #ajj fathoms exhibit any markings of colour1 and even the few that do so are questionable inhabitants of those depths4 ,between #cj and #ce fathoms1 the proportion of marked to plain shells is rather less than one in three2 and between the margin and two fathoms the striped or mottled species exceed one-half of the total number4 ,in our own seas1 ,professor ,forbes observes that testacea taken from below #ajj fathoms1 even when they are individuals of species vividly striped or banded in shallower zones1 are quite white or colourless4 ,at between #fj and #hj fathoms1 striping and banding are rarely presented by our shells1 especially in the northern provinces2 from #ej fathoms1 shallow bands1 colours1 and patterns1 are well marked4 ,the relation of these arrangements of colour to the degree of light penetrating the different zones of depth is a subject well worthy of minute inquiry4 ,,natural ,,water-,,purifiers4 ,mr4 ,warrington kept for a whole year twelve gallons of water in a state of admirably balanced purity by the following beautiful action3 ,in the tank1 or aquarium1 were two gold fish1 six water-snails1 and two or three specimens of that elegant aquatic plant ,valisperia sporalis1 which1 before the introduction of the water-snails1 by its decayed leaves caused a growth of slimy mucus1 and made the water turbid and likely to destroy both plants and fish4 ,but under the improved arrangement the slime1 as fast as it was engendered1 was consumed by the water-snails1 which reproduced it in the shape of young snails1 which furnished a succulent food to the fish4 ,meanwhile the ,valisperia plants absorbed the carbonic acid exhaled by the respiration of their companions1 fixing the carbon in their growing stems and luxuriant blossoms1 and refreshing the oxygen 7during sunshine in visible little streams7 for the respiration of the snails and the fish4 ,the spectacle of perfect equilibrium thus simply maintained between animal1 vegetable1 and inorganic activity1 was strikingly beautiful2 and such means might possibly hereafter be made available on a large scale for keeping tanked water sweet and clean4--,quarterly ,review1 #ahej4 ,,how ,,to ,,imitate ,,sea-,,water4 ,the demand for ,sea-water to supply the ,marine ,aquarium--now to be seen in so many houses--induced ,mr4 ,gosse to attempt the manufacture of ,sea-water1 more especially as the constituents are well known4 ,he accordingly took ,scheveitzer's analysis of ,sea-water for his guide4 ,in one thousand grains of sea-water taken off ,brighton1 it gave3 water1 #ifdgdd2 chloride of sodium1 #bgjei2 chloride of magnesium1 #cfff2 chloride of potassium1 #igee2 bromide of magnesium1 #jbi2 sulphate of magnesia1 #bbie2 sulphate of lime1 #adjg2 carbonate of lime1 #jjcc3 total1 #iiiiih4 ,omitting the bromide of magnesium1 the carbonate of lime1 and the sulphate of lime1 as being very small quantities1 the component parts were reduced to common salt1 #c oz42 ,epsom salts1 oz42 chloride of magnesium1 #bjj grains troy2 chloride of potassium1 #dj grains troy2 and four quarts of water4 ,next day the mixture was filtered through a sponge into a glass jar1 the bottom covered with shore-pebbles and fragments of stone and fronds of green sea-weed4 ,a coating of green spores was soon deposited on the sides of the glass1 and bubbles of oxygen were copiously thrown off every day under the excitement of the sun's light4 ,in a week ,mr4 ,gosse put in species of ,actinia ,bowerbankia1 ,cellularia1 ,serpula1 c4 with some red sea-weeds2 and the whole throve well4 ,,velocity ,,of ,,impressions ,,transmitted ,,to ,,the ,,brain4 ,professor ,helmholtz of ,knigsberg has1 by the electro-magnetic method1#eh ascertained that the intelligence of an impression made upon the ends of the nerves in communication with the skin is transmitted to the brain with a velocity of about #aie feet per second4 ,arrived at the brain1 about one-tenth of a second passes before the will is able to give the command to the nerves that certain muscles shall execute a certain motion1 varying in persons and times4 ,finally1 about #a_/ajjth of a second passes after the receipt of the command before the muscle is in activity4 ,in all1 therefore1 from the excitation of the sensitive nerves till the moving of the muscle1 #a to #b_/ajths of a second are consumed4 ,intelligence from the great toe arrives about #a_/cjth of a second later than from the ear or the face4 ,thus we see that the differences of time in the nervous impressions1 which we are accustomed to regard as simultaneous1 lie near our perception4 ,we are taught by astronomy that1 on account of the time taken to propagate light1 we now see what has occurred in the fixed stars years ago2 and that1 owing to the time required for the transmission of sound1 we hear after we see is a matter of daily experience4 ,happily the distances to be traversed by our sensuous perceptions before they reach the brain are so short that we do not observe their influence1 and are therefore unprejudiced in our practical interest4 ,with an ordinary whale the case is perhaps more dubious2 for in all probability the animal does not feel a wound near its tail until a second after it has been inflicted1 and requires another second to send the command to the tail to defend itself4 ,,photographs ,,on ,,the ,,retina4 ,the late ,rev4 ,dr4 ,scoresby explained with much minuteness and skill the varying phenomena which presented themselves to him after gazing intently for some time on strongly-illuminated objects1--as the sun1 the moon1 a red or orange or yellow wafer on a strongly-contrasted ground1 or a dark object seen in a bright field4 ,the doctor explained1 upon removing the eyes from the object1 the early appearance of the picture or image which had been thus 8photographed on the ,retina10 with the photochromatic changes which the picture underwent while it still retained its general form and most strongly-marked features2 also1 how these