,transcriber's ,note4 ,this is ,paper #ch from the ,smithsonian ,institution ,united ,states ,national ,museum ,bulletin #bdj1 comprising ,papers #cd-dd1 which will also be available as a complete e-book4 ,the front material1 introduction and relevant index entries from the ,bulletin are included in each single-paper e-book4 ,corrections are listed at the end of the e-book4 ,,smithsonian ,,institution ,,united ,,states ,,national ,,museum ,,bulletin #bdj ,illustration ,,smithsonian ,,press ,,museum ,,of ,,history ,,and ,,technology ,,contributions ,,from ,,the ,,museum ,,of ,,history ,,and ,,technology ,papers #cd-dd ,on ,science and ,technology ,,smithsonian ,,institution 4 ,,washington1 ,d4,c4 #aiff ,publications of the ,united ,states ,national ,museum ,the scholarly and scientific publications of the ,united ,states ,national ,museum include two series1 ,proceedings of the ,united ,states ,national ,museum and ,united ,states ,national ,museum ,bulletin4 ,in these series1 the ,museum publishes original articles and monographs dealing with the collections and work of its constituent museums--,the ,museum of ,natural ,history and the ,museum of ,history and ,technology--setting forth newly acquired facts in the fields of anthropology1 biology1 history1 geology1 and technology4 ,copies of each publication are distributed to libraries1 to cultural and scientific organizations1 and to specialists and others interested in the different subjects4 ,the ,proceedings1 begun in #ahgh1 are intended for the publication1 in separate form1 of shorter papers from the ,museum of ,natural ,history4 ,these are gathered in volumes1 octavo in size1 with the publication date of each paper recorded in the table of contents of the volume4 ,in the ,bulletin series1 the first of which was issued in #ahge1 appear longer1 separate publications consisting of monographs 7occasionally in several parts7 and volumes in which are collected works on related subjects4 ,bulletins are either octavo or quarto in size1 depending on the needs of the presentation4 ,since #aijb papers relating to the botanical collections of the ,museum of ,natural ,history have been published in the ,bulletin series under the heading ,contributions from the ,united ,states ,national ,herbarium1 and since #aiei1 in ,bulletins titled ,contributions from the ,museum of ,history and ,technology1 have been gathered shorter papers relating to the collections and research of that ,museum4 ,the present collection of ,contributions1 ,papers #cd-dd1 comprises ,bulletin #bdj4 ,each of these papers has been previously published in separate form4 ,the year of publication is shown on the last page of each paper4 ,,frank ,a4 ,,taylor ,director1 ,united ,states ,national ,museum ,,contributions ,,from ,,the ,,museum ,,of ,,history ,,and ,,technology3 ,,paper #ch ,,the ,,earliest ,,electromagnetic ,,instruments ,robert ,a4 ,chipman ,,electrostatic ,,instruments ,,before #ahjj #abc ,,instrumenting ,,voltaic ,,or ,,galvanic ,,electricity1 #ahjj-ahbj #abd ,,electrical ,,instrumentation1 #ahjj-ahbj #abe ,,oersted',s ,,discovery #abf ,,beginnings ,,of ,,electromagnetic ,,instrumentation #abf ,,chronology ,,and ,,priority #abg ,,original ,,electromagnetic ,,multipliers #abi ,,conclusions #ace ,,acknowledgments #acf ,illustration3 ,figure #a4--,,models ,,of ,,various ,,electromagnetic ,,instruments created by ,schweigger1 ,poggendorf and ,cumming in #ahba1 made for an exhibit in the ,museum of ,history and ,technology1 ,smithsonian ,institution4 7,smithsonian photo #didic47 ,robert ,a4 ,chipman ,,the ,,earliest ,,electromagnetic ,,instruments ,the history of the early stages of electromagnetic instrumentation is traced here through the men who devised the theories and constructed the instruments4 ,despite the many uses made of voltaic cells after ,volta's announcement of his pile invention in #ahjj1 two decades passed before ,oersted discovered the magnetic effects of a voltaic circuit4 ,as a result of this and within a five-month period1 three men1 apparently independently1 announced the invention of the first electromagnetic instrument4 ,this article details the merits of their claims to priority4 ,,the ,,author3 ,robert ,a4 ,chipman is chairman of the ,department of ,electrical ,engineering at the ,university of ,toledo in ,toledo1 ,ohio1 and consultant to the ,smithsonian ,institution4 ,electrostatic ,instruments before #ahjj ,it is the fundamental premise of instrument-science that a device for detecting or measuring a physical quantity can be based on any phenomenon associated with that physical quantity4 ,although the instrumentation of electrostatics in the #ahth century1 for example1 relied mainly on the phenomena of attraction and repulsion and the ubiquitous sparks and other luminosities of frictional electricity1 even the physiological sensation of electric shock was exploited semiquantitatively by ,henry ,cavendish in his well-known anticipation of ,ohm's researches4 ,likewise1 ,volta in #ahjja described at length how the application of his pile to suitably placed electrodes on the eyelids1 on the tongue1 or in the ear1 caused stimulation of the senses of sight1 taste and hearing2 on the other hand1 he reported that electrodes in the nose merely produced a more or less painful pricking feeling1 with no impression of smell4 ,the discharges from the ,leyden jars of some of the bigger frictional machines1 such as van ,marum's at ,leyden1 were found by #aghe to magnetize pieces of iron and to melt long pieces of metal wire4#b ,the useful instruments that emerged from all of this experience were various deflecting electrometers and electroscopes 7the words were not carefully distinguished in use71 including the important goldleaf electroscope ascribed to ,abraham ,bennet in #aghg4c ,in #aghf1 ,galvani first observed the twitching of the legs of a dissected frog produced by discharges of a nearby electrostatic machine1 thereby revealing still another effect of electricity4 ,he then discovered that certain arrangements of metals in contact with the frog nerves produced the same twitching1 implying something electrical in the frog-metal situation as a whole4 ,although ,galvani and his nephew ,aldini drew from these experiments erroneous conclusions involving animal electricity1 which were disputed by ,volta in his metal-contact theory1 it is significant from the instrumentation point of view that the frog's legs were unquestionably by far the most sensitive detector of metal-contact electrical effects available at the time4 ,without their intervention the development of this entire subject-area1 including the creation of chemical cells1 might have been delayed many years4 ,volta himself realized that the crucial test between his theory and that of ,galvani required confirming the existence of metal-contact electricity by some electrical but nonphysiological detector4 ,he performed this test successfully with an electroscope1 using the condensing technique he had invented more than a decade earlier4 ,instrumenting ,voltaic or ,galvanic ,electricity1 #ahjj-ahbj ,in his famous letter of ,march #bj1 #ahjj1 written in ,french from ,como1 ,italy1 to the president of the ,royal ,society in ,london1 ,volta made the first public announcement of both his pile 7the first ,english translator used the word column71 and his crown of cups 7the same translator used chain of cups for ,volta's couronne de tasses74 ,the former consisted of a vertical pile of circular disks1 in which the sequence copper-zinc-pasteboard1 was repeated #aj or #bj or even as many as #fj times1 the pasteboard being moistened with salt water4 ,the crown of cups could be most conveniently made with drinking glasses1 said ,volta1 