- 
 
 .. L i v 
 
FROM THE LIBRARY OF 
 DR. CHARLES SINGER 
 
^> ^ 
 
 7 
 1 ' 
 
MEDALLION AND AUTOGRAPH 
 FKOM MONUMENT TO PHIL1IT REIS AT FRIEDRICHSDORF. 
 
PHILIPP REIS; 
 
 INVENTOR OF 
 
 THE TELEPHONE 
 
 A BIOGKAPHICAL SKETCH, 
 
 WITH DOCUMENTARY TESTIMONY, TRANSLATIONS OF THE 
 
 ORIGINAL PAPERS OF THE INVENTOR AND 
 
 CONTEMPORARY PUBLICATIONS. 
 
 BY 
 
 SILVANUS P. THOMPSON, B.A., D.Sc., 
 
 PROFESSOR OF EXPERIMENTAL PHYSICS IN UNIVERSITY COLLEGE, BRISTOL. 
 
 LONDON: 
 
 E. & F. K SPON, 16, CHAEING CEOSS. 
 NEW YORK: 35, MURRAY STREET. 
 
 1883. 
 
Tt+Ts 
 
 PREFACE. 
 
 THE title of this little work sufficiently indicates its nature 
 and scope. The labour of preparing it has not been slight, 
 and has involved the expenditure of much time in prose- 
 cuting inquiries both in this country and in Germany 
 amongst the surviving contemporaries of Philipp Eeis. To 
 set forth the history of this long-neglected inventor and of 
 his instrument, and to establish upon its own merits, without 
 special pleading, and without partiality, the nature of that 
 much-misunderstood and much-abused invention, has been 
 the aim of the writer. The thought that he might thus be of 
 service in rendering justice to the memory of the departed 
 worthy has inspired him to his task. He has nothing to 
 gain by making Eeis's invention appear either better or 
 worse than it really was. He has therefore preferred to let 
 the contemporary documents and the testimony of eye- 
 witnesses speak for themselves, and has added that which 
 seemed to him desirable in the way of argument in the form 
 of four appendices. 
 
 The author's acknowledgments are due in an especial 
 manner to Mr. Albert Stetson, A.M., of Cohasset, Massa- 
 chusetts, who has given him much valuable assistance in the 
 collection of information both in Germany and in this 
 country, and who has also assisted in the translation of some 
 
 590 
 
PREFACE. 
 
 of the contemporary documents to be found in the work. 
 To the friends, acquaintances, and pupils of Philipp Eeis, 
 and especially to the surviving members of the family at 
 Friedrichsdorf, who have most kindly furnished many de- 
 tails of information, the author would express his most 
 cordial thanks. The testimony now adduced as to the aim 
 of Philipp Eeis's invention, and the measure of success which 
 he himself attained, is such, in the author's opinion, and in 
 the opinion, he trusts, of all right-thinking persons, to place 
 beyond cavil the rightfulness of the claim which Eeis him- 
 self put forward of being the inventor of the Telephone. 
 Full and sufficient as that testimony is, much more remains 
 as yet unpublished. The author has, for example, been 
 permitted to examine a mass of evidence collected by the 
 Dolbear Telephone Company, which entirely corroborates 
 that which is here presented. It is, however, for certain 
 reasons beyond the author's control, deemed well at the 
 present moment to withhold this testimony for a little while 
 from publication. The appearance of this volume at the 
 present time needs no apology from the author. He is 
 conscious that all he can do will add little or nothing to 
 the lustre with which the name of Philipp Eeis will be 
 handed down to posterity. When the Jubilee of Philipp 
 Eeis comes to be celebrated in 1884 (January 7th), the 
 world will find out its indebtedness to the great man whose 
 thoughts survive him. 
 
CONTENTS. 
 
 PAGE 
 
 PREFACE ...... . . . v 
 
 LIST OF ILLUSTRATIONS . viii 
 
 I BIOGRAPHY OF THE INVENTOR ...... 1 
 
 II. THE INVENTOR'S APPARATUS . . . . .14 
 
 (a) Transmitters. 
 (5) Receivers. 
 
 III. THE CLAIM OF THE INVENTOR ...... 35 
 
 IV. CONTEMPORARY DOCUMENTS ...... 50 
 
 V. TESTIMONY OF CONTEMPORARY WITNESSES .... 112 
 
 APPENDIX 
 
 I. COMPARISON OF REIS'S TRANSMITTERS WITH RECENT INSTRU- 
 MENTS ......... 131 
 
 II. ON THE VARIATION OF ELECTRIC RESISTANCE AT A POINT OF 
 
 IMPERFECT CONTACT IN A CIRCUIT .... 143 
 
 III. COMPARISON OF REIS'S RECEIVERS WITH RECENT INSTRUMENTS 154 
 
 IV. ON THE DOCTRINE OF UNDULATORY CURRENTS . . .165 
 SCHEDULE OF AUTHORITIES AND REFERENCES .... 180 
 ADDITIONAL REFERENCES CONCERNING REIS'S TELEPHONE 182 
 
LIST OP ILLUSTRATIONS. 
 
 PAGE 
 
 Medallion-portrait of the Inventor (from the Medallion executed 
 FIG. by Kumpf in 1878), and Autograph. . . Frontispiece 
 
 1. Vignette. Tomb of Philipp Reis, at Friedrichsdorf . . 13 
 
 2. First Transmitter (the Wooden Ear) back view ... 16 
 
 3. front . . .1C 
 
 4. side . .16 
 
 5. section,, ... 16 
 
 6. details . . . 17 
 
 7. Second Transmitter (Tin Tube) 19 
 
 8. Third Transmitter (Collar-box) 19 
 
 9. Fourth Transmitter (Bored Block) 20 
 
 10. section ... 21 
 
 11. Sixth Transmitter (Wooden Cone) 22 
 
 12. Eeis's Photograph of himself, holding his Telephone (Seventh 
 
 Form) in his Hand 23 
 
 13. Seventh Transmitter (" Hochstift " Form) .... 24 
 
 14. Eighth Transmitter (Lever Form) 25 
 
 15. Ninth Transmitter (Transitional Form) .... 26 
 
 16. section . 26 
 
 17. Tenth Transmitter (Square Box) 27 
 
 18. opened .... 27 
 
 19. First Receiver (Violin Form) . . . . . .29 
 
 20. Second Receiver (Cigar-box) ...... 30 
 
 21. Third Receiver (Electromagnet) 32 
 
 22. Fourth Receiver (Knitting-needle) 33 
 
 23. ..... 33 
 
 24. Curve of Condensation and Rarefaction in Sound-wave . . 53 
 
 25. Telephone ("Bored Block") shown to Physical Society of 
 
 Frankfort-on-the-Main . . 55 
 
LIST OF ILLUSTRATIONS. ix 
 
 FIG. PAGE 
 
 26. Sound Curves 58 
 
 27. 59 
 
 28. Facsimile sketch from Reis's Letter to Mr. Ladd ... 83 
 
 29. The Telephone (from Reis's Prospectus) .... 86 
 
 30. (from Miiller-Poiallet's Physics) ... 97 
 
 31. Details of Transmitter ( ) . . . 97 
 
 32. Receiver ( ) . . . 97 
 
 33. The Telephone (from Pisko's Acoustics) . . . .100 
 
 34. (from Kuhn's Handbook) .... 109 
 
 35. Cone used in Transmitter ........ 117 
 
 36. Metal Tympanum 117 
 
 37. Second Receiver (Cigar-box) 118 
 
 38. Receiver with Lid 118 
 
 39. Projected form of Receiver with Electromagnet . . .119 
 
 40. . 119 
 
 41. Sketch of Experimental Transmitter ..... 122 
 
 42. Yeates' Receiver for Reis's Telephone 128 
 
 43. Berliner's Transmitter 136 
 
 44. Blake's Transmitter 137 
 
 45. Comparative Series of Transmitters ..... 139 
 
 46. Comparative Series of Receivers ...... 157 
 
 47. Curves from Reis's Memoir " On Telephony " . . .173 
 
 48. Curves from Bell's Specification (U.S. Patent) . . .173 
 
 PLATE 
 
 I. Curves from Yon Legat's Report on Reis's Telephone. 
 II. Reis's Telephone, from Yon Legat's Report. 
 
PHILIPP EEIS. 
 
 CHAPTEK I. 
 
 BIOGRAPHY OF THE INVENTOR. 
 
 [Compiled chiefly from papers left by the deceased, and from the bio- 
 graphical notice of the late Professor Schenk.] 
 
 PHILIPP EEIS, or, as his full name appears from his auto- 
 biographical sketch to have been, Johann Philipp Eeis, was 
 born on the 7th of January, 1834, at Gelnhausen, in the 
 principality of Cassel. His father, who belonged to the 
 Evangelical Church, was a master baker, but also pursued 
 farming to some extent, as the circumstances of small 
 provincial towns generally require. As his mother had died 
 young, his paternal grandmother undertook the bringing up 
 of the boy. " While my father," writes Herr Eeis, " strove 
 constantly to cultivate my mental powers by instruction 
 concerning the things which surrounded me (by discussing 
 that which was actually observed), my grandmother turned 
 her activity to training my disposition and to the develop- 
 ment of the religious sentiments to which she was eminently 
 fitted by the experiences of a long life, by being well-read, 
 and especially by her gift of narration." 
 
 On attaining his sixth year the boy was sent to the 
 common school of his native town. His teachers soon re- 
 cognised that he possessed no ordinary endowments, and 
 
 B 
 
PEILIPP BEIS, 
 
 sought to induce his father to entrust him later to a higher 
 institution of learning. His father agreed to this ; and the 
 plan was to have been carried out after the boy had passed 
 the middle-class of the common school. How the father 
 contemplated the carrying out of the plan is not known ; 
 he died ere the son had yet completed his tenth year. 
 
 As a considerable number of children from Frankfort- 
 on-the-Main and its neighbourhood, attended that time 
 Garnier's Institute at Friedrichsdorf, near Homburg, the 
 idea occurred to his guardian and his grandmother to 
 entrust the boy to this school. He entered there when in 
 his eleventh year. " The foreign languages, English and 
 French, taught in the Institute, attracted me specially. The 
 library of the Institute, rich and well chosen for its size, gave 
 my mind excellent nourishment." At the end of his four- 
 teenth year he had passed through the school, organised as 
 it then was, and he now went to Hassel's Institute at 
 Frankfort-on-the-Main. His delight in the study of language 
 induced him to learn Latin and Italian. And here, also, 
 the taste for the study of natural sciences and mathematics 
 appears to have been awakened in him. The lively zeal with 
 which he applied himself to both these disciplines induced 
 his teachers to advise his guardian that he should allow the 
 boy to attend the Polytechnic School at Carlsruhe, on 
 finishing his course at the Institute. " All the endeavours 
 of my well-wishing teachers shattered themselves, however, 
 against the will of one of my guardians, who was also my 
 uncle. He wished that I should follow mercantile pursuits. 
 ... I wrote him at that time that I should, indeed, be 
 obedient and learn the pursuit prescribed for me, but that I 
 should in any case continue my studies later." 
 
 On the 1st of March, 1850, Philipp Eeis entered the colour 
 establishment of Mr. J. F. Beyerbach, of Frankfort, as an 
 apprentice. By diligence and punctuality he soon won the 
 
INVENTOR OF THE TELEPHONE. 
 
 esteem of his principal. All his leisure time he bestowed 
 upon his further education. He took private lessons in 
 mathematics and physics, and attended the lectures of 
 Professor E. Bottger, on Mechanics, at the Trade School. 
 And so the end of his apprenticeship arrived. At the 
 conclusion of it he entered the Institute of Dr. Poppe, in 
 Frankfort. " Several of my comrades in this establishment, 
 young people of sixteen to twenty years old, found it, as I 
 did, a defect that no natural history, history, or geography, 
 was taught. We determined, therefore, to instruct one 
 another in these subjects. I undertook geography, and 
 formed from this first occasion of acting as teacher the con- 
 viction that this was my vocation. Dr. Poppe confirmed me 
 in this view and aided me by word and deed." 
 
 In the year 1851, whilst resident in Frankfort, Eeis had 
 become a member of the Physical Society of that city. This 
 Society, which still flourishes, then held, and still continues 
 to hold, its meetings in the Senckenburg Museum. Lectures 
 in Chemistry and Physics are delivered by resident professors 
 in regular courses every week throughout the winter, under 
 the auspices of this Society ; and every Saturday evening is 
 devoted to the exposition of recent discoveries or inventions 
 in the world of physical science, astronomy, etc. The most 
 active members of this Society during the time of Eeis's 
 connection with it were the late Professor Bottger, Professor 
 Abbe (now of Jena), and Dr. Oppel, all of whom contributed 
 many valuable original memoirs to the JakresbericJite, or 
 Annual Eeports, published by the Society. Amongst its 
 corresponding and honorary members it counted the names 
 of all the best scientific men of Germany, and also the names 
 of Professor Faraday, Professor Sturgeon, and Sir Charles 
 Wheatstone. Doubtless the discussion of scientific questions 
 at this Society greatly influenced young Eeis. He remained 
 for three years a member, but dropped his connexion for a 
 
 B 2 
 
PHILIPP REIS, 
 
 time on leaving Frankfort. He subsequently rejoined the 
 Society in the session of 1860-61, remaining a member until 
 1867, when he finally resigned. 
 
 In the winter of 1854-5 we find him most zealously busied 
 with preparations for carrying out his decision to become a 
 teacher. In 1855, he went through his year of military 
 service at Cassel. Eeturning to Frankfort, he worked away 
 with his customary and marvellous energy, attended lectures 
 on mathematics and the sciences, worked in the laboratory, 
 and studied books on Pedagogy. " Thus prepared, I set my 
 mind on going to Heidelberg in order to put the finishing 
 touch to my education as teacher. I wanted to settle down 
 in Frankfort in this capacity, and undertake instruction in 
 mathematics and science in the various schools. Then in 
 the spring of 1858, I visited my former master, Hofrath 
 Gamier, in whom I had ever found a fatherly friend. When 
 I disclosed to him my intentions and prospects, he offered me 
 a post in his Institute. Partly gratitude and attachment, 
 and partly the ardent desire to make myself right quickly 
 useful, induced me to accept the proffered post." 
 
 In the autumn of the year 1858 he returned to Friedrichs- 
 dorf, and in September 1859 he married and founded his 
 peaceful home. 
 
 Until Easter, 1859, he had but few lessons to give ; that 
 he utilised every moment of his spare time most conscien- 
 tiously in earnest activity and sound progress is nothing 
 more than was to be expected from what has been said 
 above. 
 
 It was during this time that Eeis undertook the first ex- 
 perimental researches of an original nature. Working almost 
 alone, and without any scientific guide, he was led into lines 
 of thought not previously trodden. He had conceived an 
 idea that electrical forces could be propagated across space 
 without any material conductor in the same way as light is 
 
INVENTOR OF THE TELEPHONE. 
 
 propagated. He made many experiments on the subject, 
 the precise nature of which can never now be known, but in 
 which a large concave mirror was employed in conjunction 
 with an electroscope and a source of electrification. The 
 results which he obtained he embodied in a paper, of which 
 no trace now remains, bearing as its title ' On the Eadiation 
 of Electricity/ This paper he sent in 1859 to Professor 
 Poggendorff for insertion in PoggendorfFs well-known 
 ' Annalen der Physik.' Greatly to his disappointment the 
 memoir was not accepted by Professor Poggendorff. Its 
 rejection was a great blow to the sensitive and highly strung 
 temperament of the young teacher ; and as will be seen was 
 not without its consequences. 
 
 The other piece of original work undertaken at this time 
 was the research which resulted in his great invention the 
 Telephone. From the brief biographical notes written by 
 the lamented inventor in 1868 we extract the following : 
 
 " Incited thereto by my lessons in Physics in the year 
 1860, I attacked a work begun much earlier concerning the 
 organs of hearing, and soon had the joy to see my pains 
 rewarded with success, since I succeeded in inventing an 
 apparatus, by which it is possible to make clear and evident 
 the functions of the organs of hearing, but with which also 
 one can reproduce tones of all kinds at any desired distance 
 by means of the galvanic current. I named the instrument 
 ' Telephon.' The recognition of me on so many sides, which 
 has taken place in consequence of this invention, especially 
 at the Naturalists' Association (Versammlung Deutscher 
 Naturforscher) at Giessen, has continually helped to quicken 
 my ardour for study, that I may show myself worthy of the 
 luck that has befallen me." 
 
 His earliest telephones were made by his own hands, in a 
 little workshop behind his house, whence he laid on wires 
 into an upper room. He also carried a wire from the physical 
 
PHILIPP REIS, 
 
 cabinet of Garnier's Institute across the playground into one 
 of the class-rooms for experimental telephonic communica- 
 tion ; and a firmly established tradition of the school is still 
 preserved, that the boys were afraid of making a noise in 
 that class-room for fear Herr Eeis should hear them in his 
 place amongst his favourite instruments. 
 
 In 1862 Eeis sent once again to Professor Poggendorff a 
 memoir, this time on the Telephone. This, in spite of the 
 advocacy of Professor Bottger and of Professor Miiller of 
 Freiburg, both of whom wrote, was declined by Professor 
 Poggendorff, who treated the transmission of speech by 
 electricity as a myth. Eeis, who was convinced that the 
 rejection was because he was " only a poor schoolmaster," 
 was more deeply pained than ever. 
 
 Of the various public exhibitions of the Telephone given 
 by Eeis in the years 1861 to 1864, much will be found in 
 the latter part of this book in which the contemporary 
 notices are reprinted. The first public lecture was in 1861, 
 before the Physical Society of Frankfort (see p. 50), the 
 last the above-mentioned occasion at Giessen (see p. 93) in 
 1864. By this time Eeis's invention was becoming widely 
 known. In addition to his own lectures on the subject, the 
 Telephone had been the subject of lectures in various parts 
 of Germany. It was lectured upon by Professor Buff in 
 Geissen twice, by Professor Bottger both in Frankfort and 
 in Stettin ; by Professor . H. Pick, by Professor Osann of 
 Wurtzburg, by Professor Paul Eeis of Mainz, and by others. 
 In 1863 Eeis's Telephone was shown by Dr. Otto Volger, 
 Founder and President of the Free German Institute (Freies 
 Deutsches Hochstift), to the Emperor of Austria and to King 
 Max of Bavaria, then on a visit to Frankfort. 
 
 Telephones were being sent to various parts of the world. 
 They were to be found in the Physical Laboratories of Munich, 
 Erlangen, Wiesbaden, Vienna, and Cologne. They were 
 
INVENTOR OF THE TELEPHONE. 
 
 sent to distant parts of the world, to London,* to Dublin, to 
 Tiflis in the Caucasus. In Manchester, before the Literary 
 and Philosophical Society, Eeis's Telephone was shown in 
 1865 by Professor Clifton, who, however, from not having 
 Eeis's own original memoirs on the subject before him, 
 utterly mistook if the Journal of Proceedings be not in error 
 the nature of the instrument, and not knowing the theory 
 of vibration of the tympanum so beautifully demonstrated 
 by Eeis, imagined the instrument to be a mere harmonic 
 telegraph for transmitting code signals in fixed musical 
 tones ! Telephones, too, were becoming an article of commerce 
 and, good and bad,t were being bought for the purpose of 
 placing them in collections of scientific apparatus. The 
 invention was, however, too soon for the world. To Eeis's 
 great disappointment, the Physical Society of Frankfort took 
 no further notice of the invention, the lustre of which shone 
 upon them. He resigned his membership in the Society in 
 October 1867. The Free German Institute of Frankfort, to 
 which Eeis had next betaken himself, though electing him 
 to the dignity of honorary membership, left the invention 
 aside as a philosophic toy. The Naturalists' Assembly, 
 including all the leading scientific men of Germany, had 
 indeed welcomed him at Giessen ; but too late. The sensitive 
 temperament had met with too many rebuffs, and the fatal 
 disease with which he was already stricken told upon his 
 energies. In particular the rejection of his earlier researches 
 had preyed upon his disposition. It is narrated by eye- 
 witnesses still living, how, after his successful lecture on the 
 
 * An autograph letter of Philipp Eeis to Mr. W. Ladd, the well-known 
 instrument maker of Beak Street, London, describing his telephone, is 
 still preserved, and is now in possession of the Society of Telegraph 
 Engineers and Electricians of London. It is reproduced at p. 81. 
 
 t As to the difference in quality of the instruments, see the testimony 
 of the maker, Albert of Frankfort, on p. 44. Prof. Pisko (see p. 101) seems 
 to have had a peculiarly imperfect instrument. 
 
8 PHILIPP REIS, 
 
 Telephone at Giessen, Keis was asked by Professor Poggen- 
 dorff, who was present, to write an account of his instrument 
 for insertion in the ' Annalen/ to which request Eeis's reply 
 was : " Ich danke IJinen recht sehr, Herr Professor ; es ist zu 
 spat. Jetzt will i c h nicht ihn schicken. Mein Apparat wird 
 ohne Beschreibung in den Annalen lekannt werden" 
 
 Haemorrhage of the lungs and a loss of voice, which 
 eventually became almost total, intervened to incapacitate 
 him for work, and especially from working with the telephone. 
 In 1873 he disposed of all his instruments and tools to 
 Garnier's Institute. To Herr Garnier he made the remark 
 that he had showed the world the way to a great invention, 
 which must now be left to others to develop. At last the 
 end came. The annual Eeport of Garnier's Institute for the 
 academic year 1873-1874 contains the following brief notice 
 of the decease and labours of Philipp Eeis : 
 
 " At first active in divers subjects of instruction, he soon 
 concentrated his whole faculties upon instruction in Natural 
 Science, the subject in which his entire thought and work lay. 
 Witnesses of this are not only all they who learned to know 
 him in Frankfort, in the period when he was preparing for 
 his vocation as teacher, but also his colleagues at the Institute, 
 his numerous pupils, and the members of the Naturalists' 
 Association (Naturforscher Versammlung) at Giessen, who, 
 recognising his keen insight, his perseverance and his rich 
 gifts, encouraged him to further investigations in his newly 
 propounded theories. To the Association at Giessen he 
 brought his Telephone. To the Association at Wiesbaden, 
 in September 1872, he intended to exhibit a new ingeniously 
 constructed gravity-machine, but his state of health made it 
 impossible. This had become such during several years, that 
 he was enabled to discharge the duties of his post only by 
 self-control of a special, and, as is generally admitted, 
 unusual nature; and the practice of his vocation became 
 
INVENTOR OF THE TELEPHONE. 
 
 more difficult when his voice also failed. In the summer of 
 1873 he was obliged, during several weeks, to lay aside his 
 teaching. As by this rest and that of the autumn vacation 
 an improvement in his condition occurred, he acquired new 
 hopes of recovery, and resumed his teaching in October with 
 his customary energy. But it was only the last flickering 
 up of the expiring lamp of life. Pulmonary consumption, 
 from which he had long suffered, laid him in December upon 
 the sickbed, from which after long and deep pains, at five 
 o'clock in the afternoon, on the 14th of January, 1874, he 
 was released by death." 
 
 The closing words of his autobiographical notes, or " curri- 
 culum vitce" as he himself styled them, were the fol- 
 lowing : 
 
 " As I look back upon my life I can indeed say with the 
 Holy Scriptures that it has been ' labour and sorrow/ But I 
 have also to thank the Lord that He has given me His 
 blessing in my calling and in my family, and has bestowed 
 more good upon me than I have known how to ask of Him. 
 The Lord has helped hitherto ; He will help yet further." 
 
 In 1877, when the Magneto-Telephones of Graham Bell 
 began to make their way into Europe, the friends of Philipp 
 Eeis were not slow to reclaim for their deceased comrade the 
 honours due to him. In December 1877, as the columns 
 of the Neue Frankfurter Presse show, a lecture was given 
 upon the history of the Telephone, at the Free German 
 Institute, in Frankfort, by Dr. Volger, its President, the same 
 who in 1863 had shown the Telephone to the Emperor of 
 Austria. On that occasion the Telephone of Eeis's own 
 construction, presented by him to the Institute after his 
 exhibition of it in 1862, was shown. 
 
 Early in 1878 a subscription was raised by members of the 
 Physical Society of Frankfort for the purpose of erecting a 
 monument to the memory of their former colleague. This 
 
10 
 
 PHILIPP EEIS, 
 
 monument, bearing a portrait medallion, executed by the 
 sculptor, Carl Kumpf, was duly inaugurated on Sunday, 
 December 8, 1878, when an appropriate address was pro- 
 nounced by the late Dr. Fleck, of Frankfort. The ' Jahres- 
 bericht,' of the Physical Society for 1877-78 (p. 44), contains 
 the following brief record : 
 
 " The Society has erected to the memory of its former 
 member, the inventor of the Telephone, Philipp Eeis 
 (deceased in 1874), teacher, of Friedrichsdorf (see 'Jahres- 
 bericht/ 1860-61, pp. 57-64; and 1861-62, p. 13), in the 
 cemetery of that place, a monument which was inaugurated 
 on the 8th of December, 1878. This monument, an obelisk 
 of red sandstone, bears in addition to the dedication, a well- 
 executed medallion portrait of Philipp Eeis, modelled by the 
 sculptor, A. C. Eumpf, and executed galvanoplastically by 
 G. v. Kress." 
 
 The inscription on Eeis's monument in the Friedrichsdorf 
 Cemetery is : 
 
 HIER EUHT 
 
 PHILIPP KEIS 
 
 GEB. 7. JANUAE 1834 
 GEST. 14. JANUAR 1874 
 
 SEINEM VERDIENSTVOLLEN 
 
 MITGLIEDE 
 DEM EEFINDER DBS 
 
 TELEPHOKS 
 DER PHYSIKALISCHE VEREIN 
 
 ZU 
 FBANKFURT-A-M. 
 
 ERRICHTET 
 1878 
 
INVENTOR OF THE TELEPHONE. 
 
 11 
 
 PRINCIPAL DATES IN EEIS'S LIFE. 
 
 1834 January 7 . 
 
 1850 March 1 . . 
 
 1855 
 
 1858 
 
 1859 September 14. 
 
 1860 
 
 1861 October 26 
 
 November 16. 
 
 1861 December 
 
 1862 May 8 . 
 May 11 . 
 
 Philipp Eeis born. 
 
 Apprenticed to Beyerbach. 
 
 Year of Military Service at Cassel. 
 
 Settled in Friedrichsdorf. 
 
 Married. 
 
 Invented the Telephone. 
 
 Eead Paper "On Telephony by the 
 Galvanic Current " before the Phy- 
 sical Society of Frankfort-on-the- 
 Main. 
 
 Eead Paper to the Physical Society 
 of Frankfort-on-the-Main, entitled 
 "Explanation of a new Theory 
 concerning the Perception of Chords 
 and of Timbre as a Continuation 
 and Supplement of the Eeport on 
 the Telephone." 
 
 Wrote out his Paper "On Tele- 
 phony/' as printed in the ' Jahres- 
 bericht.' 
 
 Notice in ' Didaskalia ' of Eeis's 
 invention. 
 
 Lectured and showed the Telephone 
 to the Free German Institute 
 (Freies Deutsches Hochstift) in 
 Frankfort-on-the-Main. 
 
 Article on the Telephone, communi- 
 cated by Inspector Von Legat to the 
 Austro-German Telegraph Society, 
 and subsequently printed in its 
 ' Zeitschrift ' (Journal). 
 
12 
 
 PEILIPP EEIS, 
 
 1863 July 4 . . 
 September 6 . 
 Sept. 17-24 . 
 
 1864 February 13 . 
 
 September 21 
 
 1872 September 
 
 1874 January 14 
 
 Showed his improved Telephone to 
 the Physical Society of Frank - 
 fort-on-the-Main. 
 
 Eeis's Telephone shown to the Em- 
 peror of Austria and the King of 
 Bavaria, then visiting Frankfort. 
 
 Meeting of the "Deutscher Natur- 
 forscher " at Stettin ; Eeis's Tele- 
 phone shown there by Professor 
 Bottger. 
 
 Meeting of the " Oberhessische Ge- 
 sellschaft fur Natur- und Heil- 
 kunde " at Giessen ; Lecture by 
 Professor Buff, and exhibition by 
 Eeis of his Telephone. 
 
 Meeting of the "Deutscher Natur- 
 forscher" at Giessen. Eeis gave 
 an explanation of the Telephone 
 and the history of its invention, 
 and exhibited it in action before 
 the most distinguished scientific 
 men of Germany. 
 
 Meeting of the "Deutscher Natur- 
 forscher " at Wiesbaden ; Eeis 
 announced to show his "Fall- 
 maschine," but prevented by ill- 
 health. 
 
 Philipp Eeis died. 
 
IN YEN TOE OF THE TELEPHONE. 
 
 13 
 
 Of 
 
 Fig. 1. 
 Monument to Pliilipp Reis in the Cemetery at Friedrichsdorf. 
 
14 PHILIPP BEIS, 
 
 CHAPTEE II. 
 
 THE INVENTOR'S APPARATUS. 
 
 IN describing the various forms successively given by the 
 inventor to his apparatus, as he progressed, from the earliest 
 to the latest, it will be convenient to divide them into two 
 groups, viz. the Transmitters and the Eeceivers. 
 
 A. Eeis's Transmitters. 
 
 So far as can be learned, Eeis constructed transmitters in 
 some ten or twelve different forms. The complete series in 
 this course of evolution does not now exist, but the principal 
 forms still remain and will be described in their historical 
 order. Theoretically, the last was no more perfect than the 
 first, and they all embody the same fundamental idea : they 
 only differ in the mechanical means of carrying out to a 
 greater or less degree of perfection the one common principle 
 of imitating the mechanism of the human ear, and applying 
 that mechanism to affect or control a current of electricity by 
 varying the degree of contact at a loose joint in the circuit. 
 
 First Form. THE MODEL EAR. 
 
 Naturally enough the inventor of the Telephone began 
 with crude and primitive * apparatus. The earliest form of 
 
 * Dr. Messel, F.C.S., a former pupil of Reis, and an eye-witness of his 
 early experiments, makes, in a letter to Professor W. F. Barrett, the 
 
INVENTOR OF THE TELEPHONE. 15 
 
 telephone-transmitter now extant, was a rough model of the 
 human ear carved in oak wood, and of the natural size, as 
 shown in Figs. 2, 3, 4, & 5. 
 
 The end of the aperture a was closed by a thin membrane 
 &, in imitation of the human tympanum. Against the centre 
 of the tympanum rested the lower end of a little curved 
 lever c d, of platinum wire, which represented the " hammer " 
 bone of the human ear. This curved lever was attached to 
 the membrane by a minute drop of sealing-wax, so that it 
 followed every motion of the same. It was pivoted near its 
 centre by being soldered to a short cross-wire which served 
 as an axis ; this axis passing on either side through a hole 
 in a bent strip of tin-plate screwed to the back of the wooden 
 ear. The upper end of the curved lever rested in loose 
 contact against the upper end g of a vertical spring, about one 
 inch long, also of tin-plate, bearing at its summit a slender 
 and resilient strip of platinum foil. An adjusting-screw, h, 
 served to regulate the degree of contact between the vertical 
 spring and the curved lever. The conducting- wires by which 
 the current of electricity entered and left the apparatus were 
 connected to the screws by which the two strips of tin-plate 
 
 following very interesting statement : " The original telephone was of a 
 most primitive nature. The transmitting instrument was a bung of a 
 beer-barrel hollowed out, and a cone formed in this way was closed with 
 the skin of a German sausage, which did service as a membrane. To this 
 was fixed with a drop of sealing-wax a little strip of platinum correspond- 
 ing to the hammer of the ear, and which closed or opened the electric 
 circuit, precisely as in the instruments of a later date. The receiving 
 instrument was a knitting needle surrounded with a coil of wire and placed 
 on a violin to serve as a sounding board. It astonished every one quite 
 as much as the more perfect instruments of Bell now do. The instrument 
 I have described has now passed into the hands of the Telegraph Depart- 
 ment of the German Government." [The instrument now in the museum 
 of the Keichs Post-Amt in Berlin is not this, but is the first of the " Im- 
 proved " Telephones described later by Reis in his " Prospectus " (see 
 p. 85), and is stamped " Philipp Reis," " 1863," " No. 1."] S.P.T. 
 
16 
 
 PHILIPP REIS, 
 
 were fixed to the ear. In order to make sure that the current 
 from the upper support of tin should reach the curved lever, 
 
 Fig. 2. 
 
 Fig. 4 
 
 Fig. 5. 
 
INVENTOR OF THE TELEPHONE. 
 
 17 
 
 another strip of platinum foil was soldered on the side of the 
 former, and rested lightly against the end of the wire-axis, as 
 shown in magnified detail in Fig. 6. If now any words or 
 
 Fig. 6. 
 
 sounds of any kind were uttered in front of the ear the 
 membrane was thereby set into vibrations, as in the human 
 ear. The little curved lever took up these motions precisely 
 as the " hammer "-bone of the human ear does ; and, like the 
 " hammer "-bone, transferred them to that with which it was 
 in contact. The result was that the contact of the upper end 
 of the lever was caused to vary. With every rarefaction of 
 the air the membrane moved forward and the upper end of 
 the little lever moved backward and pressed more firmly 
 than before against the spring, making better contact and 
 allowing a stronger current to flow. At every condensation 
 of the air the membrane moved backwards and the upper end 
 of the lever moved forward so as to press less strongly than 
 before against the spring, thereby making a less complete 
 contact than before, and by thus partially interrupting the 
 passage of the current, caused the current to flow less freely. 
 
 c 
 
18 PHILJPP EEIS, 
 
 The sound waves which entered the ear would in this fashion 
 throw the electric current, which flowed through the point of 
 variable contact, into undulations in strength. It will be 
 seen that this principle of causing the voice to control the 
 strength of the electric current by causing it to operate upon 
 a loose or imperfect contact, runs throughout the whole of 
 Eeis's telephonic transmitters. In later times such pieces of 
 mechanism for varying the strength of an electric current 
 have been termed current-regulators.* It would not be 
 inappropriate to describe the mechanism which Eeis thus 
 invented as a combination of a tympanum with an electric 
 current-regulator, the essential principle of the electric 
 current-regulator being the employment of a loose or im- 
 perfect contact between two parts of the conducting system, 
 so arranged that the vibrations of the tympanum would alter 
 the degree of contact and thereby interrupt in a correspond- 
 ing degree the passage of the current. 
 
 Mr. Horkheimer, a former pupil of Eeis, informs me that 
 a much larger model of the ear was also constructed by 
 Eeis. No trace of this is, however, known. 
 
 Second Form. TIN TUBE. 
 
 The second form, a tube constructed by Eeis himself, of 
 tin, is still to be seen in the Physical cabinet of Garnier's 
 Institute, at Friedrichsdorf, and is shown in Fig. 7. It 
 consists of an auditory tube a, with an embouchure represent- 
 ing the pinna or flap of the ear. This second apparatus 
 shows also a great similarity with the arrangement of the 
 ear, having the pinna or ear-flap, the auditory passage, and 
 the drum-skin (a, b, c). Upon the bladder c there still 
 remains some sealing-wax, by means of which a little strip 
 
 * Or sometimes " tension-regulators," though the latter term is acknow- 
 ledged by most competent electricians to be indcscriptive and open to 
 objection. 
 
INVENTOR OF THE' TELEPHONE. 10! 
 
 of platinum, for the all-essential loose-contact that controlled 
 the current, had formerly been cemented to the apparatus. 
 
 Fig. 7. 
 
 Third Form. THE COLLAR-BOX. 
 
 The third form, also preserved in the collection in Garnier's 
 Institute, is given in Fig. 8, which, with the preceding, is 
 taken by permission from the pamphlet of the late Professor 
 Schenk, consists of a round tin box, the upper part of which 
 fits upon the lower precisely like the lid of a collar-box. 
 Over this lid 6, which is 15 centimetres in diameter, was 
 
 Fig. 8. 
 
 formerly stretched the vibrating membrane, there being also 
 an inner flange of metal. Into a circular aperture below 
 opened an auditory tube- a, with an embouchure representing 
 the pinna. The precise arrangements of the contact-parts of 
 this apparatus are not known. Mr, Horkheimer, who aided 
 Eeis in his earlier experiments, has no knowledge o this 
 form,* which he thinks was ; made later than June* 1862. 
 
 c 2 
 
20 
 
 PHILIPP REIS, 
 
 This is not improbable, as the design with horizontal mem- 
 brane more nearly approaches that of the tenth form, the 
 " Square-box " pattern. 
 
 Fourth Form, THE BOEED-BLOCK. 
 
 The instrument described by " Keis in his paper " On 
 Telephony," in the Annual Eeport of the Physical Society of 
 Frankfort-on-the-Main, for 1860-61 (see p. 50), comes next 
 in order. The inventor's own description of this telephone 
 (Fig. 9) is as follows : 
 
 + 
 
 " In a cube of wood, r s t u v w x, there is a conical hole a, 
 closed at one side by the membrane & (made of the lesser 
 intestine of the pig), upon the middle of which a little strip 
 of platinum is cemented as a conductor [or electrode]. This 
 is united with the binding screw p. From the binding 
 screw n there passes likewise a thin strip of metal over the 
 middle of the membrane, and terminates here in a little 
 platinum wire, which stands at right-angles to the length 
 and breadth of the strip. From the binding-screw p a 
 
INVENTOR OF THE TELEPHONE. 
 
 21 
 
 conducting wire leads through the battery to a distant 
 station." The identical apparatus used by Eeis was after- 
 wards given by him to Professor Bottger, who later gave it 
 to Hofrath Dr. Th. Stein, of Frankfort, from whose hands it 
 has recently passed into the possession of the author of this 
 work. It possesses one feature not shown in the original 
 cut, viz. an adjusting screw, li, which, so far as the writer can 
 learn, was put there by Eeis himself. There appears no 
 reason to doubt this, since there was an adjusting screw in 
 Eeis's very earliest form of transmitter, the wooden ear. A 
 section of the actual instrument is given in Fig. 10. 
 
 Fig. 10. 
 
 Fifth Form. THE HOLLOW CUBE. 
 
 Another form, a mere variety of the preceding, is described 
 as follows by Professor Bottger in his " Polytechnisches 
 Notizblatt " (see p. 61) : 
 
 " A little light box, a sort of hollow cube of wood, has a 
 large opening at its front side and a small one at the back of 
 the opposite side. The latter is closed with a very fine 
 membrane (of pig's smaller intestine) which is strained stiff. 
 A narrow springy strip of platinum foil, fixed at its outer 
 part to the wood, touches the membrane at its middle ; a 
 second platinum strip is fastened by one of its ends to the 
 
23 PHILIPP REIS, 
 
 wood at another spot, and bears at its other end a fine 
 horizontal spike, which touches the other little platinum 
 strip where it lies upon the membrane," 
 
 Sixth Form. THE WOODEN CONE. 
 
 Another transmitter, also a mere variety of the Fourth 
 Form, has been described to me by Herr Peter, of Friedrichs- 
 dorf, who assisted Reis in his earlier experiments. Fig. 11 
 
 Fig. 11. 
 
 is prepared from a rough sketch furnished me by the kindness 
 of Karl Reis. Herr Peter describes the apparatus as having 
 been turned out of a block of wood by Reis upon his own 
 lathe. The conical hole was identical with that of Fig. 9, 
 but the surrounding portions of the wood were cut away, 
 leaving a conical mouth-piece. 
 
 Seventh Form. " HOCHSTIFT " FORM. 
 