pictures1 when they had almost faded away1 could at pleasure1 and for a considerable time1 be renewed by rapidly opening and shutting the eyes4 ,,direct ,,exploration ,,of ,,the ,,interior ,,of ,,the ,,eye4 ,dr4 ,s4 ,wood of ,cincinnati states1 that by means of a small double convex lens of short focus held near the eye1--that organ looking through it at a candle twelve or fifteen feet distant1--there will be perceived a large luminous disc1 covered with dark and light spots and dark streaks1 which1 after a momentary confusion1 will settle down into an unchanging picture1 which picture is composed of the organs or internal parts of the eye4 ,the eye is thus enabled to view its own internal organisation1 to have a beautiful exhibition of the vessels of the cornea1 of the distribution of the lachrymas secretions in the act of winking1 and to see into the nature and cause of musc volitantes4 ,,nature ,,of ,,the ,,candle-,,flame4 ,m4 ,volger has subjected this ,flame to a new analysis4 ,he finds that the so-called flame-bud1 a globular blue flaminule1 is first produced at the summit of the wick3 this is the result of the combustion of carbonic oxide1 hydrogen1 and carbon1 and is surrounded by a reddish-violet halo1 the veil4 ,the increased heat now gives rise to the actual flame1 which shoots forth from the expanding bud1 and is then surrounded at its inferior portion only by the latter4 ,the interior consists of a dark gaseous cone1 containing the immediate products of the decomposition of the fatty acids1 and surrounded by another dark hollow cone1 the inner cap4 ,here we already meet with carbon and hydrogen1 which have resulted from the process of decomposition2 and we distinguish this cone from the inner one by its yielding soot4 ,the external cap constitutes the most luminous portion of the flame1 in which the hydrogen is consumed and the carbon rendered incandescent4 ,the surrounding portion is but slightly luminous1 deposits no soot1 and in it the carbon and hydrogen are consumed4--,liebig's ,annual ,report4 ,,how ,,soon ,a ,,corpse ,,decays4 ,mr4 ,lewis1 of the ,general ,board of ,health1 from his examination of the contents of nearly #ajj coffins in the vaults and catacombs of ,london churches1 concludes that the complete decomposition of a corpse1 and its resolution into its ultimate elements1 takes place in a leaden coffin with extreme slowness4 ,in a wooden coffin the remains1 with the exception of the bones1 vanish in from two to five years4 ,this period depends upon the quality of the wood1 and the free access of air to the coffins4 ,but in leaden coffins1 #ej1 #fj1 #hj1 and even #ajj years are required to accomplish this4 8,i have opened10 says ,mr4 ,lewis1 8a coffin in which the corpse had been placed for nearly a century2 and the ammoniacal gas formed dense white fumes when brought in contact with hydrochloric-acid gas1 and was so powerful that the head could not remain in it for more than a few seconds at a time40 ,to render the human body perfectly inert after death1 it should be placed in a light wooden coffin1 in a pervious soil1 from five to eight feet deep4 ,,musket-,,balls ,,found ,,in ,,ivory4 ,the ,ceylon sportsman1 in shooting elephants1 aims at a spot just above the proboscis4 ,if he fires a little too low1 the ball passes into the tusk-socket1 causing great pain to the animal1 but not endangering its life2 and it is immediately surrounded by osteo-dentine4 ,it has often been a matter of wonder how such bodies should become completely imbedded in the substance of the tusk1 sometimes without any visible aperture2 or how leaden bullets become lodged in the solid centre of a very large tusk without having been flattened1 as they are found by the ivory-turner4 ,the explanation is as follows3 ,a musket-ball aimed at the head of an elephant may penetrate the thin bony socket and the thinner ivory parietes of the wide conical pulp-cavity occupying the inserted base of the tusk2 if the projectile force be there spent1 the ball will gravitate to the opposite and lower side of the pulp-cavity4 ,the pulp becomes inflamed1 irregular calcification ensues1 and osteo-dentine is formed around the ball4 ,the pulp then resumes its healthy state and functions1 and coats the osteo-dentine enclosing the ball1 together with the root of the conical cavity into which the mass projects1 with layers of normal ivory4 ,the hole formed by the ball is soon replaced1 and filled up by osteo-dentine1 and coated with cement4 ,meanwhile1 by the continued progress of growth1 the enclosed ball is pushed forward to the middle of the solid tusk2 or if the elephant be young1 the ball may be carried forward by growth and wear of the tusk until its base has become the apex1 and become finally exposed and discharged by the continual abrasion to which the apex of the tusk is subjected4--,professor ,owen4 ,,nature ,,of ,,the ,,sun4 ,to the article at pp4 #ei-fj should be added the result obtained by ,dr4 ,woods of ,parsonstown1 and communicated to the ,philosophical ,magazine for ,july #ahed4 ,dr4 ,woods1 from photographic experiment1 has no doubt that the light from the centre of flame acts more energetically than that from the edge on a surface capable of receiving its impression2 and that light from a luminous solid body acts equally powerfully from its centre or its edges3 wherefore ,dr4 ,woods concludes that1 as the sun affects a sensitive plate similarly with flame1 it is probable its light-producing portion is of a similar nature4 ,note to 8,,is ,,the ,,heat ,,of ,,the ,,sun ,,decreasing80 at page #fe4--;,dr4 ,vaughan of ,cincinnati has stated to the ,british ,association3 8,from a comparison of the relative intensity of solar1 lunar1 and artificial light1 as determined by ,euler and ,wollaston1 it appears that the rays of the sun have an illuminating power equal to that of #ad1jjj candles at a distance of one foot1 or of #cejj1jjjjjj1jjjjjj1jjjjjj1jjjjjj candles at a