with separated inch-square plates of copper and zinc in salt water in each glass1 the copper sheet in one glass being joined by some intermediate conductor and soldered joints to the zinc in the next glass4 ,volta considered the crown of cups and the pile to be essentially identical1 and as evidences of the electrical nature of the latter1 said3 444 if it contains about #bj of these stories or couples of metal1 it will be capable not only of emitting signs of electricity by ,cavallo's electrometer1 assisted by a condenser1 beyond #aj deg4 or #ae deg41 and of charging this condenser by mere contact so as to make it emit a spark1 etc41 but of giving to the fingers with which its extremities 7the bottom and top of the column7 have been touched several small shocks1 more or less frequent1 according as the touching has been repeated4 ,each of these shocks has a perfect resemblance to that slight shock experienced from a ,leyden flask weakly charged1 or a battery still more weakly charged1 or a torpedo in an exceedingly languishing state1 which imitates still better the effects of my apparatus by the series of repeated shocks which it can continually communicate4#d ,the effects provided by ,volta's pile and crown-of-cups are therefore electroscope deflection1 sparks1 and shocks4 ,later in the letter1 he describes the stimulation of sight1 taste1 and hearing as noted earlier1 but nowhere does he mention chemical phenomena of any kind1 or the heating of a wire joining the terminals of either device4 ,hence1 except for the additional physiological responses1 he adds nothing to the catalog of observations on which instruments might be based4 ,his familiarity with the moods of the torpedo 7electric eel7 seems to be intimate4 ,the reading of ,volta's letter to the ,royal ,society on ,june #bf1 #ahjj1 its publication in the ,society's ,philosophical ,transactions 7in ,french7 immediately thereafter1 and its publication in ,english in the ,philosophical ,magazine for ,september #ahjj1e gave scientists throughout ,europe an easily constructed and continuously operating electric generator with which innumerable new physical1 chemical1 and physiological experiments could be made4 ,editor-engineer ,william ,nicholson read ,volta's letter before its publication and1 by the end of ,april1 he and surgeon ,anthony ,carlisle had built a voltaic pile4 ,applying a drop of water to improve the connection of a wire lying on a metal plate1 they happened to notice gas bubbles forming on the wire1 and pursued the observation to the point of identifying the electrical decomposition of water into hydrogen and oxygen4 ,within two or three years innumerable electrochemical reactions had been described1 some of which1 one might think1 could have served as operating principles for electrical instruments4 ,although the phenomena of gas formation and metal deposition were in fact widely used as crude indicators of the polarity and relative strength of voltaic piles and chemical cells during the period #ahjj-ahbj 7and the gas bubbles were made the basis of a telegraph receiver by ,s4 ,t4 ,soemmering71 the quantitative laws of electrolysis were not worked out by ,faraday until after #ahcj1 and not until #ahcd was he satisfied that the electrolytic decomposition of water was sufficiently well understood to be made the basis for a useful measuring instrument4 ,describing his water-electrolysis device in that year1 he wrote3 ,the instrument offers the only actual measurer italics his of voltaic electricity which we at present possess4 ,for without being at all affected by variations in time or intensity1 or alterations in the current itself1 of any kind1 or from any cause1 or even of intermissions of actions1 it takes note with accuracy of the quantity of electricity which has passed through it1 and reveals that quantity by inspection2 ,i have therefore named it a ,,voltaelectrometer4#f ,in passing1 ,faraday commented that the efforts by ,gay-,lussac and ,thenard to use chemical decomposition as a measure of the electricity of the voltaic pile in #ahaa had been premature because the principles and precautions involved were not then known4 ,he also noted that the details of metal deposition in electrolysis were still not sufficiently understood to permit its use in an instrument4#g ,the heating of the wires in electric circuits must have been observed so early and so often with both electrostatic and voltaic apparatus1 that no one has bothered to claim or trace priorities for this effect4 ,the production of incandescence1 however1 and the even more dramatic combustion or explosion of metal-foil strips and fine wires has a good deal of recorded history4 ,among the first to burn leaf metal with a voltaic pile was ,j4 ,b4 ,tromsdorff of ,erfurt who noted in #ahja the distinctly different colors of the flames produced by the various common metals4 ,in the succeeding few years1 ,humphry ,davy at the ,royal ,institution frequently1 in his public lectures1 showed wires glowing from electric current4 ,early electrical instrumentation based on the heating effect took an unusual form4 ,shortly after #ahjj1 ,w4 ,h4 ,wollaston1 an ,english ,m4,d41 learned a method for producing malleable platinum4 ,he kept the process secret1 and for several years enjoyed an extremely profitable monopoly in the sale of platinum crucibles1 wire1 and other objects4 ,about #ahaj1 he invented a technique for producing platinum wire as fine as a few millionths of an inch in diameter1 that has since been known as ,wollaston wire4 ,for several years preceding #ahbj1 no other instrument could compare the strengths of two voltaic cells better than the test of the respective maximum lengths of this wire that they could heat to fusion4 ,one can sympathize with ,cumming's comment in #ahba about the difficulty in soldering wires that are barely visible4#h ,electrical ,instrumentation1 #ahjj-ahbj ,the #bj years following the announcement of the voltaic-pile invention were years of intense experimental activity with this device4 ,many new chemical elements were discovered1 beginnings were made on the electrochemical series of the elements1 the electric arc and incandescent platinum wires suggested the possibilities of electric lighting1 and various electrochemical observations gave promise of other practical applications such as metal-refining1 electroplating1 and quantity production of certain gases4 ,investigators were keenly aware that all of the available means for measuring and comparing the electrical aspects of their experiments 7however vaguely these electrical aspects may have been conceived71 were slow1 awkward1 imprecise1 and unreliable4 ,the atmosphere was such that prominent scientists everywhere were ready to pounce immediately on any reported discovery of a new electrical effect1 to explore its potentialities for instrumental purposes4 ,into this receptive environment came ,h4 ,c4 ,oersted's announcement of the magnetic effects of a voltaic circuit1 on ,july #ba1 #ahbj4i ,illustration3 ,figure #b4--;,,galvanometer ,,was ,,the ,,name given by ,bischof to this goldleaf electrostatic instrument in #ahjb1 #ah years before ,ampere coupled the word with the use of ,oersted's electromagnetic experiment as an indicating device4 ,oersted's ,discovery ,many writers have expressed surprise that with all the use made of voltaic cells after #ahjj1 including the enormous cells that produced the electric arc and vaporized wires1 no one for #bj years happened to see a deflection of any of the inevitable nearby compass needles1 which were a basic component of the scientific apparatus kept by any experimenter at this time4 ,yet so it happened4 ,the surprise is still greater when one realizes that many of