 The engraving presented below (Fig. 12). has been engraved 
 with the utmost fidelity by Mr, J. D. Cooper, from a photo- 
 graph lent to the author by Ernest Horkheimer, Esq., of 
 Manchester, a former pupil of Reis. The original photograph 
 was taken in 1862, having been sent by Reis in June of that 
 year to Mr. Horkheimer, who had left for England. The 
 photograph was taken by Reis himself with his own camera, 
 the exposure being managed by a slight movement of the 
 
INVENTOR OF THE TELEPHONE. 
 
 foot, actuating a pneumatic contrivance of Keis's own inven- 
 tion, which was originally designed to turn over the pages 
 of a music book at the piano. Reis is here represented as 
 holding in his hand the telephone with which he had a few 
 days preceding (May 11, 1862) achieved such success at his 
 
 lecture before the Freies Deutsches Hochstift (Free German 
 Institute) in Frankfort (see p. 66). This instrument was 
 constructed by Eeis, young Horkheimer assisting him in the 
 construction. Mr. Horkheimer has very obligingly indicated 
 
PEILIPP REIS, 
 
 from memory the form of the instrument but dimly seen in 
 the photograph in a sketch from which Fig. 13 has been 
 prepared. Mr. Horkheimer adds that the cone was a wooden 
 one ; and that the square patch behind at the back was, he 
 thinks, a box to contain an electro-magnet. 
 
 Fig. 13. 
 
 Eighth Form. LEVER FORM. 
 
 The Transmitter described with so much minuteness by 
 Inspector von Legat in his Eeport on Eeis's Telephone in 
 1862 (see p. 70), differs from the earliest and latest forms, 
 so much so that some have doubted whether this form was 
 really invented by Keis. It is not described anywhere else 
 than in Legat's Keport (in the " Zeitschrift " of the Austro- 
 German Telegraph Union, reprinted also in Dingler's 
 Journal), except in Kuhn's Handbook, where, however, the 
 description is taken from Legat. Nevertheless a comparison 
 of this instrument (Fig. 14) with the original model of the 
 ear, from which Eeis started, will show that it embodies no 
 new point. There is, first, a conical tube to receive the 
 sound, closed at its end with a tympanum of membrane. 
 There is next a curved lever, c d, the lower end of which rests 
 against the centre of the membrane. Thirdly, there is a ver- 
 tical spring, g, which makes contact lightly against the upper 
 
INVENTOR OF THE TELEPHONE. 
 
 25 
 
 end of the curved lever. Lastly, there is an adjusting screw. 
 It may be further pointed out that in each case the current 
 enters (or leaves, as the case may be) the lever at its middle 
 point. This form of transmitter is so closely allied indeed 
 to the primitive " ear " as to be alike in every feature save 
 the external form of the sound-gathering funnel. The only 
 reasonable doubt is not whether it be, as Legat asserts, Keis's 
 
 Fig. 14. 
 
 transmitter, but whether it ought not in chronological order 
 to rank second. Legat's paper was not published, however, 
 till 1862, whilst the fourth form was described by Eeis in 
 1861. No trace of any instrument corresponding in form to 
 Fig. 14, save modern reproductions from Legat's drawing, has 
 been found. The instrument held by Keis in his harjd in 
 the photograph (Fig. 12) is so strikingly like the form 
 described by Legat, that it furnishes an additional reason for 
 
26 
 
 PH1LIPP REIS, 
 
 accepting Legat's statement that this transmitter really is 
 Reis's invention. 
 
 Fig. 15. 
 
 Fiff. 1C 
 
INVENTOE OF THE TELEPHONE. 
 
 27 
 
 Ninth Form. TRANSITIONAL FORM. 
 
 Our knowledge of this form is derived solely from infor- 
 mation and sketches supplied by Mr. E. Horkheimer, who 
 assisted Eeis in its construction. Figs. 15 and 16 are 
 engraved after Mr. Horkheimer's sketches. The conical 
 mouthpiece was of wood : the contact pieces of platinum. 
 The point c was attached to a springy slip of brass, g, fixed 
 across the wooden box ; and the adjusting-screw, li, served to 
 regulate the degree of initial pressure at the point of contact 
 which controlled the current. 
 
 Tenth Form. THE SQUARE Box. 
 
 The last form of Reis's Transmitter is that which has 
 become best known, being the only one (except Fig. 9) which 
 found its way into the market. It is here named, for the sake 
 of distinction, as the " Square Box " pattern. It consisted of 
 
 Fig. 17. Fig. 18. 
 
 a square wooden box, having a hinged lid. Fig. 17 is repro- 
 duced from Eeis's " Prospectus " (see page 85), whilst 
 Fig. 18 is taken from Prof. Schenk's biographical pamphlet. 
 
28 PHILIPP EEIS, 
 
 In this instrument the idea of the human ear is still carried 
 out. The tin funnel, with its flaring embouchure, still repre- 
 sents the auditory tube and pinna. The tympanum, no 
 longer at the very end of the tube, is strained across a circular 
 aperture in the lid. Upon it rests the strip of platinum foil 
 which serves as an electrode, and resting in loose contact 
 with this lies the little angular piece of metal which Eeis 
 called the " Hammerchen." Above all lay a circular glass 
 disk (a cover to keep out the dust), which was removed 
 when the instrument was used. So sensitive did this form 
 prove itself that it was found unnecessary to speak right into 
 the mouthpiece, and the speaker in practice talked or sang 
 with his mouth at some little distance vertically above the 
 instrument ; a method which had the advantage of not so 
 soon relaxing the membrane by the moisture of the breath. 
 The figures show also the auxiliary apparatus attached at 
 the side, consisting of a key for interrupting the circuit 
 (added at first to enable the experimenters to single out the 
 " galvanic tones" from the reproduced tones, and later 
 applied, as Eeis explains in his " Prospectus," on page 87), 
 and an electro-magnet to serve as a " call," by which the lis- 
 tener at the other end could signal back to the transmitter. 
 
 This form of instrument, which has been so frequently 
 described in the Text-books of Physics, was constructed for 
 sale first by Albert of Frankfort, later by Ladd of London, 
 Konig of Paris, and Hauck of Vienna. Further details con- 
 cerning it will be found in this book, in Eeis's " Prospectus," 
 and in other contemporary documents. 
 
 Although this form is the one most commonly referred to 
 as " the Eeis Telephone," it is evident from a consideration 
 of the entire group of forms that Eeis's invention was in no 
 way limited to one individual pattern of instrument. For in 
 all these forms there was embodied one all-embracing prin- 
 ciple ; that of controlling the electric current by the voice 
 
INVENTOR OF TEE TELEPHONE. 29 
 
 working upon a point of imperfect contact, by the agency of a 
 tympanum, thereby opening or closing the circuit to a greater 
 or less degree, and so regulating the flow of the current. 
 
 B. Reis's Receivers. 
 
 First Form. THE VIOLIN EECEIVER. 
 
 The first form of apparatus used by Eeis for receiving the 
 currents from the transmitter, and for reproducing audibly 
 that which had been spoken or sung, consisted of a steel 
 knitting-needle, round which was wound a spiral coil of silk- 
 covered copper-wire. This wire, as Eeis explains in his 
 lecture " On Telephony," was magnetised in varying degrees 
 by the successive currents, and when thus rapidly magnetised 
 and demagnetised, emitted tones depending upon the fre- 
 quency, strength, etc., of the currents which flowed round it. 
 It was soon found that the sounds it emitted required to be 
 strengthened by the addition of a sounding-box, or resonant- 
 case. This was in the first instance attained by placing the 
 needle upon the sounding-board of a violin. At the first 
 trial it was stuck loosely into one of the /-shaped holes of the 
 
 Fig 19. 
 
 violin (see Fig. 19) : subsequently the needle was fixed by its 
 lower end to the bridge of the violin. These details were 
 furnished by Herr Peter, of Friedrichsdorf, music-teacher in 
 
30 
 
 PHIL1PP EEIS, 
 
 Garnier's Institute, to whom the violin belonged, and who 
 gave Eeis, expressly for this purpose, a violin of less value 
 than that used by himself in his profession. Eeis, who was 
 not himself a musician, and indeed had so little of a musical 
 ear as haidly to know one piece of music from another, kept 
 this violin for the purpose of a sounding-box.. It has now 
 passed into the possession of Garnier's Institute. It was in 
 this form that the instrument was shown by Eeis in October 
 1861 to the Physical Society of Frankfort. 
 
 Second Form. THE CIGAR-BOX EECEIVER. 
 
 Later a shallow rectangular wooden box was substituted 
 for the violin, and the spiral was laid horizontally upon it 
 (Fig. 20). The date when this modification was made was 
 
 Fig. 20. 
 
 either at the end of 1861 or the early spring of 1862. A 
 cigar-box was the actual sounding-box, and the needle was 
 supported within the coil, but not touching it, with its ends 
 resting upon two wooden bridges. 
 
 Third Form. THE ELECTRO-MAGNET EECEIVER. 
 Though the precise history of this form of telephonic 
 receiver is defective, there can be little doubt that it was 
 conceived by Eeis amongst his earliest researches. When 
 there were in common use so many electric and telegraphic 
 instruments in which an electro-magnet is employed to move 
 an armature to and fro, it is not surprising that Eeis should 
 
INVENTOR OF THE TELEPHONE. 31 
 
 have thought of availing himself of this method for repro- 
 ducing the vibrations of speech. Speaking of the two parts 
 of his invention, the Transmitter and the Eeceiver, Eeis 
 himself says :* " The apparatus named the ' Telephone/ con- 
 structed by me, affords the possibility of evoking sound- 
 vibrations in every manner that may be desired. Electro-mag- 
 netism affords the possibility of calling into life at any given 
 distance vibrations similar to the vibrations that have been 
 produced, and in this way to give out again in one place the 
 tones that have been produced in another place." A remark, 
 almost identical with this, is also made by Inspector von 
 Legat (see p. 74) in his Eeport on Eeis's Telephone. It 
 may be here remarked that the form of this receiver is 
 known only from the figure and description given in that 
 Keport, and from the extract therefrom printed in Kuhn's 
 ' Handbook ' (see p. 109). Keis seems to have very soon 
 abandoned this form, and to have returned to the needle, 
 surrounded by a coil, in preference to the electro-magnet. The 
 electro-magnet form is, however, of great importance, because 
 its principle is a complete and perfect anticipation of that of 
 the later receivers of Yeates, of Gray, and of Bell, who each, 
 like Keis, employed as receiver an electro-magnet the function 
 of which was to draw an elastically mounted armature back- 
 wards and forwards, and so to throw it into vibrations corre- 
 sponding to those imparted to the transmitting apparatus. 
 Fig. 21 shows the disposition of the electro-magnet, and of 
 its vibratory armature upon a sounding-board. This appa- 
 ratus was a good deal larger than most of Keis's instruments. 
 The sounding-board was nearly a foot long : the coils of the 
 electro-magnet were six inches long, and over an inch thick. 
 The armature, a rod of iron of elliptical section, was affixed 
 cross-wise at the end of a "light and broad J) vertical lever, 
 
 * See Die OeschicJite und Entwickelung des Elektrisclien Fernsprech- 
 wesens (issued, officially from the. Imperial German Post-office, 1880), p. 7L 
 
32 
 
 PHILIPP REIS, 
 
 about seven inches long, which seems to have been made of 
 wood, as in Legat's Report it is also denominated as a 
 "plank" (Balken). 
 
 Fourth Form. THE KNITTING-NEEDLE KECEIVER. 
 
 The final form adopted by Eeis for his Keproducing- 
 apparatus is that commonly known as the Knitting-needle 
 Eeceiver. It differs only from the first form in that the 
 needle and its surrounding spiral no longer stand upright on 
 
INVENTOR OF THE TELEPHONE. 
 
 33 
 
 a violin, but lie horizontally upon a rectangular sounding- 
 box of thin pine wood. The coil of silk-covered copper wire 
 is wound upon a light wooden bobbin, instead of being 
 twisted round the needle itself. Two wooden bridges stand 
 
 Fig. 22. 
 
 Fig. 23. 
 
 upon the sounding-box, and through these pass the pro- 
 truding ends of the needle, whilst an upper box or lid, 
 hinged to the lower at the back, is added above. Figs. 22 
 and 23 show this form, the former being reproduced from 
 Keis's own Prospectus (see p. 85), the latter being from 
 Miiller-Pouillet's ' Text-book of Physics ' (see p. 95). Herr 
 
 D 
 
34 PHILIPP REIS, 
 
 Albert, mechanician, of Frankfort, who made and sold the 
 Reis telephones, says that the upper box was added at his 
 suggestion. Originally it was so constructed (see Tig. 22), 
 that when closed it pressed upon the steel needle. In the 
 instruments of later date, the notches which fitted over the 
 needle were cut so deeply (see Fig. 23), that the lid did not 
 press upon the wire. Eeis's own instructions are (see p. 86) 
 that the sound is intensified by firmly pressing the lid 
 against the needle, as was done occasionally by the listeners 
 who pressed their ears against the lid in order to hear more 
 distinctly. The little key seen at the end of the sounding- 
 box, in Fig. 22, was used for interrupting the current and so 
 to telegraph back signals to the transmitter. 
 
INVENTOR OF THE TELEPHONE. 35 
 
 CHAPTER III. 
 
 THE CLAIM OF THE INVENTOR. 
 
 IN the present century, when so many facilities exist for the 
 diffusion of knowledge, and when every new discovery and 
 invention is eagerly welcomed and immediately noised 
 abroad to every country of the globe, it is hard to believe 
 that the inventor of an instrument of the highest scientific 
 value, destined to play an important part in social and com- 
 mercial life, should have been suffered to live and die in 
 unrecognised obscurity. Still harder is it to believe that his 
 invention passed into almost complete oblivion, unacknow- 
 ledged by most of the leading scientific men of his day and 
 generation. But hardest of all is it to believe that when 
 at last attempts were made to give to him, whose name and 
 fame had thus been permitted to languish, the credit of the 
 splendid researches in which he wore his life away, those 
 attempts could be met on the one hand by an almost complete 
 apathy, and on the other by a chorus of denial, not only 
 that any such invention was made, but that the inventor had 
 ever intended to invent anything of the kind. Yet nothing 
 less than this has happened. Philipp Reis, the inventor of 
 the Telephone, the first to scheme, and carry out into 
 execution, an instrument for conveying to a distance by 
 means of electric currents the tones of human speech and 
 human song, is no longer amongst the living. He cannot 
 
 D 2 
 
36 PHIL1PP REI8, 
 
 reclaim for himself the honours that have been showered 
 upon the heads of others, who, however worthy of those 
 honours they were none will deny that were only not the 
 first to deserve them. In his quiet grave, in the obscurity of 
 the German village where his daily work was done, he sleeps 
 undisturbed by the strife of tongues. To him it matters 
 nothing now, whether his genius be recognised and his 
 invention applauded, or whether ignorance, and calumny, and 
 envy, alike decry both. Nevertheless, the memory of him 
 and of his work will live, and will descend to posterity as of 
 one whom his own generation knew not, whose peculiar 
 greatness passed unheeded save by a chosen few. Nor will 
 posterity be the less ready to accord honour to him who in his 
 own day could not even obtain justice. Yet something more 
 than a mere historic justice for the poor schoolmaster of Fried- 
 richsdorf does the world owe ; justice to the great invention 
 that is now imperishably associated with his name : justice 
 to the struggling family whom, instead of enriching, it 
 impoverished ; and, not least, the justice of patience, whilst 
 the story of his life and work, and the words he himself has 
 written thereupon, are unfolded. 
 
 The point at issue, and for which justice has been invoked, 
 and of which ample proof is given in these pages, is not 
 whether Philipp Keis invented a telephone that is not denied 
 but whether Philipp Eeis invented the Telephone. The 
 irony of fate, not .to say the curious ignorance which is often 
 called by a less polite name, has decreed by the mouth of 
 popular scientific writers, of eminent engineers, and of accom- 
 plished barristers, that Reis's invention was not an instrument 
 for transmitting human speech at all was not intended 
 even for this that it was a purely musical instrument in its 
 inception, and that it has always so remained. These clever 
 persons begin to persuade themselves of this view, and forth- 
 with invent a question-begging epithet, and dub the instru- 
 
INVENTOR OF THE TELEPHONE. 37 
 
 ment as a mere " tone-telephone " / If some unprejudiced 
 person ventures to speak of Eeis's instrument as having, as 
 a matter of history, transmitted speech, all the contemptuous 
 reply that he gets from the eminent somebody, who poses as 
 an authority for the moment, is : Oh, but, you know, it was 
 only a tone-telephone, a musical toy, and when some one was 
 singing to it you fancied you caught the words of the song 
 which, during singing, were occasionally projected along with 
 the music. I've always regarded the accounts of its transmission 
 of speech as a good joke ; all it could possibly do was occasionally 
 to utter an articulate noise in combination with a musical tone. 
 Besides, you know, Mr. Reis was a musical man, who only 
 intended it to sing, and if it spoke it only spoke by accident ; but 
 such an accident never did or could occur, because the construc- 
 tion of it shows that it not only did not but could not transmit 
 speech. If Mr. Eeis had really penetrated the fundamental 
 principle of the articulating telephone, he would have arranged 
 his instruments very differently ; and then, you know, if he 
 really had transmitted speech the discovery would have attracted 
 so much attention at the time. Moreover, if he had meant it to 
 talk, he would have called it the articulating telephone, and not 
 a telephone for transmitting tones, you know ; no one before 
 Graham Bell ever dreamed of using a tympanum to catch 
 articulate sounds, or had he done so he would have been 
 laughed at. 
 
 To all such clap - trap as this and there has been 
 enough ad nauseam of such the one reply is silence, and a 
 mute appeal to the original writings of Eeis and his con- 
 temporaries, and to the tangible witness of inexorable 
 scientific facts. All the most important of these will be 
 found in their appropriate places. They amply establish the 
 following points : 
 
 I. Eeis's Telephone was expressly intended to transmit 
 speech. 
 
38 PHILIPP REIS, 
 
 II. Eeis's Telephone, in the hands of Eds and his con- 
 temporaries, did transmit speech. 
 
 III. Eeis's Telephone will transmit speech. 
 
 Before proceeding to discuss these three points we will 
 pause for a moment, first to clear away a lurking verbal 
 fallacy, then to point out the partial historic acknowledg- 
 ment already conceded to Eeis's claims. 
 
 Eeis did not call his instrument an " articulating telephone." 
 Neither did he call it a <( tone telephone." He called it 
 simply " The Telephone " (Das Telephon),* as will be seen in 
 his own first memoir (p. 57). He did speak of his instru- 
 ment again and again as an instrument "for reproducing 
 tones." But it must be remembered that the German word 
 Ton (plural Tone) used by Eeis is more nearly equivalent to 
 our English word " sound," and includes articulate as well as 
 musical tones, unless the context expressly indicates other- 
 wise. So that when Eeis talked of the Reproduction of 
 Tones he was using words which did not limit his meaning 
 to musical tones, as indeed his memoirs show in other ways. 
 He started from a consideration of the mechanical structure 
 of the human ear, and endeavoured to construct an instrument 
 on those lines because the ear can take up all kinds of tones. 
 Eeis was not so foolish as to imagine that the construction of 
 the human ear was solely designed for musical, to the exclusion 
 of articulate tones. We are not aware that the epithet, Tone- 
 
 * The name " Telephone " had already been applied by Sir C. Wheat- 
 stone (183 L) to an acoustic arrangement for transmitting sounds through 
 wooden rods to a distant place in a purely mechanical manner. It is 
 needless to observe that speech as well as music can be thus transmitted ; 
 and though Wheatstone gave telephonic concerts, this does not prove (nor 
 do telephonic concerts given through Eeis's instrument prove) that speech 
 could not be transmitted also. The name " Fernsprecher," now used in 
 Germany for the Telephone, was only suggested in 1877 by Dr. Stephan, 
 Postmaster of the German Empire, in obedience to the absurd fashion 
 which has raged since 1871 in Germany of rejecting words of classic 
 derivation. 
 
INVENTOR OF THE TELEPHONE. 39 
 
 Telephone, was ever applied to Eeis's instruments until it 
 became advisable (!) to seek a means of disparaging an old 
 invention in order to exalt a new one. And it is a curious 
 point that the true musical " tone-telephones," i.e. instruments 
 designed expressly to transmit specific musical tones for the 
 purpose of multiple telegraphy, were invented (by Varley, 
 Gray, La Cour, Graham Bell, and Edison) long after Eeis's 
 Telephone, between the years 1870 and 1876. All these 
 were dependent practically upon the tuning-fork system of 
 vibration, whereas Eeis's system was based on the tympanum 
 of the ear. To classify Eeis's invention with these would be 
 absurd. 
 
 Having shown the fallacy bound up in the term " tone- 
 telephone," we will dismiss the point with the remark that 
 henceforth it will be a waste of time to argue with any person 
 who applies that question- begging epithet to Eeis's in- 
 vention. 
 
 Partial historic acknowledgments of Eeis's claims as 
 inventor of The Telephone have been made from time to time 
 by those best qualified to speak. 
 
 Mr. Edison, the inventor of the famous lamp-black button 
 transmitter, which he christened later as " The Carbon Tele- 
 phone," has himself stated in his account of his inventions,* 
 that he was started upon this line of investigation by having 
 put into his hand, by the late Hon. Mr. W. Orton, a manu- 
 script translation of Legat's Eeport on Eeis's Telephone, 
 given in the Journal of the Austro-German Telegraph Union 
 (see Translation, p. 70). So that he was, therefore, aware 
 at least of this : that in Eeis's instruments " single words 
 uttered, as in reading, speaking, and the like, were perceptible 
 indistinctly, nevertheless, here also the inflexions of the 
 voice, the modulations of interrogation, exclamation, wonder, 
 
 * See proceedings in U. S. Court (Dowd suit), Edison's second answer, 
 and Prescott's ' The Speaking Telephone,' p. 218. 
 
40 PHILIPP EEIS, 
 
 command, etc., attained distinct expression." So far as Mr. 
 Edison is concerned, therefore, Eeis is his starting-point by 
 his own direct avowal. 
 
 Professor Graham Bell has not failed to acknowledge his 
 indebtedness to Eeis, whose entry " into the field of telephonic 
 research " he explicitly draws attention to by name, in his 
 " Eesearches in Electric Telephony," read before the American 
 Academy of Sciences and Arts, in May 1876, and repeated 
 almost verbatim before the Society of Telegraph Engineers, 
 in November 1877. In the latter, as printed at the time, 
 Professor Bell gave references to the researches of Eeis, to 
 the original paper in Dingler's 'Polytechnic Journal' (see 
 Translation, p. 61) ; to the particular pages of Kuhn's 
 volume in Karsten's 'Encyclopaedia' (see p. 106), in which 
 diagrams and descriptions of two forms of Eeis's Telephone 
 are given ; and where mention is also made of the success 
 with which exclamatory and other articulate intonations of 
 the voice were transmitted by one of these instruments ; and 
 to Legat's Eeport, mentioned above (and given in full on 
 p. 70). Professor Bell has, moreover, in judicial examina- 
 tion before one of the United States Courts expressly and 
 candidly stated,* that whilst the receivers of his own early tone- 
 telephones were constructed so as to respond to one musical 
 note only, the receiver of Eeis's instrument, shown in Legat's 
 Esport (as copied in Prescott's ' Speaking Telephone,' p. 10), 
 and given on p. 109 of this work, was adapted to receive 
 tones of any pitch, and not of one tone only. It is further 
 important to note that in Professor Bell's British Patent he 
 does not lay claim to be the inventor, but only the improver 
 of an invention : the exact title of his patent is, " Improve- 
 ments in Electric Telephony (Transmitting or causing sounds 
 for Telegraphing Messages) and Telephonic Apparatus." 
 
 * Published volume of Proceedings in the United States Patent Office, 
 before the Commissioner of Patents. Evidence for A. G. Bell, p. 6. 
 
INVENTOR OF THE TELEPHONE. 41 
 
 So far as Professor Bell is concerned, therefore, he is guilt- 
 less of stigmatising the Eeis instrument as a mere " tone- 
 telephone." 
 
 Professor Dolbear, the inventor of the " Static Eeceiver " 
 form of Telephone, is still more explicit in avowing Keis's 
 claim. In the report of his paper on "the Telephone," 
 read, March 1882, before the Society of Telegraph Engineers 
 and of Electricians* we find : " The speaker could testify 
 that the instrument would talk, and would talk well. The 
 identical instruments employed by Eeis would do that, so 
 that Eeis's transmitters would transmit. Secondly, his 
 receiver would receive; and Eeis did transmit and receive 
 articulate speech with such instruments." 
 
 As far as Professor Dolbear is concerned, therefore, he 
 admits in unequivocal terms the whole claim of Eeis to be 
 the inventor of The Telephone. 
 
 Count du Moncel, author of a work on the Telephone, which 
 has run through several editions, though he has classified 
 Eeis's instrument as a mere " tone- telephone," has recently 
 admitted! that he was, until the year 1882, ignorant of 
 some of Eeis's instruments and of his original papers. He 
 has, moreover, added these words : " Nevertheless, it would 
 not be just not to acknowledge that the Eeis Telephone formed 
 the starting-point of all the others ; " also these significant 
 lines : " It is probable that in this matter, as in the greater 
 number of modern inventions, the original inventor obtained 
 only insignificant results, and that it was the man who first 
 succeeded in arranging his apparatus so as to obtain really 
 striking results that received the honour of the discovery and 
 rendered it popular." 
 
 So far as the Count du Moncel is concerned, therefore, 
 the claims of Philipp Eeis to be the inventor of the tele- 
 
 * Proc. Soc. Telegr. Engin. and Electr. vol. xi. p. 134, 1882. 
 t ' Electrical Review,' July 22, 1882, p. 49. 
 
42 PHILIPP REIS, 
 
 phone are admitted, though hesitatingly, to be historically 
 just. 
 
 We now return to the proof of the three points previously 
 enunciated. 
 
 I. Reis's Telephone was expressly intended to 
 transmit speech. 
 
 Keis's first instrument was (see p. 16) nothing else than a 
 model of the mechanism of the human ear. Why did he 
 choose this fundamental type which runs through all his in- 
 struments from first to last ? The reason is given in his own 
 first memoir (p. 51), " How could a single instrument repro- 
 duce at once the total actions of all the organs operated in human 
 speech? This was ever the cardinal question!' Eeis con- 
 structed his instrument therefore with intent to reproduce 
 human speech. For this reason he borrowed from the ear 
 the suggestion of a tympanum. Of the operation of the tym- 
 .panum he had the most exact and perfect conception. He 
 says (p. 54), " Every tone, and every combination of tones " 
 and this includes articulate tones, of course, and is just as 
 true of them as of any other kind " evokes in our ear, if it 
 enters it, vibrations of the drum-skin, the motions of which may 
 le represented ly a curve!' And further : " As soon, therefore, as 
 it shall become possible, at any place and in any prescribed manner, 
 to set up vibrations whose curves are like those of any given 
 tone, or combination of tones, we shall then receive the same im- 
 pression as that tone or combination of tones would have pro- 
 duced upon us!' Again, it is clear that his study of acoustics 
 led him to employ the tympanum, because of its special value 
 in responding to all the complex vibrations of human speech. 
 It is no less significant that when a decade later Varley, 
 Gray, and Bell, set themselves to invent tone-telephones for 
 the purpose of multiple telegraphy, they abandoned tympa- 
 nums as being unsuitable for tone-telephones, and in lieu 
 
INVENTOR OF THE TELEPHONE. 43 
 
 thereof employed vibrating tongues like those of tuning- 
 forks. Eeis's use of the tympanum had a very definite 
 meaning then ; it meant nothing less than this : I intend my 
 instrument to transmit any sound that a human ear can 
 hear. That it was explicitly within his intention to transmit 
 speech is confirmed by another passage of his first memoir 
 (p. 58), wherein he remarks with a shade of disappointment 
 that though " the consonants are for the most part tolerably 
 distinctly reproduced, the vowels are not yet to an equal 
 degree." To his own pupils and co-workers he communi- 
 cated his ideas. One of the former, Mr. E. Horkheimer, now 
 of Manchester, expressly says (see p. 117) that Eeis's inten- 
 tion was to transmit speech, and that the transmission of 
 music was an afterthought adopted for the convenience of 
 public exhibition, just as was the case with the public exhi- 
 bitions of Bell's Telephone fifteen years later. 
 
 Nor did this imperfection cause Eeis to hide his intentions 
 from the world. He modestly claimed such success as he , 
 had obtained, and left the rest. In 1863 he drew up a 
 Prospectus (given in extenso on p. 85), which was printed to 
 accompany the instruments 4 which were sold ; and of which 
 copies are still extant. In this document he says : " Besides 
 the human voice, according to my experience, there can 
 also be reproduced the tones of good organ pipes, from F 
 to c, and those of a piano." In this same Prospectus 
 (p. 87) occur the instructions for the use of the signal call 
 by which the listener communicates his wishes to the speaker. 
 Those instructions run : " One beat = sing ; two beats = 
 speak." Can any sane person doubt that Eeis intended his 
 instrument to transmit speech, when such directions stand 
 printed in his own Prospectus ? Legat's Eeport (1862) 
 speaks of Eeis's instrument as intended (see p. 77) to speak, 
 and further describes the use of an elliptic cavity to which 
 the listener can apply his ear. Kuhn (1866) (see p. 106) says 
 
44 PEILIPP REIS, 
 
 that the square-box transmitter (Figs. 17, 18) did not send 
 speech well, and complains that he could only get from it an 
 indistinguishable noise. Doubtless he spoke too loudly. 
 Pisko (1865) speaks of the Eeis instrument as intended for 
 speaking (p. 105). Further, in the letter which Eeis wrote 
 in 1863 to Mr. W. Ladd, of London, he expressly emphasises 
 by underscoring the word that his Telephone can transmit 
 "any sound" that is sufficiently loud, and he refers to the 
 speaker and listener at the two ends of the line as " the cor- 
 respondents." The only reply henceforth possible to any 
 person who shall assert that Keis's Telephone was not ex- 
 pressly intended to transmit articulate speech is the good 
 honest retort : impudentissime mentiris. 
 
 II. Reis's Telephone, in the hands of Reis and his 
 contemporaries, did transmit speech. 
 
 Of the performance of his instruments Eeis speaks modestly 
 and carefully, nothing extenuating of his failures, nothing 
 exaggerating of his successes. I shall not attempt to be 
 wiser than he ; nor seek to make out his instrument to have 
 been either more perfect or more reliable than he himself 
 knew it to be. The membrane tympanum of his transmitter 
 was liable to become relaxed by the moisture of the breath 
 rendering the instrument as Graham Bell found fifteen 
 years later with his membrane magneto-transmitters uncer- 
 tain in its action. Moreover, in some earlier forms of Eeis's 
 transmitter, notably those with a vertical tympanum, the 
 adjustment of the contact-points that controlled the current 
 was a matter of delicacy requiring experience and practice, 
 so that casual experimenters failed to obtain the results 
 which Eeis himself obtained ;* they obtaining only a noisy 
 
 * Mr. E. Albert, of the firm of J. W. Albert and Sohn, of Frankfurt, 
 to whom Keis entrusted the manufacture of Telephones for public sale, thus 
 writes : " The most important part was the membiane, because the delicacy 
 
INVENTOR OF TEE TELEPHONE. 45 
 
 snarl where he obtained intelligible speech. Lastly, the 
 very delicacy of the essential parts, the conducting strips of 
 metal which lay lightly in contact against one another, mili- 
 tated against a uniformity of success when tried with dif- 
 ferent voices, some of wmVh were too low to produce any 
 effect, others so loud as to rattle the delicate contact-pieces in 
 a manner fatal to the attainment of the desired result. 
 
 In spite of all these drawbacks, which were not inherent in 
 the principle of the instrument, there is plenty of evidence 
 that Reis's Telephone did transmit speech. Eeis himself records 
 this fact : 
 
 (1.) In 1861, in his memoir ' On Telephony ' (see p. 58), 
 " The consonants are for the most part tolerably distinctly re- 
 produced, lut the vowels not yet in an equal degree" 
 
 (2.) In his ' Prospectus ' (p. 86) Eeis says that the tones of 
 organ-pipes and of the piano can be reproduced as well as 
 the tones of the human voice, " according to my experience." 
 
 (3.) The fact is attested by Inspector Wilhelm von Legat, 
 in his Keport in the ' Zeitschrift ' (p. 77), 1862. After alluding 
 to the indistinctness of the vowels, he says : " Single words, 
 uttered as in reading, speaking, and the like, were perceptible 
 
 of the apparatus depended principally upon that part. As it was not 
 possible to make every membrane equally good, so it came about that 
 instruments of different degrees of superiority came into use, and various 
 decisions were arrived at as to the ability of the instrument to perform 
 the functions for which it was designed. Those who happened to have a 
 poor instrument were able to hear but little ; while those who possessed a 
 good instrument were astonished at its performances. A good instrument 
 reproduced the words sung into it in such a manner that not only the 
 pitch but also the words of the song were perfectly understood, even when 
 the listener was unacquainted with the song and the words." 
 
 M. St. Ed me, of Paris, who contributed to ' Cosmos,' vol. xxiv. p. 349, 
 1864, an article on Reis's Telephone, of which he had seen an example in 
 Konig's atelier, said that when the scale was sung it needed a trained ear 
 to distinguish the notes amidst the noises of the receiver. He must have 
 got hold of an uncommonly bad transmitter with a flabby tympanum to 
 have failed so completely. 
 
46 PH1LIPP REIS, 
 
 indistinctly, nevertheless, here also the inflexions of the voice, the 
 modulations of interrogation, exclamation, wonder, command, etc., 
 attained distinct expression" 
 
 (4.) Professor Quincke, of Heidelberg, testifies (see p. 113) 
 that he heard and understood words spoken through a Reis 
 Telephone in 1864. 
 
 (5.) Professor Bottger, editor of the ' Polytechnisches Notiz- 
 blatt,' in 1863 says (see p. 90)': "The experimenters could 
 even communicate words to one another, though certainly 
 indeed, only such as had often been heard by them." 
 
 (6.) Dr. Eudolph Messel, an old pupil of Reis, and an eye- 
 witness of his early experiments, has written * : " There is 
 not a shadow of a doubt about Reis having actually achieved 
 imperfect articulation. I personally recollect this very distinctly, 
 and could find you plenty more people who witnessed the 
 same." 
 
 (7.) Herr Peter, a former colleague of Philipp Reis, whose 
 testimony will be found on page 126, narrates how he doubted 
 the powers of the instrument until he had verified them for 
 himself by speaking into it words which could not possibly 
 be premeditated. 
 
 (8.) Mr. E. Horkheimer, who aided Reis in his earlier work, 
 though he left Germany when the development of tfre 
 instrument was yet very far from complete, has even given 
 (see p. 117) a list of the words and expressions which he has 
 heard transmitted by the earlier forms of the instrument. 
 
 (9.) Herr Philipp Schmidt, brother-in-law of Philipp Reis, 
 and now acting-paymaster in the Imperial German Navy at 
 Wilhelmshavn, says : " he succeeded finally in reproducing at 
 a distance, words and whole sentences." " There never was 
 any understanding between my brother-in-law and myself as 
 
 * Letter of Dr. Messel to Professor W. F. Barrett quoted, in Professor 
 Barrett's memoir, ' On the Electric Telephone,' read Nov. 19, 1877, to the 
 Dublin Royal Society. Vide Proc. Boy. Soc. Dubl. 1877. 
 
INVENTOR OF THE TELEPHONE. 47 
 
 to particular words and sentences: on the contrary, these 
 were quite spontaneous." 
 
 (10.) Mr. S. M. Yeates, of Dublin, who in 1865 constructed 
 a modified Eeis Telephone (see p. 128), has thus described the 
 performance of the instrument : " Before disposing of the 
 apparatus, I showed it at the November meeting (1865) of 
 the Dublin Philosophical Society, when both singing and 
 the distinct articulation of several words were heard through it, 
 and the difference letween the speakers' voices clearly recognised!' * 
 
 It is difficult to conceive how testimony on this point could 
 be stronger. From so many different sources it is alike 
 agreed that with the instrument presumably in good 
 adjustment Eeis's Telephone, in the hands of Eeis and his 
 contemporaries, did transmit articulate speech. 
 
 III. Reis's Telephone will transmit speech. 
 
 Eeis's Telephone consists of two parts : a " transmitter," 
 into which the speaker speaks; and a "receiver," at which 
 the hearer listens. Their various forms have been described 
 in detail in the preceding chapter. All that we are con- 
 cerned with at this place is, whether these instruments will 
 at the present day do what is asserted. The writer has 
 tested every form of Eeis's transmitter, save only some of the 
 tentative historic forms shown in Figs. 2-8, 13, 15, & 16, ante, 
 and has found them perfectly competent to transmit speech, 
 provided proper precautions were taken : namely, that the 
 contacts were clean and in adjustment, that the tympanum 
 was tightly stretched, and that the speaker did not speak too 
 loudly : f in other words, that the instruments were properly 
 used. Any one who wants not to succeed in transmitting 
 speech with Eeis's transmitter has only to neglect these 
 reasonable precautions. It is not, therefore, difficult to fail. 
 
 * See Barrett's ' Telephones Old and New ' (1878), p. 12. 
 f See Reis's own remark at bottom of p. 57. 
 
48 PEILIPP EEIS, 
 
 The writer has also tested both the better-known forms of 
 Keis's receiver (Figs. 21, 22, & 23), and finds that both are 
 perfectly competent to receive speech electrically and repro- 
 duce it audibly, both vowels and consonants being perfectly 
 distinct and articulate, though never as loud as in more 
 modern forms of telephone-receiver. From a steel wire, 
 magnetised, as prescribed by Eeis, by surrounding it with a 
 coil of wire through which the current passes, the writer has 
 obtained articulation exceeding in perfection of definition, 
 both of vowels and of consonants, the articulation of any other 
 telephone-receiver he has ever listened to. Perhaps it may 
 be objected that it is difficult to listen to a steel wire. Eeis 
 met this difficulty in his own way by mounting his steel wire 
 upon a small sounding-box to strengthen the sounds, and 
 added a flat upper case against which the ear of the listener 
 can be pressed, and which can be removed, or opened as a 
 lid, when a whole audience is to hear simultaneously the tones 
 of the instrument when working in a loud and disagreeable 
 manner, as a transmitter of the coarser vibrations of a loudly 
 sung melody. The lid is not wanted for this latter purpose 
 is an encumbrance; which, nevertheless, by its presence 
 proves the more delicate functions of the instrument. Eeis's 
 instructions in his ' Prospectus/ p. 86, are that pressing this 
 lid down firmly upon the steel core increases the loudness of 
 the sounds. Any one who wants not to succeed in receiving 
 speech with Eeis's receiver has, as before, only to neglect 
 reasonable precautions. He has only to use an imperfect or 
 bad transmitter, or use it carelessly, or put the receiver to a 
 sufficient distance from his ear, to attain this result. There 
 are people who have failed to make Eeis's receiver receive. 
 
 This is not the place to discuss a doctrinaire objection 
 sometimes raised, that it is theoretically impossible for Eeis's 
 instruments to work. For the moment we are concerned 
 with the practical question : Do they work ? No one 
 
INVENTOR OF THE TELEPHONE. 49 
 
 practically experienced in telephones, even if he should 
 deny that Eeis had any such intention, will dispute that 
 they can now be made to transmit speech. Professor Dolbear, 
 himself no mean authority on telephones, testifies, as quoted 
 above (p. 41), "that the instruments would talk, and would 
 talk well" He would, indeed, be a bold man who would 
 come forward to deny what can be shown any day as an 
 experimental fact : that Rds's Telephone will transmit speech. 
 