distance of #ie1jjj1jjj miles4 ,it follows that the amount of light which flows from the solar orb could be scarcely produced by the daily combustion of #bjj globes of tallow1 each equal to the earth in magnitude4 ,a sphere of combustible matter much larger than the sun itself should be consumed every ten years in maintaining its wonderful brilliancy2 and its atmosphere1 if pure oxygen1 would be expended before a few days in supporting so great a conflagration4 ,an illumination on so vast a scale could be kept up only by the inexhaustible magazine of ether disseminated through space1 and ever ready to manifest its luciferous properties on large spheres1 whose attraction renders it sufficiently dense for the play of chemical affinity4 ,accordingly suns derive the power of shedding perpetual light1 not from their chemical constitution1 but from their immense mass and their superior attractive power40 ,,planetoids4 ---------------------------------------- ------------------------ ,no4 discovered ,date of ,place of by each ,name4 ,discovery4 ,discoverer4 ,discovery4astronomer4 ---------------------------------------- ------------------------ ,mercury1 ,mars1 ,known ,venus1 ,jupiter1 to the 444 444 -- ,earth1 ,saturn1 ancients4 ,uranus #agha1 ,march #ac ,w4 ,herschel ,bath -- ,neptune#ei #ahdf1 ,sept4 #bc ,galle ,berlin -- #a ,ceres #ahja1 ,jan4 #a ,piazzi ,palermo #a #b ,pallas #ahjb1 ,march #bh ,olbers ,bremen #a #c ,juno #ahjd1 ,sept4 #a ,harding ,lilienthal #a #d ,vesta #ahjg1 ,march #bi ,olbers ,bremen #b #e ,astra #ahde1 ,dec4 #h ,encke ,driesen #a #f ,hebe #ahdg1 ,july #a ,encke ,driesen #b #g ,iris #ahdg1 ,august #ac;,hind ,london #a #h ,flora #ahdg1 ,oct4 #ah ,hind ,london #b #i ,metis #ahdh1 ,april #be ,graham ,markree #a #aj ,hygeia #ahdi1 ,april #ab ,gasperis ,naples #a #aa ,parthenope #ahej1 ,may #aa ,gasperis ,naples #b #ab ,victoria #ahej1 ,sept4 #ac ,hind ,london #c #ac ,egeria #ahej1 ,nov4 #b ,gasperis ,naples #c #ad ,irene #ahea1 ,may #ai ,hind ,london #d #ae ,eunomia #ahea1 ,july #bi ,gasperis ,naples #d #af ,psyche #aheb1 ,march #ag ,gasperis ,naples #e #ag ,thetis #aheb1 ,april #ag ,luther ,bilk #a #ah ,melpomene #aheb1 ,june #bd ,hind ,london #e #ai ,fortuna #aheb1 ,august #bb;,hind ,london #f #bj ,massilia #aheb1 ,sept4 #ai ,gasperis ,naples #f #ba ,lutetia #aheb1 ,nov4 #ae ,goldschmidt ,paris #a #bb ,calliope #aheb1 ,nov4 #af ,hind ,london #g #bc ,thalia #aheb1 ,dec4 #ae ,hind ,london #h #bd ,themis #ahec1 ,april #e ,gasperis ,naples #g #be ,phocea #ahec1 ,april #f ,chacornac ,marseilles #a #bf ,proserpine #ahec1 ,may #e ,luther ,bilk #b #bg ,euterpe #ahec1 ,nov4 #h ,hind ,london #i #bh ,bellona #ahed1 ,march #a ,luther ,bilk #c #bi ,amphitrite #ahed1 ,march #a ,marth ,london #a #cj ,urania #ahed1 ,july #bb ,hind ,london #aj #ca ,euphrosyne #ahed1 ,sept4 #a ,furguson ,washington #a #cb ,pomona #ahed1 ,oct4 #bf ,goldschmidt ,paris #b #cc ,polyhymnia #ahed1 ,oct4 #bh ,chacornac ,paris #b #cd ,circe #ahee1 ,april #f ,chacornac ,paris #c #ce ,leucothea #ahee1 ,april #ai ,luther ,bilk #d #cf ,atalante #ahee1 ,oct4 #e ,goldschmidt ,paris #c #cg ,fides #ahee1 ,oct4 #e ,luther ,bilk #e #ch ,leda #ahef1 ,jan4 #ab ,chacornac ,paris #d #ci ,ltitia #ahef1 ,feb4 #h ,chacornac ,paris #e #dj ,harmonia #ahef1 ,march #ca ,goldschmidt ,paris #d #da ,daphne #ahef1 ,may #bb ,goldschmidt ,paris #e #db ,isis #ahef1 ,may #bc ,pogson ,oxford #a #dc ,ariadne #aheg1 ,april #ae ,pogson ,oxford #b #dd ,nysa #aheg1 ,may #bg ,goldschmidt ,paris #f #de ,eugenia #aheg1 ,june #bh ,goldschmidt ,paris #g #df ,hastia #aheg1 ,august #af,pogson ,oxford #c #dg ,aglaia #aheg1 ,sept4 #ae ,luther ,bilk #f #dh ,doris #aheg1 ,sept4 #ai ,goldschmidt ,paris #h #di ,pales #aheg1 ,sept4 #ai ,goldschmidt ,paris #i #ej ,virginia #aheg1 ,oct4 #d ,furguson ,washington #b #ea ,nemausa #aheh1 ,jan4 #bb ,laurent ,nismes #a #eb ,europa #aheh1 ,feb4 #f ,goldschmidt ,paris #aj #ec ,calypso #aheh1 ,april #h ,luther ,bilk #g #ed ,alexandra #aheh1 ,sept4 #aa ,goldschmidt ,paris #aa #ee 7,not named7 #aheh1 ,sept4 #aa ,searle ,albany #a ---------------------------------------- ------------------------ ,,the ,,comet ,,of ,,donati4 ,while this sheet was passing through the press1 the attention of astronomers1 and of the public generally1 was drawn to the fact of the above ,comet passing 7on ,oct4 #ah7 within nine millions of miles of the planet ,venus1 or less than #i_/ajjths of the earth's distance from the ,sun4 8,and 7says ,mr4 ,hind1 the astronomer71 it is obvious that if the comet had reached its least distance from the sun a few days earlier than it has done1 the planet might have passed through it2 and ,i am very far from thinking that close proximity to a comet of this description would be unattended with danger4 ,the inhabitants of ,venus will witness a cometary spectacle far superior to that which has recently attracted so much attention here1 inasmuch as the tail will doubtless appear twice as long from that planet as from the earth1 and the nucleus proportionally more brilliant40 ,this ,comet was first discovered by ,dr4 ,g4 ,b4 ,donati1 astronomer at the ,museum of ,florence1 on the evening of the #b;d of ,june1 in right ascension #ada #ah1 and north declination #bc #dg1 corresponding to a position near the star ,leonis4 ,previous to this date we had no knowledge of its existence1 and therefore it was not a predicted comet2 neither is it the one last observed in #aeef4 ,at the date of discovery it was distant from the earth #bbh1jjj1jjj of miles1 and was an excessively faint object in the largest telescopes4 ,the tail1 from ,october #b to #af1 when the comet was most conspicuous1 appears to have maintained an average length of at least #dj1jjj1jjj miles1 subtending an angle varying from #cj to #dj4 ,the dark line or space down the centre1 frequently remarked in other great comets1 was a striking characteristic in that of ,donati4 ,the nucleus1 though small1 was intensely brilliant in powerful