the contemporary natural philosophers were firmly persuaded1 even in the absence of positive evidence1 that there must be a connection between electricity and magnetism4 ,oersted himself held this latter opinion1 and had been seeking electromagnetic relationships more or less deliberately for several years before he made his decisive observations4 ,his familiarity with the subject was such that he fully appreciated the immense importance of his discovery4 ,this accounts for his employing a rather uncommon method of publication4 ,instead of submitting a letter to a scientific society or a report to the editor of a journal1 he had privately printed a four-page pamphlet describing his results4 ,this1 he forwarded simultaneously to the learned societies and outstanding scientists all over ,europe4 ,written in ,latin1 the paper was published in various journals in ,english1 ,french1 ,german1 ,italian and ,danish during the next few weeks4#aj ,in summary1 he reported that a compass needle experienced deviations when placed near a wire connecting the terminals of a voltaic battery4 ,he described fully how the direction and magnitude of the needle deflections varied with the relative position of the wire1 and the polarity of the battery1 and stated ,from the preceding facts1 we may likewise collect that this conflict performs circles4444 ,oersted's comment that the voltaic apparatus used should be strong enough to heat a metallic wire red hot does not excuse the #bj-year delay of the discovery4 ,beginnings of ,electromagnetic ,instrumentation ,the mere locating of a compass needle above or below a suitably oriented portion of a voltaic circuit created an electrical instrument1 the moment ,oersted's effect became known1 and it was to this basic juxtaposition that ,ampere quickly gave the name of galvanometer4#aa ,it cannot be said that the scientists of the day agreed that this instrument detected or measured electric current1 however4 ,volta himself had referred to the current in his original circuits1 and ,ampere used the word freely and confidently in his electrodynamic researches of #ahbj-ahbb1 but ,oersted did not use it first and many of the ,german physicists who followed up his work avoided it for several years4 ,as late as #ahcb1 ,faraday could make only the rather noncommittal statement3 ,by current ,i mean anything progressive1 whether it be a fluid of electricity or vibrations or generally progressive forces4#ab ,nevertheless1 whatever the words or concepts they used1 experimenters agreed that ,oersted's apparatus provided a method of monitoring the strength of a voltaic circuit and a means of comparing1 for example1 one voltaic battery or circuit with another4 ,it was perfectly clear1 from ,oersted's pamphlet1 that if a compass needle was deflected clockwise when the wire of a particular voltaic circuit lay above it in the magnetic meridian1 the same needle would also be deflected clockwise if the wire was turned end-for-end and placed below the compass needle1 without changing the rest of the circuit4 ,anyone perceiving this fact might deduce1 as a matter of logic1 that if the wire of the circuit was first passed above the needle1 in the magnetic meridian1 then folded and returned in a parallel path below the needle1 the deflecting effect on the needle would be repeated1 and a more sensitive indicator would result1 assuming that any additional wire introduced has not affected the circuit excessively4 ,since #ahba1 historical accounts of the origins of electromagnetism seem to have limited their credit assignments for the conception and observation of this electromagnetic doubling effect 7or multiplying effect1 if the folding is repeated7 to three persons4 ,almost without exception1 however1 these accounts have given no specific information as to precisely what each of these three accomplished1 what physical form their respective creations took1 what experiments they performed1 and what functional understanding they apparently had of the situation4 ,the usual statement is simply that a compass needle was placed in a coil of wire4#ac ,the main purpose of the present review is to recount some of these details4 ,the following are the three candidates whose names are variously associated with the invention of the first constructed electromagnetic instrument1 or multiplier1 or primitive galvanometer4 ,,johann ,,salomo ,,christoph ,,schweigger 7#aggi-aheg7 in #ahbj had already been editor for several years of the ,journal fuer ,chemie und ,physik1 and was professor of chemistry at the ,university of ,halle4 ,,johann ,,christian ,,poggendorf 7#agif-ahgg7 in #ahbj had only recently entered the ,university of ,berlin as a student following several years as an apothecary's apprentice and a brief period as an apothecary4 ,four years later1 he succeeded ,gilbert as editor of the influential ,annalen der ,physik1 a position he held for more than #ej years4 ,,james ,,cumming 7#agga-ahfa7 in #ahbj was professor of chemistry at ,cambridge ,university4 ,chronology and ,priority ,the earliest established date in the multiplier record is ,september #af1 #ahbj1 when ,schweigger read his first paper to the ,natural ,philosophy ,society of ,halle4 ,there seems to be no reason to doubt that this report justifies the frequently used label ,schweigger's multiplier4 ,in an exuberant support of ,schweigger's position1 ,speter#ad with no mention of ,cumming and no hint of invention details1 shows that ,poggendorf in #ahba admitted ,schweigger's priority1 but suffered some lapse of memory #dj years later when writing sections of his biographical dictionary1 leaving a distinct suggestion that the invention was his4 ,further confusion for later generations resulted from some ambiguous entries in the ,allgemeine ,deutsche ,biographie of #ahhh4 ,the name multiplier seems not to have originated with ,schweigger himself4 ,speter credits it to ,meineke as working editor of ,schweigger's ,journal1 but ,seebeck seems to have used it much earlier4#ae ,conceding priority of conception to ,schweigger 7,cumming has not been a real competitor on this point7 does not alter the fact that all three seem to have reached their results independently of one another1 that the first work of each on this subject was published within a period of five months1 that there were significant differences in their conceptions of the uses and the optimum design of their devices and that between them they provided an adequate foundation for the subsequent development of the galvanometer to become the primary electrical-measuring instrument4 ,in the matter of publication1 ,schweigger1 as editor of what was popularly called ,schweigger's ,journal1 had an obvious advantage1 and presented his experiments beginnings on page #a of the first volume of his ,journal for #ahba1 published ,january #a of that year4#af ,oersted's paper had appeared two volumes previously4 ,he began by referring to ,oersted's discovery as the most interesting to be presented in a thousand years of the history of magnetism4 ,he was1 in fact1 so impressed with the epochal nature of ,oersted's achievement that he commemorated it by giving his ,journal a second title so that volume one of the new title could begin in the year after ,oersted's publication4 ,poggendorf1 as a relatively junior student1 had no such easy access to publicity1 but he had a staunch admirer in one of his professors1 ,paul ,erman at the ,university of ,berlin4 ,erman added a seven-page postscript on ,poggendorf's invention to his book ,outline of the ,physical ,aspects of the ,electro-chemical ,magnetism ,discovered by ,professor ,oersted1 published before ,april #ahba1ag with an introductory paragraph3 ,herr ,poggendorf1 who is one of