 We have now shown that Philipp Eeis was the undisputed 
 inventor of an instrument which he called the Telephone, 
 which instrument can now be used to transmit speech ; which 
 was then used to transmit speech ; and which was invented 
 on purpose to transmit speech. So far the result of the 
 examination into the facts of the case is conclusive enough. 
 A more complete case could hardly be desired. No honest 
 person could hesitate for want of proof, either greater in 
 amount or more direct to the point. 
 
 Nevertheless, I propose in another section to go a little 
 further and to prove a technical point of highest interest ; 
 namely, that there is not in the Telephone Exchanges of 
 England to-day, any single telephone to be found in which 
 the fundamental principles of Eeis's Telephone are not the 
 essential and indispensable features. These considerations 
 being, however, of a strictly technical nature, will be best 
 considered in an Appendix. As, however, we are able to 
 show that those instruments which are now in daily use for 
 transmitting speech, embody the two fundamental principles 
 upon which Eeis based the instrument which he called " Das 
 Telephon" it would be dishonest to the memory of the 
 deceased inventor to claim anything less than that he was 
 the " first and true inventor " of the Telephone. 
 
50 PHILIPP RE1S, 
 
 CHAPTER IV. 
 
 CONTEMPORARY DOCUMENTS. 
 
 THE following documents, drawn from the scientific literature 
 of the time, are placed in chronological order, beginning with 
 the first memoir published by Philipp Reis himself, in the 
 Jaliresbericht of the Physical Society of Frankfort, for th,e 
 year 1860-61. Every care has been taken that the trans- 
 lations here given shall be faithful in every detail to the 
 originals. All notes and comments by the translator are 
 distinguished by being enclosed in square brackets. 
 
 [1.] ON TELEPHONY BY THE GALVANIC CURRENT. 
 By PHILIPP REIS. 
 
 [Translated from the Annual Report (Jahresbericht) of the Physical 
 Society of Frankfurt am-Main, for 1860-1861.] 
 
 THE surprising results in the domain of Telegraphy, have 
 often already suggested the question whether it may not also 
 be possible to communicate the very tones of speech direct to 
 a distance. Researches aiming in this direction have not, 
 however, up to the present time, been able to show any 
 tolerably satisfactory result, because the vibrations of the 
 media through which sound is conducted, soon fall off so 
 greatly in their intensity that they are no longer perceptible 
 to our senses. 
 
 A reproduction of the tones at some distance by means of 
 
INVENTOR OF THE TELEPHONE. 51 
 
 the galvanic current, has perhaps been contemplated ; but at 
 all events the practical solution of this problem has been 
 most doubted by exactly the very persons who by their 
 knowledge and resources should have been enabled to grasp 
 the problem. To one who is only superficially acquainted 
 with the doctrines of Physics, the problem, if indeed he 
 becomes acquainted with it, appears to offer far fewer points 
 of difficulty because he does not foresee most of them. Thus 
 did I, some nine years ago (with a great penchant for what 
 was new, but with only too imperfect knowledge in Physics), 
 have the boldness to wish to solve the problem mentioned ; 
 but I was soon obliged to relinquish it, because the very first 
 inquiry convinced me firmly of the impossibility of the 
 solution. 
 
 Later, after further studies and much experience, I perceived 
 that my first investigation had been very crude and by no 
 means conclusive : but I did not resume the question seriously 
 then, because I did not feel myself sufficiently developed to 
 overcome the obstacles of the path to be trodden. 
 
 Youthful impressions are, however, strong and not easily 
 effaced. I could not, in spite of every protest of my reason, 
 banish from my thoughts that first inquiry and its occasion ; 
 and so it happened that, half without intending it, in many a 
 leisure hour the youthful project was taken up again, the diffi- 
 culties and the means of vanquishing them were weighed, 
 and yet not the first step towards an experiment taken. 
 
 How could a single instrument reproduce, at once, the 
 total actions of all the organs operated in human speech ? 
 This was ever the cardinal question. At last I came 
 by accident to put the question in another way : How 
 does our ear take cognizance of the total vibrations of all the 
 simultaneously operant organs of speech ? Or, to put it more 
 generally: How do we perceive the vibrations of several 
 bodies emitting sounds simultaneously ? 
 
 E 2 
 
52 PHILIPP REIS, 
 
 In order to answer this question, we will next see what 
 must happen in order that we may perceive a single tone. 
 
 Apart from our ear, every tone is nothing more than the con- 
 densation and rarefaction of a body repeated several times in a 
 second (at least seven to eight times *). If this occurs in the 
 same medium (the air) as that with which we are surrounded, 
 then the membrane of our ear will be compressed toward the 
 drum-cavity by every condensation, so that in the succeeding 
 rarefaction it moves back in the opposite direction. These 
 vibrations occasion a lifting-up and a falling-down of the 
 " hammer " [malleus bone] upon the " anvil " [incus bone] 
 with the same velocity, or, according to others, occasion an 
 approach and a recession of the atoms of the auditory 
 ossicles, and give rise, therefore, to exactly the same number 
 of concussions in the fluid of the cochlcea, in which the 
 auditory nerve and its terminals are spread out. The greater 
 the condensation of the sound-conducting medium at any 
 given moment, the greater will be the amplitude of vibration 
 of the membrane and of the " hammer," and the more power- 
 ful, therefore, the blow on the " anvil " and the concussion of 
 the nerves through the intermediary action of the fluid. 
 
 The function of the organs of hearing, therefore, is to impart 
 faithfully to the auditory nerve, every condensation and 
 rarefaction occurring in the surrounding medium. The 
 function of the auditory nerve is to bring to our consciousness 
 the vibrations of matter resulting at the given time, both 
 according to their number and their magnitude. Here, first, 
 certain combinations acquire a distinct name : here, first the 
 vibrations become musical tones or discords (Misstone). 
 
 That which is perceived by the auditory nerve, is, therefore, 
 
 * [This was the number formerly accepted on the authority of Despretz 
 as the minimum number of vibrations that could evoke the sensation of a 
 tone in the human ear. The limit now more usually recognized is that of 
 Helmholtz, who assigns from thirty to forty double vibrations per second 
 as the minimum.] S. P. T. 
 
INVENTOR OF THE TELEPHONE. 53 
 
 merely the action of a force affecting our consciousness, and as 
 such may be represented graphically, according to its duration 
 and magnitude, by a curve. 
 
 Fig. 24. 
 
 Let the line a, b, indicate any given length of time, and 
 the curve above the line a condensation ( + ), the curve below 
 the line a rarefaction ( ), then every ordinate erected at the 
 end of an abscissa will give [according to the height of it], at 
 a moment indicated by the position of the foot of the 
 ordinate, the strength of the condensation that is causing the 
 drum- skin to vibrate. 
 
 Our ear can perceive absolutely nothing more than is 
 capable of being represented by similar curves, and this 
 method is completely sufficient to bring before our clear 
 consciousness every tone and every combination of tones. 
 
 If several tones are produced at the same time, then the 
 medium that conducts sound is placed under the influence of 
 several simultaneous forces ; and the two following laws 
 hold good : 
 
 If all the forces operate in the same sense, the resultant 
 motion is proportional in magnitude to the sum of the forces. 
 
 If the forces operate in opposite senses, the resultant 
 motion is proportional in magnitude to the difference of the 
 opposing forces. 
 
 Let us exhibit the condensation-curves for three tones 
 each singly (Table I.)* : then, by adding together the ordinates 
 
 * [The three plates or tables with which Keis accompanied his Memoir, 
 containing a variety of undulatory curves corresponding to various com- 
 binations of tones, both of musical concords and of dissonant sounds, are 
 not reprinted in this book in their entirety. Table I. contained three sets, 
 the first of which is reproduced by photo-lithography in reduced facsimile 
 
54 PHILIPP REIS, 
 
 corresponding to equal abscissae, we can determine new 
 ordinates and develop a new curve which we may call the 
 combination-curve [or resultant curve]. Now this gives us 
 just exactly what our ear perceives from the three simul- 
 taneous tones. It ought to cause us as little wonder that 
 a musician can recognize the three tones, as that (as is the 
 fact) a person conversant with the science of colour, can 
 recognize in green, blue and yellow tints. The combination- 
 curves of table I. present, however, very little difficulty, since 
 in them all the proportions of the component curves recur 
 successively. In chords consisting of more than three tones 
 (Table II.), the proportions of the components are no longer 
 so easy to recognize in the drawing. But it is also difficult 
 to an accomplished musician, in such chords to recognize the 
 individual notes. 
 
 Table III. shows us a discord. Why discords affect us so 
 unpleasantly I leave provisionally to the contemplation of 
 the gentle reader, as I may perhaps return to this point in 
 another memoir. 
 
 It follows from the preceding that : 
 
 (1.) Every tone and every combination of tones evokes in 
 our ear, if it enters it, vibrations of the drumskin, the motions 
 of which may be represented by a curve.* 
 
 (2.) The motions of these vibrations evoke in us the per- 
 ception (sensation) of the tone: and every change in the 
 motion must change the sensation. 
 
 in Fig. 47, p. 173. It was also reproduced by W. von Legat in his 
 Report from which Plate I. at end of this book is copied, Fig. 1 of that 
 plate being the same as Fig. 1 of Eeis's Table I. Fig. 2 of Plate 1, was 
 in like manner copied by Legat from the first figure of Reis's Tahle II., and 
 Fig. 3 of Plate I., which represents the curves of a non-harmonious com- 
 bination is the same as Reis's Table III., the only difference being that in 
 Reis's Table III. the irregular undulations of the resultant curve were 
 emphasised by being labelled ' Dissonanz.'] S. P. T. 
 
 * [This is true for speech-tones as well as for musical tones. Each kind 
 of tone may be represented by its own characteristic curve.] S. P. T. 
 
INVENTOR OF THE TELEPHONE. 
 
 55 
 
 As soon, therefore, as it shall be possible at any place and 
 in any prescribed manner, to set up vibrations whose curves 
 are like those of any given tone or combination of tones, we 
 shall receive the same impression as that tone or combina- 
 tion of tones would have produced upon us.* 
 
 Taking my stand on the preceding principles, I have suc- 
 ceeded in constructing an apparatus by means of which I am 
 in a position to reproduce the tones of divers instruments, 
 yes, and even to a certain degree the human voice. It is 
 very simple, and can be clearly explained in the sequel, by 
 aid of the figure : 
 
 f - ' ' 4 
 
 In a cube of wood, r s t u v w x, there is a conical hole, a, 
 closed at one side by the membrane b (made of the lesser 
 intestine of the pig), upon the middle of which a little strip 
 of platinum is cemented as a conductor of the current [or 
 electrode]. This is united with the binding-screw, p. From 
 
 * [This is the fundamental principle, not only of the telephone, but ot 
 the phonograph ; and it is wonderful with what clearness Reis had grasped 
 his principle in 1861.] S. P. T. 
 
56 PHILIPP REIS, 
 
 the binding-screw n there passes likewise a thin strip of 
 metal over the middle of the membrane, and terminates here 
 in a little platinum wire which stands at right angles to the 
 length and breadth of the strip. 
 
 From the binding-screw, p, a conducting-wire leads 
 through the battery to a distant station, ends there in a spiral 
 of copper-wire, overspun with silk, which in turn passes into 
 a return-wire that leads to the binding-screw, n. 
 
 The spiral at the distant station is about six inches long, 
 consists of six layers of thin wire, and receives into its middle 
 as a core a knitting-needle, which projects about two inches 
 at each side. By the projecting ends of the wire the spiral 
 rests upon two bridges of a sounding-box. (This whole piece 
 may naturally be replaced by any apparatus by means of 
 which one produces the well-known " galvanic tones.") 
 
 If now tones, or combinations of tones, are produced in the 
 neighbourhood of the cube, so that waves of sufficient strength 
 enter the opening a, they will set the membrane I in vibra- 
 tion. At the first condensation the hammer-shaped little 
 wire d will be pushed back. At the succeeding rarefaction 
 it cannot follow the return- vibration of the membrane, and 
 the current going through the little strip [of platinum] 
 remains interrupted so long as until the membrane, driven by 
 a new condensation, presses the little strip (coming from p) 
 against d once more. In this way each sound-wave effects 
 an opening and a closing of the current. 
 
 But at every closing of the circuit the atoms of the iron 
 needle lying in the distant spiral are pushed asunder from 
 one another. (Muller-Pouillet, ( Lehrbuch der Physik/ see 
 p. 304 of vol. ii. 5th ed.). At the interruption of the current 
 the atoms again attempt to regain their position of equili- 
 brium. If this happens then in consequence of the action 
 and reaction of elasticity and traction, they make a certain 
 
INVENTOR OF THE TELEPHONE. 57 
 
 number of vibrations, and yield the longitudinal tone * of the 
 needle. It happens thus when the interruptions and restora- 
 tions of the current are effected relatively slowly. But if these 
 actions follow one another more rapidly than the oscillations 
 due to the elasticity of the iron core, then the atoms cannot 
 travel their entire paths. The paths travelled over become 
 shorter the more rapidly the interruptions occur, and in pro- 
 portion to their frequency. The iron needle emits no longer 
 its longitudinal tone, but a tone whose pitch corresponds to 
 the number of interruptions (in a given time). But this is 
 saying nothing less than that the needle reproduces the tone 
 which was imparted to the interrupting apparatus. 
 
 Moreover, the strength of this tone is proportional to the 
 original tone, for the stronger this is, the greater will be the 
 movement of the drum-skin, the greater therefore the move- 
 ment of the little hammer, the greater finally the length of 
 time during which the circuit remains open, and consequently 
 the greater, up to a certain limit, the movement of the atoms 
 in the reproducing wire [the knitting needle], which we 
 perceive as a stronger vibration, just as we should have 
 perceived the original wave. 
 
 Since the length of the conducting wire may be extended 
 for this purpose, just as far as in direct telegraphy, I give to 
 my instrument the name " Telephon." 
 
 As to the performance attained by the Telephone, let it 
 be remarked, that, with its aid, I was in a position to 
 make audible to the members of a numerous assembly (the 
 Physical Society of Frankfort-on-the-Main) melodies which 
 were sung (not very loudly) into the apparatus in another 
 house (about three hundred feet distant) with closed doors. 
 
 Other researches show that the sounding-rod [i.e. the 
 
 * [That is, at any single demagnetisation of the needle, it vibrates and 
 emits the same tone as if it had been struck or mechanically caused to 
 vibrate longitudinally.] S. P. T. 
 
58 PHILIPP REIS, 
 
 knitting needle] is able to reproduce complete triad chords 
 (" Dreiklange ") of a piano on which the telephone [i.e. the 
 transmitter] stands ; and that, finally, it reproduces equally 
 well the tones of other instruments harmonica, clarionet, 
 horn, organ-pipes, &c., always provided that the tones belong 
 to a certain range between F and / *. 
 
 It is, of course, understood' that in all researches it was 
 sufficiently ascertained that the direct conduction of the sound 
 did not come into play. This point may be controlled very 
 simply by arranging at times a good shunt-circuit directly 
 across the spiral [i.e. to cut the receiving instrument out of 
 circuit by providing another path for the currents of elec- 
 tricity], whereby naturally the operation of the latter 
 momentarily ceases. 
 
 Until now it has not been possible to reproduce the tones 
 of human speech with a distinctness to satisfy everybody. 
 The consonants are for the most part tolerably distinctly 
 reproduced, but the vowels not yet in an equal degree. Why 
 this is so I will endeavour to explain. 
 
 According to the researches of "Willis, Helmholtz, and 
 others, vowel sounds can be artificially produced by causing 
 the vibrations of one body to reinforce those of another 
 periodically, somewhat after the following scheme : 
 
 An elastic spring is set in vibration by the thrust of the 
 
 Fig. 26. 
 
 tooth of a cog-wheel : the first swing is the greatest, and 
 each of the others is less than the preceding one (see Fig. 26) 
 
 * [This range was simply due to the degree of tension of the tympanum ; 
 another tympanum differently stretched, or of different proportions, would 
 have a different range according to circumstances.] S. P. T. 
 
INVENTOR OF THE TELEPHONE. 59 
 
 After several vibrations of this sort (without the spring 
 coming to rest) let another thrust be given by the tooth ; the 
 next swing will again be a maximum one, and so on. 
 
 The height or depth of the sound produced in this fashion 
 depends upon the number of vibrations made in a given 
 time ; but the quality of the note depends upon the number 
 of variations of amplitude (Anschwellungen) occurring in the 
 same time. 
 
 Two vowels of equal pitch may be distinguished from each 
 other somewhat after the manner represented by the curves 
 (1) (2) : while the same tone devoid of any vowel quality, is 
 represented by curve (3). 
 
 Fig. 27. 
 
 Our organs of speech create the vowels probably in the 
 same manner by a combined action of the upper and lower 
 vocal chords, or of the latter and of the cavity of the mouth. 
 
 Now my apparatus gives the number of the vibrations, 
 but with far less strength than the original ones ; though 
 also, as I have cause to think, always proportional to one 
 another up to a certain degree. But because the vibrations 
 are throughout smaller, the difference between large and small 
 vibrations is much more difficult to recognize than in the 
 original waves, and the vowel is therefore more or less 
 indefinite. 
 
60 PEILIPP EEIS, 
 
 Whether my views with respect to the curves representing 
 combinations of tones are correct, may perhaps be deter- 
 mined by aid of the new phonautograph described by 
 Duhamel. (See Yierordt's ' Physiology/ p. 254.) 
 
 There may probably remain much more yet to be done for 
 the utilisation of the telephone in practice (zur praktischen 
 Verwerthung des Telephons). For physics, however, it has 
 already sufficient interest in that it has opened out a new 
 field of labour. 
 
 PHILIPP EEIS. 
 
 Friedrichsdorf, near Frankfort-on- the- Main, 
 in December 1861. 
 
 [Though the foregoing memoir, as printed in the ' Jahres- 
 bericht/ of the Physical Society of Frankfort-on-the-Main, 
 is dated "December 1861," it was delivered verbally on 
 October 26th preceding, as the ' Proceedings ' of the Society 
 show. From the ' Jahresbericht ' for the succeeding year we 
 learn that three weeks after the delivery of this communi- 
 cation Eeis made a second communication to the Society on 
 a kindred matter. The entry is as follows (' Proceedings f x>f 
 the Society, p. 13) : "On the 16th November, by the same: 
 Explanation of a new Theory concerning the Perception of 
 Chords and of Timbre (' Klangfarben '), as a Continuation and 
 Supplement of the Memoir on the Telephone." So far as can 
 now be learned, the substance of this communication was 
 embodied in the latter part of the paper " On Telephony," 
 when written out in December for publication. On the 8th of 
 January, 1862, the formal thanks of the Society were voted 
 to Eeis for the manuscript which he had contributed to the 
 ' Jahresbericht/ 
 
 It is of interest, moreover, to note that the matter did not 
 immediately drop. Professor Bottger, who as one of the 
 regular lecturers of the Physical Society, held fortnightly dis- 
 
INVENTOR OF THE TELEPHONE. 61 
 
 courses on matters of scientific novelty, took occasion on the 
 7th of December to recur to the subject then attracting so 
 much attention. The title of his discourse (see ' Proceedings ' 
 of the Society, p. 11) was " Application of an Experiment 
 relating to the Transmission of Musical Tones to any desired 
 distance by means of the Galvanic Current." It is not quite 
 certain whether Reis was present on this occasion. Early in 
 the spring of 1863, appeared in Bottger's ' Polytechnisches 
 Notizblatt' (No. 6 of that year) an article which contains in 
 condensed form Bottger's discourse. This article was copied 
 into Dingler's 'Polytechnisches Journal' for May 1863. 
 vol. clxviii.p. 185, and also into the 'Polytechnisches Central- 
 blatt' for July 1863, vol. xxix. p. 858. An extract of Reis's 
 own paper, condensed from the ' Jahresbericht ' by Dr. Roeber 
 (now President of the Physical Society of Berlin), appeared 
 in the ' Berliner Berichte ' (i. e. the ' Fortschritte der Physik ') 
 for 1861, vol. xvii. pp. 171-173. It is interesting to note 
 that Reis's paper was then deemed worthy to stand in the 
 pages of the ' Fortschritte ' by the side of the classic researches 
 of Thomson on Regelation, and of Maxwell on Magnetic 
 Lines of Force. The following is a translation of Bottger's 
 notice mentioned above.] 
 
 [2.] ON THE TRANSMISSION OF TONES TO A DISTANCE AS 
 FAR AS DESIRED, BY THE HELP OF ELECTRICITY (TELEPHONY). 
 
 [Translated from the original notice by Professor Bottger, which ap- 
 peared in Bottger's * Polytechnischen Notizblatt,' 1863, No. 6, p. 81, in 
 Dingler's * Polytechnisches Journal,' 1863, vol. clxviii. p. 185, and in the 
 1 Polytechnisches Centralblatt,' 1863, t. xxix. p. 858.] 
 
 Two decades ago we had not yet gone beyond the first 
 attempts to give signals at a great distance by the aid of 
 electricity. Since then telegraphy has attained such a com- 
 pleteness, and the telegraph wire has reached such a universal 
 extension, that there seems little left for even the boldest 
 wish to desire. 
 
62 PHILIPP EEIS, 
 
 Now there crops up a first serious research to reproduce 
 tones at any desired distance by the aid of electricity. This 
 first experiment which has been crowned with some success, 
 has been made by the teacher of Natural Science at Fried- 
 richsdorf, not far from Frankfort-on-the-Main, Herr Ph. Eeis, 
 and has been repeated in the Auditorium of the Physical 
 Society in Frankfort, before numerous assembled members on 
 the 26th of October, 1861. He caused melodies to be sung 
 not very loudly into one part of his apparatus, which was 
 placed in a building (the Burger-Hospital), about 300 feet 
 distant, with closed windows and doors. These same melodies 
 were audible to the members in the meeting-hall by means of 
 the second part of the apparatus. These wonderful results 
 were attained with the following simple pieces of apparatus. 
 A little light box, a sort of hollow cube of wood, has a large 
 opening at its front side, and a small one at the back on the 
 opposite side. The latter is closed with a very fine membrane 
 (of pig's smaller-intestine) which is strained stiff. A narrow 
 springy strip of platinum foil, fixed at its outer part to the 
 wood, touches the membrane at its middle ; a second platinum 
 strip is fastened by one of its ends to the wood at another 
 spot, and bears at its other end a fine horizontal spike, which 
 touches the other little platinum strip where it lies upon the 
 membrane. 
 
 As is known, tones arise from rarefactions and condensa- 
 tions of the air following quickly after one another. If these 
 motions of the air, known as waves, strike upon the thin 
 membrane, they press it against the little plate of platinum 
 with which it is in contact, and immediately let it vibrate 
 back again into the hollow cube (or so-called artificial ear) : 
 they act so that the membrane now takes a form hollowed 
 toward the cube, now bulged toward the outside. The little 
 plate of platinum touching it thereby acquires a vibrating 
 motion, so that it now is pressed against the spike of the 
 second [platinum plate], now leaves the same. 
 
INVENTOR OF THE TELEPHONE. 63 
 
 If now one little plate of platinum be united by a wire 
 with one pole of a voltaic battery, and the electricity be led, 
 by a wire fastened to the other pole of the battery, to any 
 desired distance ; there carried through a spiral, about six 
 inches long, made of a six fold winding of very thin covered 
 copper wire ; thence led back to the second platinum strip on 
 the wooden cube through a second insulated wire ; then at 
 every vibration of the membrane an interruption in the 
 current of electricity takes place because the platinum point 
 no longer touches the other little strip of platinum. Through 
 the hollow of the wire-spiral there is stuck a thin iron wire 
 (a strong knitting-needle), which is ten inches long, and 
 which rests upon two bridges of a sounding-board by its ends 
 which project on both sides about two inches out of the 
 spiral. 
 
 It is known * that if an electric current be led through a 
 
 * [The so-called "galvanic tone" heard on opening or closing the circuit 
 was well-known, and Wertheim had shown that this tone was, for any 
 given rod of iron, identical with its " longitudinal tone," i.e. the tone pro- 
 duced by striking it on the end so as to produce longitudinal vibrations. 
 But it was one of the most important discoveries in Reis's researches that 
 such a rod could take up any tone in obedience to the vibrations forced 
 upon it by periodic interruptions in the magnetising current in the spiral 
 of any degree of rapidity within very wide limits. The translator has had 
 occasion to examine this point, ar.d has found iron, steel, and cobalt wires 
 varying from 4 to 10 inches in length, including some used by Reis him- 
 self as receivers, to be capable of taking up vibrations from as slow as 40 
 per second to the very shrillest whistle audible to human ears, or exceeding 
 36,000 per second. It is sometimes also mistakenly supposed that such a wire 
 can respond only to the vibrations of tones that are musical, not to those 
 that are articulate, including both consonants and vowels. This, however, 
 is an entire mistake. For, using such a wire as a receiver (surrounded by its 
 proper coil and mounted with an appropriate sounding board, or, better still, 
 tympanum), in conjunction with a well-adjusted transmitter, the articula- 
 tion transmitted surpasses that obtainable with any of the ordinary mag- 
 netic receivers in distinctness, though not in loudness. This discovery of 
 Reis's is of the greatest importance, especially as some who ought to know 
 better have very unjustly denied the capability of this part of the apparatus 
 to act as a telephone receiver for articulate sounds.] S. P. T. 
 
64 PHILIPP EEIS, 
 
 spiral which surrounds an iron rod in the manner described, 
 at every interruption of the same a tone is audible arising 
 from the vibration of the rod. If the closings and interrup- 
 tions of the circuit follow one another relatively slowly, then 
 there is produced by the changes of position of the molecules 
 of the rod, evoked by the electricity, a tone, the so-called 
 longitudinal tone of the rod, which is dependent upon the 
 length and stoutness of the rod. But if the closings and 
 interruptions of the electric current in the spiral follow one 
 another more rapidly than the vibrations of the smallest 
 particles of the iron rod,* which vibrations are determined 
 by its elasticity, then these particles cannot complete their 
 paths, receive new impacts, their vibrations become smaller, 
 but quicker, and follow one another as frequently as the in- 
 terruptions. The iron rod then no longer gives its longi- 
 tudinal tone, but a tone, which is higher according as the 
 interruptions are more frequent in the given time, or lower, 
 as they are less frequent. It is known that the height and 
 depth of tones depends only on the number of air-waves 
 which follow one another in a second. We have seen 
 above that by this is determined the number of interrup- 
 tions of the electric current of our apparatus by means of 
 the membrane and the platinum strip. The iron wire must 
 therefore give out the tone in the same height or depth as 
 that which struck the membrane. Now since a very far 
 leading of the electricity makes it suffer scarcely any weak- 
 ening in proper apparatus, it is intelligible that one can 
 make the tone which acts on the membrane at one place 
 audible, by means of the iron rod, at any desired distance. 
 
 * [This limit is a mistake of Professor Bottger's. The longitudinal 
 tone of an unstrained iron or steel wire 10 inches long would be a note 
 about four octaves above the middle c of the piano ; whereas, in fact, any 
 note of the whole piano-gamut down to the lowest note, can be reproduced 
 by such a wire, as stated in preceding footnote.] S. P. T. 
 
INVENTOR OF THE TELEPHONE. 65 
 
 That the tone is made audible at a distance by the electric 
 agitations, and not by direct conduction of the sound-waves 
 through the wires is proved in the most evident way of all, 
 because one instantly hears no more the tone through the 
 spiral when a good short circuit is made, as, for example, by 
 laying upon the two wires which conduct the electricity a 
 strip of sheet metal right in front of the spiral. 
 
 The reproduced tones are, of course, somewhat weaker than 
 the original ones, but the number of vibrations is similar. If 
 thus the reproduction [of tones] in exactly similar height 
 and depth is easily attained, it is however difficult for our 
 ear, amidst the always smaller vibrations, to which the 
 diminished strength of the tone is due, to evaluate exactly 
 the magnitude of the vibrations. But the character of the 
 tone depends upon the number of variations of amplitude 
 (Anschwellungen), that is to say, depends upon whether, for 
 example, in the tones which have similar pitch and therefore 
 a similar number of waves per second, the fourth, sixth, 
 eighth, tenth, or sixteenth wave is stronger than the others. 
 For physicists have shown that an elastic spring is set in 
 vibration by the thrust of the teeth of a cog-wheel ; the first 
 vibration is the greatest, all those that follow being less. If 
 there comes, before the spring comes to rest, a fresh thrust 
 from a cog, then the next vibration is again equal to the 
 greatest first vibration without the spring making any more 
 vibrations on. that account ; and by this means vowel-tones 
 may be artificially produced. 
 
 One may also be yet far removed from being able to carry 
 on a conversation with a friend dwelling a hundred miles 
 distant, and recognise his voice, as if he sat near us ; but it 
 can no longer be maintained that this is impossible. Indeed 
 the probability that this will be attained * is already become 
 
 * [Professor Bottger had not to wait long for the fulfilment to a very 
 large degree of this anticipation; for within six months Dingler's Journal, 
 
PEILIPP EEIS, 
 
 as great as the probability of the reproduction of natural 
 colours in photography has become through the notable 
 researches of Mepce. 
 
 [The second public exhibition which Eeis made of the 
 telephone was, like the first, in Frankfort-on-the-Main, but 
 this time before a Society known as the Freies Deutsches 
 Hochstift, or Free German Institute, a kind of Athenaeum 
 Club for the city of Frankfort, now for many years established 
 in the well-known house where the poet Goethe was born, 
 in the Grosse Hirschgraben. In 1862, however, the" Free 
 German Institute held its meetings in another building 
 known as the Saalbau. And on May the llth of that year 
 Philipp Eeis lectured upon and exhibited the Telephone. 
 A journal which appeared then, and still appears, in 
 Frankfort, with the title of ' Didaskalia,' devoted to light 
 literary and artistic news, popular science, and general in- 
 telligence of an informing character, ordinarily inserted 
 notices of the chief meetings of the Hochstift. On this occa- 
 sion a preliminary paragraph was inserted in the following 
 terms : ] 
 
 [3.] TELEPHONY, i.e. SOUND-TRANSMISSION. 
 
 [TRANSLATION FROM ' DIDASKALIA,' MAY STH, 1862.] 
 
 The excellent physicist, Mr. Phil. Reis, of Friedrichsdorf, 
 calls by this name his surprising invention for using the 
 telegraph line to transmit really audible tones. Our readers 
 will perhaps remember having heard some time since of this 
 
 iu which this article appeared, contained Legat's report on Keis's instru- 
 ments, in which not only were various modifications in their construction 
 made known, but also the transmission of voice-tones, not yet perfectly 
 but with recognisable modulations and intonations, was recorded. Reis 
 had, indeed, succeeded nearly as well as this with his first instrument, as 
 his memoir of 1861 shows. See p. 58.] 
 
INVENTOR OF TEE TELEPHONE. 67 
 
 invention, the first trials with which Mr. Eeis performed 
 here in the Physical Society. Since then the invention has 
 been constantly developed, and will, no doubt, become of 
 great importance. 
 
 [The lecture which followed this announcement was duly 
 given on the llth of May. In the Saalbau there is a suite 
 of four rooms. The Lecture to the assembled members of the 
 Hochstift was delivered in the Auditorium, at one end of 
 the suite : the wires were passed through the two intervening 
 rooms to the fourth chamber, where the transmitter was 
 placed, the doors being closed. The battery and wires were 
 borrowed from the Physical Society for this occasion, per- 
 mission for their use having .been granted on May 2nd, 
 as appears in a formal entry in the minute-book. The fol- 
 lowing notice of Eeis's discourse, believed to have been 
 written by Dr. Volger, Founder and first President of the 
 Hochstift, appeared in ' Didaskalia ' for May 14th.] 
 
 [4.] TRANSLATION FROM ' DIDASKALIA/ 12TH MAY, 1862. 
 
 Yesterday's meeting of the Free German Institute was a 
 very numerously attended one from the fact that the subject 
 in the order of business, " Telephony by Transmission of the 
 Galvanic Current," as explained by the inventor himself, 
 Mr. Phil. Eeis, excites so great an interest that it rightly 
 deserves the most general attention. 
 
 In a lecture exceedingly interesting, universally under- 
 stood, clear, and concise, Mr, Eeis gave a historical outline 
 of the origin and development of his idea of the practical 
 possibility of the transmission of tones in a galvanic way. 
 
 His first attempts were mostly unsuccessful in solving the 
 cardinal question propounded by him. " How is it possible 
 that a single instrument can reproduce at once the total action 
 of all the organs operated in human speech ? " Until finally 
 it occurred to him to seek the solution of the problem in the 
 
68 PHILIPP EEIS, 
 
 question, "How does our ear take cognisance of the total 
 vibrations of all the organs of speech acting at once ? " or 
 " How do we perceive the vibrations of several bodies sound- 
 ing at once ? " 
 
 In order to answer this question the lecturer went more 
 closely into the anatomy of the ear and into the formation of 
 tones in general. After this was determined, he took up 
 again his experiments in reference to the transmission of 
 tones by means of galvanism. 
 
 Afterwards Mr. Eeis constructed considerably enlarged 
 the parts of the ear necessary for hearing, by which it was 
 finally possible for him to transmit the tones brought to the 
 mechanically-imitated ear. 
 
 The experiments by him some months ago in the Physical 
 Society, were, to the astonishment of all, exceedingly plain 
 and clear, whereas the experiment following the lecture of 
 yesterday was less successful. This was due partly to the 
 poor conductivity of the wires, partly to the locality. 
 
 Although much is still left to be done for the practical 
 utilisation (Verwerthung) of the telephone, yet a new and 
 interesting field of labour is hereby opened to physics. 
 
 [No more complete report than the foregoing is to be found, 
 and it is believed that the discourse, which like all those 
 given by Eeis was delivered extempore, was never committed 
 to writing. Its resemblance to the discourse of the preceding 
 autumn before the Physical Society is great ; and indeed it 
 may be said that all Reis's discourses upon the telephone 
 were practically identical in their contents. A few months 
 after this lecture, Reis presented a pair of instruments, trans- 
 mitter and receiver, to the Hochstift. These instruments 
 were not the same as those used by Reis at his lecture, but 
 were of the " improved " type, whilst those used by Reis at 
 his lecture to the Hochstift, were, so far as respects the trans- 
 mitter at least, more like the form described by W. von Legat, 
 
INVENTOR OF THE TELEPHONE. 69 
 
 and figured in Plate II., Fig. A;* and according to Mr. 
 Horkheimer, who helped Eeis on this occasion, the trans- 
 mitter was provided with a conical mouthpiece of wood. The 
 transmitter presented later by Eeis is of the " square-box " 
 form (Fig. 17), and is stamped, " 1863, Philipp Eeis, 2," 
 and the receiver is of the " knitting-needle " form (Fig. 23). 
 These instruments are carefully preserved by the Hochstift in 
 the " Goethehaus," amongst their archives " in everlasting 
 remembrance " of the inventor. A few months later, in 1863, 
 the Emperor of Austria and the late king Max of Bavaria 
 were residing at Frankfurt and visited the " Goethehaus ; " 
 and on this occasion Eeis's instruments were shown to these 
 distinguished visitors by the Founder and President of the 
 Hochstift, Dr. Volger. 
 
 In honour of his brilliant invention Eeis was, shortly 
 after his lecture, elected an honorary member of the Freies 
 Deutschcs Hochstift.] 
 
 [The next document in order is a Eeport by Wilhelm von 
 Legat, communicated to the Austro-German Telegraph Union 
 (Verein) in 1862, and printed in the ' Journal ' of that Society. 
 It was reprinted verbatim in Dingler's ' Polytechnisches 
 Journal,' for 1863, vol. clxix. p. 29. This Eeport is of great 
 importance. It is quoted by Graham Bell, in his earliest 
 account of his telephone. It was this Eeport, moreover, 
 which in 1875 or 1876, in a translated manuscript form, was 
 put into Mr. Edison's hands by the then President of the 
 Western Union Telegraph Company, and which formed the 
 starting-point of Edison's subsequent work.] 
 
 [* Compare * Die Geschichte und Entwickelung des Fernsprechwesens,' 
 a pamphlet issued officially in 1880 from the Imperial German Post-Office 
 in Berlin, p. 6.] 
 
70 PH1LIPP &EIS, 
 
 [5.] ON THE KEPRODUCTION OF TONES IN THE ELECTRO - 
 GALVANIC WAY. 
 
 By v. LEGAT, Inspector of the Eoyal Prussian Telegraphs in 
 
 Cassel. 
 
 [Translated from the Journal of the Austro-German Telegraph Society 
 (edited by Dr. Brix), vol. ix. p. 125, 1862. (Zeitschrift des deutsch- 
 osterreichischen Telegraphen-Ve reins, 1862.)] 
 
 It might not be uninteresting to make known to wider 
 circles the following ideas concerning the reproduction of 
 tones in an electro-galvanic way, which have recently been 
 put forward by Herr Philipp Eeiss [sic] of Friedrichsdorf, 
 before the Physical Society, and before the meetings of the 
 Free German Institute (Freies Deutsches Hochstift) in 
 Frankfort-on-the-Main ; also to state what has hitherto been 
 attained in the realisation of this project, in order that 
 building upon the collected experiences and the efficacy of 
 the galvanic current, what has already been made service- 
 able to the human intellect for the advancement of its corre- 
 spondence, may in this respect also be turned to profit. 
 
 In what is here announced we are concerned not with the 
 action of the galvanic current in moving telegraphic apparatus 
 of whatever construction for producing visible signals, but 
 with its application for the production of audible signals of 
 tones! 
 
 The air-waves, which by their action within our ears 
 awaken in us the sensation of sound, by first of all setting 
 the drum-skin into a vibrating motion, are thence, as is 
 known, conveyed to the inner part of the ear and to the 
 auditory nerves lying there by a lever apparatus of the 
 most marvellous fineness, the auditory ossicles (including 
 " Hammer," " Anvil," and " Stirrup "). The experiment for 
 the reproduction of tones is based upon the following : viz. 
 
INVENTOR OF THE TELEPHONE. 71 
 
 to employ an artificial imitation of this lever-apparatus and 
 to set it in motion by the vibrations of a membrane like the 
 drum-skin in the ear, and thus to open and close a galvanic 
 circuit which is united by a metallic conductor with a distant 
 station. 
 
 Before the description of the necessary apparatus is 
 followed out, it might be necessary, however, to go back to 
 the point how our ear perceives the vibrations of a given 
 tone, and the total vibrations of all the tones simultaneously 
 acting upon it ; because by this means will be determined 
 the various requisite conditions which must be fulfilled by 
 the transmitting and receiving apparatus for the solution of 
 the problem that has been set. 
 
 Let us consider first the processes which take place in 
 order that a single tone should be perceived by the human 
 ear ; so shall we find that each tone is the result of a condensa- 
 tion and rarefaction several times repeated in a certain period 
 of time. If this process is going on in the same medium 
 (the air) in which our .ear is situated, the membrane will at 
 every condensation be forced toward the hollow of the drum 
 and at every rarefaction will move itself in the opposite 
 direction. 
 
 These vibrations necessitate a similar motion of the auditory 
 ossicles, and thereby a transference to the auditory nerves is 
 effected. 
 
 The greater the condensation of a sound-conducting medium 
 at any given moment, the greater also will be tlje amplitude 
 of vibration of the membrane and of the auditory ossicles 
 and of their action ; and in the converse case the action will 
 be proportionally less. It is, therefore, the function of the 
 organs of hearing to communicate with fidelity to the auditory 
 nerves every condensation and rarefaction occurring in the 
 surrounding medium ; whilst it remains to be the function of 
 the auditory nerves to bring to our consciousness the number 
 
72 PHILIPP REIS, 
 
 as well as the magnitude of the vibrations ensuing in a given 
 time. 
 