instruments1 and for some time bore high magnifiers to much greater advantage than is usual with these objects4 ,in several respects this comet resembled the famous ones of #agdd1 #afhj1 and #ahaa1 particularly as regards the signs of violent agitation going on in the vicinity of the nucleus1 such as the appearance of luminous jets1 spiral offshoots1 c41 which rapidly emanated from the planetary point and as quickly lost themselves in the general nebulosity of the head4 ,on the #eth ,oct4 the most casual observer had an opportunity of satisfying himself as to the accuracy of the mathematical theory of the motions of comets in the near approach of the nucleus of ,donati's to ,arcturus1 the principal star in the constellation ,bootes4 ,the circumstance of the appulse was very nearly as predicted by ,mr4 ,hind4 ,the comet1 according to the investigations by ,m4 ,loewy1 of the ,observatory of ,vienna1 arrived at its least distance from the sun a few minutes after eleven o'clock on the morning of the #cjth of ,september2 its longitude1 as seen from the sun at this time1 being #cf #ac1 and its distance from him #ee1jjj1jjj miles4 ,the longer diameter of its orbit is #ahd times that of the earth's1 or #ce1ajj1jjj1jjj miles2 yet this is considerably less than #a_/ajjjth of the distance of the nearest fixed star4 ,as an illustration1 let any one take a half-sheet of note-paper1 and marking a circle with a sixpence in one corner of it1 describe therein our solar system1 drawing the orbits of the earth and the inferior planets as small as he can by the aid of a magnifying-glass4 ,if the circumference of the sixpence stands for the orbit of ,neptune1 then an oval filling the page will fairly represent the orbit of ,donati's comet2 and if the paper be laid upon the pavement under the west door of ,st4 ,paul's ,cathedral1 ,london1 the length of that edifice will inadequately represent the distance of the nearest fixed star4 ,the time of revolution resulting from ,mr4 ,loewy's calculations is #bdie years1 which is about #ejj years less than that of the comet of #ahaa during the period it was visible from the earth4 ,that the comet should take more than #bjjj years to travel round the above page of note-paper is explained by its great diminution of speed as it recedes from the sun4 ,at its perihelion it travelled at the rate of #abg1jjj miles an hour1 or more than twice as fast as the earth1 whose motion is about #ajjj miles a minute4 ,at its aphelion1 however1 or its greatest distance from the sun1 the comet is a very slow body1 sailing at the rate of #dhj miles an hour1 or only eight times the speed of a railway express4 ,at this pace1 were it to travel onward in a straight line1 the lapse of a million of years would find it still travelling half way between our sun and the nearest fixed star4 ,as this comet last visited us between #bjjj and #bdie years since1 we know that its appearance was at an interesting period of the world's history4 ,it might have terrified the ,athenians into accepting the bloody code of ,draco4 ,it might have announced the destruction of ,nineveh1 or of ,babylon1 or the capture of ,jerusalem by ,nebuchadnezzar4 ,it might have been seen by the expedition which sailed round ,africa in the reign of ,pharaoh ,necho4 ,it might have given interest to the foundation of the ,pythian games4 ,within the probable range of its last visitation are comprehended the whole of the great events of the history of ,greece2 and among the spectators of the comet may have been the so-called sages of ,greece and even the prophets of ,holy ,writ3 ,thales might have attempted to calculate its return1 and ,jeremiah might have tried to read its warning4--,abridged from a ,communication from ,mr4 ,hind to the ,times1 and from a ,leader in that ,journal4 ,,footnotes3 #a ,from a photograph1 with figures1 to show the relative size of the tube aperture4 #b ,weld's ,history of the ,royal ,society1 vol4 ii4 p4 #ahh4 #c ,dr4 ,whewell 7,bridgewater ,treatise1 p4 #bff7 well observes1 that ,boyle and ,pascal are to hydrostatics what ,galileo is to mechanics1 and ,copernicus1 ,kepler1 and ,newton are to astronomy4 #d ,the ,rev4 ,mr4 ,turnor recollects that ,mr4 ,jones1 the tutor1 mentioned1 in one of his lectures on optics1 that the reflecting telescope belonging to ,newton was then lodged in the observatory over the gateway2 and ,mr4 ,turnor thinks that he once saw it1 with a finder affixed to it4 #e ,the story of the dog 8,diamond0 having caused the burning of certain papers is laid in ,london1 and in ,newton's later years4 ,in the notes to ,maude's ,wenleysdale1 a person then living 7#aghj7 relates1 that ,sir ,isaac being called out of his study to a contiguous room1 a little dog1 called ,diamond1 the constant but incurious attendant of his master's researches1 happened to be left among the papers1 and by a fatality not to be retrieved1 as it was in the latter part of ,sir ,isaac's days1 threw down a lighted candle1 which consumed the almost finished labour of some years4 ,sir ,isaac returning too late but to behold the dreadful wreck1 rebuked the author of it with an exclamation 7ad sidera palmas71 8,o ,diamond6 ,diamond6 thou little knowest the mischief done60 without adding a single stripe4 ,m4 ,biot gives this fiction as a true story1 which happened some years after the publication of the ,principia2 and he characterises the accident as having deprived the sciences forever of the fruit of so much of ,newton's labours4--,brewster's ,life1 vol4 ii4 p4 #aci1 note4 ,dr4 ,newton remarks1 that ,sir ,isaac never had any communion with dogs or cats2 and ,sir ,david ,brewster adds1 that the view which ,m4 ,biot has taken of the idle story of the dog ,diamond1 charged with fire-raising among ,newton's manuscripts1 and of the influence of this accident upon the mind of their author1 is utterly incomprehensible4 ,the fiction1 however1 was turned to account in giving colour to ,m4 ,biot's misrepresentation4 #f ,bohn's edition4 #g ,when at ,pisa1 many years since1 ,captain ,basil ,hall investigated the origin and divergence of the tower from the perpendicular1 and established completely to his own satisfaction that it had been built from top to bottom originally just as it now stands4 ,his reasons for thinking so were1 that the line of the tower1 on that side towards which it leans1 has not the same curvature as the line on the opposite1 or what may be called the upper side4 ,if the tower had been built upright1 and then been made to incline over1 the line of the wall on that side towards which the inclination was given would be more or less concave in that direction1 owing to the nodding or 8swagging over0 of the top1 by the simple action of gravity acting on a very tall mass of masonry1 which is more or less elastic when placed in a sloping position4 ,but the contrary is the fact2 for the line of wall on the side towards which the tower leans is decidedly more convex than the opposite side4 ,captain ,hall had therefore no doubt whatever that the architect1 in rearing his successive courses of stones1 gained or stole a little at each layer1 so as to render his work less and less overhanging as he went up2 and thus1 without betraying what he was about1 really gained stability4--,see ,patchwork4 #h ,lord ,bacon proposed that1 in order to determine whether the gravity of the earth arises from the gravity of its parts1 a clock-pendulum should be swung in a mine1 as was recently done at ,harton colliery by the ,astronomer-,royal4 ,when1 in #ahab1 ,ampre noted the phenomena of the pendulum1 and showed that its movement was produced only when the eye of the observer was fixed on the instrument1 and endeavoured to prove thereby that the motion was due to a play of the muscles1 some members of the ,french ,academy objected to the consideration of a subject connected to such an extent with superstition4 #i ,this curious fact was first recorded by ,pepys1 in his ,diary1 under the date #cast of ,july #affe4 #aj ,the result of these experiments for ascertaining the variation of the gravity at great depths1 has proved beyond doubt that the attraction of gravitation is increased at the depth of #abej feet by #a_/aijjj part4 #aa ,see the account of ,mr4 ,baily's researches 7with two illustrations7 in ,things not generally ,known1 p4 vii41 and 8,weight of the ,earth10 p4 #af4 #ab ,fizeau gives his result in leagues1 reckoning twenty-five to the equatorial degree4 ,he estimates the velocity of light at #gj1jjj such leagues1 or about #baj1jjj miles in the second4 #ac ,see ,things not generally ,known1 p4 #hh4 #ad ,some time before the first announcement of the discovery of sun-painting1 the following extract from ,sir ,john ,herschel's ,treatise on ,light1 in the ,encyclopdia ,metropolitana1 appeared in a popular work entitled ,parlour ,magic3 8,strain a piece of paper or linen upon a wooden frame1 and sponge it over with a solution of nitrate of silver in water2 place it behind a painting upon glass1 or a stained window-pane1 and the light1 traversing the painting or figures1 will produce a copy of it upon the prepared paper or linen2 those parts in which the rays were least intercepted being the shadows of the picture40 #ae ,in his book on ,colours1 ,mr4 ,doyle informs us that divers1 if not all1 essential oils1 as also spirits of wine1 when shaken1 8have a good store of bubbles1 which appear adorned with various and lively colours40 ,he mentions also that bubbles of soap and turpentine exhibit the same colours1 which 8vary according to the incidence of the sight and the position of the eye20 and he had seen a glass-blower blow bubbles of glass which burst1 and displayed 8the varying colours of the rainbow1 which were exceedingly vivid40 #af ,the original idea is even attributed to ,copernicus4 ,m4 ,blundevile1 in his ,treatise on ,cosmography1 #aeid1 has the following passage1 perhaps the most distinct recognition of authority in our language3 8,how prooue 7prove7 you that there is but one world8 ,by the authoritie of ,aristotle1 who saieth that if there were any other world out of this1 then the earth of that world would mooue 7move7 towards the centre of this world10 c4 ,sir ,isaac ,newton1 in a conversation with ,conduitt1 said he took 8all the planets to be composed of the same matter with the earth1 viz4 earth1 water1 and stone1 but variously concocted40 #ag ,sir ,william ,herschel ascertained that our solar system is advancing towards the constellation ,hercules1 or more accurately to a point in space whose right ascension is #bde #eb #cj1 and north polar distance #dj #bb2 and that the quantity of this motion is such1 that to an astronomer placed in ,sirius1 our sun would appear to describe an arc of little more than a second every year4--,north-,british ,review1 ,no4 #c4 #ah ,see ,m4 ,arago's researches upon this interesting subject1 in ,things not generally ,known1 p4 #d4 #ai ,this eloquent advocacy of the doctrine of 8,more ,worlds than ,one0 7referred to at p4 #ea7 is from the author's valuable ,outlines of ,astronomy4 #bj ,professor ,challis1 of the ,cambridge ,observatory1 directing the ,northumberland telescope of that institution to the place assigned by ,mr4 ,adams's calculations and its vicinity on the #dth and #abth of ,august #ahdf1 saw the planet on both those days1 and noted its place 7among those of other stars7 for re-observation4 ,he1 however1 postponed the comparison of the places observed1 and not possessing ,dr4 ,bremiker's chart 7which would at once have indicated the presence of an unmapped star71 remained in ignorance of the planet's existence as a visible object till the announcement of such by ,dr4 ,galle4 #ba ,for several interesting details of ,comets1 see 8,destruction of the ,world by a ,comet10 in ,popular ,errors ,explained and ,illustrated1 new edit4 pp4 #afe-afh4 #bb ,the letters of ,sir ,isaac ,newton to ,dr4 ,bentley1 containing