the most excellent ornaments of the lecture room and laboratory of the ,university here1 carried out a very coherent and well-conceived investigation of electro-chemical magnetism1 leading step-by-step to a method of amplifying this activity-phenomenon by means of itself4 ,the postscript begins by referring to the condenser ,kondensator just brought to my attention by ,herr ,poggendorf and explains that he cannot release his treatise without preliminary announcement of this subject of the highest importance4 7,it can be inferred from the text that the name condenser was chosen because of the device's enhancing of magnetic measurements analogously to the enhancing of electric measurements by ,volta's electrostatic condenser47 ,immediately on reading the book1 ,schweigger published extracts1 mainly of the postscript1 with indignant comments on ,erman's remissness 7or worse7 in having failed to mention ,schweigger's prior work4#ah ,however1 ,erman was not alone in his unawareness1 if it was that1 of ,schweigger's discovery4 ,rival editor ,gilbert of the ,annalen der ,physik reviewed ,erman at much greater length than ,schweigger1 reprinting most of the postscript with evident enthusiasm1 and stating in his preamble that the invention is attributed to a young physicist studying here in ,berlin1 ,herr ,poggendorf4#ai ,only in a footnote is the reader directed to another footnote in the next article in the volume1 where ,gilbert finally states that he cannot leave unmentioned the fact that this amplifying apparatus seems to be due to ,herr ,professor ,schweigger4 ,he then quotes rather fully from ,schweigger's first two papers4#af ,oersted in #ahbc explained the situation thus3 ,the work of ,m4 ,poggendorf1 having been mentioned in a book on electromagnetism by the celebrated ,m4 ,erman published very shortly after its discovery1 became known to many scientists before that of ,m4 ,schweigger4 ,this is the reason for the same apparatus carrying different names4#bj ,the same confusion is well illustrated by the paper to which ,gilbert attached his confessional footnote mentioned above4 ,written by ,professor ,raschig of ,dresden1 on ,april #c1 #ahba1 the paper is entitled ,experiments with the ,electro-magnetic ,multiplier1 but the device1 throughout the paper1 is repeatedly referred to in the phrase ,poggendorf's condenser1 or rather multiplier1 an awkward combination that suggests editorial intervention4#ba ,the work of ,james ,cumming at ,cambridge is described in two papers which he read to the ,cambridge ,philosophical ,society in #ahba1 which were then duly published in the ,transactions of that ,society4 ,the first1 ,on the ,connexion of ,galvanism and ,magnetism1 was read ,april #b1 #ahba1bb and the second1 ,on the ,application of ,magnetism as a ,measure of ,electricity1 was read a few weeks later on ,may #bast4#bc ,though he quotes some unrelated #ahth-century experiments by ,ritter in ,germany1 an #ahjg publication of ,oersted's1 and electromagnetic experiments with solenoids performed by ,arago and ,ampere in late #ahbj1 ,cumming makes no mention of ,schweigger or ,poggendorf1 and never uses the word multiplier4 ,it1 therefore1 seems probable that his work was done without knowledge of the ,german publications or inventions4 ,original ,electromagnetic ,multipliers ,of the three sets of instruments made1 respectively1 by ,schweigger1 ,poggendorf and ,cumming1 those of ,schweigger are the most elementary1 and the least realistic from a practical point of view4 ,he makes little effort to investigate the effect of any design parameters1 but presents some odd conductor configurations that involve unimportant variations of the basic principle4 ,the following extracts from his first three papers#ac contain the major references to his conception1 construction1 and use of his multiplier4 ,,paper ,,read ,,in ,,halle1 ,,september #af1 #ahbj ,that a powerful voltaic pile is required for these experiments 7of ,oersted7 ,i have confirmed in my physics lectures1 using an electric pile that was so strong it would easily produce potassium metal the second and third day after it was built4 ,however1 ,i soon saw that the electromagnetic effect was related1 not to the pile1 but to the simple circuit1 and ,i was thereby led to perform the experiment with much greater sensitivity4 ,to amplify these electromagnetic phenomena of the simple circuit it seemed to me necessary to adopt a different arrangement from that initiated by ,volta1 in order that the electrical phenomena of his simple circuit might be raised to a higher degree4 ,since a reversal of the effect occurs according to whether the connecting-wire lies over or under the needle1 and likewise according to whether the wire leads from the positive or negative pole1 thence ,i say it is an easy inference that a doubling of the effect is attainable1 which is verified in practice4 ,i present to the ,society the simple doubling apparatus ,verdoppelungs-,apparat1 where the compass is placed between two wires passing around it4 ,a multiplication of the effect is easily obtained when the wire is not just once but many times wound around4 ,a single turn suffices1 however1 to demonstrate ,oersted's experiments1 using small strips of zinc and copper dipped in ammonium-chloride solution4 ,amid innumerable1 rambling theorizations 7such as1 that hydrogenation affects magnetism as oxidation affects galvanism1 or sulphur1 phosphorous and carbon are especially significant in magnetism1 since iron in combination with any of these inflammable materials becomes a magnet-material71 ,schweigger announces that he looked for the reactive force of the needle on the connecting wire in the simple ,oersted experiment1 and that he used his amplifying apparatus to look for magnetic effects from an electrostatic machine1 but without success in both cases4 ,he suggests that he will continue with many more electromagnetic experiments because with the use of the doubling-apparatus1 the needle1 instead of needing for excitation a cell capable of generating sparks1 approaches more closely the sensitivity of a twitching nerve4 ,however1 additional special experiments are required to find to what limits the amplification can be increased by the method ,i have created in the construction of this doubling-apparatus1 using multiple turns of wire4 ,illustration3 ,figure #c4--,,this ,,wire ,,bow-,,pattern was the first illustration ,schweigger gave of his doubling apparatus1 though he had presented a verbal description of a single-coil arrangement somewhat earlier4 ,the purpose of the bow pattern was to show that compass needles at the centers of the two loops deflected in opposite directions4 7,from ,journal fuer ,chemie und ,physik47 ,,paper ,,read ,,in ,,halle1 ,,november #d1 #ahbj ,the first half of this paper describes successful observations of the reaction-force of a magnetic needle on the connecting wire of a voltaic circuit1 achieved by pivoting the connecting wire in the form of brass needles above and below the compass needle4 ,though the multiplier configuration of needle and wire is in fact present here1 ,schweigger does not mention it1 evidently regarding this as a separate project4 ,he continues4 ,in my lecture of ,september #afth1 ,i showed that ,oersted's results depend1 not on the voltaic cell1 but only on the connecting circuit4 ,the principle ,i have used for amplification of the effects1 for the construction of an electromagnetic battery as it were1 was the winding of wire around the compass1 and ,i now present to the ,society a bow-pattern of multiple-wound1 wax-insulated wire1 ,figure #c4 ,there were no illustrations with ,schweigger's first paper4 ,while a single wire1 using the weak electric