 Here in our consciousness a definite name is given to a 
 certain composition, and here the vibrations brought to the 
 consciousness become " tones." 
 
 That which is perceived by our auditory nerves is conse- 
 quently the effect upon our consciousness of a force which, 
 according to its duration and magnitude, may for the sake of 
 better comprehension, be exhibited graphically. 
 
 Let, for example, the length of the line a b be any definite 
 duration of time, and let the curves above this line denote 
 the condensations ( + ), and the curves below this line the 
 
 rarefactions ( ) ; then every ordinate erected at the 
 extremity of an abscissa gives us the strength of the con- 
 densation in consequence of which the drum-skin vibrates, 
 at the moment indicated by the position of the foot of the 
 ordinate. 
 
 Anything more than that which is exhibited in this way 
 or by similar curves our ear cannot in the least perceive, and 
 this is sufficient to bring to our consciousness each single 
 tone and each given combination of tones. For, if several 
 tones are produced at the same time, the sound-conducting 
 medium is put under the influence of several simultaneously 
 acting forces which are subject to the laws of mechanics. 
 
 If all the forces operate in the same sense, then the 
 magnitude of the motion is proportional to the sum of the 
 forces. If the forces act in opposite directions, the magnitude 
 of the motion is proportional to the difference between the 
 opposing forces. 
 
 Consequently it is possible out of the condensation-curves 
 of several simultaneously-occurring tones to compound, by the 
 
INVENTOR OF THE TELEPHONE. 73 
 
 foregoing principles, a condensation-curve which exactly 
 expresses that which our ear experiences on the reception of 
 these simultaneously-acting tones. The objection ordinarily 
 made to this, that a musician, or even any one, is able to 
 hear separately the single tones of which this combined 
 curve is built and constructed, cannot be admitted as a proof 
 to the contrary ; for one expert in the science of colour will, 
 for example, in the same way discern in green a mixture of 
 yellow and blue in their various shades : and the one 
 phenomenon equally with the other may be referred back 
 to this ; that, to the person concerned, the factors which make 
 up the product of that which reaches his consciousness are 
 well known. 
 
 According to that which has been already explained, it is 
 easy to construct the condensation-curves of various tones, 
 chords, &c., and for the sake of clearness some examples 
 follow : 
 
 .Fig. 1, Plate I.,* shows a combination curve of three tones, 
 in which all the proportions of the components recur 
 successively. 
 
 Fig. 2 shows such a curve of more than three tones, in 
 which the proportions in the drawing can no longer so 
 evidently be given; yet the practised musician would here 
 recognise them, even although in practice it might be 
 difficult for him to single out, in such chords, the separate 
 tones. 
 
 This method of exhibiting the action of tones upon the 
 human ear offers the advantage of a very clear perception of 
 the process ; and that which is exhibited (Fig. 3) shows also 
 why a discord must affect our ear unpleasantly. 
 
 This apparent digression from the aim set forth was neces- 
 sary in order to indicate that as soon as it is possible for us 
 to create anywhere, and in any manner whatever, vibrations 
 
 * [Plate VIII. of the original in Vol. IX. of the Zeitschrift.j 
 
74 PHILIPP ItEIS, 
 
 whose curves and magnitudes are similar to the vibrations of 
 any given tone, or of any given combination of tones, we 
 shall have the same impression as this original tone or this 
 original combination of tones would have produced upon us. 
 
 The apparatus hereafter described offers the possibility of 
 creating these vibrations in every fashion that may be desired, 
 and the employment of electro-galvanism gives us the 
 possibility of calling into life, at any given distance, vibra- 
 tions similar to the vibrations that have been produced, and 
 in this way to reproduce at any place the tones that have 
 been originated at another place. 
 
 In Fig. 4, Plate II.,* herewith presented, A is the trans- 
 mitter (Tonabgeber), and B the receiver (Tonempf anger), 
 which two instruments are set up at different stations. I 
 make, however, the preliminary remark that the manner of 
 joining the instruments for interchangeable use backward and 
 forward is here omitted for the sake of clearness, and the 
 more so because the whole is not here propounded as a final 
 fact, but in order to bring that which has been hitherto 
 accomplished to the knowledge of a wider circle. The 
 possibility of the working of the apparatus to a greater 
 distance than that which at present limits in practice the 
 direct working of the galvanic current may also be left out 
 of consideration, since these points may be easily rendered 
 possible by mechanical precautions, and do not affect the 
 essential part of the phenomena now described. 
 
 Let us next turn to the transmitter, Fig. A. It is put 
 into communication on one side with the metallic conductor 
 leading to the neighbouring station, and by means of this 
 with the receiver, Fig. B ; on the other side it is connected, 
 by means of the electro-motive power, C, with the earth or 
 a metallic return-conductor. 
 
 The transmitter, Fig. A, consists of a conical tube, a b, of 
 * [Plate IX. of the original Memoir.] 
 
INVENTOR OF THE TELEPHONE. 75 
 
 about 15 centimetres length, 10 centimetres in the front, 
 and 4 centimetres in the back aperture. 
 
 (In the practical investigations it has been established that 
 the choice of material for this tube is without influence on 
 the use of the apparatus, and moreover a greater length of 
 the same for the certainty [of action] of the apparatus is 
 without effect. A greater width of the cylinder spoils the 
 usefulness of the apparatus ; and it is recommended that 
 the interior surface be as smooth as possible.) 
 
 The narrow hinder aperture of the cylinder is closed 
 by a membrane, o, of collodion, and on the middle of the 
 circular surface formed by this membrane rests one end, c, 
 of the lever, c d, the fulcrum (point of support), e, of which, 
 supported on a bearing, remains joined to the metallic 
 conductor. 
 
 The choice of the length of the two arms of the lever, c e 
 and e d, is determined by the laws of force of levers. It is 
 recommended that the arm, c e, be constructed longer than 
 the arm ed, in order to bring the smallest movement at c 
 into action at d with the greatest possible force ; but, on the 
 other hand, it is desirable to make the lever itself as light as 
 possible, in order that it may follow the motions of the mem- 
 brane. An uncertain following of the lever, c d } produces 
 impure tones at the receiving station. In the condition of 
 rest the contact, d g, is closed, and a delicate spring, n, holds 
 the lever firmly in this position of rest. 
 
 The second part of this apparatus, the pillar, /, consists of 
 a metallic support, which is united with one pole of the 
 battery, C, while the second pole of the battery is carried to 
 the metallic conductor of the other station. 
 
 Upon the support, /, there is a spring, g, with a contact, 
 which corresponds to the contact at d of the lever c d } and 
 whose position is regulated by a screw, h. 
 
 In order not to weaken the action of the apparatus by the 
 
76 PH1LIPP REIS, 
 
 communication of the air- waves which are produced in using 
 the apparatus, against the back of the membrane, it is recom- 
 mended, in using the apparatus, to place over the tube, a I, 
 at right angles to its longitudinal axis, a screen of about 
 50 centimetres diameter, which fixes tight upon the outer 
 surface of the tube. 
 
 The receiver, Fig. B, consists of an electro-magnet, m m, 
 which reposes upon a sounding-box, u w, and whose wire 
 coils are respectively connected with the metallic conductor 
 and with the earth or metallic return-conductor. 
 
 Opposite the electro-magnet, m m, stands an armature, 
 which is connected with a lever, i, which is long as possible, 
 but light and broad. 
 
 The lever, i, is fastened, pendulum- wise, to the support, k, 
 and its movements are regulated by the screw, I, and the 
 spring, p. 
 
 In order to improve the action of the apparatus, this 
 receiver can be placed in one focus of an elliptically arched 
 cavity of corresponding size, in which case, then, the ear of 
 him who is listening to the reproduced tones may be placed 
 at the second focus of this cavity. 
 
 The action of the two apparatuses here described, is the 
 following : 
 
 In a condition of rest the galvanic circuit is closed. 
 
 In the apparatus, Fig. A, by speaking (singing, or leading 
 into it the tones of an instrument) into the tube a b, in 
 consequence of the condensation and rarefaction of the air 
 present in this tube, there will be evoked a motion of the 
 membrane closing the tube at its narrow end, corresponding 
 to this condensation or rarefaction. The lever, c d, follows the 
 motion of the membrane, and opens and closes the galvanic 
 circuit at d g, so that by each condensation of the air in the 
 tube an opening, and at each rarefaction a closing of the 
 galvanic circuit ensues. 
 
INVENTOR OF THE TELEPHONE. 77 
 
 In consequence of this process, the electro-magnet of Fig. B 
 (the receiver) will be demagnetised and magnetised correspond- 
 ingly with the condensations and rarefactions of the mass of air 
 in the tube A, a b [the mouth-piece of the transmitter], and the 
 armature belonging to the magnet will be set into vibrations 
 similar to those of the membrane in the transmitting 
 apparatus. The plank, i, connected with the armature, 
 conveys these similar vibrations to the air surrounding the 
 apparatus, Fig. B, which finally transmits to the ear of the 
 listener the tones thus produced. 
 
 We are not, therefore, dealing here with a propagation of 
 sound through the electric current, but only with a trans- 
 ference to another place of the tones that have been produced, 
 by a like cause being brought into play at this second place, 
 and a like effect produced. 
 
 Here, however, it must not be overlooked that the pre- 
 ceding apparatus reproduces, indeed, the original vibrations 
 in equal number, but that equal strength in the reproduced 
 vibrations has not yet been attained, and the production of 
 these is reserved for a completion of the apparatus. 
 
 One consequence of this temporary incompleteness of the 
 apparatus, is that the slighter differences of the original 
 vibrations are more difficult to discern : that is to say, the 
 vowel appears more or less indistinct, the more so since each 
 tone is dependent, not only on the number of vibrations of 
 the medium, but also on the condensation or rarefaction of the 
 same. 
 
 By this it is also explained, that, in the practical investiga- 
 tions heretofore carried on, chords, melodies, etc., were trans- 
 mitted with marvellous fidelity ; while single words uttered 
 as in reading, speaking, and the like, were perceptible more 
 indistinctly. Nevertheless, here also the inflexions of the 
 voice, the modulations of interrogation, exclamation, wonder, 
 command, &c., attained distinct expression. 
 
78 PEILIPP EEIS, 
 
 There remains no doubt, that before expecting a practical 
 utilisation with serviceable results (praktische Verwerthung 
 mit Nutzen), that which has been here spoken of will require 
 still considerable improvement, and in particular mechanical 
 science must complete the apparatus to be used ; yet I am 
 convinced by repeated practical experiments that the prose- 
 cution of the subject here explained is of the highest 
 theoretical interest, and that our intelligent century will not 
 miss the practical utilisation (Verwerthung) of it. 
 
 [This article was also reprinted verbatim in Dingle r's 
 Polytechnisches Journal, vol. clxix. p. 29, 1863.] 
 
 [A peculiar interest is attached to the foregoing article, 
 partly on account of the unique nature of the instruments 
 therein described, partly because of the mystery attaching to 
 the author of the article. Wilhelm von Legat was Inspector 
 of the Eoyal Prussian Telegraphs at Cassel. How or when 
 he became acquainted with Philipp Eeis is not known pos- 
 sibly whilst the latter was performing his year of military 
 service at Cassel in 1855. None of Eeis's intimate friends-or 
 colleagues now surviving can give any information as to the 
 nature of von Legat's relations with Eeis, as not even his 
 name is known to them, save from this Eeport. Yet he 
 was for one year only (1862), the year in which this Eeport 
 was made, a member of the Physical Society of Frankfort-on- 
 the-Main. It is possible that he may have been present at 
 Eeis's discourse in the preceding October. It is probable 
 that he was present at Eeis's subsequent discourse in May, 
 1862, to the Freies Deutsches Hochstift. Dr. Brix, then 
 editor of the ' Journal of the Telegraph Union/ informs me 
 that Inspector von Legat based his article upon information 
 derived direct from Eeis, whom he knew, and that the article 
 was submitted to Eeis before being committed to the ' Journal.' 
 
INVENTOR OF THE TELEPHONE. 79 
 
 The particular form of transmitter described in von Legat's 
 Eeport (see also p. 25, ante) has also some important points 
 in common with that believed to have been used by Eeis at 
 the Hochstift. Neither of the specific forms described by In- 
 spector von Legat are now known to be extant. Inquiries 
 made in Frankfort and in Cassel have failed to find any trace 
 of them. Neither at the local Naturalists' Society, nor any- 
 where else in Cassel, did von Legat describe the invention. 
 He met with a tragic end during the Bavarian War in 1866, 
 in the battle near Aschaffenburg, having, according to some, 
 been shot, or, according to others, fallen from his horse.] 
 
 [The next extract is from an article entitled ' Telephonic,' 
 which appeared in a journal of science published at Leipzig, 
 under the title ' Aus der Natur.' This article is essentially a 
 paraphrase of Eeis's memoir read to the Physical Society in 
 the preceding December (see p. 50), and contains the same 
 illustrations, including a cut of the transmitter identical with 
 Fig. 9, p. 20.] 
 
 [6.] Aus DER NATUR. (Vol. xxi. 1862. July-October, 
 pp. 470-474.) 
 
 " Until now, however, it was not possible to reproduce 
 human speech with a distinctness sufficient for every person. 
 The consonants are mostly tolerably distinctly reproduced, 
 but the vowels not in an equal degree." 
 
 [About this time there arose a Correspondence in the 
 'Deutsche Industrie Zeitung' ('German Journal of Industry ') 
 concerning the telephone. In No. xvi. p. 184 (1863), a 
 correspondent who signs himself " K " asks whether the 
 account of the telephone is true ? In No. xviii. p. 208, 
 there is given a brief answer; and No. xxii. contains, on 
 
80 PHILIPP REIS, 
 
 p. 239, an extract from Legat's Eeport, on Eeis's Telephone 
 (see p. 70 of this work), together with an editorial remark 
 to the effect that he had received a letter from Herr J. F. 
 Quilling, of Frankfort-on-the-Main, who gives the information 
 that in the transmission of singing in the telephone, the 
 singer could be recognized by his voice.] 
 
 [7.] [EXTRACT FROM THE ANNUAL EEPORT OF THE PHYSICAL 
 SOCIETY OF FRANKFORT-ON-THE-MAIN (1863).] 
 
 . . . .; "and on the 4th of July, 1863, by Mr. Philipp 
 Eeis, teacher, of Friedrichsdorf, On the Transmission of Tones 
 to any desired Distance, by the help of Electricity, with the 
 production of an Improved Telephone, and Exhibition of 
 Experiments therewith" 
 
 [This was Eeis's second occasion of bringing his Telephone 
 before the Physical Society. The instrument had now 
 assumed the " square-box " pattern described at p. 27 of this 
 work.] 
 
 [8.] LETTER OF PHILIPP EEIS. 
 
 [In July 1863, Mr. W. Ladd, the well-known instrument- 
 maker of London, bought one of Eeis's Telephones of Messrs. 
 J. W. Albert and Son of Frankfort. Philipp Eeis wrote to 
 Mr. Ladd the following letter of instructions, having heard 
 that Mr. Ladd proposed to exhibit the instrument at the 
 approaching meeting of the British Association. The auto- 
 graph letter, written in English, is still preserved, and has 
 been presented by Mr. Ladd to the Society of Telegraph 
 Engineers and of Electricians of London.] 
 
INVENTOR OF THE TELEPHONE. 81 
 
 " Institut Garni or, 
 
 " Friedrichsdorf. 
 
 " DEAR SIR ! 
 
 " I am very sorry not to have been in Francfort 
 when you were there at Mr. Albert's, by whom I have been 
 informed that you have purchased one of my newly-invented 
 instruments (Telephons). Though I will do all in my power 
 to give you the most ample explanations on the subject, I 
 am sure that personal communication would have been 
 preferable ; specially as I was told, that you will show the 
 apparatus at your next sientifical meeting and thus introduce 
 the apparatus in your country. 
 
 " Tunes * and sounds of any kind are only brought to our 
 conception by the condensations and rarefactions of air or 
 any other medium in which we may find ourselves. By every 
 condensation the tympanum of our ear is pressed inwards, by 
 every rarefaction it is pressed outward and thus the tympanum 
 performs oscillations like a pendulum. The smaller or greater 
 number of the oscillations made in a second gives us by help 
 of the small bones in our ear and the auditory nerve the idea 
 of a higher or lower tune. 
 
 " It was no hard labour, either to imagine that any other 
 membrane besides that of our ear, could be brought to make 
 similar oscillations, if spanned in a proper manner and if 
 taken in good proportions, or to make use of these oscillations 
 for the interruption of a galvanic current. 
 
 * [This word, as the context and ending of the paragraph shows, should 
 have been spelled tones. The letter, written in English by Eeis himself, 
 is wonderfully free from inaccuracies of composition ; the slip here noted 
 being a most pardonable one since the plural of the German " ton " is 
 " tonen" the very pronunciation of which would account for the confusion 
 in the mind of one unaccustomed to write in English. So far as is known, 
 this is the only piece of English composition ever attempted by Reis. 
 S. P. T.] 
 
 G 
 
82 PHILIPP REIS, 
 
 " However these were the principles wich (sic) guided me 
 in my invention. They were sufficient to induce me to try 
 the reproduction of tunes [i.e., tones see footnote. S. P. T.] 
 at any distance. It would be long to relate all the fruitless 
 attempts, I made, until I found out the proportions of the 
 instrument and the necessary tension of the membrane. The 
 apparatus you have bought, is now, what may be found most 
 simple, and works without failling when arranged carefully in 
 the following manner. 
 
 " The apparatus consists of two separated parts ; one for 
 the singing station A, and the other for the hearing station B.* 
 
 " The apparatus A, a square box of wood, the cover of 
 which shows the membrane (c) on the outside, under glass. 
 In the middle of the latter is fixed a small platina plate to 
 which a flattened copper wire is soldered on purpose to 
 conduct the galvanic current. Within the cercle you will 
 further remark two screws. One of them is terminated by a 
 little pit in which you put a little drop of quiksilver ; the 
 other is pointed. The angle, which you find lying on the 
 membrane, is to be placed according to the letters, with the 
 little whole [hole] (a) on the point (a) the little platina -foot 
 (b) into the quicksilver screw, the other platina foot will then 
 come on the platina plate in the middle of the membrane. 
 
 " The galvanic current coming from the battery (which I 
 compose generally of three or four good elements) is introduced 
 at the conducting screw near (b) wherefrom it proceeds to the 
 quicksilver, the movable angle, the platina plate and the com- 
 plementary telegraph tof the conducting screw (s). From 
 
 * [Reis here sketched a figure identical in all its parts with that which 
 a fortnight later was issued in his ' Prospectus.' His sketch is reproduced 
 in facsimile in Fig. 28.] 
 
 f [This was the little auxiliary signalling apparatus at the side of the 
 box, placed there for the same reasons as the auxiliary call-bell attached 
 to modern telephones.] 
 
INVENTOR OF THE TELEPHONE. 83 
 
84 PH1LIPP REI8, 
 
 here it goes through the conductor to the other station B and 
 from there returns to the battery. 
 
 " The apparatus B, a sonorous box on the cover of which 
 is placed the wire-spiral with the steel axis, wich will be 
 magnetic when the current goes through the spiral. A second 
 little box is fixed on the first one, and laid down on the steel 
 axis to increase the intensity of the reproduced sounds. On 
 the small side of the lower box you will find the correspondent 
 part of the complementary telegraph. 
 
 " If a person sing at the station A, in the tube (x) the 
 vibrations of air will pass into the box and move the membrane 
 above ; thereby the platina foot (c) of the movable angle will 
 be lifted up and will thus open the stream at every con- 
 densation of air in the box. The stream will be re-established 
 at every rarefaction. For this manner the steel axis at 
 station B will be magnetic once for every full vibration ; and 
 as magnetism never enters nor leaves a metal without dis- 
 turbing the equilibrium of the atoms, the steel-axis at station 
 B must repeat the vibrations at station A and thus reproduce 
 the sounds which caused them. 
 
 " Any * sound will be reproduced, if strong enough to- .set 
 the membrane in motion. 
 
 " The little telegraph, which you will find on the side of 
 the apparatus is very usefull and agreable for to give signals 
 between both of the correspondents. At every opening of the 
 stream and next following shutting the station A will hear a 
 little clap produced by the attraction of the steel spring. 
 Another little clap will be heard at station (B) in the wire- 
 spiral. By multiplying the claps and producing them in 
 different measures you will be able as well as I am to get 
 understood by your correspondent. 
 
 "I am to end, Sir, and I hope, that what I said will be 
 
 * [This word is underscored in Reis's original letter.] 
 
INVENTOR OF THE TELEPHONE. 85 
 
 sufficient to have a first try ; afterward you will get on quite 
 
 alone. 
 
 " I am, Sir, 
 
 " Your most obediant Servant, 
 
 " PH. EEIS. 
 " Friedrichsdorf, 13/7, 63." 
 
 [9.] REIS'S PROSPECTUS. 
 
 [The following " Prospectus " of instructions was drawn up 
 by Reis to accompany the Telephones which were sold by 
 Herr Wilh. Albert of Frankfort. The author of this book is 
 in possession of original copies, of which a number are extant. 
 The " Prospectus " was also reprinted in its entirety at 
 page 241 of Professor Pisko's book ' Die neueren Apparate 
 der Akustik/ published at Vienna in 1865.] 
 
 TELEPHOK 
 
 Each apparatus consists, as is seen from the above illustra- 
 tion, of two parts : the Telephone proper, A, and the Repro- 
 duction apparatus [Receiver], C. These two parts are placed 
 at such a distance from each other, that singing, or the tones 
 of a musical instrument, can be heard from one station to the 
 other in no way except through the apparatus itself. 
 
 Both parts are connected with each other, and with the 
 battery, B, like ordinary telegraphs. The battery must be 
 capable of effecting the attraction of the armature of the 
 electromagnet placed at the side of station A (3-4 six-inch 
 Bunsen's elements suffice for several hundred feet distance). 
 
 The galvanic current goes then from B to the screw, d, 
 thence through the copper strip to the little platinum plate 
 at the middle of the membrane, then through the foot, c, of 
 the angular piece to the screw, &, in ivlwse little concavity a 
 
86 
 
 PHILIPP REI8, 
 
 drop of quicksilver is put. From here the current then goes 
 through the little telegraph apparatus, e-f, then to the key 
 of station C, and through the spiral past i back to B. 
 
 If now sufficiently strong tones are produced before the 
 sound-aperture, S, the membrane and the angle-shaped little 
 hammer lying upon it are set in motion by the vibrations ; 
 the circuit will be once opened and again closed for each 
 full vibration, and thereby there will be produced in the iron 
 wire of the spiral at station C the same number of vibrations 
 
 Fig. 29. 
 
 which there are perceived as a tone or combination of tones 
 (chord). By imposing the little upper case (Oberkastchen) 
 firmly upon the axis of the spiral the tones at C are greatly 
 strengthened. 
 
 Besides the human voice (according to my experience) 
 there also can be reproduced the tones of good organ-pipes 
 from F c and those of a piano. For the latter purpose A 
 is placed upon the sounding-board of the piano. (Of thirteen 
 
INVENTOR OF THE TELEPHONE. 87 
 
 triads (Dreiklange) a skilled experimentor could with all 
 exactness recognise ten). 
 
 As regards the telegraph apparatus placed at the side, it 
 is clearly unnecessary for the reproduction of tones, but it 
 forms a very agreeable addition for convenient experimenting. 
 By means of the same, it is possible to make oneself 
 understood right well and certainly by the other party. This 
 takes place somewhat in the following manner: After the 
 apparatus has been completely arranged, one convinces one- 
 self of the completeness of the connexion and the strength 
 of the battery by opening and closing the circuit, whereby 
 at A the stroke of the armature is heard, and at C a very 
 distinct ticking. 
 
 By rapid alternate opening and closing at A it is asked at 
 C whether one is ready for experimenting, whereupon C 
 answers in the same manner. 
 
 Simple signals can by agreement be given from both 
 stations by opening and closing the circuit one, two, three, 
 or four times ; for example : 
 
 1 beat = Sing. 
 
 2 beats = Speak, &c. 
 
 I telegraph the words thus that I number the letters of 
 the alphabet and then transmit their numbers 
 
 1 beat = a. 
 
 2 beats = 6. 
 
 3 = c. 
 
 4 = d. 
 
 5 = e t &c. 
 
 z would accordingly be designated by twenty-five beats. 
 
 This number of beats would, however, appear wasteful of 
 time, and would be uncertain in counting, wherefore I employ 
 
88 PHILIPP EEIS, 
 
 for every five beats a dactyl-beat (Dactylusschlag), and there 
 results ^ ^ for e.. 
 
 ^ >^ and one beat for/, &c. 
 
 2, = - ^, ^ ^^, -, * ' ', - -, 
 which is more quickly and easily executed and easier to 
 understand. 
 
 It is still better if the letters are represented by numbers 
 which are in inverse proportion to the frequency of their 
 
 occurrence. 
 
 PHIL. EEIS, 
 
 Teacher at L. F. Garnier's Institute for boys. 
 Friedrichsdorf, near Homburg-by-the-Height, 
 August 1863. 
 
 o 
 
 [The foregoing " Prospectus " was accompanied by a further 
 document printed as a postscript by Keis, at the top of which 
 the figure of the instrument was repeated, and which ran as 
 follows : ] 
 
 "P.P., 
 
 " Since two years ago I succeeded in effecting the 
 possibility of the reproduction of tones by the galvanic 
 current, and in setting up a convenient apparatus therefor, 
 the circumstance has found such a recognition from the most 
 celebrated men of science, and so many calls to action have 
 come to me, that I have since striven to improve my originally 
 very incomplete apparatus, so that the experiments might 
 thereby become accessible to others. 
 
 " I am now in the position to offer an apparatus which 
 fulfils my expectations, and with which each physicist may 
 succeed in repeating the interesting experiments concerning 
 reproduction of tones at distant stations. 
 
 " I believe I shall fulfil the wish of many if I undertake to 
 bring these improved instruments into the possession of the 
 
INVENTOR OF THE TELEPHONE. 89 
 
 [physical] cabinets. Since the preparation of the same 
 requires a complete acquaintance with the leading principles 
 and a tolerable experience in this matter, I have decided 
 myself to prepare the most important parts of the same, and 
 to leave the fashioning of the accessory parts, as also of the 
 external adornments, to the mechanician. 
 
 " The distribution of the same I have made over to Herr 
 J. Wilh. Albert, mechanician, in Frankfort-on-the-Main, and 
 have placed him in the position to deliver these instruments 
 in two qualities, differing only in external adornment, at the 
 prices of 21 florins and 14 florins (12 thalers and 8 thalers 
 current), inclusive of packing. Moreover, the instruments 
 can also be obtained direct from me at the same prices, upon 
 a cash remittance of the amount. 
 
 " Each apparatus will be tested by me before sending off, 
 and will then be furnished with my name, an order-number, 
 and with the year of manufacture. 
 
 " Friedrichsdorf, near Homburg-by-the-Height, 
 " in August 1863. 
 
 " PHIL. EEIS, 
 " Teacher at L. F. Garnier's Institute for Boys." 
 
 [In September of the same year the telephone was shown 
 by Prof. K. Bottger at the meeting of the German Naturalists' 
 Association (Naturforscher), which met on that occasion at 
 Stettin. Little or nothing is known of what took place at 
 this exhibition, but Professor von Feilitzsch, of the neighbour- 
 ing University of Greifswald, has informed the author of 
 this work that the Telephone there shown was of the form 
 figured in Eeis's Prospectus (p. 86), and that Eeis claimed at 
 that time to be able to transmit words by his instruments. 
 In the same autumn the following notice appeared in 
 Bottger' s ' Notizblatt,' and was copied thence into Dingler's 
 ' Journal/ and other scientific papers.] 
 
90 PHILIPP EEIS, 
 
 [10,] ON THE IMPROVED TELEPHONE. 
 
 [Translated from the original notice which appeared in Bottger's ' Poly- 
 technisches Notizblatt,' 1863, Ko. 15, p. 225, and in Dingler's ' Poly- 
 technisches Journal,' 1863, vol. clxix. p. 399.] 
 
 At the meeting of the Physical Society of Frankfort-on- 
 the-Main, on the 4th of July, a member of this Society, Herr 
 Ph. Eeis, of Friedrichsdorf, near Homburg-vor-der-Hohe, 
 exhibited some of his improved Telephones (means for the 
 reproduction of tones at any desired distance by the galvanic 
 current). It is now two years since Herr Eeis first gave 
 publicity to his apparatus,* and though even already at that 
 time the performances of the same in their simple artless 
 form were capable of exciting astonishment, yet they had 
 then the great defect that experimenting with them was only 
 possible to the inventor himself. The instruments exhibited 
 in the above-named meeting scarcely reminded one of the 
 earlier ones. Herr Eeis has also striven to give them a 
 form pleasing to the eye, so that they may now occupy a 
 worthy place in every Physical Cabinet. These new apparatus 
 may now also be handled by every one with facility, jand 
 work with great certainty. Melodies gently sung at a 
 distance of about 300 feet were repeated by the instrument 
 which was set up, much more distinctly than previously. 
 The scale was reproduced especially sharply. The experi- 
 menters could even communicate words to one another, 
 though certainly indeed only such as had often been heard 
 by them. In order moreover that others who are less 
 accustomed [to experimenting] may be able to understand 
 one another through the apparatus, the inventor has placed 
 on the side of the same a little arrangement,! which accord- 
 
 * [Compare Bottger Polyt. Notizbl. 1863, p. 81, the notice translated 
 at p. 61 preceding.] S. P. T. 
 
 f [This rather obscure passage refers to the call-key or communicator 
 fixed to the side of the instruments, and which as the inventor explains in 
 
INVENTOR OF THE TELEPHONE. 91 
 
 ing to his explanation is completely sufficient, the speed of 
 communication of which is indeed not so great as that of 
 modern Telegraphs, but which works quite certainly, and 
 requires no special skill on the part of the one experimenting 
 with it. 
 
 We would bring to the notice of gentlemen who are 
 professional physicists that the inventor of these interesting 
 pieces of apparatus now has them prepared for sale under 
 his oversight (the important parts he makes himself), and 
 the same can be procured from him direct, or through the 
 mechanician, Mr. Wilhelm Albert, of Frankfort-on-the-Main, 
 at 14 and at 21 florins, in two qualities, differing only in 
 external adornment. 
 
 [A review, written by Dr. Rober of Berlin, of this and 
 other articles relating to the Telephone appeared subsequently 
 in the ' Fortschritte der Physik,' 1863, p. 96.] 
 
 [Another consequence of the publicity thus given to the 
 Telephone was the appearance of an article on that instru- 
 ment, under the title of " Der Musiktelegraph," in a popular 
 illustrated weekly family paper, ' Die Gartenlaube,' published 
 at Leipzig. This article, from the pen, it is believed, of Dr. 
 Oppel of Frankfort, is made up chiefly of slightly altered 
 extracts from the previously quoted documents. The form 
 of the instrument described is identical with that described 
 in Reis's ' Prospectus,' and the figure given in the ' Garten- 
 laube/ No. 51, p. 809, is a reprint, apparently from the same 
 wood-block of the figure which heads Reis's Prospectus, and 
 which is reproduced on p. 86 of this work. The only 
 passage of further interest is a brief sentence relating to the 
 
 his Prospectus (see p. 87), to be intended, like the call-bell or communicator 
 of modern telephones, as a means of sending signals to the speaker, and 
 which, as the Prospectus says, can also be used as any call-bell can for 
 telegraphing words by a pre-arranged code of signals.] S. P. T. 
 
92 PHILIPP SETS, 
 
 exhibition of the Telephone at the German Naturalists' 
 Assembly at Stettin in 1863, and is as follows : ] 
 
 [11.] " Now in order also to give to a still wider circle, 
 especially to technologists (Fachmannern), the opportunity 
 of witnessing with their own eyesight th^ efficiency of this 
 apparatus, lately, in fact essentially improved, Professor 
 Bottger of Frankfort-on-the-Main exhibited several experi- 
 ments therewith at the meeting of the German Naturalists 
 (Naturforscher) and Physicians recently held at Stettin, in 
 the Section for Physics ; which [experiments] would certainly 
 have been crowned with still greater success if the place of 
 meeting had been in a less noisy neighbourhood, and had 
 been filled with a somewhat less numerous audience." 
 
 [The next extract is a brief record from the Eeport of a 
 scientific society meeting in Giessen, which during the 
 Austro-Prussian war of 1866 had become disorganised, and 
 which in 1867 published a condensed account of its proceed- 
 ings for the preceding years. Amongst those proceedings 
 was a lecture by the late Professor Buff, at which Eeis's 
 Telephone was shown, and at which Keis himself is believed 
 to have been present.] 
 
 [12.] [EXTRACT FROM THE ' TWELFTH KEPORT OF THE UPPER- 
 HESSIAN ASSOCIATION FOR NATURAL AND MEDICAL SCIENCE,' 
 (' Oberhessische Gesellschaft fur Natur und Heilkunde,') 
 Giessen, February 1867.] 
 
 P. 155. Eeport on the doings and condition of the Associa- 
 tion from the 1st of July, 1863, to the 1st of July, 1865, by 
 Herr Gymnasiallehrer Dr. W. Diehl. 
 
 ... On the 13th of February [1864], ' On the Tones of 
 the Magnet, with Application to the Telephone, with experi- 
 ments,' by Professor Buff. 
 
INVENTOR OF THE TELEPHONE. 93 
 
 EXHIBITION OF THE TELEPHONE TO THE NATURALISTS' ASSO- 
 CIATION OF GERMANY. (DEUTSCHE NATURFORSCHER VER- 
 SAMMLUNG.) 
 
 [By far the most important of all the public exhibitions 
 given by Eeis of his Telephone, was that which took place on 
 the 21st of September, 1864, at Giessen, on the occasion 
 of the meeting of the German Naturalists' Association 
 (Versammlung Deutsche Naturforscher). Here were as- 
 sembled all the leading scientific men of Germany, including 
 the following distinguished names, many of whom are still 
 living : Prof. Buff (Giessen), Prof. Poggendorff (Berlin), 
 Prof. Bohn (Frankfurt-a.-M., now of Aschaffenburg), Prof. 
 Jolly (Munich), Dr. Geissler (Bonn), Prof. Weber (Gottingen), 
 Prof. Pllicker (Bonn), Prof. Quincke (Heidelberg), Prof. 
 Dellmann (Kreutznach), Prof. Bottger (Frankfurt-a.-M. and 
 Mainz), Prof. Kekule (Bonn), Prof. Gerlach (Erlangen), 
 Dr. J. Frick (Carlsruhe), Dr. F. Kohlrausch (Wlirtzburg), 
 Prof. Eeusch (Tubingen), Prof. J. Mliller (Freiburg), Prof. 
 Helmholtz (Heidelberg), Prof. Melde (Marburg), Prof. Kopp 
 (Marburg), Prof. A. W. Hoffmann (London, now of Berlin), 
 Mons. Hofmann (Paris, optician), Hofrath Dr. Stein (Frank- 
 furt-a.-M.), Dr. W. Steeg (Homburg), Mons. Hartnack (Paris, 
 and of Pottsdam), Prof. G. Wiedemann (Basel, now of Leipzig), 
 E. Albert (Frankfurt-a.-M., mechanician), Dr. Thudichum 
 (London), W. Schultze (York, apothecary), Dr. J. Barnard 
 Davis (Shelton), E. J. Chapman (London, chemist), Dr. L. 
 Beck (London, chemist), Prof. Chas. J. Himes (U.S.A., 
 chemist), E. W. Blake (New Haven, U.S.A., student), C. G. 
 Wheeler (United States Consul in Niirnberg), and many 
 others. Dr. C. Bohn (now of Aschaffenburg) was Secretary 
 of the Association, and also Secretary of the Section of 
 Physics. The meetings of this Section were held in the 
 Laboratory of Professor Buff. Eeis came over from Fried- 
 
94 PHILIPP REIS, 
 
 richsdorf accompanied by his young brother-in-law, Philipp 
 Schmidt. A preliminary trial on the morning of that day 
 was not very successful, but at the afternoon sitting, when 
 communications were made to the Section by Prof. Buff, by 
 Eeis himself, and by Prof. Poggendorff, the instrument was 
 shown in action with great success. Eeis expounded the 
 story how he came to think of combining with the electric 
 current interrupter a tympanum in imitation of that of the 
 human ear, narrating his researches in an unassuming 
 manner that won his audience completely to him ; and the 
 performance of the instrument was received with great 
 applause. Various professors essayed to experiment with 
 the instrument, with varying degrees of success according to 
 whether their voices suited the instrument or not. Amongst 
 these were Prof. Bottger and Prof. Quincke of Heidelberg, 
 whose account of the occasion is to be found on p. 112. Dr. 
 Bohn, the Secretary of the Section, wrote for the ' Journal ' 
 (Tagesblatt), issued daily, the following notice.] 
 
 [13.] EXTRACT FROM THE EEPORT OF THE GERMAN NATU- 
 RALISTS' SOCIETY, HELD AT GIESSEN (1864). 
 
 "Afternoon sitting on 21st September, 1864. 
 
 " Prof. Buff speaks about the tones of iron and steel rods 
 when magnetised, and exhibits the corresponding experiments. 
 
 " Dr. Eeis demonstrates his Telephone, gives thereupon an 
 explanation and the history of this instrument. 
 
 " Prof. Poggendorff produces tones in a metal cylinder, 
 the slit up edges of which touch one another firmly, and 
 which is placed loosely round an induction-bobbin through 
 which there goes an interrupted current." 
 
 [This occasion was the crowning point of Philipp Eeis's 
 career, and might have proved of even greater importance 
 but for two causes : the inventor's precarious health, and the 
 indifference with which the commercial world of Germany 
 viewed this great invention. Where the keen insight of Eeis 
 
INVENTOR OF THE TELEPHONE. 95 
 
 contemplated the vast possibilities opened out by the invention 
 of a new mode of inter-communication, others saw only an 
 ingenious philosophical toy, or at best a pleasing illustration 
 of certain known principles of acoustic and electric science. 
 And in spite of the momentary enthusiasm which the 
 exhibition of the Telephone had evoked, the interest in it 
 dwindled away. A few of the public journals of that date, 
 noticed the invention in eulogistic terms and spoke of the 
 prospect it afforded of communication between distant friends 
 and of simultaneous concerts being given in different towns, 
 all transmitted telephonically from one orchestra. But the 
 invention came too early. The public mind was not yet 
 prepared to take it up, and the enthusiasm died away. Still 
 in a few of the more important books on Physics, Acoustics, 
 and Electricity, the matter continued to receive attention. In 
 the well-known Muller-Pouillet's ' Textbook of Physics ' 
 (Lehrbuch der Physik) edited by Professor J. Mliller ; in the 
 ' Technical Physics ' of Hessler, of Vienna, edited by Pro- 
 fessor Pisko ; in Pisko's ' Eecent Apparatus of Acoustics,' 
 and particularly in Kuhn's admirable ' Handbook of Applied 
 Electricity,' the Telephone was accepted as a definite conquest 
 of science, and was described and figured. From the works 
 named we transcribe the extracts which follow, and which 
 sufficiently explain themselves.] 
 
 [14.] EXTRACT FROM MULLER-POUILLET'S ' TEXTBOOK OF 
 PHYSICS AND METEOROLOGY' (LEHRBUCH DER PHYSIK 
 UND METEOROLOGIE). 
 