suggestions for the ,boyle ,lectures1 possess a peculiar interest in the present day4 8,they show0 7says ,sir ,david ,brewster7 8that the nebular hypothesis1 the dull and dangerous heresy of the age1 is incompatible with the established laws of the material universe1 and that an omnipotent arm was required to give the planets their positions and motions in space1 and a presiding intelligence to assign to them the different functions they had to perform40--,life of ,newton1 vol4 ii4 #bc ,the constitution of the nebul in the constellation of ,orion has been resolved by this instrument2 and by its aid the stars of which it is composed burst upon the sight of man for the first time4 #bd ,several specimens of ,meteoric ,iron are to be seen in the ,mineralogical ,collection in the ,british ,museum4 #be ,life of ,sir ,isaac ,newton1 vol4 i4 p4 #fb4 #bf ,description of the ,monster ,telescope1 by ,thomas ,woods1 ,m4,d4 #dth edit4 #ahea4 #bg ,this instrument also discovered a multitude of new objects in the moon2 as a mountainous tract near ,ptolemy1 every ridge of which is dotted with extremely minute craters1 and two black parallel stripes in the bottom of ,aristarchus4 ,dr4 ,robinson1 in his address to the ,british ,association in #ahdc1 stated that in this telescope a building the size of the ,court-house at ,cork would be easily visible on the lunar surface4 #bh ,mr4 ,hopkins supports his ,glacial ,theory by regarding the ,waves of ,translation1 investigated by ,mr4 ,scott ,russell1 as furnishing a sufficient moving power for the transportation of large rounded boulders1 and the formation of drifted gravel4 ,when these waves of translation are produced by the sudden elevation of the surface of the sea1 the whole mass of water from the surface to the bottom of the ocean moves onward1 and becomes a mechanical agent of enormous power4 ,following up this view1 ,mr4 ,hopkins has shown that 8elevations of continental masses of only #ej feet each1 and from beneath an ocean having a depth of between #cjj and #djj feet1 would cause the most powerful divergent waves1 which could transport large boulders to great distances40 #bi ,it is scarcely too much to say1 that from the collection of specimens of building-stones made upon this occasion1 and first deposited in a house in ,craig's ,court1 ,charing ,cross1 originated1 upon the suggestion of ,sir ,henry ,delabeche1 the magnificent ,museum of ,practical ,geology in ,jermyn ,street2 one of the most eminently practical institutions of this scientific age4 #cj ,mr4 ,r4 ,mallet1 ,f4,r4,s41 and his son ,dr4 ,mallet1 have constructed a seismographic map of the world1 with seismic bands in their position and relative intensity2 and small black discs to denote volcanoes1 femaroles1 and soltataras1 and shades indicating the areas of subsidence4 #ca ,it has been computed that the shock of this earthquake pervaded an area of #gjj1jjj miles1 or the twelfth part of the circumference of the globe4 ,this dreadful shock lasted only five minutes2 and nearly the whole of the population being within the churches 7on the feast of ,all ,saints71 no less than #cj1jjj persons perished by the fall of these edifices4--,see ,daubeny on ,volcanoes2 ,translator's note1 ,humboldt's ,cosmos4 #cb ,mr4 ,murray mentions1 on the authority of the ,rev4 ,dr4 ,robinson1 of the ,observatory at ,armagh1 that a rough diamond with a red tint1 and valued by ,mr4 ,rundell at twenty guineas1 was found in ,ireland1 many years since1 in the bed of a brook flowing through the county of ,fermanagh4 #cc ,the use of malachite in ornamental work is very extensive in ,russia4 ,thus1 to the ,great ,exhibition of #ahea were sent a pair of folding-doors veneered with malachite1 #ac feet high1 valued at #fjjjl42 malachite cases and pedestals from #aejjl4 to #cjjjl4 a-piece1 malachite tables #djjl41 and chairs #aejl4 each4 #cd ,longfellow has written some pleasing lines on 8,the ,fiftieth ,birthday of ,m4 ,agassiz4 ,may #bh1 #aheg10 appended to 8,the ,courtship of ,miles ,standish10 #aheh4 #ce ,the sloth only deserves its name when it is obliged to attempt to proceed along the ground2 when it has any thing which it can lay hold of it is agile enough4 #cf ,dr4 ,a4 ,thomson has communicated to ,jameson's ,journal1 ,no4 #aab1 a ,description of the ,caves in the ,north ,island1 with some general observations on this genus of birds4 ,he concludes them to have been indolent1 dull1 and stupid2 to have lived chiefly on vegetable food in mountain fastnesses and secluded caverns4 ,in the picture-gallery at ,drayton ,manor1 the seat of ,sir ,robert ,peel1 hangs a portrait of ,professor ,owen1 and in his hand is depicted the tibia of a ,moa4 #cg ,according to the law of correlation1 so much insisted on by ,cuvier1 a superior character implies the existence of its inferiors1 and that too in definite proportions and constant connections2 so that we need only the assurance of one character1 to be able to reconstruct the whole animal4 ,the triumph of this system is seen in the reconstruction of extinct animals1 as in the above case of the ,dinornis1 accomplished by ,professor ,owen4 #ch ,not only at ,london1 but at ,paris1 ,vienna1 ,berlin1 ,turin4 ,st4 ,petersburg1 and almost every other capital in ,europe2 at ,liege1 ,caen1 ,montpellier1 ,toulouse1 and several other large towns1--wherever1 in fact1 there are not great local obstacles1--the tendency of the wealthier inhabitants to group themselves to the west is as strongly marked as in the ,british metropolis4 ,at ,pompeii1 and other ancient towns1 the same thing maybe noticed2 and where the local configuration of the town necessitates an increase in a different direction1 the moment the obstacle ceases houses spread towards the west4 #ci ,by far the most complete set of experiments on the ,radiation of ,heat from the ,earth's ,surface at ,night which have been published since ,dr4 ,wells's ,memoir ,on ,dew1 are those of ,mr4 ,glaisher1 ,f4,r4,s41 ,philos4 ,trans4 for #ahdg4 #dj ,the author is largely indebted for the illustrations in this new field of research to ,lieutenant ,maury's valuable work1 ,the ,physical ,geography of the ,sea4 ,sixth edition4 ,harper1 ,new ,york2 ,low1 ,son1 and ,co41 ,london4 #da ,it is the chloride of magnesia which gives that damp sticky feeling to the clothes of sailors that are washed or wetted with salt water4 #db ,this fraction rests on the assumption that the dilatation of the substances of which the earth is composed is equal to that of glass1 that is to say1 #a_/ahjjj for #a4 ,regarding this hypothesis1 see ,arago1 in the ,annuaire for #ahcd1 pp4 #agg-aij4 #dc ,electricity1 traversing excessively rarefied air or vapours1 gives out light1 and doubtless also heat4 ,may not a continual current of electric matter be constantly circulating in the sun's immediate neighbourhood1 or traversing the planetary spaces1 and exerting in the upper regions of its atmosphere those phenomena of which1 on however diminutive a scale1 we have yet an unequivocal manifestation in our ,aurora ,borealis8 #dd ,could we by mechanical pressure force water into a solid state1 an immense quantity of heat would be set free4 #de ,see ,mr4 ,hunt's popular work1 ,the ,poetry of ,science2 or1 ,studies of ,physical ,phenomena of ,nature4 ,third edition1 revised and enlarged4 ,bohn1 #ahed4 #df ,canton was the first who in ,england verified ,dr4 ,franklin's idea of the similarity of lightning and the electric fluid1 ,july #ageb4 #dg ,this is mentioned in ,procli ,diadochi ,paraphrasis ,ptolem41 #afce4 7,delambre1 ,hist4 de l',astronomie ancienne47 #dh ,the first ,variation-,compass was constructed1 before #aebe1 by an ingenious apothecary of ,seville1 ,felisse ,guillen4 ,so earnest were the endeavours to learn more exactly the direction of the curves of magnetic declination1 that in #aehe ,juan ,jayme sailed with ,francisco ,gali from ,manilla to ,acapulco1 for the sole purpose of trying in the ,pacific a declination instrument which he had invented4--,humboldt4 #di ,gilbert was surgeon to ,queen ,elizabeth and ,james ,i41 and died in #afjc4 ,whewell justly assigns him an important place among the 8practical reformers of the physical sciences40 ,he adopted the ,copernican doctrine1 which ,lord ,bacon's inferior aptitude for physical research led him to reject4 #ej ,this illustration1 it will be seen1 does not literally correspond with the details which precede it4 #ea ,mr4 ,crosse gave to the meeting a general invitation to ,fyne ,court2 one of the first to accept which was ,sir ,richard ,phillips1 who1 on his return to ,brighton1 described in a very attractive manner1 at the ,sussex ,institution1 ,mr4 ,crosse's experiments and apparatus2 a report of which being communicated to the ,brighton ,herald1 was quoted in the ,literary ,gazette1 and thence copied generally into the newspapers of the day4 #eb ,these experiments were performed at the expense of the ,royal ,society1 and cost #ajl4 #es4 #f;d4 ,in the ,paper detailing the experiments1 printed in the #deth volume of the ,philosophical ,transactions1 occurs the first mention of ,dr4 ,franklin's name1 and of his theory of positive and negative electricity4--,weld's ,hist4 ,royal ,soc4 vol4 i4 p4 #dfg4 #ec ,in this year ,andrew ,crosse said3 8,i prophesy that by means of the electric agency we shall be enabled to communicate our thoughts instantaneously with the uttermost parts of the earth40 #ed ,to which paper the writer is indebted for many of these details4 #ee ,these illustrations have been in the main selected and abridged from papers in the ,companion to the ,almanac1 #aheh1 and the ,penny ,cyclopdia1 #b;d supp4 #ef ,newton was1 however1 much pestered with inquirers2 and a ,correspondent of the ,gentleman's ,magazine1 in #aghd1 relates that he once had a transient view of a ,ms4 in ,pope's handwriting1 in which he read a verified anecdote relating to the above period4 ,sir ,isaac being often interrupted by ignorant pretenders to the discovery of the longitude1 ordered his porter to inquire of every stranger who desired admission whether he came about the longitude1 and to exclude such as answered in the affirmative4 ,two lines in ,pope's ,ms41 as the ,correspondent recollects1 ran thus3 8#8,is it about the longitude you come8' ,the porter asks3 #8,sir ,isaac's not at home4'0 #eg ,in trying the merits of ,harrison's chronometers1 ,dr4 ,maskelyne acquired that knowledge of the wants of nautical astronomy which afterwards led to the formation of the ,nautical ,almanac4 #eh ,a slight electric shock is given to a man at a certain portion of the skin2 and he is directed the moment he feels the stroke to make a certain motion1 as quickly as he possibly can1 with the hands or with the teeth1 by which the time-measuring current is interrupted4 #ei ,through the calculations of ,m4 ,le ,verrier4 ,,general ,,index ,abodes of the ,blest1 #eh4 ,acarus of ,crosse and ,weeks1 #bah4 ,accuracy of ,chinese ,observers1 #aei4 ,adamant1 ,what was it81 #abc4 ,aeronautic ,voyage1 ,remarkable1 #afi4 ,agassiz1 ,discoveries of1 #abg4 ,air1 ,weight of1 #ad4 ,all the ,world in ,motion1 #aa4 ,alluvial ,land of ,egypt1 #aaj4 ,ancient ,world1 ,science of the1 #a4 ,animals in ,geological ,times1 #abh4 ,anticipations of the ,electric ,telegraph1 #bbj-bbd4 ,arago on ,protection from ,storms1 #aei4 ,arctic ,climate1 ,phenomena of1 #afb4 ,arctic ,explorations1 ,rae's1 #afb4 ,arctic ,regions1 ,scenery and ,life of1 #ahj4 ,arctic ,temperature1 #afa4 ,armagh ,observatory ,level1 ,change of1 #add4 ,artesian ,fire-,springs1 #aah4 ,artesian ,well of ,grenelle1 #aad4 ,astronomer1 ,peasant1 #aja4 ,astronomer's ,dream verified1 #hh4 ,astronomers1 ,triad of ,contemporary1 #ajj4 ,astronomical ,observations1 ,nicety of1 #ajb4 ,astronomy and ,dates on ,monuments1 #ee4 ,astronomy and ,geology1 ,identity of1 #ajd4 ,astronomy1 ,great ,truths of1 #ed4 ,atheism1 ,folly of1 #c4 ,atlantic1 ,basin of the1 #aga4 ,atlantic1 ,gales of the1 #aga4 ,atlantic ,telegraph1 the1 #bbf-bbh4 ,atmosphere1 ,colours of the1 #adg4 ,atmosphere compared to a ,steam-engine1 #aeb4 ,atmosphere1 ,height of1 #adg4 ,atmosphere1 the1 #adf4 ,atmosphere1 the purest1 #aej4 ,atmosphere1 ,universality of the1 #adg4 ,atmosphere weighed by ,pascal1 #adh4 ,atoms of ,elementary ,bodies1 #ac4 ,atoms1 the ,world of1 #ac4 ,aurora ,borealis1 ,halley's hypothesis of1 #aih4 ,aurora ,borealis1 ,splendour of the1 #afe4 ,australian ,cavern1 ,inmates of1 #acg4 ,australian ,pouch-,lion1 #acg4 ,axis of ,rotation1 the1 #aa4 ,barometer1 ,gigantic1 #aea4 ,barometric ,measurement1 #aea4 ,batteries1 ,minute and ,vast1 #bjd4 ,birds1 ,gigantic1 of ,new ,zealand1 ,extinct1 #aci4 8,black ,waters1 the10 #ahb4 ,bodies1 ,bright1 the ,smallest1 #ca4 ,bodies1 ,compression of1 #ab4 ,bodies1 ,fall of1 #af4 ,bottles and ,currents at ,sea1 #agb4 ,boulders1 ,how transported to ,great ,heights1 #aje4 ,boyle on ,colours1 #di4 ,boyle1 ,researches of1 #f4 ,brain1 ,impressions transmitted to1 #bce4 ,buckland1 ,dr41 his ,geological ,labours1 #abg4 ,building-,stone1 ,wear of1 #ajh4 ,burnet's ,theory of the ,earth1 #abe4 ,bust1 ,magic1 #cf4 ,candle-flame1 ,nature of1 #bcg4 ,canton's ,artificial ,magnets1 #aif4 ,carnivora of ,britain1 ,extinct1 #acb4 ,carnivores1 ,monster1 of ,france1 #ach4 ,cataract1 ,great1 in ,india1 #ahc4 ,cat1 ,can it see in the ,dark81 #ea4 ,caves of ,new ,zealand and its ,gigantic ,birds1 #adj4 ,cave ,tiger or ,lion of ,britain1 #acc4 ,central ,heat1 ,theory of1 #aaf4 ,chabert1 8the ,fire ,king10 #aib4 ,chalk ,formation1 the1 #ajh4 ,changes on the ,earth's ,surface1 #adb4 ,chantrey1 ,heat-,experiments by1 #aib4 ,children's powerful ,battery1 #bjd4 ,chinese1 the1 and the ,magnetic ,needle1 #aid4 ,chronometers1 ,marine1 ,how rated at ,greenwich ,observatory1 #bbi4 ,climate1 finest in the ,world1 #adi4 ,climate1 ,variations of1 #adh4 ,climates1 ,average1 #adi4 ,clock1 ,how to make ,electric1 #bab4 ,cloud-ring1 the ,equatorial1 #aef4 ,clouds1 ,fertilisation of1 #aea4 ,coal1 ,torbane-,hill1 #abc4 ,coal1 ,what is it81 #abc4 ,cold in ,hudson's ,bay1 #afj4 ,colour of a ,body1 and its ,magnetic ,properties1 #aig4 ,colours and ,tints1 ,chevreul on1 #cg4 ,colours most frequently hit in ,battle1 #cf4 ,comet1 the1 of ,donati1 #bdj1 #bda4 ,comet1 ,great1 of #ahdc1 #hd4 ,comets1 ,magnitude of1 #hd4 ,comets visible in ,sunshine1 #hd4 ,computation1 ,power of1 #aj4 ,coney of ,scripture1 #acg4 ,conic ,sections1 #aj4 ,continent ,outlines not fixed1 #ade4 ,corpse1 ,how soon it decays1 #bcg4 8,cosmos1 ,science of the10 #aj4 ,crosse1 ,andrew1 his ,artificial ,crystals and ,minerals1 #baf-bai4 ,crosse ,mite1 the1 #bah4 ,crystallisation1 ,reproductive1 #bf4 ,crystallisation1 ,theory of1 #bd4 ,crystallisation1 ,visible1 #be4 ,crystals1 ,immense1 #bd4 8,crystal ,vault of ,heaven10 #ee4 ,davy1 ,sir ,humphry1 obtains ,heat from ,ice1 #aij4 ,davy's great ,battery at the ,royal ,institution1 #bjd4 ,day1 ,length of1 and ,heat of the ,earth1 #ahf4 ,day's ,length at the ,poles1 #fe4 ,declination of the ,needle1 #aig4 ,descartes' ,labours in ,physics1 #i4 ,desert1 ,intense ,heat and ,cold of the1 #afc4 ,dew-drop1 ,beauty of the1 #aeg4 ,dew-fall in one year1 #aeg4 ,dew graduated to supply ,vegetation1 #aeg4 ,diamond1 ,geological ,age of1 #abb4 ,diamond ,lenses for ,microscopes1 #dj4 8,diamond10 ,newton's ,dog1 #h4 ,dinornis elephantopus1 the1 #aci1 #adj4 ,dinotherium1 or ,terrible ,beast1 the1 #acf4 ,diorama1 ,illusion of the1 #cg4 ,earth and ,man compared1 #bb4 ,earth1 ,figure of the1 #ba4 ,earth1 ,mass and ,density of1 #ba4 ,earth's ,annual ,motion1 #ab4 ,earth's ,magnitude1 to ascertain1 #ba4 ,earth's ,surface1 ,mean ,temperature of1 #bc4 ,earth's ,temperature1 ,interior1 #aaf4 ,earth's ,temperature ,stationary1 #bc4 ,earth1 the1 a 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,water decomposed by ,electricity1 #bjh4 ,water1 ,running1 ,force of1 #aad4 ,waters of the ,globe gradually decreasing1 #aac4 ,water-,purifiers1 ,natural1 #bcd4 ,waterspouts1 ,how formed in the ,java ,sea1 #afj4 ,waves1 ,cause of1 #ahc4 ,waves1 ,force of1 #ahd4 ,waves1 ,rate of ,travelling1 #ahc4 ,wenham-,lake ,ice1 ,purity of1 #afa4 ,west1 ,superior ,salubrity of1 #aej4 8,white ,water10 and ,luminous ,animals at ,sea1 #agc4 ,winds1 ,transporting ,power of1 #afc4 ,wollaston's ,minute ,battery1 #bjd4 ,world1 ,all the1 in ,motion1 #aa4 ,world1 the1 in a ,nutshell1 #ac4 ,worlds1 ,more than ,one1 #ef4 ,worlds to come1 #eh4 ,,london3 ,,robson1 ,,levey1 ,,and ,,franklyn1 ,,great ,,new ,,street ,,and ,,petter ,,lane1 ,e4,c4 ,transcriber's ,notes ,punctuation1 hyphenation1 and spelling were made consistent when a predominant preference was found in this book2 otherwise they were not changed4 ,simple typographical errors were corrected2 occasional unbalanced quotation marks retained4 ,ambiguous hyphens at the ends of lines were retained4 ,some numbers in equations include a hyphen to separate the fractional and integer parts4 ,these are not minus signs1 which1 like other arithmetic operators1 are surrounded by spaces4 ,the original book apparently used a smaller font for multiple reasons1 but as those reasons were not always clear to the ,transcriber1 smaller text is indented by #b spaces in the ,plain ,text version of this e,book1 and is displayed smaller in other versions4 ,footnotes1 originally at the bottoms of pages1 have been collected and repositioned just before the ,index4 ,page #ei3 8#ie #afbc #aedahe0 was misprinted as 8#ie #afbc #aedahe0 and has been corrected here4 ,the ,table of ,contents does not list the 8,phenomena of ,heat0 chapter1 which begins on page #ahe2 nor the ,index1 which begins on page #bdb4 ,page #ie3 8adjustible0 was printed that way4 ,page #aea3 ,missing closing quotation mark added after 8rapidly evaporate in space40 ,it may belong elsewhere4 ,page #bba3 ,missing closing quotation mark not added for phrase beginning 8it is a fine invention04