circuit here1 deflects the magnetic needle only #cj deg4 or #dj deg41 if the compass is placed in one of the openings of this pattern1 the needle is deflected #ij deg4 to the east1 or in the other opening #ij deg4 to the west1 using the same weak electric circuit4444 ,the bow-pattern device has novelty interest only1 adding nothing to the elucidation of the multiplier phenomenon4 ,the same is true of ,schweigger's next proposal1 shown in figure #d4 444 ,i will now add another apparatus1 which is just an extension of the previous one1 whereby the needle can take up any angle from #j deg4 to #ahj deg4 ,a short length of circular glass tubing1 of inside diameter large enough to contain a compass needle1 stands with its axis vertical and has single or multiple loops of wire wound on it in vertical diametral planes4 ,in the illustration1 successive plane coils are inclined at #cj deg4 to one another4 444 the electric current flows through the whole wire1 and the needle moves under all of these currents1 and coming always into another loop can take any desired angle4 ,with much further theorizing about the correlation of magnetism with the cohesion of bodies1 ,schweigger states again his evaluation of his discovery3 ,oersted succeeded in electromagnetic research by using a spark-producing cell1 which could make a wire glow4 ,my amplifying electromagnetic device needs only a weak circuit of copper1 zinc1 and ammonium chloride solution4#bd ,illustration3 ,figure #d4--,,schweigger ,,made ,,this peculiar construction of wire coils1 wound endwise on a short vertical section of glass tubing with a compass needle inside1 merely to startle his ,halle audience with the fact that the compass needle could rest in any of several stable positions4 7,from ,journal fuer ,chemie und ,physik47 ,illustration3 ,figure #e4--,,schweigger',s ,,suggestion of one possible design for an amplifying electromagnetic indicator4 ,the components are wooden rods and insulated wire4 ,position b referred to in the text is at the bottom of the diagram between the letters a and c4 7,from ,journal fuer ,chemie und ,physik47 ,,further ,,words ,,about ,,the ,,new ,,magnetic ,,phenomena ,this was presumably written between ,november #d1 #ahbj1 and the ,january #a1 #ahba1 publication date of his ,journal4 ,these wonderful new electrical effects#be are most easily rendered perceptible with the help of the previously described wire loops4 ,to focus attention on just one of the windings of ,figure #c1 we sketch a new drawing1 ,figure #e4444 ,since it is of major importance that these loops be made of silk-covered wire lying evenly on one another1 it is convenient to wind the loops on two small slotted sticks of wood1 although it is also possible to hold the wires together with wax or shellac1 or to tie them together in an orderly manner with silk thread4444 ,in ,figure #e1 ,aa and ,cc represent little slotted rods of wood on which the silk-covered wire is wound4 ,only three windings are shown in the figure1 but ,i generally adopt three times that many4 ,now t is connected with the copper and d with the zinc1 and the compass ,b set between the rods ,aa and ,cc with the coil perpendicular to the magnetic meridian and the terminals d1 t at the east4 ,the instant ,z and ,k are dipped in the ammonium chloride solution1 the needle turns around and stays with the north pole point south4444 ,if now the compass is taken out of the coil and put in position b1 all effects are reversed1 and are considerably weaker1 for obvious reasons4444 ,it is of the same significance whether we bring the compass from ,b to b in ,figure #e1 or from mesh #a to mesh #b in ,figure #c1 only that in the latter case1 because the compass is enclosed by the two sides1 a stronger effect results4444 ,if now the coil is rotated 444 so that the face previously north now faces south1 then on connecting the electric circuit there is absolutely no trace of effect on the needle1 assuming that the terminal wires are not reversed4444 ,it seems unnecessary to note that our magnetic coil can be placed in the direction of the magnetic meridian or at any arbitrary angle with it4444 ,following several pages of further talk about the relation of cohesion to magnetism and about unipolar and bipolar conductors1 the only additional item of interest is the observation that discharges of a ,leyden jar 7,kleistichen ,flasche7 strong enough to burn strips of leaf gold and to magnetize an iron rod in a coil1 produced no compass-needle deflections1 even with the help of the amplifying apparatus4 ,schweigger1 therefore1 described the basic multiplier idea clearly enough in his first paper1 but offered no sketch of the simplest construction until the third paper4 ,in the second paper1 meanwhile1 he had illustrated two peculiar designs involving the principle in less elementary ways4 ,his indifference to whether the wire loops lie in the magnetic meridian 7fig4 #c7 or perpendicular to it 7fig4 #e7 or at any other arbitrary angle to it1 reveals a poor appreciation of the measuring-instrument potentialities4 ,his conception seems to be primarily that of a detector4 ,poggendorf's invention1 as first reported by ,erman and presented to a wider audience by ,gilbert#bf was described as consisting of typically #dj to #ej turns of #a_/aj-line diameter1 silk-covered copper wire tied tightly together1 with the whole pressed laterally to form an elliptical opening in which a pivoted compass needle could move freely while maintaining clearance of about #b lines from the wire at all points4#bg ,this magnetic condenser can be a great boon to electro-chemistry1 said ,erman1 for it avoids all the difficulties of electric condensers4 ,he noted that1 using the condenser1 ,poggendorf had already established the electric series for a great number of bodies1 discovered various anomalies about conductivities1 and found a way of detecting dissymmetry of the poles of a compass needle4 ,on the other hand1 even with the condenser1 no magnetic effects have so far been obtainable from a strong tourmaline1 or from a #ab1jjj-pair1 ,zamboni dry cell4 ,poggendorf's own account of his work finally appeared as a very long article in the journal known as ,oken's ,isis4#bh ,the editorial controversies mentioned earlier may have occasioned this use of a periodical of such minor status in the fields of physics and chemistry4 ,the source of ,poggendorf's vision of the multiplier principle was a little different from ,schweigger's inspiration4 ,aiming at some detailed analysis of ,oersted's observation1 ,poggendorf ran the connecting wire of his cell-circuit along a vertical line to just above or below the pivot-point of the compass needle1 then1 after a right-angle bend1 horizontally above or below one of the poles of the needle4 ,as he studied the deflections produced for all four possible positions of such a wire1 with both cell polarities1 he came to realize that if a rectangular wire loop in a vertical plane enclosed a compass needle1 all parts of the horizontal sides of the loop would produce additive deflections4 ,by a separate experiment1 he showed that the vertical sides of the loop would also increase the deflections4 ,he saw at the same time that the effect of additional turns would be cumulative4 ,the multiple surrounding of the needle by a silk-covered wire1 in a plane perpendicular to the long axis of the needle1 affords the physicist a very simple and sensitive means of detecting the slightest trace of galvanism1 or of magnetism produced by it1 so that ,i have given the name of magnetic condenser to this construction1 though ,i attach no special value to this name 444 ,in analyzing the astonishingly increased power which the condenser gives to the