 [Published at Brunswick, Sixth ed., 1863, vol. ii. page 352, 
 fig. 325; and Seventh ed., 1868, vol. ii. pages 386-388, 
 figs. 348-350. The following translation is from the latter 
 edition.] 
 
 " This tone. . . . has Reis used for the construction of his 
 Telephone. 
 
96 PEILIPP REIS, 
 
 " Figure 348 * exhibits Eeis's interrupting apparatus. In 
 the lid of a hollow cube of wood A, a circular opening is made, 
 which is closed by an elastic membrane (pig's lesser intestine) 
 strained over it. Upon the centre of this membrane is glued 
 a little plate of platinum, which stands in conductive com- 
 munication with the clamping-screw a by means of a quite 
 thin little strip of metal / (distinctly visible in Fig. 349) 
 [Fig. 31]. 
 
 " Upon the middle of the little platinum plate, rests a short 
 little platinum pencil, which is fastened at g to the under- 
 side of the strip of tin-plate h g i, one end of which, h, rests 
 upon the little metal pillar I, while a little platinum spike 
 fastened upon its under-side at i t dips into the hollow of the 
 little metal pillar k, containing some quicksilver. The clamp- 
 ing-screw b, is put into conductive communication with the 
 little metal pillar k. 
 
 " From one pole of the battery there goes a conducting- 
 wire to the clamping-screw a of the interrupting apparatus 
 Fig. 348 [Fig. 30], from the other pole of the same there 
 goes a wire to the clamping-screw d of the reproducing 
 apparatus, Fig. 350 [Fig. 32], which is to be presently 
 described. The clamping- screw c, of this apparatus, is con- 
 nected by a wire with &, Fig. 348 [Fig. 30]. The clamping- 
 screws c and d are connected with the ends of the wire of the 
 small magnetising spiral M, Fig. 350 [Fig. 32] ; with the con- 
 nexion described above, the current of the current-generator 
 (battery) goes, therefore, through the spiral M. 
 
 " As soon now as the- sound-waves of an adequately 
 powerful tone enter through the mouth-piece S into the 
 hollow cube A, the elastic membrane which closes this at the 
 top is set into vibrations. Each wave of condensation on 
 entering lifts the little platinum plate together with the 
 little spike which sits upon it ; but if the membrane swings 
 
 * [Fig. 30 of this book.] 
 
INVENTOR OF THE TELEPHONE. 
 
 97 
 
 downwards, the tin-piece Ji g i, with the little spike at i, 
 cannot follow it quick enough ; there therefore occurs here, 
 at each vibration of the membrane, an interruption of the 
 
 Fig. 30. 
 
 Fig. 31. 
 
 Fig. 32. 
 
98 PHILIPP REIS, 
 
 current which lets itself be recognised by a little spark 
 appearing at the place of interruption. 
 
 " Now in the spiral M is stuck a knitting-needle, which, as 
 the figure shows, is fastened into a sounding-board. A lid 
 provided with second sounding-board may be clapped over 
 the spiral, and the tone be thereby greatly strengthened. 
 
 " If now, tones are produced before the mouth-piece S, 
 whilst one sings into the same or whilst one blows organ- 
 pipes, one at once hears at the reproducing apparatus a 
 peculiar creaking noise which is independent of the pitch of 
 the tones produced at the interrupting apparatus, but, beside 
 this, those tones are themselves reproduced ~by the steel wire dis- 
 tinctly perceptibly, and indeed Eeis found that this is the case 
 for all tones between F and /. 
 
 "In Keis's experiments the interrupting apparatus was 
 300 feet distant from the spiral, and was indeed set up in 
 another house with closed doors. But since the length of the 
 conducting wire can be extended just as far as in direct 
 telegraphy, Keis gave to his apparatus the name Telephone 
 (Jahresbericht des physikalischen Vereins zu Frankfurt-a.-M. 
 fur 1860/61)." 
 
 [15.] EXTRACT FROM PISKO'S ' DIE NEUEREN APPARATE DER 
 
 AKUSTIK.' 
 
 [This book, ' The more recent Apparatus of Acoustics/ by 
 Dr. Francis Joseph Pisko, Professor of Physics in the Gewer- 
 beschule in Vienna, was published at Vienna in 1865. At 
 that time the novelties in acoustics were Konig's apparatus 
 for the graphic study of sounds, Konig's manometric flames, 
 Schaffgotsch's singing flames, Helmholtz's ' Eesearches 
 on the Quality of Sounds,' Duhamel's Vibrograph, Scott 
 and Konig's Phonautograph, and Keis's Telephone. The 
 account given of the latter is more detailed in some respects 
 than any other published at the time.] 
 
INVENTOR OF THE TELEPHONE. 
 
 Page 94. PKINCIPLE OF THE " TELEPHON " OF EEIS. 
 
 51. (a) Allied to the Membrane Phonautograph is the 
 " Telephon" of Eeis* (Fig. 33). Upon the little membrane, 
 m m, in the middle, is fastened with adhesive wax the round 
 end s of a light strip of platinum, n s, so that the platinum 
 strip can join in with all the vibrations of the membrane. 
 Very near to the central end, s, of the little platinum strip, 
 n s, a platinum spike stands, in such a way that it is brought 
 into contact, by the vibrations of the membrane, with the 
 platinum strip that vibrates with the latter. Suppose now 
 that the outer end, n, of the platinum strip and the platinum 
 spike are connected with the poles of a galvanic battery, then, 
 by the vibration of the membrane the galvanic current will, 
 according to the phase of the vibration, be alternately esta- 
 blished and interrupted. Inserted in this circuit, an electro- 
 magnetic bell, or an electro-magnetic telegraph, will give 
 signals to great distances that somebody is speaking ; f though, 
 obviously, it cannot inform what is being spoken. 
 
 * [References."] Telephon von Eeis im Jahresbericljt des physikalischen 
 Vereins zu Frankfurt-a.-M. fur 1860-1861, pag. 57 bis 64. Muller- 
 Pouittet, Physik, 1863, 6. Auflage, II pag. 352, Fig. 325. Berl. Ber. fur 
 1861, xvii. pag. 171 bis 173. Der Musiktelegraph in der " Gartenlaube " 
 1863, Nr. 51, pag. 807 bis 909. Aus der Katur 1862, xxi. pag. 470 bis 
 484 ; Konig's Catalog, 1865, pag. 5. 
 
 f [This part of the apparatus is in fact a " call," serving precisely the 
 same function as the call-bell attached to ordinary telephones, by which 
 the subscriber can be "called up" to listen to the instrument. It is not 
 without importance to observe that this function was perfectly well-known 
 at the time ; fur it was gravely argued during a former telephone law-suit 
 in England that the presence of this " signal-call " at the side of the Reis 
 Transmitter was a proof that it was intended to transmit singing only 
 and not speech, or "else there would not have been that little Morse- 
 instrument at the side by which to talk " ! This suggestion is, however, 
 self-evidently absurd, because if this had been the case the little electro- 
 magnetic Morse telegraph would have been fixed, not on the side of the 
 transmitter but on that of the receiver. Reis himself explains the use of 
 the " call " (see p. 87) in his " Prospectus."] S. P. T. 
 
 H 2 
 
100 
 
 PHILIPP REIS, 
 
 (5.) As is known, an iron wire around which flow rapidly- 
 interrupted powerful galvanic currents, is thereby thrown 
 into tones which, according to circumstances, may be longi- 
 
 tudinal or transverse or both together. Such an iron wire, 
 lying in a multiplying wire-coil, Gf, Eeis inserted at the second 
 [receiving] station, C. The wire emitted sounds when the 
 
INVENTOR OF THE TELEPHONE. 101 
 
 membrane was set into vibrations by singing or speaking 
 (at S, Fig. 33) into the hollow cubical piece A. In the inves- 
 tigations made by me with the telephone, the rod (of iron) 
 never altered the pitch of its tone with the most different 
 kinds of tones and clangs, and always gave only the rhythm 
 of the words sung or spoken into the piece A (the trans- 
 mitter) at S. Usually the air of the song that was sung could 
 be recognised by its rhythm.* The special researches on 
 these points follow in paragraph 53. However, it is so far 
 clear that there is still plenty of time yet before we have the 
 simultaneous concerts, and the transmission of singing to 
 different towns, as the daily newspapers have sanguinely 
 expected. The apparatus of Eeis is certainly a " Telephone " 
 but not a " Phonic Telegraph." The single means of trans- 
 mission for song and speech and that only for moderate 
 distances remains the old familiar speaking-tube. Never- 
 theless, the experiment of Eeis must ever be reckoned 
 amongst the most beautiful and interesting of school-experi- 
 ments. And since the means for this are so simple, the 
 apparatus of Eeis will certainly find a speedy entrance into 
 educational establishments that are only moderately endowed. 
 It is easily proved that the tones of the wire in the telephone 
 do not arise from acoustic conduction, for by cutting out the 
 coil from the circuit the tones immediately cease. 
 
 1. The Telephone of Keis originally consisted of a cube of 
 wood with a conical boring. The smaller opening was strained 
 over with a membrane. A knitting-needle which served for a 
 sounding wire projected about 2 inches on each side of the 
 multiplying coil, and lay upon the two bridges of a sounding- 
 box. The surrounding helix consisted of six layers of thin 
 wire. Fig. 33 shows the Telephone as it is constructed at the 
 
 * [Professor Pisko seems to have got hold of an unusually unfortunate 
 specimen of the instrument if he could make it neither speak nor sing. 
 His transmitter must have been in exceedingly bad condition to fail so 
 completely.] 
 
102 PEILIPP REIS, 
 
 present time by the mechanician, Albert, in Frankfort, and by 
 the mechanician, Hauck, in Vienna, according to the directions 
 of the inventor. 
 
 [52.] Details about the Telephone. 
 
 (a.) The same (Fig. 33) consists in its essentials : 
 
 1. Of a transmitter, A ; 
 
 2. Of a receiver, C ; 
 
 3. Of a galvanic battery, B, and lastly, 
 
 4. Of the conducting wires that connect them. 
 
 (&.) The transmitter, A, is essentially a parallelepipedal 
 body of wood. The upper part, u x, of it is cut out of one 
 piece [of wood] with square cross -section, the side, xx, of 
 which measures 9 centimetres, and its height, ux,2'8 cen- 
 timetres. 
 
 This part is moveable upon a hinge on the lower little box, 
 A A. If the cover, x u, is laid back, one sees that a small 
 circle of 3' 9 centimetres diameter has been cut out in the 
 same. Into this hole passes a brass collar with a flange 
 8 millimetres broad, which is furnished at one side with a 
 groove like a pulley. Over the collar there is stretched the 
 membrane, ra m, by means of a silk thread lying in the 
 shoulder of the same. This circular membrane is surrounded 
 by a wider circular aperture, I ~b, = 8 5 centimetres. A shovel- 
 shaped little strip of platinum, n s, lies (over it) leading to 
 the brass binding-screw, d, with the circular part, s, falling 
 upon the centre of the membrane. 
 
 By means of some sealing-wax this circular part is fastened 
 to the membrane, and thereby compelled to take part in the 
 vibrations of the same. The further transmission of the 
 galvanic current from the centre takes place by means of a 
 platinum or steel point resting in a cup of mercury, which is 
 
INVENTOR OF TEE TELEPHONE. 103 
 
 extended in a screw, which transmits the current farther. 
 The point a serves as a support for the angular hook, a s b, 
 which in general is supported like a tripod, in order that the 
 point of contact, s, may remain as constant as possible. The 
 hook, a s b, is simply struck with a hole at a upon a project- 
 ing point, and lies upon a broader under part. From b the 
 galvanic circuit proceeds by means of an overspun wire to the 
 brass key e (A, Fig. 33), and from there farther in the 
 direction represented by the arrow. 
 
 The lower part A A of the transmitter is put together of 
 thin wood and forms a parallelepiped, whose height = 6*8 cm., 
 and whose width = 7'7 cm. An inclined mouthpiece of 
 tin with funnel-shaped opening serves to receive the tones. 
 The longer side of this mouthpiece measures 6 * 7 cm., the 
 shorter 4 7 cm. ; the longer diameter of the widening measures 
 7*15 cm., the shorter diameter 7*5 cm., and finally the 
 diameter of the narrow tube 3 9 cm. 
 
 It is clear that, if necessary, the platinum strip can be 
 replaced by a strip of thin sheet-brass, the platinum or steel 
 points by iron. Only in this case the points of contact must be 
 oftener cleaned to a metallic polish. 
 
 (c.) The receiver (Zeichengeber) C is in general a double 
 resonant box, whose upper part, " the cover," is moveable 
 upon two hinges, and can be laid back. The length of this 
 cover is 16*4 cm., its width 9*5 cm., and its height 3 '2 cm. 
 The length of the lower box measures 22-9 cm., its width 
 9 *6 cm., and its height 2*5 cm. The under part of the 
 resonant box bears two wooden bridges, which stand about 
 7 ' 4 cm. from each other, and which serves as supports for 
 the 21 5 cm. long, and 9 cm. thick iron needle destined for 
 reproducing the tones. The length of spiral wound over the 
 needle, and designed for making an electro-magnet of the 
 same, is 15 cm. The wooden covers of both parts, scraped 
 
104 PEILIPP REIS, 
 
 as thin as possible, and the greatest breadth of the circular 
 holes shown in the figure, measures 13 mm. 
 
 (d.) For a battery one can successfully use a small Smee's 
 consisting of four elements, or two larger Bunsen's cells. 
 
 The conductor must be at least sufficiently long that one 
 cannot perceive the tones that are produced. For corre- 
 spondence between the two stations the inventor has employed 
 the electro-magnetic telegraph arrangement, e v g h, seen in 
 the mechanism, and easily understood. An agreement in 
 reference to corresponding signs can be easily arranged, and 
 the simplest way is to accept the signals arranged by the 
 inventor. (See ' Prospectus.') 
 
 The receiver C gives, when the key e is pressed, the cor- 
 responding telegraphic signals by means of tones in the rod 
 E E, while at the transmitter, A, the electro-magnet v gives 
 the signals by means of the springy armature z. 
 
 [53.] Experiments with the Telephone. 
 
 (a.) As soon as one brings the mouth to the funnel S and 
 sings, the membrane of the transmitter, A, vibrates in a 
 corresponding manner, and the iron rod, E E, at the second 
 station begins to give forth a tone. Every time a spark is 
 seen at the first station s, the rod ^at the other station 
 certainly gives forth a tone. The same is true when one 
 hears the peculiarly snarling tone which arises from the 
 stroke of the vibrating platinum strip against the spike of 
 angular hook resting upon it. 
 
 The appearance of these sparks or of the peculiar snarling 
 at the transmitter A gives the sign to the observers at the 
 station A that the rod in C is giving a tone. Tones and 
 melodies which were sung into the sound aperture, and 
 especially sounds in which the teeth and bones of the head 
 also vibrated (so-called humming tones), always evoked 
 
INVENTOE OF THE TELEPHONE. 105 
 
 a tone in the rod or needle E E, and indeed, as already 
 mentioned ( 51), without change in the pitch, but only 
 with the reproduction of the rhythm of the respective song 
 or words. 
 
 The pitch of the tone excited at C in the rod E E was in 
 the apparatus at my disposal h its strength not very great 
 and its clang snarly, similar to that of a lightly sounding 
 reed- whistle, somewhat like that of a child's wooden trumpet. 
 The cuticle lying about the heart of the smaller and even the 
 larger mammals (from calves, &c.) makes the best membranes. 
 Goldbeater's-skins reproduce only the deeper tones. The 
 cover of the sounding-box appeared in my apparatus 
 superfluous, and indeed the tone was somewhat stronger 
 without the cover. 
 
 1. In experiments with the telephone, one must look closely 
 as to whether the ends of the platinum strip is still fastened to 
 the membrane, and one must, if necessary, press upon the 
 membrane. If the strip will no longer stick, heat a knife-blade, 
 touch a small piece of sealing wax with it, and carry thus 
 the melted sealing-wax to the under side of the round end 
 of the platinum-strip, n s. Then press it immediately on the 
 membrane, m m. 
 
 Ph. Eeis showed his apparatus in very primitive form for the first 
 time in October, 1861, to the Physical Society at Frankfort-on-the-Main ; 
 on July 4th, 1863, before the same society, he showed the form represented 
 in Fig. 33. This time he experimented upon a distance of 300 feet. Pro- 
 fessor Boettger brought the apparatus before the Naturforscher-Versamm- 
 lung at Stettin (1863) in the section for Physics. 
 
 ***** 
 
 [16.] HESSLER'S ' TEXT-BOOK OF TECHNICAL PHYSICS/ 
 vol. i. p. 648. 
 
 [Next in chronological order comes a notice of the 
 Telephone in Hessler's ' Lehrbuch der technischen Physik,' 
 edited by Prof. Pisko, and published at Vienna in 1866. The 
 brief account given in this work adds nothing to the accounts 
 previously given, and is evidently written by some person 
 
106 PHILIPP REIS, 
 
 ignorant of Eeis's own work, for beside omitting all mention 
 of the transmission of speech by the instrument, or of its 
 being constructed upon the model of the human ear, the 
 writer appears not even to know how to spell Keis's name,* 
 and speaks of him as " Eeuss."] 
 
 [17.] KUHN'S 'HANDBOOK OF APPLIED ELECTRICITY,' 
 
 (' Handbuch der Angewandten Elektricitatslehre,' von Carl 
 Kuhn), being vol. xx. of Karsten's ' Universal Encyclopaedia of 
 Physics ' (Karsten's ' Allgemeine Encyclopadie der Physik '). 
 
 [Karsten's ' Encyclopaedia of Physics,' which has been for 
 many years a standard work of reference, both in Germany 
 and in this country, consists of a number of volumes, each of 
 which is a complete treatise, written by the very highest 
 authorities in Germany. Thus Helmholtz contributed the 
 volume on Physiological Optics, Lamont that on Terrestrial 
 Magnetism, whilst the names of Dr. Brix, Professor von 
 Feilitzsch, and others, are included amongst the authors. 
 Carl Kuhn, who wrote vol. xx., was Professor in the Eoyal 
 Lyceum of Munich, and member of the Munich Academy. 
 Kuhn's volume on ' Applied Electricity,' published in 1866, 
 
 * This error has been copied by Count du Moncel, along with the other 
 defects of the article, into the fifth volume of his * Applications of Elec- 
 tricity,' published in 1878. It is rather amusing now to read, at p. 106, 
 of Du Moncel's treatise that " Heisler " (sic) " pretends " that the telephone 
 of " Eeuss," which " appears " to have been invented " anterior to the year 
 1866," was capable of transmitting vocal melodies ! Count du Moncel, 
 though he has since posed as an authority on the telephone, did not in 
 1878 shine in that capacity, for on the very same page of the Count's book 
 may be found the following astounding sentiment : " Jf it is true, as Sir 
 W. Thomson has assured us, that at the Philadelphia Exhibition of 1876 
 there was a telegraphic system transmitting words, we may recognize," &c. 
 Count du Moncel has since found out that it is true that there was a 
 Telephone in Philadelphia in 1876 : perhaps he will next discover that 
 " Reuss" did, "anterior to the year 1866," actually "appear" to transmit 
 not only what "Heisler" "pretends" he did, but that he also transmitted 
 spoken words. S. P. T. 
 
INVENTOE OF THE TELEPHONE. 107 
 
 is to be found on the shelves of almost every library of any 
 pretensions in Great Britain. The account given therein of 
 Eeis's Telephone is interesting, because it describes two 
 forms, both of transmitter and of receiver. In fact the 
 descriptions and figures are taken almost directly from von 
 Legat's Eeport (p. 70), and from Eeis's Prospectus (p. 87). 
 The extract translated below includes all the matter that is 
 of importance.] 
 
 P. 1017. The researches established by Eeis on the 26th 
 of October, 1861, in Frankfurt* have already shown that 
 if the current interruptions follow one another almost con- 
 tinuously and very rapidly, in a spiral arranged with a thin 
 iron core, the iron wire can be set into longitudinal vibra- 
 tions, whereby therefore the same is constrained to reproduce 
 tones of different pitch. 
 
 * * # * 
 
 [Here follows a reference to Petrina's Electric Harmonica.] 
 
 * * * * 
 
 From the communications made known by Legat, it' 
 follows that " the ideas concerning the reproduction of tones 
 by means of electro-galvanism which were put forward some 
 time since by Philipp Eeis of Friedrichsdorf, before the 
 Physical Society, and the meeting of the Free German 
 Institute in Frankfort-on-the-Main," relate to similar arrange- 
 ments. " What has hitherto been attained in the realisation 
 of this project," Legat announces in his report, and we 
 extract therefrom only that part which gives an explanation 
 of the disposition of the telegraphic apparatus, with which it 
 is said to be possible to produce the vibrations and the 
 excitement of tones in any desired manner, and by which 
 the employment of electro-galvanism is said to make it 
 
 * Ueber Fortpflanzung der Tone auf wilkiihrlich weite Entfermmgen, 
 mit Hiilfe der Elektricitiit (Telephonic). Polyt. Journ. clxviii. 185 ; aus 
 Bottger's Notizbl. 1863, Nr. 6. "[See translation on page 61.] 
 
108 PHILIPP REIS, 
 
 possible "to. call into life at any given distance vibrations 
 similar to the vibrations that have been produced, and in this 
 way to reproduce at any place the tones that have been 
 originated at another place." 
 
 This apparatus consists of the tone-indicator (transmetteur) 
 and the tone-receiver (recepteur). The tone-indicator 
 (Fig. 34, p. 1 09) consists of a conical tube, a b, having a 
 length of about 15 cm., a front aperture of about 10 cm., 
 and a back aperture of about 4 cm., the choice of the 
 material and the greater length of which is said to be in- 
 different, while a greater width is said to be injurious ; the 
 surface of the inner wall should be as smooth as possible. 
 The narrow back aperture of the tube is closed by a 
 membrane, o, of collodion, and upon the centre of the circular 
 surface formed by this membrane rests the one end, c, of the 
 lever, c d, the supporting-point of which, e t being held by 
 a support, remains in connection with the metallic circuit. 
 This lever, the arm, c e y of which must be considerably 
 longer than c d, should be as light as possible, so that it 
 can easily follow the movements of the membrane, because 
 an uncertain following of the lever, c d, will produce 
 impure tones at the receiving station. During the state of 
 rest the contact, d g, is closed, and a weak spring, n, keeps 
 the lever in this state of rest. Upon the metallic support, /, 
 which is in connection with one pole of the battery, there is 
 a spring, g, with a contact corresponding to the contact of the 
 lever, c d, at d, the position of which is regulated by means of 
 the screw, h. In order that the effect of the apparatus may 
 not be weakened by the produced waves of air communicat- 
 ing themselves towards the back part, a disc " of about 
 50 (?) cm. diameter, which rests fixedly upon the exterior 
 wall of the tube," is to be placed above the tube, a b, at right 
 angles with its longitudinal axis. 
 
 The tone-receiver consists of an electro-magnet, m m, which 
 
INVENTOR OF THE TELEPHONE. 
 
 109 
 
110 PHILIPP REIS, 
 
 rests upon a resounding-board, u w, and the surrounding coils 
 of which are connected with the metallic circuit and the 
 earth. Opposite to the electro-magnet there stands an 
 armature, which is connected with a lever, i, as long as 
 possible but light and broad, and which lever together with 
 the armature, is fastened like a pendulum to the support k ; 
 its movements are regulated by the screw I and the spring q. 
 " In order to increase the effect of the apparatus, this tone- 
 receiver may be placed in the one focus of an elliptically 
 hollowed cavity of sufficient size, while the ear of the person 
 who listens to the reproduced sounds ought to be placed at 
 the second focus of the cavity." The action of the two 
 apparatus, the general manner of connection of which may be 
 seen from the illustrations at the one station being the 
 tone-indicator, at the other the tone-receiver is the follow- 
 ing : By speaking into, singing, or conducting the tones of 
 an instrument into the tube, a I, there is produced in the 
 tone-indicator (Fig. 34) in consequence of the condensation 
 and rarefaction of the enclosed column of air, a motion of the 
 membrane, c, corresponding to these changes. The lever, c d, 
 follows the movements of the membrane, and opens or closes 
 the circuit according as there occurs a condensation or rare- 
 faction of the enclosed air. In consequence of these actions, 
 the electro-magnet, m m (Fig. 13), is correspondingly demag- 
 netised or magnetised, and the armature (and the armature- 
 lever) belonging to it is set into vibrations similar to 
 those of the membrane of the transmitting apparatus. By 
 means of the lever, i, connected with the armature, the 
 similar vibrations are transmitted to the surrounding air, 
 and these sounds thus produced finally reach the ear of the 
 listener (the sounding-board increasing the effect). As 
 regards the effectiveness of this apparatus, the author 
 remarks that while the similar number of the produced 
 vibrations is reproduced by the receiver, their original 
 
INVENTOR OF THE TELEPHONE. Ill 
 
 strength has not yet been obtained by it. For this reason 
 also small differences of vibration are difficult to hear, and 
 during the practical experiments hitherto made, chords, 
 melodies, &c., could be, it is true, transmitted with asto- 
 nishing (?) fidelity, while single words in reading, speaking, 
 
 &c., were less distinctly perceived. 
 
 * * * * 
 
 [The rest of the article deals with the "square-box" transmitter 
 described in Eeis's Prospectus, and adds nothing to the information already 
 published.] 
 
 [This is the last of the contemporary documents bearing 
 upon the performance of Eeis's instruments. From the 
 prominent notice obtained at the time by the inventor, it is 
 clear that his invention was even then accorded an honour- 
 able place amongst the acknowledged conquests of science. 
 A critical examination of this body of evidence proves not 
 only the substantial nature of Eeis's claim, but that the 
 claim was openly recognised and allowed by the best autho- 
 rities of the time. The thing was not done in a corner.] 
 
112 PHILIPP BEIS, 
 
 CHAPTEE V. 
 
 TESTIMONY OF CONTEMPORARY WITNESSES. 
 
 1. Professor G. Quincke. 
 
 2. Professor C. Bohn. 
 
 3. Herr Leon Gamier. 
 
 4. Ernest Horkheimer, Esq. 
 
 5. Dr. K. Messel, F.C.S. 
 
 6. Herr Heinrich Holt. 
 
 7. Herr Heinrich F. Peter. 
 
 8. Mr. Stephen M. Yeates. 
 
 9. Dr. William Frazer. 
 
 PROFESSOR G. QUINCKE, 
 
 Professor of Physics in the University of Heidelberg. 
 
 [Professor Quincke, whose name is so well known in connection with 
 his researches in molecular physics and in many problems of the highest 
 interest to those acquainted with electrical science, was one of those 
 present at the Naturforscher Yersammlung held at Giessen in 1864, where 
 Reis's Telephone was publicly exhibited by its inventor, see page 93, 
 ante. His testimony, coming from so high authority, is therefore of 
 exceptional value.] 
 
 " DEAR SIR, 
 
 " I was present at the Assembly of the German Na- 
 turalists' Association (Naturforscher Versammlung) held in 
 the year 1864 in Giessen, when Mr. Philipp Eeis, at that 
 time teacher in the Gamier Institute at Friedrichsdorf, near 
 Frankfort-on-the-Main, showed and explained to the assembly 
 the Telephone which he had invented. 
 
 " I witnessed the performance of the instruments, and, with 
 the assistance of the late Professor Bottger, heard them for 
 myself. 
 
 " The apparatus used consisted of two parts a transmitter 
 
INVENTOR OF THE TELEPHONE. 113 
 
 and a receiver. The transmitter was a box, one side of which 
 was furnished with a tube into which the speaking was to 
 be done. At the top or the side of the box there was a cir- 
 cular opening, covered by a tympanum of membrane, upon 
 which was fastened a piece of platinum. This piece of 
 platinum was in communication with one pole of the galvanic 
 battery. Over the membrane, resting upon the platinum, and 
 in contact with it, was a piece of metal furnished with a 
 platinum point, also in connection with one pole of the 
 battery. 
 
 " The receiver consisted of a common knitting needle of 
 steel, surrounded by a magnetising coil of insulated wire, which 
 also formed a part of the circuit, the whole resting on a 
 resonant box. 
 
 " I listened at the latter part of the apparatus, and heard 
 distinctly both singing and talking. I distinctly remember 
 having heard the words of the German poem, ' Ach ! du lieber 
 Augustin, Alles ist hin ! '" &c. 
 
 " The members of the Association were astonished and 
 delighted, and heartily congratulated Mr. Eeis upon the 
 success of his researches in Telephony. 
 
 (Signed) " DR. G. QUINCKE, Professor. 
 " Heidelberg, 10th March, 1883." 
 
 PROFESSOR C. BOHN. 
 
 [Professor C. Bohn, of Aschaifenburg, was formerly Secretary to the 
 German " Naturforscher " Association, was also Secretary to the Physical 
 Section of this Society (vide p. 93). In that capacity he had every 
 opportunity of knowing what was going on in science ; hence the following 
 (translated) letter, addressed to the author of this book, is of peculiar 
 value.] 
 
 " MOST ESTEEMED SlR, 
 
 " I willingly answer, as well as I am able to do so, the 
 questions put by you. In order to explain that my recollec- 
 
 i 
 
114 PHILIPP RE IS, 
 
 tions may not have all the sharpness that might be wished, 
 I make the following prefatory statement. I have, about 
 1863, held numerous conferences with Mr. Eeis and with my 
 deceased colleague, Professor H. Buff, of Giessen, and on 
 these occasions have argued the question how it is that the 
 transmission of thoughts to a distance by the sensation of 
 the ear has a distinctly less value than transmission by that 
 which is written. . . . 
 
 " And now to your questions. I was not at Stettin in 1863. 
 At the experiments at Giessen in the Naturforscher Assembly 
 on 21st September, 1864, 1 was present ; the short notice about 
 them in the journal (' Tagesblatt ') is from my pen. I was 
 Secretary of the Assembly and of the Physical Section. I 
 remember, however, almost absolutely nothing about these 
 experiments. But I remember well that previously therefore 
 probably as early as 1863 having jointly made the experi- 
 ments with Eeis's telephone in Buff's house in Giessen. . . . 
 I have myself, as speaker and as hearer, at least twice, in the 
 presence of Eeis, made the experiments. 
 
 " It was known to me (in 1863-64) that Eeis intended to 
 transmit words, and certainly spoken words as well as* those 
 sung. My interest in the matter was, however, a purely 
 scientific one, not directed to the application as a means of 
 profit. 
 
 "With great attention the sense of the words was understood. 
 I have understood such myself, without knowing previously 
 what would be the nature of the communication through the 
 telephone. Words sung, especially well accentuated and 
 peculiarly intoned, were somewhat better (or rather less 
 incompletely) understood than those spoken in the ordinary 
 manner. There was indeed a boy (son of Privy-Councillor 
 Ihering, now of Gottingen, then of Giessen), who was known 
 as specially accomplished as a speaker. He had a rather 
 harsh North-German dialect, and after the first experiments 
 
INVENTOR OF THE TELEPHONE. 115 
 
 hit on the right way to speak best, essential for understand- 
 ing. I myself did not understand Professor Buff through the 
 telephone. Whether the speaker could be recognized by his 
 voice I doubt. We knew beforehand each time who speaks. 
 Yet I remember that a girl could be distinguished from 
 that boy by the voice. 
 
 " The ear was at times laid upon the box of the apparatus, 
 also upon the table which supported the telephone. Then it 
 was attempted to hear at a distance, with the ear in the air ; in 
 this respect, when singing, with good result. At times the 
 lid was taken off, or the same was connected more or less 
 tightly or loosely with the lower part. The result of these 
 changes I can no longer give with distinctness. . . . 
 
 " Should you desire further information, I am ready to give 
 you it according to my best knowledge. 
 
 " Hochachtungsvoll ergebenster, 
 
 "DR. C. BOHN. 
 
 " Aschaffenburg, 
 
 " Wth September, 1882." 
 
 LEON GARNIER. 
 
 [Herr Leon Gamier, Proprietor and Principal of the Gamier Institute at 
 Friedrichsdorf, is the son of the late Burgomaster Gamier, who founded 
 the establishment, and who, as previously narrated, encouraged Philipp 
 Reis in his work and offered him the post of teacher of Natural Science. 
 Herr Leon Gamier owns the small collection of instruments which Reis 
 left behind, and which are preserved in the Physical Cabinet attached to 
 the Institute, where also may be seen the gravitation machine an 
 ingenious combination of the principles of Atwood's and Morin's machines 
 and the automatic weather-recorder invented by Reis, both, however, 
 very greatly out of repair. Herr Garnier has furnished to a friend the 
 following particulars about Reis and his invention.] 
 
 " I knew Philipp Beis, now deceased, during his life-time. 
 . . . About the year 1859, he was employed by my father, 
 then proprietor and director of the Friedrichsdorf Garnier 
 Institute, as teacher of mathematics and natural sciences. 
 
 i 2 
 
116 PHILIPP EEIS, 
 
 He employed his hours of leisure in experimenting for 
 himself in a house occupied by himself, and in which he had 
 established a physical laboratory with a view mainly of 
 realizing an idea which he had conceived sometime before of 
 transmitting the human voice over divers metallic conductors 
 by means of a galvanic current. ... I remember especially, 
 that, standing at the end of the wire or conductor, Mr. Eeis 
 speaking through his instrument, I distinctly hea,rd the 
 words : ' Guten Morgen, Herr Fischer ' (Good morning, 
 Mr. Fischer) ; ' Ich komme gleich ' (I am coming directly) ; 
 Passe auf!' (Pay attention!); 'Wie viel Uhr ist es?' 
 (What o'clock is it?); <Wie heisst du?' (What's your 
 name?) We often spoke for an hour at a time. The 
 distance was about 150 feet. 
 
 " LEON GARNIER." 
 
 ERNEST HORKHEIMER, ESQ. 
 
 " Manchester, Dec. 2, 1882. 
 " Professor S. P. THOMPSON, 
 
 "DEAR SIR, 
 
 " In reply to your favour of 31st instant, I shall be 
 very happy to give you all the information I can with respect 
 to the telephonic experiments of my late friend and teacher 
 Mr. Philipp Keis. I would express my gratification at finding 
 that you are trying to put my old teacher's claims on their 
 just basis. I have always felt that in this race for telephonic 
 fame, his claims have been very coolly put aside or ignored. 
 That he did invent the Telephone there is not the remotest 
 doubt. I was, I think, a great favourite of his ; and at the 
 time his assumption was that I was destined for a scientific 
 career, either as a physicist or a chemist ; and I believe that 
 he said more to me about the telephone than to any one; and 
 I assisted him in most of his experiments prior to the spring 
 of 1862. 
 
INVENTOR OF THE TELEPHONE. 
 
 117 
 
 " Philipp Eeis intended to transmit speech by his telephone 
 this was his chief aim ; the transmitting of musical tones 
 being only an after-thought, worked out for the convenience 
 of public exhibition (which took place at the Physical Society 
 at Frankfort-on-the-Main). I myself spent considerable time 
 with him in transmitting words through the instruments. 
 We never (in my time) got the length of transmitting com- 
 plete sentences successfully, but certain words, such as ' Wer 
 da?' 'gewiss' 'warm,' 'halt' were undoubtedly transmitted 
 without previous arrangement. I believe Eeis made similar 
 experiments with his brother-in-law. 
 
 " I recollect the instrument in the shape of the human ear 
 very well : it was Eeis's earliest form of transmitter. The 
 transmitter underwent a great many changes, even during my 
 time. The form you sketch (Fig. 9, p. 20) was almost the 
 oldest one, and was soon superseded by the funnel-shape 
 (Fig. 35). 
 
 Fig. 35. 
 
 Fig. 36. 
 
 The back was always closed by a tympanum of bladder, and 
 many a hundred bladders were stretched, torn, and discarded 
 during his experiments. I recollect him stating to me that 
 he thought a very thin metal tympanum would eventually 
 become the proper thing, and one was actually tried, coated 
 over on one side with shellac, and on the other likewise 
 except at the point of contact (Fig. 36). I believe it was 
 made of very thin brass, but at the time the experiments 
 were not satisfactory. Talc was also tried, but without 
 success, the platinum contacts being in all cases preserved. 
 
118 
 
 PHILIPP REIS, 
 
 " I remember very well indeed the receiver with a steel 
 wire, surrounded by silk-covered copper wire. The first one 
 was placed on an empty cigar-box, arranged thus : 
 
 Fig. 37. 
 
 " The wire was a knitting-needle and the copper wire was 
 spooled on a paper case, ft \ 
 
 " The spiral was supported by a little block of wood, so as 
 to allow the knitting-needle not to touch it anywhere. Later 
 on a smaller cigar-box was invented as a cover thus ; (Fig. 38) 
 having two holes cut into it like the /-holes in a violin. 
 
 Fig. 38. 
 
 " The practice was to place the ear close to the receiver, 
 more particularly so when the transmission of words was 
 attempted. 
 
 " The spiral was, during the early experiments, placed on a 
 violin in fact, a violin which I now possess was sometimes 
 used, as it was of a peculiar shape, which Eeis thought would 
 help the power of tone. 
 
 " I have already enumerated some of the words which were 
 
INVENTOR OF THE TELEPHONE. 
 
 119 
 
 transmitted, but there were many more ; on one occasion a 
 song, known in this country as ' The Young Eecruit ' (Wer 
 will unter die Soldaten) was transmitted, the air and many 
 of the words being clearly intelligible. 
 
 " I do not recollect seeing the receiver shewn in the wood- 
 cut (Fig. 21), but Eeis often said that he would make such 
 a one, although the sketch he made for me then differed in 
 some details from your woodcut. Eeis intended to keep me 
 fully informed of all he could achieve, but, immediately after 
 leaving his tuition, I fell ill, and was laid up for a very long 
 time. Shortly afterwards I left for England, and then he 
 died, and I never saw him again. The electromagnet form 
 was certainly strongly in his mind at the time we parted, 
 and he drew many alternative suggestions on paper, which 
 have probably been destroyed; but the electromagnets in 
 all of them were placed upright, sometimes attached to the 
 top of a hollow box, and sometimes to the bottom of a box 
 arranged thus (Figs. 39, 40) ; but, to my recollection, they 
 never got beyond the stage of drawings, whatever he may 
 have done after he and I parted company. 
 
 Fig. 39. 
 
 V U 
 
 Fig. 40. 
 
 " In conclusion, I beg to send you herewith a photograph 
 of Philipp Eeis (see Fig. 12, p. 23), holding in his hand the 
 instrument I helped him to make, and which photograph he 
 took of himself, exposing the camera by a pneumatic arrange- 
 ment of his own, and which formed part of a little machine 
 which he concocted for turning over the leaves of music-books. 
 
 " The instrument used by Eeis at the Physical Society may 
 
120 PHILIPP REIS, 
 
 have been the square block form : I believe that this cone- 
 form was not quite completed then. At the Saalbau (Hoch- 
 stift), however, I am sure the instrument shown in my photo- 
 graph was employed ; not with a tin cone, but a wooden one. 
 I send you herewith a sketch of what I remember that 
 instrument to have been. I am not absolutely certain 
 whether in the instrument there was not an electromagnet 
 introduced, but I think not. My recollection leads me to 
 suppose that the electromagnet arrangement was added sub- 
 sequently. Thinking it over again, I should, however, think 
 that the instrument in the photo must have been one in 
 which a bent lever was placed behind the tympanum, and 
 that the rectangular patch seen above was a wooden casing 
 to shelter the parts. There may be some confusion in my 
 mind as to the position of this box, but I somehow think 
 the rectangular patch is only part of a larger box which is 
 not apparent in the photograph. I have no idea where 
 the original instrument is now, but I should hardly think 
 it could be in existence. Eeis used to take some in- 
 struments to pieces to utilise parts in subsequent experi- 
 ments, and I recollect how keen he used to be about the 
 bits of platinum, which he always described as ' ein sehr 
 kostbares Metall.' What always was a great puzzle was the 
 attaching of the platinum plate to the membrane, which he 
 did generally by sealing-wax, saying at the same time : ' Es 
 ist nicht recht so, aber ich weiss nicht wie es anders gemacht 
 werden kann ! ' 
 
 " Believe me, my dear Sir, yours truly, 
 
 " ERNEST HORKHEIMER." 
 