magnetic effect of a circuit1 the first question that arises is how the effect varies with the number of turns1 whether it increases indefinitely or reaches a maximum beyond which additional turns have no effect4 ,the answer to this first question is linked to the solution of another1 viz1 whether the degrees deflection are a direct expression of the measure of the magnetic force or not4 ,to instruct myself on this point ,i made use of three separate circuits1 each containing an #h-turn condenser1 and put these as close together as possible in the magnetic meridian 444 with the needle between the windings4 ,each single circuit 444 gave a deflection of #de deg4 444 ,when two were connected the deflection was #fj deg41 and when finally all three were put in magnetic operation1 the deflection grew to only #gj deg4 ,it appears clearly from this that the angle of deflection is not in a simple ratio with the magnetic force acting on the needle4444 ,neither ,poggendorf nor ,schweigger seems to have ruled out1 on logical grounds alone1 the possibility of deflections greater than #ij deg41 with the loop-plane in the magnetic meridian1 though ,poggendorf does add a vague note that if the needle deflected too far it would encounter forces of the opposing sign4 ,poggendorf experimented with the size of the circuit wires1 finding that larger wires led to greater deflections4 ,he noted that the size of the cell plates and the nature of the cell's moist conductors would certainly have a great effect1 but that to investigate these in detail would take undue time1 and he therefore proposed to keep this part of the apparatus constant1 using one pair of zinc and copper plates #c4f inches in diameter1 separated by cloth soaked in ammonium-chloride solution4 ,poggendorf's principal quantitative study of his magnetic condenser used #ac identical coils1 each with #ajj turns4 ,in order that the turns should all be at approximately the same distance from the needle1 the coils were wound of the finest brass wire that could be silk-insulated1 the wire diameter being #j4jb lines4 ,on adding coils one at a time across the cell 7i4e41 connecting them in parallel71 the deflections were as follows3 ,turns #ajj #bjj #cjj #djj #ejj #fjj #gjj ,deflection in degrees #de #ej #ee #ei-fj #fb #fc #fd ,turns #hjj #ijj #ajjj #aajj #abjj #acjj ,deflection in degrees #fe #fe-a_/b #ff #ff #ff #ff ,adding some coils with fewer turns1 and connecting various combinations as a continuum 7i4e41 in series71 the deflections using the same cell were3 ,turns #a #e #aj #be #ej #ge #ajj #bjj ,deflection in degrees #aj #bb #bg #cj #ce-dj #dj #dj #dj ,turns #cjj #djj #ejj #fjj #gjj #hjj #ijj #ajjj ,deflection in degrees #dj #dj #da #dj #dj #dj #dj #dj ,making a few coils from wire with #a_/h-line diameter1 the deflections1 again using the same cell were3 ,turns #e #be #ej #ajj ,over #ajj ,deflection in degrees #bj-bb #dj-de #de #fe #fe ,since the needle used in these experiments was almost as long as the inside clearance of the coils1 no simple tangent law can be applied1 and it is not possible to discover an equivalent circuit in modern terms4 ,however1 the constancy of the deflections for large numbers of turns in each case indicates that the cell voltage and resistance were fairly constant1 and a rough estimate suggests that the cell resistance was comparable to the resistance of one of the #ajj-turn coils of fine wire4 ,such a value means that cell resistance limited the maximum deflections for the parallel-connected multipliers1 while coil resistance fixed the limit in the series case4 ,for all of these reasons1 it was impossible that any useful functional law could be obtained from the data4 ,poggendorf concluded only that the amplifying power of the condenser does not increase without limit1 but has a maximum value dependent on the conditions of plate area and wire size4 ,he added two other significant comments derived from various observations1 that the basic ,oersted phenomenon is independent of the earth's magnetism1 and that the phenomenon is localized1 i4e41 is not affected by distant parts of the circuit4 ,only a small fraction of ,poggendorf's paper is devoted to elucidating the properties of the condenser4 ,a similar amount is concerned with refuting various proposals1 such as those of ,berzelius and ,erman1 about distributions of magnetic polarity in a conducting wire to account for ,oersted's results4 ,more than half of the paper describes results obtained by using the condenser to compare conductivities and cell polarities under conditions where no effect had previously been detectable4 ,notable is the observation of needle deflections in circuits whose connecting wires are interrupted by pieces of graphite1 manganese dioxide1 various sulphur compounds1 etc41 materials which had previously been considered as insulators in galvanic circuits4 ,poggendorf gives these the name of semi-conductor 7halb-,leiter74 ,illustration3 ,figure #f4--;,,electromagnetic ,,instruments ,,of ,,james ,,cumming1 used at ,cambridge in #ahba4 ,one is a single-wire galvanometer1 following ,ampere's definition4 ,cumming called the multiple-turn construction galvanoscopes4 ,he showed how to increase their sensitivity by partial cancellation of the earth's magnetism at the location of the compass needle4 7,from ,transactions of the ,cambridge ,philosophical ,society1 vol4 #a1 #ahba47 ,cumming's first mention of the multiplier phenomenon1 in his paper of ,april #b1 #ahba1bb is quite casual1 and describes only a one-turn construction4 ,he speaks first of single-turn ring of thick1 brass wire1 and after noting that the sides of a circuit produce additive effects on a needle1 he comments that a flattened rectangular loop produces nearly quadruple the effect of a single wire4 ,the paper is primarily a review of ,oersted's work1 with references to electromagnetic observations before ,oersted1 and accounts of various related but nonmultiplier experiments that ,cumming has made4 ,his second paper1 of ,may #bast1 contains a fine plate 7fig4 #f7 illustrating arrangements used in investigating the subject of the paper's title ,the ,application of ,magnetism as a ,measure of ,electricity4 7,neither ,poggendorf nor any of his commentators ever illustrated his condenser47 ,although this plate is never referred to in the paper itself1 a nearby ,description gives a few comments4 ,the two wire patterns shown are noted as simply forms of spiral for increasing the electromagnetic intensity4 ,the mounted wire loop1 with enclosed compass needle and terminal mercury cups1 is clearly identical in principle with the devices of ,schweigger and ,poggendorf1 and is called a galvanoscope4 ,the largest structure illustrated does not involve the multiplying effect4 ,it is called a galvanometer1 consistent with ,ampere's definition of that word4 ,to use it1 two leads of a voltaic circuit are inserted into the mercury cups ,,ac and ,,bd1 and the board ,,efgh carrying the cups is moved vertically until some standard deflection is obtained on the compass needle below4 ,the relative strength of the circuit is then given by the calibrated position of the sliding section4 ,uncertainties are undoubtedly introduced by the arbitrary positions of the connecting wires from the test circuit to the mercury cups1 but ,cumming drew some interesting conclusions from various measurements he made4 ,observing needle deflections for various positions of the wire ,a-,b1 with a constant voltaic circuit1 he found that the tangent of the deviation varies inversely as the distance of the connecting wire from the magnetic needle4 ,here is a combination of the deflection law for a needle in a transverse horizontal field and the magnetic-force