 DR. EUDOLPH MESSEL. 
 
 [The following letter from Dr. Rudolph Messel, F.C.S., addressed to the 
 author of this hook, in reply to enquiries concerning Ileis and his inven- 
 tions, speaks for itself. Dr. Messel's letter differs from almost all the 
 
INVENTOR OF THE TELEPHONE. 121 
 
 others here reprinted in having been specially written for the purpose of 
 being inserted in this volume. S. P. T.] 
 
 " 36, Mark Lane, London, 30ta April, 1883. 
 
 " DEAR PROFESSOR THOMPSON, 
 
 " At last I find a moment to comply with your request. 
 My knowledge of Philipp Keis dates from 1860, when I 
 was a pupil at Professor Garnier's School at Friedrichsdorf, 
 of which school Eeis was one of the undermasters. Eeis, 
 naturally communicative, was very fond of talking to us boys 
 about his scientific researches. And it was on the occasion 
 of one of our daily walks together that he told me how, 
 when an apprentice at Beyerbach's (colour-manufacturer), in 
 Frankfurt-a.-M., he was one day amusing himself in watching 
 the behaviour of a small magnetic compass. This compass 
 he found, on being placed near to the base of various iron 
 columns in the warehouse, was attracted. Disturbed by the 
 entrance of one of the principals, who imagined that Eeis 
 ought to employ his time more profitably, he withdrew to a 
 stage where he could pursue his experiments unobserved. 
 Much to his surprise, he now found that the pole attracted 
 by the base was repulsed at the top of the columns, which 
 observation led him to examine other pieces of iron on the 
 premises. He next built up a column with all the weights 
 in the warehouse, and having verified his previous observa- 
 tions, he communicated what he believed to be his first and 
 great discovery either to Professor Bottger or to Dr. Oppel. 
 Great was his diappointment to learn at this interview that 
 he had unwittingly stumbled across a well-known physical 
 fact : but his disappointment stimulated in him the desire to 
 learn more of the marvellous laws and mysteries of nature. 
 That Eeis evoked a similar desire in those with whom he 
 came in contact need not cause surprise, and thus it came 
 about that Horkheimer, Kuster, Schmidt, and myself, soon 
 
122 PEILIPP REIS, 
 
 enjoyed the privilege of private instructions in physics, and 
 of being permitted to witness his telephonic experiments 
 amongst others. I was, however, very young, and am sorry 
 that much that I then saw and heard has been forgotten. 
 Keis insisted that his transmitter (which he called the 
 'ear') should be capable of performing the functions of 
 that organ, and he never tired of drawing diagrams of the 
 numerous curves of sounds to explain how necessary it was 
 that the transmitter should follow these curves before perfect 
 speaking could be attained, and which kind of curves the 
 instrument so far could reproduce. Numerous experiments 
 were made with transmitters, exaggerating or diminishing 
 the various component parts of the ear. Wooden and me- 
 tallic apparatus, rough and smooth, were constructed in order 
 to find out what was essential, and what was not. 
 
 "One form of transmitter was at that time constructed 
 which I miss amongst the various woodcuts you were good 
 enough to send me, and one which Eeis based great hopes 
 upon. The instrument was very rough, however, consisting 
 of a wooden bung of a beer-barrel (which I had hollowed out 
 for an earlier telephone it was not turned inside* like 
 others), and this was closed with a membrane. The favourite 
 ' Hammerchen ' was replaced by a straight wire, fixed in 
 the usual way with sealing-wax, and 
 the apparatus stood within a sort of 
 tripod, membrane downwards, the pin 
 just touching the surface of a drop of 
 mercury contained in a small cup form- 
 ing one of the terminals of the circuit. 
 The apparatus started off with splendid 
 results, but may probably have been abandoned on account of 
 its great uncertainty, thus sharing the fate of other of his 
 earlier instruments. In my belief it is to these mechanical 
 imperfections, due principally to the want of sufficient means 
 
INVENTOR OF THE TELEPHONE. 123 
 
 at his command, that we must look to find the reason why 
 Eeis's telephone did not come to an earlier fame. Thus Eeis 
 informed me that he intended to exhibit it once at some 
 scientific meeting at Cassel, but notwithstanding a perfect 
 rehearsal it was impossible to show the working to the audi- 
 ence ; the failure was attributed by Eeis to atmospheric influ- 
 ence (stretching of the diaphragm), and he felt much grieved 
 at having lost his chance. To make matters worse, the early 
 transmitters had no adjusting screws, and the contact was only 
 regulated by a piece of bent wire, and the ' hammer ' was fixed 
 to the membrane. Philipp Schmidt should recollect what I 
 state, as many experiments were made when only he, Eeis, and 
 myself were present, he being at one and I at the other end 
 of the apparatus. The wire was stretched from Eeis's house, 
 in the main road, through the yard to a hayloft, near the 
 garden or field. We transmitted musical sounds (organ, &c.), 
 singing popular songs (' Wer will unter die Soldaten,' ' Ich 
 hatt' einen Kameraden,' &c.) and speaking, or, more cor- 
 rectly, reading. We had a book, and were to find out what 
 part of the page the reader was just transmitting. We fre- 
 quently used a sort of 'Exercier Eeglement,' a soldiers' 
 instruction book, or something of that sort. I have a 
 distinct recollection of electromagnetic receivers being used, 
 but not of their construction, except that the use of one of 
 them was accompanied by a rattling and disturbing noise. 
 The knitting-needle put in the / of a violin was, however, 
 the more favoured receiver, but at this time, in Eeis's mind, 
 all seemed to hinge on the electromagnet, as it had before, 
 and, I dare say, did again afterwards on the transmitter. I 
 left Friedrichsdorf in '62, and rarely saw Eeis after that, 
 except a few times at Mechanicus Albert's (who made some 
 of his apparatus), and at Professor Bottger's, to whom he 
 introduced me. Eeis attended Professor Bottger's lectures 
 at the Physikalischer Verein, when in Frankfort, prior to his 
 
124 PHILIPP RE IS, 
 
 settling down at Friedrichsdorf ; but I do not know that 
 any particularly intimate relation existed between them. 
 Dr. Poppe, director of the Gewerbeschule (Trade School), 
 now deceased, on whose advice he chiefly relied, was then 
 one of his more intimate friends, Professor Oppel being 
 occasionally consulted about more intricate mathematical 
 problems. Of the 'meteorological recorder' invented by 
 Eeis I recollect but its existence, but nothing at all of a 
 1 fall-machine ' of his construction. The velocipede I only 
 recollect, because he lent it to me for a masquerade. At his 
 suggestion we altered it into a large musical-box, putting 
 Herr Peter inside, who played on the clarinet when I 
 turned a handle. Dr. Kellner states that its chief merit 
 consisted in being able to go downhill, and that poor Eeis 
 came back (uphill) puffing away, dragging his velocipede 
 behind him. Kellner no doubt could give valuable informa- 
 tion on Eeis's theory of electricity, his conviction that there 
 was only one kind of electricity, his acoustic researches, and 
 those on radiation of electricity, his galvanoplastic experi- 
 ments, &c., &c. 
 
 " In personal appearance Eeis was not very refined, but 
 he had a striking countenance and a very powerful look. 
 Though occasionally very irritable, especially with dunces, 
 he was always warm-hearted, and showed great kindness to 
 those who cared to understand him. Eeis's views of the 
 telephone may, of course, have changed after I knew him, 
 and looking at his later instruments, one of which I possess, 
 I cannot help thinking they did ; at any rate, I do not see 
 how, in these instruments, the current got interrupted at all, 
 and the instruments must have acted like microphones, 
 whether known or unknown to him. When listening to the 
 instrument he frequently said to me, " You understand it is 
 a ' molekular Bewegung ' (molecular motion). 
 
 " I am sorry that, owing to the lapse of time, I am unable 
 
INVENTOR OF THE TELEPHONE. 125 
 
 to throw more light on Eeis's original labours in a field of 
 physical science which promised so much for the future ; 
 but insufficient as are my recollections, they may not be 
 without public interest, and at any rate I am glad of this 
 opportunity of offering my humble tribute of regard and 
 affection to the memory of my old teacher and friend. 
 
 " Yours truly, 
 
 "BuDOLPH MESSEL." 
 
 HEINRICH HOLD. 
 
 [Herr Hold, formerly a colleague of Philipp Keis in the Gamier Institute 
 at Friedrichsdorf, but EOW proprietor of a leather factory in the same 
 place, was teacher of mathematics. He was in his younger days a fellow- 
 student of Professor Tyndall at Halle, and was well acquainted with 
 physical science in general. His intimate connection with Eeis, and close 
 knowledge of Keis's work, enable him to confirm the testimony of others 
 in many important points.] 
 
 To Professor S. P. THOMPSON in Bristol. 
 
 " ESTEEMED SIR, 
 
 " I have much pleasure in furnishing you with the 
 following particulars concerning my late colleague Philipp 
 Eeis, the inventor of the Telephone. He was himself educated 
 at the Garnier's Institute in Friedrichsdorf where I was also 
 teacher of mathematics. I knew him very well during his 
 life-time. Among his numerous original researches, his 
 invention of the telephone was the principal one. His idea 
 was to reproduce the tones both of musical instruments and 
 of the human voice by means of electricity, using a covered 
 wire wound in a spiral round an iron core, the same being 
 placed upon a resonant box. In this he succeeded, inasmuch as 
 with an apparatus, which he showed to the Physikalischer 
 Verein in Frankfurt-a.-M., in the year 1861, he repro- 
 duced music, singing, single words and short sentences ; all 
 of which were distinctly audible over a short distance from 
 
126 PEILIPP REIS, 
 
 his dwelling-house through the yard to the barn. Every 
 voice was not equally well adapted for speaking into the 
 apparatus, neither could every ear understand the telephone 
 language equally well. Words spoken slowly, and singing, 
 both in a middle tone, were the most easy to reproduce. I 
 helped Mr. Eeis to make many of his experiments, and have 
 spoken and sung into the telephone, the same being generally 
 heard and understood. I have also heard and understood 
 short sentences when I was standing at the end station. A 
 brother-in-law of Mr. Eeis, who is now paymaster in the 
 Imperial Navy at Wilhelmshavn, generally conducted the 
 speaking and singing in the telephone. 
 
 " HEINRICH HOLD." 
 
 HEINRICH FRIEDRICH PETER. 
 
 [Herr Peter is still Music-teacher in the Gamier Institute, and has a 
 vivid recollection of his former colleague Philipp Reis, and of the experi- 
 ments with the telephone.] 
 
 5< DEAR SIR, 
 
 "The following particulars concerning Reis's" Tele- 
 phone I have several times narrated. I was teacher of 
 music in Garnier's Institute at the time when Mr. Eeis 
 invented the telephone, in the year 1861. I was much 
 interested in his experiments, and visited him daily, giving 
 him help and making suggestions. His first idea was to 
 imitate the construction of the human ear. He constructed 
 a funnel-shaped instrument, the back of which was covered 
 with a skin of isinglass, upon which was fastened a piece of 
 platinum, against which rested a platinum point. As receiver 
 of the electric current he used a common knitting-needle, 
 surrounded by a coil of insulated green wire, which was at 
 first merely laid on a table. At first the tones were very 
 much interfered with by a buzzing noise. At my suggestion 
 
INVENTOR OF THE TELEPHONE. 127 
 
 he placed the spiral upon my violin as a resonant-box; 
 whereupon the tones were perfectly understood, though 
 still accompanied by the buzzing noise. He continued 
 experimenting, trying various kinds of membranes, and 
 made continual improvements in the apparatus. I was 
 present and assisted at the experiments at Frankfort-on- 
 the-Main, on the 26th of October, 1861 ; and after the 
 meeting broke-up, I saw the members of the Society 
 as they came and congratulated Mr. Keis on the success 
 of his experiments. I played upon the English horn, and 
 Philipp Schmidt sang. The singing was heard much 
 better than the playing. At an experiment which we made 
 at Friedrichsdorf, in the presence of Hofrath Dr. Muller, 
 Apothecary Muller, and Professor Dr. Schenk, formerly 
 Director of Garnier's Institute, an incident occurred which 
 will interest you. Singing was at first tried ; and afterwards 
 his brother-in-law, Philipp Schmidt, read long sentences from 
 Spiess's ' Turnbuch ' (Book of Gymnastics), which sentences 
 Philipp Eeis, who was listening, understood perfectly, and 
 repeated to us. I said to him, ' Philipp, you know that whole 
 book by heart ;' and I was unwilling to believe that his ex- 
 periment could be so successful unless he would repeat for 
 me the sentences which I would give him. So I then went 
 up into the room where stood the telephone, and purposely 
 uttered some nonsensical sentences, for instance : ' Die Sonne 
 ist von Kupfer ' (The sun is made of copper ), which Eeis 
 understood as, ' Die Sonne ist von Zucker ' (The sun is made of 
 sugar) ; ' Das Pferd frisst keinen Gurkensalat ' (The horse eats 
 no cucumber-salad) ; which Eeis understood as ' Das Pferd 
 frisst . . . .* (The horse eats . . . ). This was the last of 
 these experiments which we tried. Those who were present 
 were very greatly astonished, and were convinced that Eeis's 
 invention had opened out a great future. 
 
 " H. F. PETER, Musiklehrer." 
 
128 PHILIPP REIS, 
 
 STEPHEN MITCHELL YEATES, ESQ. 
 
 [Mr. Yeates is a well-known instrument-maker in the city of Dublin, 
 and, in 1865, purchased from Mr. W. Ladd, of London, a Keis's Telephone 
 of the form shown in Keis's Prospectus (Fig. 29). Mr. Yeates, after a few 
 experiments, rejected the knitting-kneedle receiver, and replaced it by the 
 instrument shown in Fig. 42, which consisted of an electromagnet mounted 
 
 Fig. 42. 
 
 above a sound-box, having a vibrating armature furnished with an ad- 
 justing screw to regulate its distance from the poles of the electromagnet. 
 This instrument worked, even when the armature was in absolute contact 
 with both poles of the electromagnet, and as the magnet did not during 
 the experiments lose its hold on the armature, it was clear that the effects 
 were due to alterations in the intensity of the magnetism of the magnet. 
 The apparatus was shewn at the November meeting of the Dublin Philo- 
 sophical Society, when singing and words were transmitted. With a 
 careful adjustment- it was possible to distinguish all the quality of the 
 note sung into the transmitter and to distinguish the difference between 
 any two voices. The instruments were then sold to the late Eev. Mr. 
 Kernan, who was then Professor of Physics in Clongowes Wood College. 
 The following recent letter from Mr. Yeates corroborates the above facts.] 
 
 " 2, Grafton Street, Dublin, 
 "March 1st, 1883. 
 
 "DEAK SIR, 
 
 " There are several residing at present in Dublin who were 
 present at my telephonic experiments in 1865 ; three of them, 
 namely, Dr. W. Frazer, Mr. A. M. Vereker, and Mr. E. C. 
 Tuke, took an active part in the experiments, and remember all 
 the circumstances connected with them. The voice of each 
 was instantly recognised in the receiver ; in fact, this point 
 attracted special attention at the time. 
 
INVENTOR OF THE TELEPHONE. 129 
 
 " I had no knowledge at that time that Eeis had used an 
 electromagnetic receiver, nor did I know that Eeis was the 
 inventor of the instrument which I got from Mr. Ladd. 
 
 " The original instrument made by me is, I believe, still 
 in the Museum at Clongowes Wood College. The President 
 kindly lent it to me some time ago, and I returned it to him 
 again after showing it to Professor Barrett. I have a cut 
 of this receiver, which I will send to you if it will be of any 
 use to you. 
 
 " Yours truly, 
 
 "S. M. YEATES." 
 
 WILLIAM FRAZER, ESQ., M.D., 
 
 "20, Harcourt Street, Dublin, 
 
 "March IB, 1883. 
 " DEAR SIR, 
 
 " I have a distinct recollection of the Telephone. We had 
 a small private club meeting once each month for scientific 
 purposes. On referring to my note-books, I find that there 
 was a meeting on Thursday evening, October 5th, 1865. It 
 was held in Nassau Street, at the residence Mr. Horatio 
 Yeates, now in Australia, and brother of Mr. Stephen Yeates. 
 The Telephone was upstairs, in the third story of the house, 
 and the voice heard in the hall. Mr. Vereker, of the Bank 
 of Ireland, Mr. John Eigby, of rifle celebrity, the two Mr. 
 Yeates, and, I think, Mr. Tuke, were present with myself. 
 There were some othets, whom I cannot now recollect, but 
 our club was small. 
 
 " Eigby sang ' Patrick's Day ' and ' God save the Queen,' 
 and various questions were asked and answered. The sepa- 
 rate words were most distinct, the singing less so ; but there 
 was no difficulty in recognising the individual who spoke by 
 his voice 1 . 
 
 " Being much interested in the subject, I got Mr. Yeates to 
 
 K 
 
130 PHILIPP REIS, 
 
 allow the apparatus to be shewn at a Conversazione (Presby- 
 terian Young Men's) at the Eotunda on October 12, at 8 P.M. 
 His assistant, Mr. Tuke, took charge of it that night. It 
 was placed in a side room off the main round room of the 
 buildings. 
 
 " I exhibited at the October 5th meeting of our club a 
 specimen termed ' Locust gum/ probably derived from some 
 Rdbinia, but really can tell you nothing more about it. There 
 is merely a brief note of it in my private memoranda. 
 
 " Yours, dear Sir, 
 
 Believe me very truly, 
 
 " WILLIAM FRAZER, 
 
 " Fellow and Examiner, Eoyal College of Surgeons, 
 " Ireland, Member of Council, Eoyal Irish 
 " Academy, &c." 
 
 " Silvanus P. Thompson, Esq., University College, Bristol." 
 
INVENTOR OF THE TELEPHONE: 131 
 
 APPENDIX I. 
 
 COMPARISON OF REIS'S TRANSMITTERS WITH RECENT 
 INSTRUMENTS. 
 
 ANY one who compares together the many different forms 
 of Reis's Transmitters cannot fail to notice that amidst the 
 great variety of form, two essential points are preserved 
 throughout, the presence of which is fundamental. These 
 two essentials are, firstly, the tympanum to collect the voice- 
 waves, and, secondly, an electric mechanism, consisting of two 
 or more parts in loose or imperfect contact with each other, 
 and so arranged in combination with the tympanum that the 
 motions of the latter should alter the degree of contact, and 
 consequently interrupt, to a greater or less degree, the 
 current of electricity flowing between the contact-pieces. It 
 was of course familiar to all electricians, long before Reis, 
 that a bad, or imperfect, or loose contact in a circuit offered a 
 resistance and interrupted the flow of an electric current. 
 In all ordinary telegraphic and electric apparatus great care 
 was taken to avoid loose and imperfect contacts by using 
 clamping-screws and solid connectors. But Reis, having 
 made up his mind (see p. 77) that the action due to the 
 magnetising current must vary in a manner correspond- 
 ing with, and therefore proportional to, the vibrations of 
 the voice, utilised this property of imperfect contacts which 
 alter their resistance according to the degree of contact, by 
 arranging his mechanism so as to apply the voice to vary 
 the degree of contact. This was the essence of his trans- 
 mitters. In other words, he applied the voice to control or 
 
 K 2 
 
132 . PEILIPP REIS, 
 
 moderate the strength of the current generated by a battery. 
 His " interrupters " may therefore with propriety be called 
 " electric current contact regulators ;" and put into technical 
 language, the essence of this part of his invention lay in the 
 combination with a tympanum of electric current regulators 
 working upon the principle of variable contact. 
 
 In another appendix is discussed the precise nature of that 
 which occurs at a point of variable or imperfect contact, and 
 which results in a corresponding change of electrical resist- 
 ance when the degree of contact is varied. Suffice it to say 
 here that it is impossible to vary the degree of contact be- 
 tween two bodies which are lightly pressing one against the 
 other, and through which an electric current is flowing, 
 without altering the resistance offered to the current by this 
 joint in the circuit. If the two surfaces are pressed together, 
 so that there is a good contact, the current flows more freely, 
 finding less resistance. If, on the other hand, by altering 
 the pressure or the amount of surface exposed, we change the 
 degree of contact and cause fewer atoms of one piece to touch 
 those of the other piece, the current meets with greater ob- 
 struction and cannot flow with such strength as before : it is 
 partially " interrupted," to use the expressive term employed 
 by Eeis. 
 
 Now this operation of varying the degree of pressure in 
 order to vary the resistance of the interrupter or contact regu- 
 lator, was distinctly contemplated by Reis. We find his 
 definite instructions, for example (see p. 75), for arranging 
 the relative lengths of the two parts of the curved lever in 
 one of his transmitters, so that the movement of one contact- 
 piece may act on the other contact-piece with the greatest 
 possible force ; in other words, he shortened his lever at the 
 working end, sacrificing its range of motion in order to get a 
 greater range of pressure at the contact-point. 
 
 It has often been said, but incorrectly, that Reis intended 
 his " interrupters " or contact regulators to make and break 
 the electric circuit abruptly in the manner of a telegraphic 
 key worked by hand. No doubt in the mouth of a profes- 
 sional telegraph operator the words "interrupting " the circuit, 
 
INVENTOR OF THE TELEPHONE. 133 
 
 and " opening " and " closing " the circuit, do now-a-days 
 receive this narrow technical meaning. But Eeis was not 
 a professional telegraph operator : he did not (see p. 87) 
 even know the signals of the Morse code, and it is self- 
 evident that he did not use the terms in any such restricted 
 or unnatural sense as abrupt " make-and-break," because he 
 proposed at the outset to interrupt the current in a manner 
 represented by the gradual rise and fall of a curve, stating 
 emphatically in his very first memoir on telephony (p. 55), 
 that to reproduce any tone or combination of tones all that 
 was necessary was " to set up vibrations whose curves are 
 like those " of the given tone or combination of tones. 
 Moreover, in the construction of almost all his transmitters, 
 even in the very first the model of the human ear he pur- 
 posely introduced certain parts which could have no other 
 effect than to prevent the occurrence of complete breaks in the 
 continuity of the current. In fact, instead of using rigid 
 supports for his interrupter, he mounted one or both of the 
 contact-parts with springs, so that one should follow the move- 
 ment of the other with a gentle pressure never amounting to 
 absolute break, except perhaps in the accidental case of a too 
 loud shout. By employing these following-springs, he intro- 
 duced, in fact the element of elasticity into his interrupter ; 
 and clearly he introduced it for the very purpose of avoiding 
 abrupt breaking of the contact. In the first form Fig. 5, p. 16 
 (the " ear "), there was one spring ; in the fourth form, Figs. 9 
 and 10, p. 21 (the "bored block"), there were two springs, 
 one of steel, curved, and one, a straight but springy strip, of 
 copper ; in the eighth form (the " lever " form), Fig. 14, p. 25, 
 there were two springs ; in the ninth form, Fig. 15, p. 26, 
 there was a springy strip of brass. In the final form, Figs. 
 17 and 18, p. 27 (the " square-box " pattern), there was, it 
 is true, a springy strip of copper, but the light adjustment of 
 contact was in this form obtained, not by a spring, but by 
 the inertia of the upper contact-piece which by its own 
 weight pressed gently upon the lower contact-piece. In 
 every one of these forms, except the last, there was moreover 
 an adjusting-screw to determine the exact degree of initial 
 
134 PEILIPP EEIS, 
 
 pressure between the contact surfaces. Doubtless the diffi- 
 culty of adjusting this screw to give the exact degree of con- 
 tact, enhanced as that difficulty was in consequence of the 
 liability of the membraneous tympanum to become flaccid 
 by the moisture of ohe breath, induced Eeis to think that 
 the later form of the apparatus in which this adjustment 
 was no longer retained would be more easy to use, or, as 
 he says in his Prospectus, more accessible to others. Yet 
 undoubtedly the absence of the spring at the contacts led 
 some persona to fancy that the instrument was intended to 
 be shouted or sung to so loudly that every vibration should 
 make the upper contact-piece jump up from the lower, 
 and as Professor Miiller even suggests (p. 98), produce a 
 spark ! But such a manner of using the instrument would 
 entirely defeat Eeis's most fundamental principle, that the 
 interruptions should be such as to correspond to the undu- 
 lating curve which represents the pressure due to vibration 
 of the sound-wave; the possibility of representing the de- 
 gree of pressure by a curve being one of the two principles 
 set forth in his paper " on Telephony " (p. 55), in which he 
 remarks, that " Taking my stand on the preceding principles, 
 I have succeeded in constructing an apparatus by means of 
 which I am in a position to reproduce .... even to a cer- 
 tain degree the human voice." Eeis was perfectly well aware, 
 as his curves show, that a complicated sound-wave does not 
 consist invariably of one condensation followed by one rare- 
 faction, but that there are all sorts of degrees of condensation 
 which may follow one another, and all capable of being 
 represented by a curve. If all sounds consisted of one rare- 
 faction following immediately after each one condensation 
 there might be some propriety in proposing that after each 
 " make " of contact there should be a " break " in the sense 
 of an abrupt or complete breach in the continuity of the 
 current. But, obviously, the fact that one condensation may 
 follow another without a rarefaction between (which Eeis's 
 curves show that he knew) must be amply sufficient to prove 
 that on Eeis's own principle his interrupter was meant to 
 produce variations in the degree of contact in exact corre- 
 
INVENTOR OF THE TELEPHONE. 135 
 
 spondence with the variations in the degree of pressure, whatever 
 these might be. Had he not meant this, he could not have 
 talked about " taking his stand " on the principle of repre- 
 senting varying pressures by an undulatory curve. Now, 
 from what has been adduced, the following points are clear : 
 
 Firstly, that the contact-regulator which Eeis combined 
 with the tympanum was meant to interrupt the current, more 
 or less, according to the varying movements imparted to it by 
 the voice. 
 
 Secondly, that Eeis intended such interruptions or varia- 
 tions of contact to be proportional to, or to " correspond " 
 with, the variations indicated by the undulatory curve of 
 varying pressures. 
 
 Thirdly, that for the purpose of preventing the occurrence 
 of abrupt breaks in the continuity of the circuit, he used 
 springs and adjusting screws, and in one form availed himself 
 of the inertia of the moving parts to attain a similar end. 
 
 It is also clear from his own prospectus, that he was aware 
 that for the simpler and ruder purpose of transmitting 
 musical airs, in which the number of the vibrations is the 
 only consideration and where each single condensation is 
 actually followed by a rarefaction, actual abrupt breaks in 
 the continuity of the circuit are admissible. Eeis chose this 
 simple case as the one capable of being readily grasped by a 
 general audience, though it was obviously only a partial ex- 
 planation of the action of the apparatus in the simplest case 
 that could be presented. 
 
 Turning now to some of the more modern transmitters, 
 we will inquire how far Eeis's fundamental principles are 
 involved in their construction. We will first take Berliner's 
 transmitter, of which Fig. 43 is a drawing, reproduced from 
 the sketch in the specification of his British Patent. This 
 transmitter consists of a tympanum of thin metal to collect 
 the sound-waves, and behind it is attached an interruptor or 
 current regulator, identical in almost every respect with that 
 of Eeis. One of the contact-pieces, marked E y circular in 
 form, is fixed to the centre of the tympanum, and vibrates 
 
136 
 
 PEILIPP KEIS, 
 
 Fig. 43. 
 
 with it, precisely as in Eeis's latest, and in some also of his 
 earlier instruments. Against this there rests in light contact 
 a second contact-piece, in the form of a small 
 blunt spike, F, screwed into a short arm, 
 loosely jointed to the part JV, where the 
 circuit is connected. As in Eeis's latest 
 transmitter (Fig. 17, p. 27), so here, the 
 contact-pieces are kept in contact by gravity. 
 When any person talks to the tympanum it 
 vibrates, and, as a result, the degree of con- 
 tact between the two surfaces is varied, 
 resulting in a greater or less interruption of 
 the current, the inertia of the upper contact- 
 piece, serving to prevent complete abrupt 
 <f break" of the circuit, except under un- 
 usually strong vibrations. In fact, if the 
 speaker talks too loudly when speaking into 
 Berliner's transmitter, he will cause abrupt 
 breaks to occur instead of partial interruptions ; and a rattling 
 noise comes in to confuse the speech at the receiving end of 
 the line. But this is precisely what occurs in a Eeis's trans- 
 mitter if one talks too loudly to it. It is obvious that if 
 Berliner's transmitter is a " make-and-break " instrument, so 
 is Eeis's, because the principle of action is identical : and 
 it is also obvious that if Berliner's instrument is capable of 
 varying the resistance at the contact-points by interrupting 
 the current in a manner corresponding to the pressures of 
 the air in the sound-waves, so also is Eeis's instrument. 
 
 It is a fact that in Berliner's instrument it is usual to 
 make the contact-pieces, or one of them, of hard artificial 
 coke-carbon, as this substance will neither fuse nor rust. But 
 Berliner's transmitter will transmit speech perfectly if the 
 contact parts be of brass, silver, platinum, carbon, or almost 
 any other good conductor. In most of Eeis's instruments 
 the contact-pieces were usually of platinum ; but they work 
 quite as well if artificial coke-carbon is substituted. In fact, 
 Eeis's principle of variable and elastic contact is applicable 
 to contact-pieces of any material that is a good enough con- 
 
INVENTOE OF THE TELEPHONE. 
 
 137 
 
 ductor of electricity and hard enough for the purpose. The 
 main improvement in Berliner's transmitter is the substi- 
 tution of the metal tympanum for the membraneous one, 
 which was liable to become flabby with moisture. 
 
 We pass on to Blake's transmitter, which is the one more 
 generally used in Great Britain than any other. The draw- 
 ing, Fig. 44, of this instrument is taken from the specifica- 
 tions of Blake's British Patent, and shews all that concerns 
 the contact-parts. It does not show 
 the accessories, the induction-coil, or 
 the form of adjusting screw and frame 
 peculiar to this instrument. Inspec- 
 tion of the figure shows that this trans- 
 mitter consists of a mouthpiece in the 
 form of a conical hole bored through a 
 stout plank of wood, and closed at the 
 back by a metal tympanum of exactly 
 the same size as that of Eeis, behind 
 which the interrupter is placed, pre- 
 cisely as in some of Eeis's instruments. 
 In this interruptor both the contact-parts 
 are supported on springs, resembling, 
 even in the curve given to them, the 
 springs Eeis used. The first of the con- 
 tact-pieces is a small metal spike. Con- 
 
 Fig. 44. 
 
 cerning it Mr. Blake remarks (page 4 of Specification) : " It is 
 desirable that it should be formed of, or plated with, some metal, 
 like platinum or nickel, which is not easily corroded. It may 
 be attached directly to the diaphragm, but I prefer to support 
 it independently, as shewn, upon a light spring." ..." This 
 method of supporting the electrode ensures its contact with the 
 other electrode under some circumstances when otherwise they 
 would be liable to be separated and the circuit broken." In fact 
 this spring serves functions precisely identical with those of 
 the springs used by Eeis. The second of the contact-pieces may 
 be described as a mass of metal at the end of a spring. Of it 
 the patentee remarks : " This weight may be of metal which 
 may serve directly as the electrode, but I have obtained better 
 
138 PHILIPP REIS, 
 
 results by applying to it, at the point of contact with the 
 other electrode, a piece of gas-coke or a hard-pressed block 
 of carbon." As a matter of fact, a mass of silver or of nickel or 
 of platinum will transmit talking perfectly, but these metals, 
 though better conductors, are more liable to corrode and fuse, 
 and may require therefore more frequent renewal, than gas- 
 coke. Since, then, it is immaterial to the action of a Blake 
 transmitter what substance is used for the contact-pieces, it 
 is clear that the principle of employing an interrupter 
 mounted on springs is the real feature of the instrument. 
 Eeis also mounted his interrupters with springs, and for the 
 very same purpose. The function of the weight on the second 
 spring of the Blake transmitter is to resist the movement of 
 the tympanum, and to " modify by its inertia the variations 
 of pressure" between the two contact-pieces. In other 
 words, it acts partly as Berliner's transmitter, by inertia. So 
 did one of Eeis's instruments, as we have seen. In the Blake 
 instrument there is the happy idea of applying both the spring- 
 principle and the inertia-principle at once. Yet, in spite of 
 this, if the speaker shouts too loudly into a Blake transmitter, 
 he will cause abrupt breaks between the contact-pieces in- 
 stead of producing partial interruptions in the contact, and 
 in that case speech will, as heard at the other end of the line, 
 be spoiled by a rattling noise. It is possible, also, with 
 Eeis's instruments to spoil the articulation by shouting too 
 loudly, and causing actual abrupt breaks in the continuity. 
 If Blake's interrupter can be worked as a make-and-break 
 in this sense, so can Eeis's : for there is not one of the 
 features which is essential to Blake's instrument that cannot 
 be found in Eeis's also. 
 
 By way of further carrying out the comparison between 
 Eeis's methods of combining his tympanum with his contact- 
 regulator, and the methods adopted by later inventors, we 
 give, in Fig. 45, ten comparative sketches, the first five of 
 which illustrate Eeis's methods. In these sketches the only 
 liberty taken is that of representing no more of the instru- 
 ments than the actual parts wanted in the comparison. No. 1 
 represents the working-parts of Eeis's first model ear, with 
 
INVENTOR OF THE TELEPHONE. 
 
 139 
 
 its curved lever, platinum-tipped spring, and adjusting screw. 
 No. 2 shows the springs, screw, and contact-pieces of Eeis's 
 bored-block transmitter (" fourth form : " compare Figs 9 and 
 10, p. 21). No. 3 shows the curved lever, the springs, and 
 
 Fig. 45. 
 
 the adjusting screw of Eeis's eighth transmitter (" lever " 
 form). No. 4 gives the working parts of Eeis's ninth trans- 
 mitter, described in detail on p. 27. No. 5, in which the 
 tympanum is placed in a vertical position, merely for con- 
 venience of comparison with the other figures, shows the 
 
140 PHILIPP KEIS, 
 
 working parts of Eeis's final form of instrument, in which 
 gravity and the inertia of the upper contact-piece enabled 
 him to dispense with the adjustment of spring and screw. 
 No. 6 shows in profile Berliner's transmitter, which may be 
 instructively compared with No. 5. No. 7 shows the working 
 part of Blake's transmitter, which should be compared with 
 Nos. 2 and 4 : even the curve of the springs imitates that 
 adopted by Keis. Nos. 8, 9, and 10 are forms of transmitter 
 devised by Edison. No. 8 is copied from Fig. 10 of the speci- 
 fication of Edison's British Patent. It will be seen that here 
 there is an interruptor placed on each side of the tympanum, 
 and that each interruptor consists of a short spike mounted 
 on a spring and furnished with an adjusting-screw. " Platina 
 foil disks," says the inventor, are to be secured to each 
 side of the diaphragm, and against these disks, as in Eeis's 
 instruments, press the contact-points of the interrupters. 
 The patentee also states (p. 7 of his Specification), that 
 for these contact-points " any substance not liable to rapid 
 decomposition " may be used. This term includes all the 
 substances used by Eeis, and a great many others. It will 
 therefore be seen that this whole device is nothing more than 
 a Eeis transmitter with the contact parts duplicated. Yet this 
 instrument was intended by Edison to transmit speech, and 
 will, like Eeis's instrument, transmit speech if properly used. 
 No. 9 of the set of sketches is taken from Fig. 25 of Edison's 
 British Specification, but omits the induction-coil and other 
 accessories, retaining the parts wanted for comparison. The 
 patentee thus describes the parts figured. "The tension- 
 regulator [meaning thereby the interruptor or contact-regu- 
 lator] is made of platina-foil upon the surface of two soft 
 rubber tubes ; one on the diaphragm, the other on the 
 adjusting-screw." It is interesting to note here how the 
 ingenuity of the later inventor led him to vary the construc- 
 tion adopted by the original inventor in substituting an 
 elastic cushion of soft rubber for the springs of the older 
 instruments. But the principle of combining a tympanum 
 with a contact-regulator, which was Eeis's fundamental 
 notion, is here also the leading idea ; and the further idea of 
 
INVENTOR OF THE TELEPHONE. 141 
 
 obviating abrupt breaks in the current by applying elastic 
 supports is also carried out. Edison even copies Eeis in 
 having an adjusting-screw, and he applies the very same 
 substance platinum foil which Keis used in his very first 
 and his very last transmitter. Edison's transmitter transmits 
 speech very fairly, even without any of such later accessories 
 as induction-coils ; and why should it not ? It is constructed 
 on the very lines, nay, with details almost identical with 
 those prescribed by Keis in describing his invention. It 
 embodies those fundamental ideas which Eeis set before 
 him when he said, "Taking my stand upon the preceding 
 principles, I have succeeded." 
 
 The last of the ten sketches of Fig. 45 is taken from 
 Edison's first American Patent specification [No. 203,014, 
 filed July 20, 1877], and shows a duplicated interrupter 
 with springs and adjusting-screws combined with a tym- 
 panum. Further comment on this arrangement is needless, 
 save to remark that in this patent for " speaking telegraphs," 
 Edison himself describes the contact-apparatus which Eeis 
 termed an " interrupter," as a " circuit-closer," or in another 
 place as " circuit-breaking connections," and, in his British 
 Patent quoted above, as a " tension-regulator." It is 
 evident that if Eeis could transmit speech by an interrupter 
 which closed and opened the circuit (always in proportion 
 to the vibrations) there is 110 reason why Edison seventeen 
 years afterwards should not accomplish the same result by a 
 similar means. But it has lately been fashionable to deny 
 that any such device as an interrupter mounted on springs 
 can transmit speech at all ! 
 
 We have now compared with Eeis's transmitters several 
 of the more modern inventions. It would be possible to carry 
 comparison further were that course needed. We have not 
 thought it worth while to rake up Edison's now discarded 
 lamp-black button transmitter ; and we have not yet spoken 
 of Crossley's transmitter nor of Theiler's transmitter, nor of 
 their parent the Hughes' microphone, nor of dozens of other 
 forms. In some of these there is no specific " tympanum," 
 but only a sounding-board of pine-wood, and in most of them 
 
142 PHILIPP REIS, 
 
 the points of loose-contact, where interruption more or less 
 complete may occur, are multiplied. But they all come back 
 in the end to Eeis's fundamental idea, namely that of setting 
 the voice to vary the degree of contact in a mechanism 
 which he called an interruptor, and which others have called 
 a current-regulator (or, less correctly, a tension-regulator) 
 which, because the degree of contact between its parts was 
 varied, caused those parts to offer more or less resistance to 
 the flow of the current, and thereby threw it into vibrations 
 corresponding to those of the sound-wave impressed upon 
 the tympanum. There is not a practical transmitter used in 
 any of the telephone exchanges of Great Britain to-day that 
 does not embody this principle. 
 
 Keis did, indeed, penetrate to the very heart the principles 
 necessary to be observed in a successful telephone. He was 
 master of the situation. For, as in every practical trans- 
 mitter in use to-day, so in his transmitter, there was a loose 
 contact in the circuit so arranged that the voice could act upon 
 it, and thereby regulate the strength of the current. If you 
 eliminate this part of the apparatus, screw up the loose- 
 contacts of your transmitters, so that your voices cannot 
 affect them, what will your telephones be worth ? No : 
 the essential principle of the transmitter " Das Telephon " 
 emphatically as its inventor styled it is variable contact; 
 and that all-essential principle was invented and applied for 
 the purpose of transmitting speech by Philipp Eeis in 1861. 
 
 If this does not suffice as a claim for the invention of the 
 Telephone transmitter, it may well be wondered what will. 
 We can dispense with all other features save this one. We 
 can even dispense with the tympanum or diaphragm which 
 Eeis introduced, and can operate on the contact-parts without 
 the intervention of this part of the combination. We can use 
 the very metals which Eeis used, and dispense with lamp- 
 black and all the fallacious rubbish that has been subsequently 
 devised about semi-conductors, whatever that term may mean. 
 We can even dispense with springs and adjusting screws. 
 But with the principle of variable contact we can not dispense. 
 That which alone is indispensable Philipp Eeis discovered, 
 
INVENTOR OF TEE TELEPHONE. 143 
 
 APPENDIX II. 
 
 ON THE VARIATION OF ELECTRIC EESISTANCE AT A POINT OF 
 IMPERFECT CONTACT IN A CIRCUIT. 
 
 EVER since electricians had experimented with voltaic 
 currents, and especially since the introduction of 'the electric 
 telegraph, it had been a familiar fact that a loose or imper- 
 fect contact in the circuit caused a resistance to the flow of 
 the current and interrupted it more or less completely. To 
 obviate the occurrence of loose or imperfect contacts, binding- 
 screws were invented ; and many were the precautions taken 
 to make tight contacts at joints in the line, the resistance of 
 which it was desirable to maintain at a minimum. Young 
 telegraphists were particularly instructed to press their keys 
 well down in signalling, because a light contact would offer 
 gome resistance which, on an increase of pressure, would dis- 
 appear. In fact, it was generally well known that the resist- 
 ance of two pieces of metal or other conducting material in 
 contact with one another might be made to vary by varying 
 the goodness or badness of the contact with the application of 
 more or less force. This fact was known to apply to good 
 conductors, such as copper and other metals, and it was known 
 to apply also to non-metallic conductors, such as plumbago. 
 Plumbago points were used by Yarley for the contacts of 
 relays ; it having been found that points of platinum were 
 liable to become fused together with the passage of the 
 current, and by so sticking rendered the instrument useless. 
 Since plumbago was known to be infusible, it was hoped that 
 a plumbago contact would prove more reliable. In practice, 
 
144 PHILIPP REIS, 
 
 however, the plumbago relay did not turn out so well. True 
 it did not fuse, or stick, or rust ; but it was even more liable 
 than platinum to form imperfect contacts, the resistance of 
 the light contact being so high that a sufficient current did 
 not pass. It is not known whether other non-metallic sub- 
 stances were tried ; probably not, because of non-metallic 
 substances plumbago is one of the few that are good con- 
 ductors. 
 
 According to Edison (British Patent, No. 792, 1882), 
 compressed graphite is a substance of great conductivity. 
 According to Faraday (' Exp. Kes.' vol. i. p. 24), retort-carbon 
 is an excellent conductor. Both graphite and retort-carbon 
 agree with the metals in the property that the electric resist- 
 ance offered at a point of contact between them varies when 
 the pressure at the contact is varied. It is indeed remarkable 
 through what wide ranges of resistance the contact between 
 two good conductors may vary. The resistance of contact 
 between two pieces of copper may be made to vary in a per- 
 fectly continuous manner by changes of pressure through a 
 range, according to Sir W. Thomson, from a small fraction of 
 one ohm, up to a resistance of many thousand ohms. The 
 same is true of silver, brass, and many other good conductors, 
 including graphite and retort-coke, though with the .latter 
 materials the range of resistances is not so great. "With par- 
 tial conductors, such as oxide of manganese, sulphide of 
 copper, sulphide of molybdenum, &c., and with bad con- 
 ductors, such as lamp-black and selenium, whose conduc- 
 tivity is millions of times less than that of graphite, copper, 
 and other good conductors, it is impossible to get equally 
 wide variations of resistance, as the amount of pressure at a 
 point which will bring the bad conductors into intimacy of 
 contact, will not turn them into good conductors. Platinum 
 being in the category of good conductors, is amongst those 
 substances which yield a very wide range of electrical resist- 
 ances at the contact-points which are submitted to varying 
 pressures, 
 
 With the very highest conductors, such as silver and 
 copper, the electrical range of contact-resistance is higher 
 
INVENTOR OF THE TELEPHONE. 145 
 
 than with those of lesser conductivity, such as lead, platinum, 
 graphite, and retort-coke. 
 
 But though the range of variation in electrical resistance at 
 contacts is highest for the best conductors, there comes in 
 another element, namely, the range of distance through which 
 the contact-pieces, or either of them, must be moved in order 
 to pass through the range of variations of resistance. This is 
 quite a different matter, for here the best conductors have 
 the smallest range, and some that are not so good a greater 
 range. In any case the available range of motion is 
 very small to be measured in minute fractions, millionth- 
 parts, perhaps, of an inch. So far as experiments go, how- 
 ever, silver has the smallest range of all, then gold, then 
 copper. Platinum and nickel have a considerably wider 
 range, plumbago and retort-coke a still wider one. 
 
 It is an extremely difficult matter to decide what is the 
 precise nature of that which goes on at a point of contact 
 between two conductors when the pressure at the point is 
 altered. The principal suggestions hitherto advanced have 
 been that the change of resistance observed is due : 
 
 (a) To the mere changes in the amount of surface in contact, 
 (ft) To a change in the resistance of the substance of the 
 conductor itself. 
 
 (c) To the formation of a minute voltaic " arc," or electric 
 
 discharge. 
 
 (d) To the change in the thickness of the intervening film 
 
 of air. 
 
 (e) To the change in resistance of the parts in contact con- 
 
 sequent on the evolution of heat by the current. 
 
 It is admitted that this last suggestion, though it might 
 account for a difference between different substances, in so 
 far as they differ from one another in the effect of heat upon 
 their specific resistance, implies as a preliminary fact that 
 the amount of surface in contact shall be varied by the pres- 
 sure. No convincing proof has yet been given that the 
 alleged layer of air or other gases has any real part to play 
 in the phenomena under discussion. Nor can the hypothesis, 
 
146 PHILIPP KEIS, 
 
 that minute voltaic arcs are formed at the contact be regarded 
 as either proven or probable. 
 
 The only two theories that have really been investigated 
 are (a) and (b) of the above series. Of these two (&) is cer- 
 tainly false, and (a) is probably, at least to a very large 
 extent, true. 
 
 It is often said by persons imperfectly acquainted with the 
 scientific facts of the case, that carbon is used in tele- 
 phone-transmitters, because the resistance of that substance 
 varies with the pressure brought to bear upon it, whilst with 
 metals no such effect is observed. This statement, taken 
 broadly, is simply false. Mr. Edison has, indeed, laid claim 
 to the " discovery " (vide Prescott's ' Speaking Telephone,' 
 p. 223), that " semi-conductors," including powdered carbon 
 and plumbago, vary their resistance with pressure. All that 
 Mr. Edison did discover was that* certain substances, whose 
 properties of being conductors of electricity had been known 
 for years, conducted better when the contact between them 
 was screwed up tightly than when loose. The experiments 
 made to test this alleged " property " of carbon are absolutely 
 conclusive. The author of this book has shown * that when 
 a rod of dense artificial coke-carbon, such as is used in many 
 forms of telephone transmitters, such as Crossley's for 
 example, is subjected to pressure varying from less than one 
 dyne per square centimetre up to twenty-three million times 
 that amount, the resistance of the rod did not decrease by so 
 much as one per cent, of the whole. In this case any doubt 
 that might have been introduced by variable contact was 
 eliminated at the outset by taking the precaution of electro- 
 plating the contacts. 
 
 In 1879, Professors Naccari and Pagliani, of the University 
 of Turin, published an elaborate series of researches f on the 
 conductivity of graphite and of several varieties of coke-carbon, 
 and found, even with great changes of pressure, that the 
 changes of electric resistance were practically too small to be 
 
 * Philosophical Magazine,' April 1882. 
 
 f ' Atti del R. Istituto Veneto di Scienze,' vol. vi. ser. 5. 
 
INVENTOE OF THE TELEPHONE. 147 
 
 capable of being measured, and that the only changes in 
 resistance appreciable were due to changes of contact. 
 
 In January 1882, Mr. Herbert Tomlinson communicated to 
 the Eoyal Society * the results of experiments on a number 
 of electric conductors. The change of conductivity by the 
 application of stress was found to be excessively small. For 
 carbon it was less than one-thousandth part of one per cent, 
 for an increase of fifteen Ibs. on the square inch in the pressure. 
 For iron it was slightly greater, and for lead nearly twice as 
 great, but with all other metals less. If this alleged pro- 
 perty were the one on which the action of telephone trans- 
 mitters depended, then lead ought to be twice as good a 
 substance as graphite ; whereas it is not nearly so good. 
 
 Professor -W. F. Barrett, in 1879,f made some experiments 
 on the buttons of compressed lamp-black used in Edison's 
 transmitter, and found that when an intimate contact was 
 satisfactorily secured at the beginning, " pressure makes no 
 change in the resistance." 
 
 In the face of all this precise evidence, it is impossible to 
 maintain the theory that the electric resistance of plumbago 
 or of any other such conductor varies under pressure. The 
 only person who has seriously spoken in favour of the theory 
 is Professor T. C. Mendenhall, but in his experiments he took 
 no precautions against variability of contacts, so that his 
 conclusions are invalid. 
 
 More recently still, Mr. 0. Heaviside and Mr. Shelf ord 
 Bidwell have experimented on the variations of resistance at 
 points of contact.:]: Mr. Heaviside's experiments were con- 
 fined to contacts between pieces of carbon, and though ex- 
 tremely interesting as showing that the resistance of such 
 contacts are not the same, even under constant pressure, when 
 currents of different strength are flowing, do not throw much 
 light on the general question, because they leave out the 
 parallel case of the metals. Mr. Bidwell's very careful 
 researches were chiefly confined to carbon and bismuth. The 
 
 * Proc. Koy. Soc. No. 218, 1882. 
 
 f See Proc. Roy. Dubl. Soc. Feb. 17, 1879. 
 
 t Vide ' The Electrician,' Feb. 10, 1883. 
 
 L 2 
 
148 PHILIPP REIS, 
 
 choice is unfortunate, because bismuth the most fusible and 
 worst conductor amongst metals (save only quicksilver) is 
 the one metal least suited for use in a telephone transmitter. 
 Mr. Bidwell's conclusions, so far as they are comparative 
 between carbon and " the metals," are therefore necessarily 
 incomplete. 
 
 Professor D. E. Hughes, whose beautiful invention, the 
 Microphone, attracted so much attention in 1878, has lately 
 thrown the weight of his opinion in favour of the view that 
 with carbon contacts the effect is due chiefly to an electric 
 discharge or arc between the loosely-contiguous parts. But 
 Professor Hughes' s innumerable experiments entirely upset 
 the false doctrine that a "semi-conductor" is necessarily 
 required for the contact-parts. Speaking recently,* he has 
 said : " I tried everything, and everything that was a con- 
 ductor of electricity spoke." In 1878, in a paper " On the 
 Physical Action of the Microphone," Professor Hughes 
 stated : f " the best results as regards the human voice were 
 obtained from two surfaces of solid gold." Hughes also 
 found carbon impregnated with quicksilver in its pores to 
 increase its conducting power to work better than non- 
 metallised carbon of inferior conductivity. Quite lately 
 Mr. J. Munro has constructed successful transmitters of 
 metal gauze, having many points of loose-contact between 
 them. 
 
 It seems, therefore, much the most probable in the present 
 state of investigations, that the electric resistance of a contact 
 for telephonic purposes is determined solely by the number 
 of molecules in contact at the surface, and by the specific 
 conductivity of those molecules. The element of fusibility 
 comes in to spoil the constancy of the surfaces in action ; 
 and hence the inadmissibility of general conclusions with 
 respect to all metals drawn from the behaviour of the most 
 fusible of them. At a mere point in contact physically with 
 another point, there may be hundreds or even millions of 
 
 * Journal Soc. Telegr. Engin. and Electricians, vol. xii. p. 137. 
 t Proc. Physical Soc. vol. ii. p. 259, 1878. 
 
INVENTOR OF TEE TELEPHONE. 149 
 
 molecules in contact with one another, all acting as so many 
 paths for the flow of the electric current. An extremely 
 small motion of approach or recession may suffice to alter 
 very greatly the number of molecules in contact, and the 
 higher the specific conductivity of the substance, and the 
 denser its molecules, the shorter need be the actual range of 
 motion to bring about a given variation in the resistance 
 offered. Just as in a system of electric lamps in parallel arc, 
 the resistance of the system of lamps increases when the 
 number of lamps through which the current is flowing is 
 diminished, and diminishes when the number of lamps con- 
 necting the parallel mains is increased; so it is with the 
 molecules at the two surfaces of contact. Diminishing the 
 number of molecules in contact increases the resistance, 
 and vice versa. Each molecule as it makes contact with a 
 molecule of the opposite surface diminishes, by so much rela- 
 tively to the number of molecules previously in contact, the 
 resistance between the surfaces. Each molecule as it breaks 
 from contact with its opposite neighbour adds to the resistance 
 between the contact-surfaces. It may therefore be that the 
 variations of resistance which are observed at contacts between 
 all conductors, from the best to the worst, are all made up, 
 though they appear to pass through gradual and continuous 
 changes, of innumerable minute makes-and-breaks of mo- 
 lecular contact. The very minuteness of each molecular 
 make-or-break, and the immense number that actually must 
 occur at every physical " point " of contact, explain why the 
 effect seems to us continuous. We owe, moreover, to Mr. 
 Edison * the experimental proof that actual abrupt makes- 
 and-breaks of contact can produce an undulating current 
 when they recur very rapidly. Whether the heating action of 
 the current itself may not also operate in changing the con- 
 ductivity of the molecules which happen at the moment to be 
 in contact is another matter. It may be so; but if this 
 should hereafter be demonstrated, it will but confirm the 
 contact-theory of these actions as a whole. 
 
 * ' Journal Soc. Telegraphic Engineers,' vol. iv. p. 117, 1874. 
 
150 PHILIPP REIS, 
 
 Assuming, then, broadly, that the observed resistance at a 
 point of contact is due to the number of molecules in contact 
 and to their individual resistances, it is evident that the 
 property of varying resistance at contact ought to be most 
 evident, ceteris paribus, in those substances which are the best 
 conductors of electricity. Unfortunately, the cetera are not 
 paria, for the question of fusibility comes in to spoil the 
 comparison ; and carbon, which has less fusibility than the 
 metals, is commonly credited with giving a better result than 
 any. This common opinion is, however, based on comparisons 
 made without taking into consideration the question of range 
 of motion between the parts in contact, and without taking 
 into consideration the point that whilst some forms of carbon 
 are excellent conductors, others do not conduct at all. In 
 a telephonic transmitter so arranged that the actual range 
 of motion shall be very small, the metals are just as good 
 as carbon some of them better. I have heard from a trans- 
 mitter with contacts of pure bright silver better articulation 
 than with any carbon transmitter. And this is exactly what 
 theory would lead one to expect. As to the suggestion that 
 plumbago makes a successful transmitter, because it is a 
 " semi-conductor " whatever that term may mean * it is 
 one of those suggestions which are peculiarly fitted to catch 
 the unscientific mind as affording an easy explanation for an 
 obscure fact ; unfortunately, like a good many other similarly 
 catching suggestions, it is not true. The very best conductor 
 silver will serve to transmit articulate speech: and so 
 will the one of the very worst conductors lamp-black ! So 
 much for this fallacious doctrine of semi-conductors ! 
 
 * The term " semi-conductor " is very rarely used by electricians, who 
 prefer the term " partial conductor " as being more correct. Moreover, 
 electricians, from Faraday downwards, are practically agreed in calling 
 plumbago a good conductor, and worthy of being classified by reason of its 
 high conductivity along with the metals. The substances known as 
 " semi-conductors " are those given in Ferguson's * Electricity,' p. 49 
 (edition of 1873), namely, alcohol, ether, dry-wood, marble, paper, straw, 
 and ice. Mascart and other eminent authorities agree in this classification. 
 It would tax even Mr. Edison's unrivalled ingenuity to make of these 
 materials a transmitter that should alter its resistance by pressure ! 
 
INVENTOR OF THE TELEPHONE. 151 
 
 Eeis used for his contact-points substances which, by reason 
 of their non-liability to fuse or oxidize, were customary in 
 electrical apparatus, and chiefly platinum. In his earliest 
 transmitter (model ear), and in his last, platinum was used. 
 In his lever-form of transmitter, so minutely described by 
 von Legat, the material is not specified. The lever-shaped 
 contact-piece was to be a conductor, and as light as possible, 
 and since all metallic parts are particularly described as 
 metallic, whilst this is not so described, the obvious inference 
 is that this was non-metallic. The number of light, non- 
 metallic conductors is so few that the description practically 
 limits choice to some form of hard carbon. No other ma- 
 terials are named by Eeis, but Pisko says (p. 103) that brass, 
 steel, or iron might be used for contacts. Any one of these 
 materials is quite competent, when made up into properly- 
 adjusted contact-points, to vary the resistance of a circuit 
 by opening and closing it in proportion to the vibrations 
 imparted to the contact-points. That is what Eeis's trans- 
 mitter was intended to do, and did. That is what all the 
 modern transmitters Blake's, Berliner's, Crossley's, Gower- 
 Bell's, Theiler's, Johnson's, Running's do, even including 
 Edison's now obsolete lamp-black button transmitter. Mr. 
 Shelford Bidwell has very well summarized the action of the 
 current-regulator in the following words: "The varying 
 pressure produces alterations in the resistance at the points 
 of contact in exact correspondence with the phases of the 
 sound-waves, and the strength of a current passing through 
 the system is thus regulated in such a manner as to fit it for 
 reproducing the original sound in a telephone." 
 
 Eeis constructed an apparatus consisting of a tympanum 
 in combination with a current-contact-regulator, or " inter- 
 rupter," which worked on this principle of variable contact, 
 and he called it " The Telephone " (see pp. 57, 85). The very 
 same apparatus we now-a-days call a " Telephone-trans- 
 mitter," or simply a " transmitter." It is curious to note 
 that Eeis seems to have regarded his receiver or " reproducing- 
 apparatus" as no new thing. He says explicitly (p. 56) 
 that his receiver might be replaced by " any apparatus that 
 
152 PHILIPP REIS, 
 
 produces the well-known galvanic tones." " The Telephone " 
 was with Eeis emphatically the transmitter. Bell in 1876 
 invented an instrument which would act either as transmitter 
 or receiver, and which, though never now used as trans- 
 mitter, is still called " a Telephone." Edison's " sound-tele- 
 graph," or "telegraphic apparatus operated by sound," was 
 patented in 1877. In his specification lie never called his 
 transmitter a " telephone ; " that name he reserved exclusivelv 
 for his receiver. He found it, however, convenient a year 
 later to rechristen his transmitter as the " carbon telephone" 
 though throughout the whole of his specification neither 
 "carbon 1 ' nor "telephone " are mentioned in connection with the 
 transmitter ! Within that year Hughes had brought out 
 another instrument " The Microphone " which, like Eeis's 
 instrument, embodied the principle of variable contact. 
 Hughes's instrument, usually constructed with contacts made 
 of loose bits of coke-carbon, was simply a Eeis's Telephone 
 minus the circular tympanum ; and the really important new 
 fact it revealed, was that very minute vibrations, such as those 
 produced by the movements of an insect, when transmitted 
 immediately through the wooden supports, sufficed to vary the 
 resistance of a telephonic circuit, though far too slight in 
 themselves to affect it if they had to be first communi- 
 cated to the air and then collected by a tympanum. Put a 
 specific tympanum to a Hughes's microphone, and you get a 
 Eeis's telephone. Take away the tympanum from a Eeis's 
 telephone, and you get a Hughes's microphone. Hughes is 
 not limited to one material, nor is Eeis. But the fundamental 
 principle of the electrical part of each is identical. The Blake 
 transmitter (Fig. 44), and the Berliner transmitter, and also 
 Liidtge's microphone,* which was even earlier than that of 
 Hughes, are all embodiments of the same fundamental 
 principle of variable contact which Eeis embodied in his 
 " Telephone." 
 
 The numerous experiments which Eeis made, and the many 
 
 * Liidtge's German Patent, dated Jan. 12, 1878, describes a " Universal 
 Telephone " in which a tympanum was applied to convey vibrations to an 
 interrupter made of hard coke-carbon. 
 
INVENTOR OF THE TELEPHONE. 153 
 
 forms of instruments which he devised, prove his conviction 
 of the importance of his invention to have been very 
 deeply rooted. He had indeed penetrated to the very soul 
 of the matter. He did not confine himself to one kind of 
 tympanum, he tried many, now of bladder, now of collodion, 
 now of isinglass, and now of thin metal. He varied the forms 
 of his instruments in many ways, introducing the element of 
 elasticity by springs and adjusting-screws. Though he 
 chiefly employed one metal for his contact-pieces, he did not 
 limit himself to that one, but left us to infer that the principle 
 of variable contact was applicable to any good conductor, 
 metallic or non-metallic. He knew better, indeed, than to 
 limit himself in any such fashion ; better, indeed, than some 
 of the eminent persons who are now so willing to ignore his 
 claims. Modern practice has taught us to improve the 
 tympanum part of Eeis's invention, and to obviate the incon- 
 veniences to which a membrane is liable : in that part we have 
 gone beyond Eeis. But in the question of contact-points 
 for opening and closing the circuit in correspondence with 
 the vibrations, we are only beginning to find how much Eeis 
 was a-head of us. We have been thrown off the track 
 blinded perhaps by the false trail of the " semi-conductor " 
 fallacy, or by the arbitrary and unnatural twist that has been 
 given by telegraphists to Eeis's expression, " opening and 
 closing the circuit," forgetting that he practically told us that 
 this operation was to be proportional to, " in correspondence 
 with," the undulations of the tympanum. When we succeed 
 in freeing ourselves from the dominance of these later ideas, 
 we shall see how much we still have to learn from Philipp 
 Eeis, and how fully and completely he had grasped the 
 problem of the Telephone. 
 
154 PHILIPP EEIS, 
 
 APPENDIX III. 
 
 COMPARISON OF REIS'S RECEIVERS WITH RECENT INSTRUMENTS. 
 
 THE receivers invented by Reis for the purpose of reconvert- 
 ing into audible mechanical vibrations the varying electric 
 currents transmitted from the speaking end of the line were 
 of two classes, viz. : 
 
 (1.) Those in which the magnetic expansion and contraction 
 of a rod of steel or iron, under the influence of the varying 
 current, set up mechanical vibrations and communicated them 
 to a sound-board. 
 
 (2.) Those in which the current by passing round the coils 
 of an electro-magnet caused the latter to vary the force with 
 which it attracted its armature, and threw the latter into 
 corresponding mechanical vibrations. 
 
 The first of these principles is embodied in the " knitting- 
 needle " receiver described above and depicted in figures 
 22 & 23 on page 33. This receiver differs wholly from 
 the later instruments of Bell, and others, and depended for 
 its action upon the phenomenon of magnetic expansion 
 discovered by Page and investigated by Joule. It was well 
 known before Reis's time that when a needle or bar of iron 
 was magnetised it grew longer, and when demagnetised it 
 grew shorter. Page detected the fact by the " tick " emitted 
 by the bar during the act of magnetisation or demagnetisation. 
 Joule measured the amount of expansion and contraction. 
 To these discoveries Reis added two new facts ; first, that if 
 the degree of magnetisation be varied with rapid fluctuations 
 corresponding to those of the sound waves impressed on the 
 
INVENTOE OF THE TELEPHONE. 155 
 
 transmitter, the expansion and contraction of the rod followed 
 these fluctuations faithfully, and therefore emitted at the 
 receiving end sounds similar to those uttered at the trans- 
 mitter. Secondly, by employing a needle of steel instead of 
 the bar of iron used by Page, Eeis obtained an instrument 
 which once used could never become completely demagnetised 
 on the cessation of the current ; it was thenceforth & permanent 
 magnet, and all that the fluctuating currents could do was to 
 vary its degree of magnetisation. Eeis carefully explained 
 in his memoir " On Telephony," how the frequency of such 
 fluctuations in the magnetising current could act in repro- 
 ducing the pitch, and further, how the amplitude of the 
 fluctuations set up vibrations of corresponding amplitude in 
 the rod : he added with significance, that tl^e quality of the 
 reproduced note depended upon a number of variations of 
 amplitude occurring in a given time. His theory of these 
 actions was that the atoms (or perhaps our modern word 
 molecules would more correctly represent what Eeis spoke of 
 as atoms) of the rod or needle were pushed asunder from one 
 another in the act of magnetisation, and that on the cessation 
 of the magnetising influence of the current, these same atoms 
 strove to return to their previous position of equilibrium, 
 and thus the oscillations of the atoms led to the vibration of 
 the needle as a whole. Whether all Eeis's speculations as to 
 the behaviour of the atoms under varying degrees of magnetis- 
 ing force are justified in the present aspect of science or not, 
 is, however, not of any great importance ; the important point 
 is, that, whether his theory be right or wrong, the instrument 
 he devised will perform the function he assigned to it : it 
 will reproduce speech, not loudly, but in reality far more 
 articulately than many of the telephonic receivers in use 
 under the names of Bell, Gower-Bell, &c. 
 
 One very curious point in connection with this " knitting- 
 needle" receiver of Eeis, is its extremely bad acoustical 
 arrangements. It was laid horizontally upon a small sound- 
 ing-box covered by a lid. If the end of the needle had been 
 made to press on the resonant-board (as indeed appears to 
 have been done at first with the violin, p. 29) the vibrations 
 
156 PHILIPP REIS, 
 
 would have been much more directly reinforced. But when 
 merely supported by two wooden bridges the direct com- 
 munication was largely lost. The pressure of the lid down- 
 wards upon the spiral, as recommended by Eeis, is no doubt 
 an important matter acoustically. It is strange that a man 
 who had grappled in so masterly a way with the acoustical 
 problem of the transmitter, and had solved it by constructing 
 that transmitter on the lines of the human ear, should not 
 have followed out to the same extent those very same 
 principles in the construction of his receiver. An extended 
 surface he did employ, in the shape of a sounding-board ; but 
 it was not applied in the very best manner in this instru- 
 ment. 
 
 The second principle applied by Eeis in the construction 
 of his telephone-receivers, was that of the electro-magnet. 
 He arranged an electro-magnet so that the fluctuating 
 currents passing round the coils set up corresponding 
 variations in the degree of force with which it attracted its 
 armature of iron, and so forced the latter to execute corre- 
 sponding mechanical vibrations. This principle is common 
 both to the receiver of Eeis, and to the later receivers of 
 Yeates, Bell, and Edison. Eeis's armature was an iron bar 
 of oval section ; Yeates's an iron strip screwed to a sound- 
 board, Bell's was an iron plate, and Edison's an iron plate 
 also. 
 
 For the better comparison of Eeis's electro-magnetic 
 receiver with those of more modern date, we here present in 
 Eig. 46 a comparative view of a number of different forms of 
 receiver in which Eeis's principle of causing an electro- 
 magnet to set up vibrations in an armature is applied. In 
 this set of figures, A and B are the suggested forms mentioned 
 in the letter of Mr. Horkheimer, p. 119, and show an electro- 
 magnet, opposite the poles of which is placed an armature 
 (a bar) which must be of iron or other metal capable of 
 having magnetism induced in it, and which, by reason of its 
 attachment to an elastic spring, is capable of being made to 
 oscillate to and fro when attracted with a varying force. 
 Eeis clearly recognised the necessity of further providing a 
 
INVENTOR OF THE TELEPHONE. 
 
 157 
 
 sufficient resounding surface by means of which the surround- 
 ing air could be set in motion ; for in the case of these two 
 suggestions the electro-magnet and its elastically-mounted 
 armature were placed within a cigar box. C is a plan of the 
 
 receiving instrument previously described and figured in 
 Plate II. and in figures 21 and 34 on pages 32 and 109. 
 In this instrument the electro-magnet was horizontal, the 
 armature, a bar of iron of oval section (which in the original 
 
158 PHILIPP EEIS, 
 
 drawing in plate II. appears to have been in reality a hollow 
 bar or tube) attached to a thin lever described as a plank, 
 pivoted like a pendulum to an upright support, but prevented 
 by a set-screw and a controlling spring from vibrating in the 
 manner of a pendulum. Such an arrangement, in fact, 
 vibrates in perfect correspondence with any vibrations that 
 may be forced upon it by the electro-magnet. The broad 
 flat surface of the lever he specially directed that it should 
 be broad and light transfers the vibrations to the air, and 
 is aided by the surface of the sounding-board on which the 
 apparatus stands. This apparatus has, therefore, all the 
 elements of a successful receiver, except only that its shape 
 renders it inconvenient for portability. But by reason, firstly 
 of its armature of iron, secondly of the elastic mounting of 
 that armature, thirdly of the extended surface presented, it is 
 admirably adapted to serve as an instrument for reproducing 
 speech. 
 
 Fig. 46 D represents the excellent electro-magnetic receiver 
 devised in 1865 by Yeates (compare Fig. 42, p. 128) to work 
 with the Eeis transmitter, and is in many respects identical 
 with the preceding form. The armature, a strip of iron, was 
 attached at one end by a very stiff steel spring to a pine- 
 wood sounding-board over a hollow box, from the- base of 
 which rose the metal pillar which supported the electro- 
 magnet. This receiver also contains all the elements of a 
 successful receiver, the armature being of a material capable 
 of inductive action, and elastically supported ; whilst the 
 sound-box provided adequate surface to communicate the 
 vibrations to the air. 
 
 We now come to the more modern instruments of Gray, 
 Bell, and Edison. So far the receivers of Eeis and of Yeates 
 were intended for reproducing any sound ; but now for the 
 first time, ten years after the date of these early telephonic 
 receivers, we meet with instruments devised with the express 
 purpose of receiving only certain selected tones. 
 
 For the purposes of multiple acoustic telegraphy, that is to 
 say for the purpose of signalling the " dots " and " dashes " 
 of the Morse code in a number of different fixed musical 
 
INVENTOR OF THE TELEPHONE. 159 
 
 notes, each of which is to be signalled out and repeated by a 
 receiver adapted to vibrate in that note alone, it is clear that 
 the instruments of Eeis, adapted as they were to transmit 
 and receive any sound that a human ear can hear, would not 
 answer. Accordingly those experimenters, who from about 
 the year 18*73 to the year 1876, applied themselves to 
 multiple telegraphy foremost amongst them being Mr. 
 Elisha Gray and Prof. Graham Bell dropped the use of the 
 tympanum in the transmitter and devised new transmitters 
 and new receivers, in most of which the ruling idea was that 
 of employing a vibrating tongue or reed, tuned up to one 
 particular note. Now it is obvious that a receiver which, 
 like those of Eeis, is adapted to receive any tone, can also 
 receive a musical note. But for the operation of " selective " 
 reception, a receiver must be employed, not only tuned to 
 one note, but tuned to the very note emitted by the particular 
 transmitter with which it is to be in correspondence. 
 Elisha Gray found this out very early in his researches. In 
 the winter of 1873-4 * he was transmitting musical tones by 
 a sort of tuning-fork interruptor, and received them on an 
 instrument shown in Fig. 46 E, which represents a form of 
 electro-magnet mounted for the purpose. It was " a common 
 electro-magnet, having a bar of iron rigidly fixed at one pole, 
 which extends across the other pole, but does not touch it by 
 about one sixty-fourth part of an inch. In the middle of 
 this armature a short post is fastened, and the whole is 
 mounted on a box made of thin pine, with openings for 
 acoustic effects." It was, in fact, very similar to Yeates's 
 receiver just described, and Gray found it capable of receiv- 
 ing not only simple musical tones but composite tones, and 
 even harmonies and discords. In fact, like Eeis's and 
 Yeates's receivers, it could receive anything that the trans- 
 mitter sent to it, even including speech. Now this did not 
 suit Gray, who wished to have selective receivers, one to take 
 up note A, another note C, &c. Accordingly in 1876 we find 
 Gray taking out a fresh patent f for selective receivers, which 
 
 * See Prescott's < Speaking Telephone,' p. 158. 
 
 f ' British Patent,' No. 1874, of the year 1876 (dated 4th May). 
 
160 PHILIPP REIS, 
 
 he also called harmonic analysers, each of which consisted of 
 " a tuned bar or reed suitably attached to an electro-magnet, 
 and the whole mounted upon a resonant box." Fig. 46 F is 
 reproduced from Gray's British patent. " A vibrating tongue 
 reed, or bar "of steel "is united with one pole of the magnet. 
 The free end of the reed passes close to, but does not touch 
 the other pole of the magnet." Gray further says that the 
 reed is made with parallel sides and tuned by cutting it 
 away at one point, as this mode prevents false nodal vibra- 
 tions from occurring. 
 
 Selective receivers for multiple telegraphy were also 
 invented by Graham Bell. The form shown in Fig. 46 / is 
 transcribed from Fig. 15 of Bell's Specification to his British 
 Patent, No. 4765, of the year 1876 (dated 9th December), 
 which the inventor thus describes : " It is preferable to 
 employ for this purpose an electro-magnet E, Fig. 15, having 
 a coil upon only one of its legs. A steel spring armature A 
 is firmly clamped by one extremity to the uncovered leg h of 
 the magnet, and its free end is allowed to project above the 
 pole of the covered leg." In fact the arrangement was 
 almost identical with, but not quite as good mechanically as 
 that patented seven months previously by Gray. The in- 
 ventor further said that a number of these instruments 
 might be placed on one circuit, and that if one of them 
 were set in vibration, only those would respond which were 
 in unison with its note ; and further that " the duration of 
 the sound may be used to indicate the dot or dash of 
 the Morse alphabet, and thus a telegraphic despatch may 
 be indicated by alternately interrupting and renewing the 
 sound." 
 
 Anything more totally different from Reis's telephone 
 than these selective harmonic telegraphs with their tuned 
 tongues can hardly be imagined. Reis was not aiming at 
 selective harmonic telegraphy ; he wanted his one instrument 
 to transmit every sound that a human ear could hear. He 
 did not dream of using a tuned bar or reed ; his typical 
 structure was the tympanum of the ear. In fact, as we have 
 seen above, the tuned reed or tongue was introduced into 
 
INVENTOR OF THE TELEPHONE. 161 
 
 telegraphy for the purpose of transmitting single selected 
 notes to the exclusion of all others. 
 
 Strange though it may seem, a tongue receiver like those 
 of Graham Bell and of Gray just described can be used for 
 receiving speech ! It is true, as Gray remarks, that a thick 
 bar of steel, cut away as described, is best adapted for its own 
 tone only. But Bell's thin steel tongue, though it has its 
 own fundamental note (and so has every tympanum, for that 
 matter) when left free to vibrate in its own time, will re- 
 produce any other note or sound that may be forced upon it 
 by the varying attraction of the electro-magnet. There is, 
 indeed, the whole difference between " free " and " forced " 
 vibrations. One of the strangest delusions that has somehow 
 grown up in recent telephonic discussions is the almost 
 incredible proposition that a tongue cannot talk because it is 
 a tongue. It would be equally veracious to affirm that an 
 ear (i.e. a tympanum) cannot hear because it is an ear. 
 
 But leaving harmonic telegraphy and its " tuned bars," 
 both Gray and Bell applied themselves to the old problem of 
 transmitting human speech. What was their very first step ? 
 They threw away their " tuned bars " and " steel springs," 
 and returned to the tympanum! Elisha Gray devised the 
 receiver shown in Fig. 46, G, taken from his caveat of date 
 February 14, 1876.* In that document Gray says : " My 
 present belief is that the most effective method of providing 
 an apparatus capable of responding to the various tones of 
 the human voice, is a tympanum, drum, or diaphragm," 
 stretched across one end of a chamber. He adds that in the 
 receiver there is (see Fig. 46, G) an electro-magnet, acting 
 upon a diaphragm to which is attached a piece of soft iron, 
 and which diaphragm is stretched across a vocalising 
 chamber. 
 
 Graham Bell's receiver (the American specification of 
 which was filed the same day as Gray's caveat) is shown 
 (in the form patented in Great Britain, Dec. 9, 1876) in 
 Fig. 46 H, which is taken from Fig. 19 of Bell's British patent. 
 
 * Prescott, ' Speaking Telephone,' p. 203. 
 
 M 
 
162 PHILIPP REIS, 
 
 " The armature," says the inventor, " is fastened loosely by 
 one extremity to the uncovered leg, h, of the electro-magnet E, 
 and its other extremity is attached to the centre of a stretched 
 membrane." The armature, in fact, was capable of vibrating 
 like a pendulum on its pivot, but was elastically restrained 
 by its attachment to the tympanum; the armature would 
 therefore vibrate in perfect correspondence with any vibra- 
 tions forced upon it by the electro-magnet. This instrument 
 as also that of Gray, was admirably adapted to receive speech, 
 for it embodied the three essential points which Eeis had 
 already discovered : viz., firstly, that the armature must be of 
 iron, or capable of being acted upon by magnetic induction ; 
 secondly, that it must be elastically mounted ; thirdly, that 
 it should present an extended surface. Bell's form of receiver 
 had the advantage over Eeis's (compare p. 158), that its 
 extended surface was a true tympanum of membrane, and 
 not a mere broad thin plank. Being a tympanum, it there- 
 fore realised Eeis's fundamental notion of imitating the 
 human ear more fully than even Eeis's own receiver did. 
 
 Figures 46, J, K, and L represent the more recent types of 
 receiver of Bell and Edison. Fig. 46 J is reproduced from 
 Fig. 20 of Bell's British Patent, and shows the substitution 
 of a thin steel plate, attached to a frame, in front of the electro- 
 magnet, for the membrane and iron armature. This form of in- 
 strument also embodies Eeis's three principles but with this 
 improvement, the armature capable of inductive action, the 
 elastic mounting, and the extended surface, are here all united 
 in one organ, the thin flexible tympanum of steel. Apart 
 from this unification of parts there is absolutely nothing in 
 this form of Bell's receiver, that Eeis did not invent fourteen 
 years before. Bell's great and most signal improvement was 
 not this beautiful mechanical modification of the Eeis 
 receiver, but lay in the entirely new suggestion to use such a 
 receiver as a tratismitter to work by magneto-electric induc- 
 tion. Two of Eeis's receivers (Fig. 21) if coupled up with 
 a battery will talk together as transmitter and receiver : but 
 Eeis did not know and never suggested this. Two of Yeates's 
 receivers (Fig. 42) if coupled up with a battery will talk 
 
INVENTOE OF THE TELEPHONE. 163 
 
 together as transmitter and receiver ; but Yeates did not know 
 and never suggested this. Bell did discover this, and thereby 
 invented a transmitter which, though now abandoned as a 
 transmitter, for want of loudness, was more reliable than the 
 anterior transmitters of Eeis had been. He made another 
 discovery, presently to bu alluded to that of putting a 
 permanent magnet into the transmitter, to enable him to 
 dispense with the battery ; but beyond this and the other 
 mechanical simplifications previously mentioned, all that he 
 discovered may be summed up by saying that he found out 
 that a receiver constructed on Eeis's principles could work as 
 a transmitter also. That was Bell's really great and im- 
 portant discovery which took all the world by storm at the 
 Centennial Exhibition of 1876. 
 