law for a long1 straight wire4 ,the latter had been determined experimentally by ,biot and ,savart1 in ,november #ahbj1 by timing the oscillations of a suspended magnet4#bi ,cumming considers his straight-wire calibrated galvanometer to be a device for measuring galvanic electricity2 on the other hand1 his multiple-loop galvanoscopes are for discovering galvanic electricity4 ,with the multiplier instrument1 he found galvanic effects 7i4e41 needle deflections7 using copper and zinc electrodes with several acids not previously known to create galvanic action4 ,a potassium-mercury amalgam electrode created a powerful cell with zinc as the positive electrode1 establishing both the metallic nature of potassium and the fact that it is the most negative of all metals4 ,in a third paper1 presented ,april #bh1 #ahbc1cj ,cumming reports use of the galvanoscope in experiments on the thermoelectric phenomena recently discovered by ,seebeck4 ,his note that for the more minute effects a compass was employed in the galvanoscope1 having its terrestrial magnetism neutralized 444 seems to be the earliest mention of this version of the astatic principle1 a technique whose dramatic effects were especially valuable in low-resistance thermoelectric circuits1 where the extra resistance of additional multiplier turns largely offsets their magnetic contribution4 ,in detail1 the needle is neutralized by placing a powerful magnet ,north and ,south on a line with its center2 and another1 which is much weaker1 ,east and ,west at some distance above it3 by means of the first the needle is placed nearly at right angles to the meridian1 and the adjustment is completed by the second4 ,on varying the length of the connecting wire of the circuit1 ,cumming found the deflections of the multiplier needle to be in a nearly reciprocal relation4 ,he speaks of the conducting power of the wire1 and seems not far from visualizing ,ohm's law1 of which no published form appeared until #ahbf4 ,ohm's own experiments were made with very similar apparatus4 ,illustration3 ,figure #g4--,,schweigger ,,multiplier used by ,oersted in #ahbc4 ,a thin magnetic needle is held in a light1 paper sling at ,f1 suspended by a fine1 vertical fiber4 7,from ,annales de ,chimie et de ,physique47 ,conclusions ,an effort has been made to show that electrical experimenters prior to ,oersted's discovery in #ahbj were in desperate need of some electrical instrument for galvanic or voltaic circuits that would combine sensitivity1 simplicity1 reliability1 and quick response4 ,the nearly simultaneous creation by ,schweigger1 ,poggendorf and ,cumming of an arrangement consisting of a coil of wire and a compass needle provided the first primitive version of a device to fill that need4 ,illustration3 ,figure #h4--;,,completely ,,useless ,,arrangement of vertical coil and horizontal1 unmagnetized needle1 presented in the ,edinburgh ,philosophical ,journal of #ahba as ,poggendorf's ,galvano-,magnetic ,condenser4 ,almost every aspect of ,poggendorf's instrument has been incorrectly represented4 ,it appears that ,schweigger is clearly entitled to credit for absolute priority in the discovery1 but the original sources suggest that both his understanding of the device and the subsequent researches he performed with it were markedly inferior to those of the other independent discoverers4 ,in using the generic label1 ,schweigger's ,multiplier1 there have been historical examples of attributing to ,schweigger considerably more sophistication than is justified4 ,figure #g shows an instrument designed by ,oersted in #ahbc1bj which he says differs in only minor particulars from that of ,m4 ,schweigger4 ,on comparing figure #g with figures #c1 #d1 or #e1 the remark seems overly generous4 ,the history of the multiplier instruments has had its fair share of erroneous reports and misleading clues4 ,a fine example is the illustration of figure #h1 taken from what is often quoted as the first report in ,english on ,poggendorf's ,galvano-,magnetic ,condenser4#ca ,the sketch is the editor's interpretation of a verbal description given him by a visiting ,danish chemist who1 in turn1 had received the information in a letter from ,oersted4 ,it incorporates1 faithful to the description1 a spiral wire 444 established vertically1 with a needle in the axis of the spiral1 yet by misunderstanding of the axial relations and of the ratio of length to diameter for the coil1 a completely meaningless arrangement has resulted4 ,the confusion is compounded by the specifying of an unmagnetized needle4 ,schweigger and ,poggendorf1 through their editorial positions1 were among the best known of all ,european scientists for several decades4 ,on one basis or another their reputations are firmly established4 ,comparison of the accounts of the early multipliers1 however1 suggests that the ,reverend ,james ,cumming1 professor of chemistry at the ,university of ,cambridge1 was a very perceptive philosopher4 ,this was well understood by ,g4 ,t4 ,bettany who wrote in the ,dictionary of ,national ,biography that ,cumming's early papers though extremely unpretentious1 were landmarks in electromagnetism and thermoelectricity1 and concluded that3 ,had he been more ambitious and of less uncertain health1 his clearness and grasp and his great aptitude for research might have carried him into the front rank of discoverers4 ,,acknowledgments ,i wish to thank ,dr4 ,robert ,p4 ,multhauf1 chairman of the ,department of ,science and ,technology in the ,smithsonian ,institution's ,museum of ,history and ,technology1 for encouragement in the writing of this paper and for the provision of opportunity to consult the appropriate sources4 ,to ,dr4 ,w4 ,james ,king of the ,american ,institute of ,physics1 ,i am grateful for many provocative discussions on this and related topics4 ,,footnotes3 #a ,a4 ,,volta1 ,on the ,electricity ,excited by the ,mere ,contact of ,conducting ,substances of ,different ,kinds1 ,philosophical ,transactions of the ,royal ,society of ,london 7#ahjj71 vol4 #ij1 pp4 #djc-dca4 #b ,some little-known but delightful observations in the prehistory of electromagnetism are described in a letter written by ,g4 ,w4 ,,schilling from ,london to the ,berlin ,academy on ,july #h1 #agfi1 published as ,sur les phenomenes de l',anguleil ,tremblante ,nouveaux ,memoires de l',academie ,royale des ,sciences et ,belles-,lettres1 #aggj 7,berlin1 #aggb71 pp4 #fh-gd1 translated to ,french from the original ,german4 ,the letter recounts a multitude of experiments with various electric eels4 ,the two observations of electromagnetic interest are that a piece of iron held by the hand in the eel's tank could be felt quivering even when the fish was stationary several inches away1 and a compass needle showed a deflection1 both in the water near the fish1 and outside the tank1 also with the fish stationary4 #c ,,abraham ,,bennet1 ,philosophical ,transactions of the ,royal ,society of ,london 7#aghg71 p4 #bf4 #d ,op4 cit4 7footnote #a71 p4 #djc4 #e ,philosophical ,magazine 7#ahjj71 vol4 #g1 pp4 #bhi-caa4 ,for a facsimile reprint1 see ,galvani-,volta 7,bern ,dibner's ,burndy ,library ,publication ,no4 #g71 ,norwalk1 ,connecticut1 #aieb4 #f ,,michael ,,faraday1 ,experimental ,researches in ,electricity1 vol4 #a 7,london1 #ahci71 paragraph #gci1 dated ,january #ahcd4 #g ,ibid41 sec4 #gda4 #h ,,james ,,cumming1 ,on the ,application of ,magnetism as a ,measure of ,electricity1 ,transactions of the ,cambridge ,philosophical ,society 7#ahba71 vol4 #a1 pp4 #bhb-bhf4 ,also published in ,philosophical ,magazine 7#ahbb71 vol4 #fj1 pp4 #bec-beg4 #i ,h4 ,c4 ,,oersted1 ,experimenta ,circa ,effectum ,conflictus ,electrici in ,acum ,magneticam 7,copenhagen1 ,july #ba1 #ahbj74 #aj ,full details of ,oersted's work and publications are in ,oersted and the ,discovery of ,electromagnetism 7,bern ,dibner's ,burndy ,library ,publication ,no4 #ah71 ,norwalk1 ,connecticut1 #aifa4 ,the original ,latin version and first ,english translation are reproduced in ,isis 7#aibh71 vol4 #cd1 pp4 #dce-ddd4 #aa ,a4 ,m4 ,,ampere1 ,annales de ,chimie et de ,physique 7#ahbj71 vol4 #ae1 p4 #fg4 ,the word galvanometer had been used much earlier by ,,bischof1 ,on ,galvanism and its ,medical ,applications1 ,the ,medical and ,physical ,journal 7#ahjb71 vol #g1 p4 #ebi1 for a form of goldleaf electroscope shown here in figure #b1 but this use of the word does not seem to have been adopted by others4 #ab ,op4 cit4 7footnote #f71 paragraph #bhc1 dated ,january #ahcc4 ,a similar attitude was expressed in the same year by ,,christie1 ,philosophical ,transactions of the ,royal ,society of ,london 7#ahcc71 vol4 #abc1 p4 #if3 ,i adopt the word current as a convenient mode of expression1 444 but ,i would not be considered as adopting any theoretical views on the subject4444 #ac ,some prominent examples of this brevity of treatment are in ,e4 ,,hoppe1 ,geschichte der ,elektrizitaet 7,leipzig1 #ahhd72 ,o4 ,,mahr1 ,geschichtliche ,einzeldarstellungen aus der ,elektrotechnik 7,berlin1 #aida72 ,r4 ,s4 ,,whipple1 ,the ,evolution of the ,galvonometer1 ,journal of ,scientific ,instruments 7#aicd71 vol4 #g1 pp4 #cg-dc2 ,,william ,,sturgeon1 ,scientific ,researches 7,bury1 #ahej72 ,a4 ,w4 ,,humphreys1 ,the ,development of the ,conception and ,measurement of ,electric ,current1 ,annals of ,science 7#aicg71 vol4 #b1 pp4 #afd-agh4 #ad ,m4 ,,speter1 ,klaerung der ,multiplikator-,prioritaetsfrage ,schweigger-,poggendorf1 ,zeitschrift fuer ,instrumentenkunde 7#aicg7 vol4 #eg1 pp4 #bi-cb4 #ae ,t4 ,,seebeck1 ,ueber den ,magnetismus der ,galvanischen ,kette1 ,abhandlungen der ,koenigliche ,akademie der ,wissenschaften zu ,berlin 7#ahbj-ahba71 pp4 #bhi-cdf4 ,the phrase ,schweigger's multiplier is used on page #cai4 ,the many experiments described in this paper added little or nothing to contemporary appreciation of the multiplier as an instrument4 #af ,j4 ,s4 ,c4 ,,schweigger1 ,journal fuer ,chemie und ,physik 7#ahba71 vol4 #ca1 pp4 #a-ah1 #ce-db4 ,pages #a-f are the paper presented in ,halle on ,september #af1 #ahbj2 pages #g-ah are the paper presented in ,halle on ,november #d1 #ahbj1 and pages #ce-db are a few additional words4 ,the preface to the whole volume is dated ,january #a1 #ahba4 ,a somewhat earlier public announcement referring to ,schweigger's discovery appeared in the ,allgemeine ,literatur-,zeitung 7,november #ahbj71 no4 #bif1 cols4 #fbb-fbd1 but this was lacking in detail and seems not to have been noticed by any scientists4 #ag ,p4 ,,erman1 ,umrisse zu den physischen ,verhaeltnissen des von ,herrn ,prof4 ,oersted entdeckten elektro-chemischen ,magnetismus 7,berlin1 #ahba74 ,hoppe 7footnote #ac7 states that ,erman's book was published in ,may2 however1 it is referred to in a letter dated ,april #c1 #ahba1 by ,,raschig1 ,annalen der ,physik 7#ahba71 vol4 #fg1 pp4 #dbg-dcf4 #ah ,op4 cit4 7footnote #af71 vol4 #cb1 pp4 #ch-ej4 #ai ,annalen der ,physik 7#ahba71 vol4 #fg1 pp4 #chb-dbf1 and footnote on pages #dbi-dcj of same volume4 ,the footnote accompanies the article by ,raschig mentioned in footnote #ag4 #bj ,h4 ,c4 ,,oersted1 ,sur le ,multiplier electro-magnetique de ,m4 ,schweigger1 et sur quelques applications qu'on en a faites1 ,annales de ,chimie et de ,physique 7#ahbc71 vol4 #bb1 pp4 #ceh-cfe4 #ba ,versuche mit dem electrisch-magnetischen ,multiplicator1 ,annalen der ,physik 7#ahba71 vol4 #fg1 pp4 #dbg-dcf4 #bb ,transactions of the ,cambridge ,philosophical ,society 7#ahba71 vol4 #a1 pp4 #bfi-bgh4 #bc ,op4 cit4 7footnote #h74 #bd ,the ,german word ,kette has been translated as circuit throughout4 ,although the equivalence of these words is clear1 for example1 in ,ohm's work of #ahbf1 the context in which ,kette is sometimes used in #ahbj and #ahba indicates that the concept of a circuit1 in the sense of the wiring external to the source of electricity1 has not been established4 ,the wiring is regarded more as something incidental1 used to close the cell1 the cell being considered essentially the whole of the apparatus4 ,this view underlies the many attempts to correlate the ,oersted phenomena with cell materials and design1 and with the use of such terms as chemical magnetism by ,erman and others4 #be ,the reference here is to the ,oersted-type experiments described in two papers by authors other than ,schweigger on pages #ai to #cd of the volume4 #bf ,op4 cit4 7footnote #ai71 pp4 #dbb-dbf4 #bg ,one line seems to have been about #a_/ab inch4 #bh ,j4 ,g4 ,,poggendorf1 ,physisch-chemische ,untersuchungen zur naeheren ,kenntniss des ,magnetismus der voltaischen ,saeule1 ,isis von ,oken 7#ahba71 vol4 #h1 pp4 #fhg-gaj4 ,most of ,poggendorf's numerical data is also in ,c4 ,h4 ,,pfaff1 ,der ,elektromagnetismus 7,hamburg1 #ahbd71 along with some of ,pfaff's own work4 #bi ,reported in ,annales de ,chimie et de ,physique 7#ahbj71 vol4 #ae1 pp4 #bbb-bbc4 #cj ,on the ,development of ,electro-,magnetism by ,heat1 ,transactions of the ,cambridge ,philosophical ,society 7#ahbc71 vol4 #b1 pp4 #dg-gf4 #ca ,account of the ,new ,galvano-,magnetic ,condenser invented by ,m4 ,poggendorf of ,berlin1 ,edinburgh ,philosophical ,journal 7,july #ahba71 vol4 #e1 pp4 #aab-aac4 99 99 99 99 99 ,u4,s4 ,,government ,,printing ,,office3 #aifd ,for sale by the ,superintendent of ,documents1 ,u4,s4 ,government ,printing ,office ,washington1 ,d4,c4 #bjdjb--,price #bj cents ,,index ,aldini1 ,giovanni1 #abd ,ampere1 ,andre ,marie1 #abg1 #abi ,arago1 ,dominique ,francois ,jean1 #abi ,bennet1 ,abraham1 #abd ,berzelius1 ,joens ,jakob1 #acc ,bettany1 ,g4 ,t41 #acf ,biot1 ,jean ,baptiste1 #ace ,carlisle1 ,anthony1 #abd ,cavallo1 ,tiberio1 #abd ,cavendish1 ,henry1 #abc ,cummings1 ,james1 #abe1 #abg1 #acc ,erman1 ,paul1 #abh1 #abi1 #acb1 #acc ,faraday1 ,michael1 #abe ,galvani1 ,luigi1 #abd ,gay-,lussac1 ,joseph ,louis1 #abe ,gilbert1 ,l4 ,w41 #abg1 #acb ,meineke1 ----1 #abh ,nicholson1 ,william1 #abd ,oersted1 ,hans ,christian1 #abe1 #acb ,ohm1 ,georg ,simon1 #abc1 #ace ,oken1 ,lorenz1 #acb ,pfaff1 ,christian ,heinrich1 #acb ,poggendorf1 ,johann ,christian1 #abg1 #acb1 #acf ,raschig1 ,christoph ,eusebius1 #abi ,ritter1 ,johann ,wilhelm1 #abi ,savart1 ,felix1 #ace ,schweigger1 ,johann ,salomo ,christoph1 #abg1 #acb1 #acf ,seebeck1 ,t41 #abh1 #ace ,soemmering1 ,s4 ,t41 #abe ,speter1 ,m41 #abg1 #abh ,thenard1 ,louis ,jacques1 #abe ,tromsdorff1 ,johann ,bartholomacus1 #abe ,van ,marum1 ,martin1 #abc ,volta1 ,alessandro1 #abc1 #abd1 #abg ,wollaston1 ,w4 ,h41 #abe ,zamboni1 ,giuseppe1 #acb ,transcriber's ,corrections4 ,obvious typographical errors have been corrected as follows3 ,page #abg3 in the magnetic meridian1 then--had meridan4 ,page #abh3 mainly of the postscript1 with--had postcript4 ,page #acd3 paper of ,april #b1 #ahba1bb is quite--had #aiba4 ,page #ace3 thermoelectric circuits1 where--had thermoelectirc4 ,page #ace3 arrangement has resulted4--had arragnement4 ,page #ace3 ,king of the ,american ,institute of ,physics4--had ,physic4 ,footnote #ac3 ,geschichte der ,elektrizitaet--had ,elektrizitat4 ,footnote #af3 ,journal fuer ,chemie und ,physik--had and4 ,footnote #bd3 ,the ,german word ,kette--had work4 ,questionable spellings have been retained as follows3 ,page #abe and ,index3 ,j4 ,b4 ,johann ,bartholomacus ,tromsdorff--should be ,johann ,bartholomaeus ,trommsdorff8 ,page #abi3 sulphur1 phosphorous and carbon444--should be phosphorus but may be misspelled in the quoted material8 ,footnote #bj3 ,sur le ,multiplier electro-magnetique444--should be ,multiplicateur8