 Bell subsequently added to his claims the substitution of 
 a permanent magnet with an iron pole-piece, in place of the 
 simple electro-magnet, thus enabling him to transmit his 
 fluctuating currents without the trouble of using a battery, 
 and the Bell transmitter, thus modified, is used to this day as 
 a receiver. Eeis had in his " knitting-needle " telephone, 
 employed a permanent magnet of steel to serve as a receiver. 
 He had not, however, applied it as Bell did to attract a plate 
 of thin steel. 
 
 Fig. 46, K, exhibits a form of electro-magnetic receiver 
 described in Edison's British Specification, No. 2909, 1877, 
 Fig. 24. This instrument, though patented seven months 
 after Bell's instrument, differs from it in no point of im- 
 portance. Its armature was a thin plate of iron, elastic, and 
 having an extended surface ; being, in fact, a tympanum. 
 
 No one can examine the set of receiving instruments col- 
 lected in Fig. 46 without being struck with the extraordinary 
 similarity of design which pervades the entire series. In 
 every one of the set there is an electro-magnet,. the function 
 of which is to set an armature * into vibration by attracting it 
 with a variable force. In every one the armature is of a 
 
 * Yet Bell's claim (British Patent Specification) runs: "I claim the 
 production cf any given sound or sounds from the armature of tho 
 receiving instrument." 
 
 M 2 
 
164 PHILIPP REIS, 
 
 material capable of magnetic induction ; that is to say, iron, 
 steel, or equivalent material. In every one of them the arma- 
 ture is either elastically mounted, or is in itself elastic. In 
 every one of them (save only the two quite recent forms, F and 
 /, which were intended not to speak, but to emit only one fixed 
 musical note) there is an extended surface (either a sound- 
 board or a tympanum) to communicate the vibrations to the 
 air. Lastly, every one of these forms, when connected with 
 the line through which the telephonic currents are being 
 transmitted, is perfectly capable of reproducing articulate 
 speech. But the inventor who had the genius to discover 
 all these essential points, and to combine them in an instru- 
 ment, and to use it to reproduce articulate speech, is surely 
 the true inventor of the system. The inventor of the system 
 embodying these essential points was Philipp Eeis. 
 
INVENTOR OF THE TELEPHONE. 165 
 
 APPENDIX IV. 
 
 ON THE DOCTRINE OF UNDULATORY CURRENTS. 
 
 "In this Specification the three words 'oscillation? ' vibration? and 
 1 undulation? are used synonymously." Graham Bell, U.S. Patent, 
 No. 174, 465, filed Feb. 14, 1876. 
 
 IN the preceding appendices it has been demonstrated that 
 all that is essential in both transmitter and receiver of a 
 Telephonic system was to be found existing in 1863 in the 
 Telephone of Eeis. There yet remains to be met the doc- 
 trinaire objection that as Eeis never explicitly mentions an 
 undulatory current as distinguished from an intermittent 
 one, he never intended to use such a current. This objection 
 is advanced only by those persons who have committed 
 themselves to the idea that speech cannot be transmitted by 
 a transmitter which opens and closes the circuit. 
 
 It is certain that Eeis did not in any of his writings ex- 
 plicitly name an undulatory current : but it is equally 
 certain that, whether he mentioned it or not, he both used 
 one and intended to use one. He did not concern himself 
 as to the precise manner in which the current fluctuated 
 provided only he attained the end in view namely, that the 
 vibrations of the armature of the receiver should be similar 
 to those of the transmitter. This he did lay down with great 
 clearness and emphasis as his g aiding principle ; and he cared 
 not about the intermediate question as to how the current did 
 the work. He told the world that the electromagnet at the 
 receiving end must be magnetised and demagnetised corre- 
 spondingly with the vibrations imparted by the air to the 
 
166 PHILIPP REIS, 
 
 tympanum of his transmitter, in order that the armature 
 might be set into vibrations similar to those of the speaker's 
 voice. If the tympanum of the transmitter vibrated or 
 oscillated or undulated the terms are synonymous so must 
 the armature of the receiver. Graham Bell has told us pre- 
 cisely the same thing : " The current traversing the coils of 
 the electromagnet E occasions an increase and diminution in 
 its intensity " [that is to say, magnetises and demagnetises 
 it], " and the armature A 1 is thrown into vibration "... 
 " and thus imparts to the air at n 1 a facsimile copy of the 
 motion of the air that acted upon the membrane n" Bell 
 agrees then absolutely in every detail with what Eeis said 
 on this point. That sound-waves should be transmitted by 
 a Telephone requires indeed a process of several stages. 
 (1.) The sound-waves must strike upon the tympanum of 
 the transmitter and make it undulate, or, oscillate, or vibrate 
 whichever term you please in a corresponding manner. 
 (2.) The undulating tympanum must act upon the circuit, 
 and either itself induce undulating or vibrating currents 
 (Bell's plan, by magnetic induction), or else throw a current 
 already flowing there, into undulations, or vibrations, or 
 oscillations (Eeis's plan, by varying contact-resistance), but 
 in either case these undulations of the current must corre- 
 spond to the original undulations of the air-waves. (3.) The 
 undulating, or vibrating, or oscillating current must run 
 round the coils of the electromagnet and cause its magnetic 
 force to undulate, or oscillate, or vibrate by demagnetising 
 it and then magnetising it, but this also must be in a manner 
 corresponding to the original undulations. (4.) Further, the 
 armature of the receiver must be set into undulations, or 
 vibrations, or oscillations corresponding to those of the force 
 of the electromagnet, and therefore to the undulations of the 
 current that is magnetising and demagnetising it, and there- 
 fore identically corresponding with the original undulations 
 of the sound-waves. (5.) The armature must communicate its 
 vibrations to the air and to the ear of the listener. Of these 
 successive stages Eeis explicitly told the world that his instru- 
 ment was to do the first one and the last three, and he several 
 
INVENTOR OF THE TELEPHONE. 167 
 
 times emphasized the statement, that the final undulations of 
 the last stage were to be similar to the original undulations 
 of the first stage. The air at the listening end, the armature 
 of the receiver, and the magnetism of the magnet, were all 
 to be set by the fluctuations of the current into undulations 
 corresponding with those of the tympanum at the speaker's 
 end, and of the waves of his voice. It is perfectly clear 
 therefore, that he regarded as self-evident the intermediate 
 stage, and he did not dwell upon the necessity of the point, 
 that his transmitting-current must also vibrate, because this 
 was obviously so, and was only an intermediate matter of 
 secondary moment. He chose rather to point out the ne- 
 cessity of unification between the first and last stages, leaving 
 it to common sense to see that the " interruption " or the 
 " opening and closing " of the circuit must be effected in a 
 manner corresponding to the undulations of the impressed 
 sound-wave. Had the " interruptions " not been of the nature 
 of corresponding variations of contact, the current could not 
 have been set into corresponding vibrations, and the armature 
 of the electromagnet could not have reproduced the vibrations 
 of the transmitter. Clearly Eeis's whole conception of tele- 
 phony included as a minor and intermediate step the fact 
 that the current was, by the action of the transmitter, caused 
 to vary in strength in correspondence with the undulations 
 of the tympanum that, in fact, it was made to undulate 
 by the action of the tympanum and of the interrupter which 
 opened and closed the circuit in obedience to the undulations 
 of the tympanum and in proportion to them. 
 
 A difficulty has been raised by telegraph operators that 
 opening and closing the circuit means opening and closing 
 the circuit in abrupt alternations of make-and-break. Eeis 
 never said so. Reis never used the phrase in this restricted 
 and technical sense. He was not a professional telegraphist, 
 and, as pointed out in Appendix L, he so arranged his contacts 
 with the following springs and other contrivances, that the 
 " opening and closing " of the circuit should not and could 
 not be abrupt. A Reis transmitter is no more a " make-and- 
 break " instrument than the Blake transmitter is. Both will 
 
168 PHILIPP EEIS, 
 
 give undulatory currents by opening and closing the circuit 
 to a greater or less degree, if spoken gently to. Both will 
 give abrupt makes-and-breaks of the circuit if shouted to, in 
 spite of the following-springs, which are used to prevent abrupt 
 interruptions. The term " opening and closing " which Eeis 
 applied to his transmitter, is used by him in exactly the same 
 way as the phrase is used by engineers in describing the 
 action of the governing throttle-valve of a steam-engine. The 
 function of the governor, we are told in treatises on en- 
 gineering, is to open and close the throttle-valve in a manner 
 corresponding to the fall or rise of the governor-balls. No 
 one in his senses imagines that the opening and closing action 
 here referred to means an absolutely abrupt intermitteiice in 
 the supply of steam. If the governor-balls rise a little by 
 increase of speed, there is a corresponding closing, propor- 
 tionate in amount to the amount of rise. If any person were 
 to impress an oscillatory motion of rise and fall upon the 
 governor, the supply of steam would be thrown into corre- 
 sponding undulations. The matter stands precisely so with 
 Eeis's " interrupter " or " regulator ; " it opens and closes the 
 circuit in a manner corresponding with the undulations com- 
 municated to it. If it did not, it would violate the principle 
 of correspondence so emphatically laid down by Eeis, 
 
 It is, however, true that Eeis's instruments, in spite of 
 springs and adjusting screws, and other devices to prevent 
 abrupt make-and-break occurring, were prone, by reason of 
 the very lightness of the parts, to break contact, if too loudly 
 spoken to. They share this fault with the more perfect 
 transmitters of Blake and Berliner which are used to-day so 
 generally. The undulatory currents of these transmitters are, 
 like those of Eeis's transmitters, liable to an occasional abrupt 
 interruption, which, though it may not seriously affect the 
 intelligibility of the words, does, to some extent, mar the 
 perfection of the articulation. Still, in practice, to judge 
 by the instruments used in the telephone exchanges of Great 
 Britain, the Blake transmitter with its liability to make-and- 
 brake abruptly is a more satisfactory instrument than the Bell 
 transmitter, which is not used at all. Now the Bell trans- 
 
INVENTOR OF THE TELEPHONE. 169 
 
 mitter working on the principle of which Bell is the first and 
 undisputed inventor, is one in which the degree of contact in 
 the circuit is never changed : for it works by the principle of 
 " induction," whereby currents are set up in a circuit that is 
 never opened or closed, either partially or wholly. Never- 
 theless the Blake transmitter, which opens and closes the cir- 
 cuit in proportion to the undulations of the tympanum, is the 
 more satisfactory instrument for producing the undulating 
 currents required to procure the all-essential correspondence 
 between the undulations of the tympanum of the transmitter 
 and those of the armature of the receiver. To sum the matter 
 up, it appears that an instrument which opens and closes the 
 circuit on Eeis's principle of transmitting is in practice a more 
 satisfactory transmitter of undulatory currents than Bell's 
 transmitter which cannot open or close the circuit in the 
 least. Eeis, with his instruments, transmitted speech as 
 Herr Hold tells us (p. 126) when the words spoken were not 
 too loud. That is a proof that he did really use, whether he 
 knew it or not, undulatory currents of electricity : and an 
 undulatory current is none the less an undulatory current, 
 even if occasionally abruptly interrupted. A speech is none 
 the less a speech, even if the orator sneeze once or twice while 
 speaking. Nay, we may go further, and say that an undu- 
 latory current is an undulatory current, even though the 
 finer ripples of the waves are lost in transmission. This is 
 what seems to have been the case with Eeis's instruments as 
 they were in 1861 and 1862. The consonants were satisfac- 
 torily transmitted, and so were all musical tones within the 
 range of the instrument. But the finer ripples of the vowels 
 were lost somehow in transmission. Eeis, whose innate 
 honour and modesty led him always rather to understate than 
 overstate the facts, most frankly acknowledged this, nay even 
 invited attention to the fact, and discussed the imperfection 
 from a high scientific standpoint. He proposed to rely for the 
 correctness of his views upon the actual recorded curves of 
 sound-waves, as taken down automatically by the then 
 newly-invented phonautograph of Scott (see p. 60). It is 
 perfectly marvellous how precise his views were upon the 
 
170 PHILIPP JREIS, 
 
 correspondence between the graphic curve or wave-form 
 of a sound and the actual sound itself; a precision amply 
 justified by the experience and the discoveries of the last 
 ten years. 
 
 This matter of representing sounds or rather the varying 
 density of the air in the sound-wave by a graphic curve, 
 was a vital one to Reis. Had he had a less clear view of the 
 nature of sound-waves than that afforded by a graphic curve, 
 I doubt whether he would ever have grasped the problem of 
 the telephone that the final vibrations, or undulations, or 
 oscillations of the armature in the receiver must correspond 
 with must be the very counterpart of those of the tym- 
 panum of the transmitter. The clearness with which Eeis 
 saw this is only surpassed by the clearness with which he 
 expressed himself upon it. For him a sound was simply a 
 complicated series of variations in the density of the air, and 
 capable, in all its complexity, of being represented by the 
 rise and fall of an undulatory curve. " Every tone, and every 
 combination of tones, evokes in our ear vibrations . . . the 
 motions of which may be represented by a curve" (p. 54). 
 " That which is perceived by the auditory nerve . . . may be 
 represented graphically according to its duration and magnitude 
 by a curve "... (p. 53). " Our ear can perceive absolutely 
 nothing more than is capable of being represented by similar 
 curves " (p. 53). The curves with which he accompanied 
 his original memoir and now reproduced in facsimile, from 
 Legat's plates, at the end of this volume are evidence of 
 the thoroughness of his grasp on the undulatory principle. 
 And he explicitly states this principle amongst " the various 
 requisite conditions which must be fulfilled by the trans- 
 mitting and receiving apparatus for the solution of the problem 
 that has been set " (Legat's Report, p. 71). He declared 
 that so soon as it should become possible " at any place, 
 and in any prescribed manner " (that is to say, whether by 
 electric undulations or by mechanical undulations, as in 
 the string of the toy telephone, or by any other ineans), " to 
 set up vibrations whose curves are like those of any given 
 tone or combination of tones," we should then receive the 
 
INVENTOR OF THE TELEPHONE. 
 
 171 
 
 same impression as that tone or combination of tones would 
 have produced upon us. 
 
 So much for Eeis's principle of correspondence of undula- 
 tions between the transmitter and the receiver ; we have seen 
 how clear and precise, yet how comprehensive it was, and how 
 the general proposition necessarily included within itself, as 
 an intermediate step, the particular minor proposition that the 
 undulations of the current must also be in correspondence 
 with the voice. 
 
 Keeping these points in mind, it is very remarkable that 
 when Graham Bell, fourteen years later, followed Eeis " into 
 the field of telephonic research," he selected the very same 
 method of expressing the relations between sounds and the 
 undulations which corresponded with them. To show how 
 remarkably in agreement the views of Eeis and Bell are upon 
 this question of representing by a curve the undulations 
 which correspond to the voice, we select the following para- 
 graphs and place them in parallel columns. 
 
 Eeis. 
 
 That which is perceived by 
 the auditory nerve . . . may 
 be represented graphically, 
 according to its duration and 
 magnitude by a curve. (Me- 
 moir ' On Telephony ' in the 
 Jahresbericht of the Physical 
 Society of Frankfurt - a. - M. 
 1860-61, p. 59.) [p. 53.] 
 
 The height or depth of 
 the sound produced . . . 
 depends upon the number of 
 vibrations made in a given 
 time. (lb. p. 63.) [p. 59.] 
 
 The greater the condensa- 
 tion of the sound-conducting 
 
 Bell. 
 
 Electrical undulations, in- 
 duced by a body capable of 
 inductive action, can be repre- 
 sented graphically, without 
 error by the same sinusoidal 
 curve which expresses the vi- 
 bration of the inducing body 
 itself, and the effect of its vi- 
 bration upon the air ; for, as 
 stated above, the rate of oscilla- 
 tion in the electrical current 
 corresponds to the rate of vi- 
 bration of the inducing body 
 that is, to the pitch of the 
 sound produced. (Specifi- 
 cation of U. S. Patent No. 
 174,465, dated March 7, 1876.) 
 
 The intensity of the current 
 varies with the amplitude of 
 
172 
 
 PHILIPP REIS, 
 
 Eeis. 
 
 medium at any given moment, 
 the greater will be the ampli- 
 tude of vibration of the mem- 
 brane. (16. p, 58.) [p. 52.] 
 . . . each tone is dependent 
 not only on the number of 
 vibrations of the medium, but 
 also on the condensation or 
 rarefaction of the same. 
 (Legat's Report, Zeitschrift des 
 D.-Oesterr. Telegr. Yereins, 
 1863, p. 125.) [p. 77.] 
 
 Let us exhibit the condensa- 
 tion curves for three tones 
 each singly (Plate I) : then, 
 by adding together the ordi- 
 nates corresponding to equal 
 abscissae, we can determine 
 new ordinates and develop a 
 new curve which we may call 
 the combination-curve. Now 
 this gives us just exactly what 
 our ear perceives from the 
 three simultaneous tones. 
 (Memoir ' On Telephony,' 
 p. 59.) [p. 54.] 
 
 Bell 
 
 the vibration that is, with 
 the loudness of the sound ; 
 
 and the polarity of the current 
 corresponds to the direction of 
 the vibrating body, that is, 
 to the condensations and 
 rarefactions of air produced 
 by the vibration. (76.) 
 
 The combined effect of A 
 and B, when induced simul- 
 taneously on the same circuit, 
 is expressed by the curve 
 A -f B, Fig. 4, which is the 
 algebraical sum of the sinu- 
 soidal curves A and B. This 
 curve A + B also indicates the 
 actual motion of the air when 
 two musical notss con- 
 sidered are sounded simul- 
 taneously. . . . (16.)- The 
 electrical movement, like the 
 aerial motion, can be repre- 
 sented by a sinusoidal curve, or 
 by the resultant of several 
 sinusoidal curves. (J6.) 
 
 The very remarkable agreement of the preceding passages 
 receives a most striking confirmation by comparing the 
 curves respectively drawn by Eeis and by Bell. These are 
 facsimiled below, Keis's " combination "-curve (Fig. 47) from 
 Plate I. of his Memoir (also Plate I. of this volume), and 
 Bell's " resultant "-curve (Fig. 48) from Fig. 4 of his United 
 States Patent Specification No. 174,465. 
 
 The most casual observer cannot fail to notice here that 
 the three lines of undulatory curves of Bell's specification 
 
INVENTOR OF THE TELEPHONE. 
 
 173 
 
 are practically identical with the three lower lines of undu- 
 latory curves of Eeis's memoir. They are, moreover, in each 
 case introduced for the sake of showing how a complex curve 
 corresponds to a compound undulation. 
 
 Eeis. 
 
 A.. 
 
 f 
 
 j 
 
 Fig. 48. 
 
 Far be it from me even to hint that either curve was 
 plagiarised from the other. Bell tells us that his curve is to 
 represent electrical oscillations, which, he adds, have the 
 same curve as that both of the vibrating body and of the air. 
 Eeis tells us that his curve is to represent the oscillations of 
 a tympanum, or of the air, or of the magnetisation of the 
 magnet, or of the armature at the receiving end. How the 
 magnetization of the electro-magnet was made to vary " cor- 
 respondingly with the condensations and rarefactions of the 
 air," as represented by such a curve, Eeis did not explicitly 
 say, but left to the common sense of his readers to infer. 
 Though the inference was obvious, Bell, who possibly had not 
 
174 PHILIPP REIS, 
 
 then read Reis's researches, seized upon this intermediate 
 stage of the process employed by Eeis, and probably quite 
 unconscious that Reis had already employed it, announced it 
 as a discovery of his own ; and then, losing sight of the point 
 that all that was wanted was to secure correspondence 
 between the initial and final stage, he magnified to an absurd 
 and unwarranted importance this intermediate correspond- 
 ence of the vibrations of the current with those of the tym- 
 panum, which correspondence any one reading Reis's papers 
 would know at once Reis had implicitly assumed and actually 
 employed when he transmitted articulate speech. 
 
 If we pass from the method of graphically representing 
 undulations by curves, and proceed to compare the language 
 in which Reis described the action of his machine in re- 
 producing the undulations imparted to the transmitter, with 
 that in which Graham Bell described the action of his 
 machine some fourteen years later, we shall find * an agree- 
 ment even more precise. 
 
 * In making these comparisons in parallel columns, I wish to repudiate 
 in the most emphatic way any sinister inference that might be drawn as 
 to Graham Bell's use of descriptions and curves identical in so many 
 points with those of Reis. For, in the first place, I believe Professor Bell 
 to be incapable of such contemptible appropriations, and the candour with 
 which he has himself invited comparison by giving various references to 
 Eeis's papers, itself precludes such inference. In the second place, I do 
 not think that at the date of these quotations Bell understood German 
 sufficiently well to comprehend Reis's very precise statement of the 
 problem of the Telephone. I simply exhibit these parallel extracts to 
 show the thoroughness with which Reis had grappled with the problem 
 with which, fourteen years later, Bell also grappled ; and to prove in the 
 most irrefragable manner, from the necessary identity in the terms 
 selected for expressing the facts of the solution of the problem, that the 
 problem to which each found a solution was identical. The circumstance 
 that does, however, puzzle me, and which does not appear in these 
 parallel extracts, is that, whilst in his original memoir, Reis speaks in 
 detail of the auditory ossicles and their movements as having suggested 
 his transmitter, and casually mentions the phonautograph of Scott in 
 support of his views, Bell, in his original lecture before the American 
 Academy, speaks in detail of Scott's phonautograph as having suggested 
 his transmitter, and casually refers to the auditory ossicles and their 
 movements. 
 
INVENTOR OF THE TELEPHONE. 
 
 175 
 
 Eeis. 
 
 The electromagnet . . . 
 will be demagnetised and mag- 
 netised correspondingly with 
 the condensations and rarefac- 
 tions of the mass of air, . . . and 
 the armature . . . will be 
 set into vibrations similar to 
 those of the membrane in 
 the transmitting apparatus. 
 (Legat's Report, Zeitschrift, 
 p. 128, 1862.) [p. 77.] 
 
 The transmitter, Fig. A, 
 consists of a conical tube . . . 
 closed by a membrane ... by 
 speaking . . . into the tube . . . 
 there will be evoked a motion 
 of the membrane. . . (op. tit.) 
 
 The apparatus . . . offers 
 the possibility of creating 
 these vibrations in every 
 fashion that may be desired, 
 and the employment of electro- 
 galvanism gives us the possi- 
 bility of calling into life, at 
 any given distance, vibrations 
 similar to the vibrations 
 that have been produced, and 
 in this way to reproduce at any 
 place the tones that have been 
 originated at another place. 
 (Legat's Eeport, op. cit.) 
 
 As soon therefore as it shall 
 be possible ... to set up 
 vibrations whose curves are 
 like those of any given tone or 
 
 Bell 
 
 The current traversing the 
 coils of the electromagnet E, 
 occasions an increase and dimi- 
 nution in its intensity, and the 
 armature A 1 is thrown into 
 vibrations . . . and thus im- 
 parts to the air at n 1 a fac- 
 simile copy of the motion of 
 the air that acted upon the 
 membrane n. (Specification 
 of British Patent, No. 4765, 
 Dec. 9th, 1876, p. 17.) 
 
 A cone A is used to con- 
 verge sound vibrations upon 
 the membrane. 
 
 When a sound is uttered in 
 the cone the membrane a is 
 set in vibration. . . . 
 
 . . . and thus electrical undu- 
 lations are created upon the 
 circuit E b e f g. . . . The 
 undulatory current passing 
 through the electromagnet / 
 influences its armature h to 
 copy the motion of the arma- 
 ture c. . . . These undula- 
 tions are similar in form 
 to the air undulations 
 caused by the sound. 
 
 that is, they are repre- 
 sented graphically by similar 
 curves. . 
 
176 
 
 PHILIPP REIS, 
 
 Eels. 
 
 combination of tones, we shall 
 receive the same impression 
 as that tone or combination of 
 tones would have produced 
 upon us. (Memoir * On Tele- 
 phony,' p. 60.) [p. 55.] 
 
 Any sound will be repro- 
 duced, if strong enough to set 
 the membrane in motion. 
 (Letter to Mr. Ladd, 1863.) 
 [P- 84.] 
 
 the armature belonging to 
 the magnet will be set into 
 vibrations similar to those 
 of the membrane in the 
 transmitting apparatus. 
 (Legat's Eeport, 1862.) [p. 77.] 
 
 Bell 
 
 A similar sound to that 
 uttered into A is then heard to 
 proceed from I. (Specification 
 of U. S. Patent, No. 174,465.) 
 
 There are many other uses 
 to which these instruments 
 may be put, such as ... the 
 telegraphic transmission of 
 noises or sounds of any 
 kind. (16.) 
 
 I would have it understood 
 that what I claim is : . . . 
 . . . Tenth. In a system of 
 electric telegraph or telephony 
 consisting of transmitting and 
 receiving instruments united 
 upon an electric circuit, I claim 
 the production in the armature 
 of each receiving instrument 
 of any given motion by subject- 
 ing said armature to an attrac- 
 tion varying in intensity, how- 
 ever such variation may be 
 produced in the magnet, and 
 hence I claim the produc- 
 tion of any given sound or 
 sounds from the armature 
 of the receiving instru- 
 ment by subjecting said arma- 
 ture to an attraction varying 
 in intensity in such manner 
 as to throw the armature 
 into that form of vibration 
 that characterizes the 
 given sound or sounds. 
 (Specification of British Pa- 
 tent, No. 4765, Dec. 9, 1876.) 
 
INVENTOR OF THE TELEPHONE. Ill 
 
 One cannot help thinking that some claims to great inven- 
 tions are just a little " too previous." 
 
 If it should still be said that Eeis's method of transmitting 
 speech, whether it did its work by undulatory currents or no, 
 was avowedly imperfect, and that therefore such a claim as 
 that quoted above is justified by the subsequent invention of 
 an instrument the articulation of which was more reliable, let 
 us compare what each inventor has said about the imper- 
 fections* of his own instrument. 
 
 Reis. Bell. 
 
 That which has here been It is a mistake, however, to 
 spoken of will still require suppose that the articulation 
 considerable improvement, was by any means perfect. . . . 
 and in particular mechanical Still the articulation was there, 
 science must complete the and I recognized the fact that 
 apparatus to be used. (Legat's the indistinctness was entirely 
 Report, 1862.) [p. 78.] due to the imperfection of the 
 
 instrument. (' Kesearches in 
 Telephony,' Journal of Soc. of 
 Telegr. Engineers, Dec. 1877.) 
 
 If it should be said that Bell is here speaking only of an 
 early and experimental form, and not of his real invention, 
 it should be remembered that Bell here refers to the appa- 
 ratus with cone and membrane, identical with that exhibited 
 at Glasgow in September, 1876, by Sir William Thomson 
 (who had received it from Bell) and by him described as 
 the very " hardihood of invention," and " by far the greatest 
 of all the marvels of the electric telegraph." It certainly 
 
 * Reis's failures were chiefly with the vowels, Bell's more particularly 
 with the consonants. Reis's contacts were liable to break, and the follow- 
 ing-springs of his contact-regulators too little pliable. Bell's transmitter 
 could not open and close the circuit proportionally with the motions of the 
 tympanum, and owing to the sluggishness due to self-induction in the coils 
 of his telephone, the induced undulations of the current failed to come up 
 in suddenness to those of the tympanum. In consequence whip sounded 
 like whim, and kiss like kith, even in the perfected Bell Telephones made 
 two years after Bell's first " improvements " in telephony were patented. 
 
178 PHILIPP REIS, 
 
 worked upon the principle of undulatory currents,* whether it 
 articulated or not. Bell had himself, speaking in May 1876, 
 before the American Academy of Arts and Sciences upon his 
 researches, even more explicitly admitted the imperfections of 
 his own instrument. 
 
 The effects were not suffi- 
 ciently distinct to admit of 
 sustained conversation through 
 the wire. Indeed, as a general 
 rule, the articulation was 
 unintelligible, excepting 
 when familiar sentences were 
 employed. (Proceedings of 
 American Academy of Arts 
 and Sciences, vol. xii. p. 7.) 
 
 Yet this most imperfect machine, of which the articulation 
 was, as a general rule, unintelligible, had, two months pre- 
 viously, had a patent granted to it as a new invention, the 
 claim being for " the method of, and apparatus for, trans- 
 mitting vocal or other sounds telegraphically, as herein 
 
 * The following very remarkable passage occurs in the evidence given 
 by Professor Graham Bell concerning Keis'.s Telephones. (See published 
 volume of ' Proceedings in the United States Patent Office before the 
 Commissioner of Patents/ Evidence for A. G. Bell, p. 14.) 
 
 Question 37. "If a Reis Telephone, made in accordance with the 
 descriptions published before the earliest dates of your invention, would in 
 use transmit and receive articulate speech as perfectly as the instruments 
 did which were used by you on June 25, 1876, at the Centennial, would 
 it be proof to you that such Reis Telephones operated by the use of un- 
 dulatory movements of electricity in substantially the same way as your 
 instruments did upon the occasion referred to ? " 
 
 Answer by Bell. " The supposition contained in the question cannot 
 be supposed. Were the question put that if I were to hear an instrument 
 give forth articulate speech transmitted electrically as perfectly as my 
 instruments did on the occasion referred to in the question, I would hold 
 this as proof that the instrument had been operated by undulatory 
 movements of electricity, I would unhesitatingly answer, Yes." 
 
 Surely no better authority is needed to support the proposition that if 
 Reis made his Telephone speak, as he said he did, he employed undulatory 
 currents. 
 
INVENTOR OF THE TELEPHONE. 179 
 
 described, by causing electrical undulations similar in form to 
 the vibrations of the air accompanying the said vocal or other 
 sounds, substantially as set forth." 
 
 If then mere mechanical imperfections do not make an 
 invention any the less a true invention capable of legal recog- 
 nition, it would be dishonest to the last degree to deny to 
 Philipp Eeis the honour of his invention, of which he honestly 
 and openly stated both the successes and the imperfections. 
 He told the world what he aimed at, and in what measure 
 success had crowned his aims. His claim to be the inventor 
 of the Telephone he considered to be justified by that measure 
 of success. If he was so far in advance of his time that the 
 world was unprepared to receive or use the splendid discovery 
 which he gave freely to it, that was not his fault ; nor does 
 neglect or apathy make him in one single degree the less en- 
 titled to the credit of his inventions. Tulit alter Jionores has 
 not unfrequently been truly said concerning the men of 
 genius who have had the misfortune to live in advance of 
 the age. 
 
 But posterity does not let the names of such truly great 
 ones perish in the dust. The inventor of the Telephone will 
 be remembered and honoured in the coming if not in the 
 present age. 
 
180 
 
 PHILIPP REIS, 
 
 SCHEDULE OF AUTHORITIES 
 
 Title of Work. 
 
 Place of 
 Issue. 
 
 Date. 
 
 Volume and 
 Page. 
 
 British 
 Museum. 
 
 ' Jahresbericht des Phy-1 
 sikalischen Vereins zu> 
 Frankfurt-am-Main ' . . j 
 
 Frankfurt- 
 a.-M. 
 
 (1860-1 
 \1863 
 
 p. 57 \ 
 p. 129 / 
 
 Ac. 4428 
 
 ' Fortsohritte der Physik "1 
 (Kronig and Beetz) . . / 
 
 Berlin .. 
 
 /1861 
 \1863 
 
 xvii. p. 171-173.. \ 
 
 ?p. 96.. ../ 
 
 Ac. 3775 
 
 Dingler's ' Polytechnisches I 
 Journal* j 
 
 Stuttgart 
 
 1863 
 
 (clxviii. p. 185-187) 
 'clxix. p. 23.. ..} 
 |clxix. p. 399 .. ) 
 
 Pp. 1780 
 
 * Polytechnisches Central- 
 Blatt ' (Schnedermann 
 and Botteher) 
 
 Cassel .. 
 
 1863 
 
 xxix. p. 858 
 
 Pp. 1615 6. 
 
 Bottger's ' Polytechni-1 
 sches Notizblatt ' . . . . J 
 
 Mainz 
 
 1863 
 
 /No. 6 \ 
 \No.l5 .. ../ 
 
 Pp. 1787 
 
 ' Didaskalia ' 1 
 
 Frankfurt- \ 
 a.-M. J 
 
 1862 
 
 May 8, May 14 .. 
 
 
 
 'Zeitschrift des Deutsch- 
 Oesterreichischen 
 Telegraphen Vereins ' { 
 (Dr. Brix) J 
 
 Berlin . . 
 
 1862 
 
 ix. p. 125 .. .. 
 
 - 
 
 Kuhn's * Handbuch der 
 angewandten Elektrici- 
 tatslehre' 
 
 Leipzig . . 
 
 1866 
 
 p. 1017-1021 .. 
 
 2244i .. 
 
 Pisko's ' Die Neueren Ap-^l 
 parate der Akustik ' . . / 
 
 Vienna . . 
 
 1865 
 
 /p. 94-103 .. ..} 
 \p. 241-243 .. ../ 
 
 8705 cc. 
 
 (Pisko's) 'Hessler's Lebr- 
 bucb der Tecbniscben 
 Physik' 
 
 Vienna . . 
 
 1866 
 
 Vol. I. p. 648 .. 
 
 
 
 Miiller Pouillet's Lebr-| 
 buch der Physik' 
 
 Brunswick 
 
 1868 
 
 Vol. II. p. 386-388 
 
 
 
INVENTOR OF TEE TELEPHONE. 
 
 181 
 
 AND KEFERENCES. 
 
 
 Royal Society. 
 
 Ronald's Library. 
 
 Institution Civil 1 
 Engineers. 
 
 Royal Institution. 
 
 Great Seal Patent 
 Office. 
 
 School of Mines. 
 
 University College, 
 London. 
 
 Bodleian Library, 
 Oxford. 
 
 King's College. 
 
 Oxford University I 
 Museum Library.! 
 
 
 1846-1860 
 
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 .. 
 
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 .. 
 
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 6546, us E 
 
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 198 e 133 
 
 
 
 
 
 
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 edition } 
 (1872) 1 
 
 
 
 v/ 
 
 (Ed. 
 
 1876) 
 
 -. 
 
 
 
 ' 
 
182 PHILIPP REIS. 
 
 ADDITIONAL REFERENCES CONCERNING REIS'S 
 TELEPHONE. 
 
 Schenk's Philipp Reis, der Er finder des Telepkons, 1878. 
 
 Sack's Die Entivickelung der elektrischen Telephonic, 1878. 
 
 Ferguson's Electricity (Ed. 1867), p. 257. 
 
 Wiedemann's Galvanismus (1874), Vol. ii. p. 598. 
 
 Gartenlaule, die; for 1863, No. 51, p. 807-809. 
 
 Am der Natur ; for 1862, xxi. p. 470-474. 
 
 Cosmos, Vol. xxiv. p. 349 (1864). 
 
 Proc. Lit. Phil. Soc. Manchester (1865), Nov. 10, 1864. 
 
 Rep. Brit. Assoc. (1863), p. 19. 
 
 Die Geschichte und Entwickelung des elektrischen Fernsprech- 
 
 wesens, 1880. (Officially issued from the Imperial German 
 
 Post-Office, Berlin.) 
 
 LONDON : PRINTED BY WILLIAM CLOWES AND SONS, LIMITED, STAMFORD STREET 
 AND CHARING CROSS. 
 
Plate.l. 
 
 REPRODUCTION OF TONES IN THE ELECTRO-GALVANIC WAY. 
 
 \ 
 
 \ 
 
 THO S KELL A SON, LITH.40.KING ST COVENT GARDEN. 
 
Pb.te.Il. 
 
 REPRODUCTION OF TONES IN THE ELECTRO-GALVANIC WAY. 
 
 HQ>-HQ 
 
 THO S KELL i SON, LITH. 40. KING S T COVEKT GARDE?:. 
 
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 A Practical Treatise on Casting and Founding, 
 
 including descriptions of the modern machinery employed in the art. By 
 N. E. SPRETSON, Engineer. Third edition, with 82 plates drawn to 
 scale, 412 pp., demy 8vo, cloth, i8j. 
 
PUBLISHED BY E. & F. N. SPON. 
 
 The Clerk of Works: a Vade-Mecum for all engaged 
 
 in the Superintendence of Building Operations. By G. G. HOSKINS, 
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 Tropical Agriculture ; or, the Culture, Preparation, 
 
 Commerce, and Consumption of the Principal Products of the Vegetable 
 Kingdom, as furnishing Food, Clothing, Medicine, etc., and in their 
 relation to the Arts and Manufactures ; forming a practical treatise and 
 Handbook of Reference for the Colonist, Manufacturer, Merchant, and 
 Consumer, on the Cultivation, Preparation for Shipment, and Commercial 
 Value, etc., of the various Substances obtained from Trees and Plants 
 entering into the Husbandry of Tropical and Sub-Tropical Regions. By 
 P. L. SIMMONDS. Second edition, revised and improved, 515 pages, 
 8vo, cloth, i/. \s. 
 
 Steel: its History, Manufactiire, and Uses. By 
 
 J. S. JEANS, Secretary of the Iron and Steel Institute. 860 pages and 
 2$ plates, 8vo, cloth, 36^. 
 
 American Foundry Practice: Treating of Loam, 
 
 Dry Sand, and Green Sand Moulding, and containing a Practical Treatise 
 upon the Management of Cupolas, and the Melting of Iron. By T. D. 
 WEST, Practical Iron Moulder and Foundry Foreman. Second edition, 
 with numerous illustrations, crown 8vo, cloth, los. 6d. 
 
 The Maintenance of Macadamised Roads. By T. 
 
 CODRINGTON, M.I.C.E, F.G.S., General Superintendent of County Roads 
 for South Wales. 8vo, cloth, 6s. 
 
 Hydraulic Steam and Hand Power Lifting and 
 
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 With 1$ plates, 8vo, cloth, i8j. 
 
 Pumps and P limping Machinery. By F. COLYER, 
 
 M.I.C.E., M.I.M.E. With 23 jolding plates, 8vo, cloth, 12s. 6d. 
 
 Tables of the Principal Speeds occurring in Mechanical 
 
 Engineering, expressed in metres in a second. By P. KEERAYEFF, Chief 
 Mechanic of the Obouchoff Steel Works, St. Petersburg ; translated by 
 SERGIUS KERN, M.E. Fcap. 8vo, sewed, 6d. 
 
 Girder Making and the Practice of Bridge Building 
 
 in Wrought Iron, illustrated by Examples of Bridges, Piers, and Girder 
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CATALOGUE OF SCIENTIFIC BOOKS 
 
 Spons Dictionary of Engineering, Civil, Mechanical, 
 
 Military, and Naval', with technical terms in French, German, Italian, 
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 Seepage 15. 
 
 A Treatise on the Origin, Progress, Prevention, and 
 
 Cure of Dry Rot in Timber; with Remarks on the Means of Preserving 
 Wood from Destruction by Sea- Worms, Beetles, Ants, etc. By THOMAS 
 ALLEN BRITTON, late Surveyor to the Metropolitan Board of Works, 
 etc., etc. With 10 plates, crown 8vo, cloth, 'js. 6d. 
 
 Metrical Tables. By G. L. MOLESWORTH, M.I.C.E. 
 
 32mo, cloth, is. 6d. 
 
 CONTENTS. 
 
 General Linear Measures Square Measures Cubic Measures Measures of Capacity 
 Weights Combinations Thermometers. 
 
 A Handbook of Electrical Testing. By H. R. 
 
 KEMPE, Member of the Society of Telegraph Engineers. New edition, 
 revised and enlarged, with 81 illustrations. Crown 8vo, cloth, I2s. 6d. 
 
 Electro -Telegraphy. By FREDERICK S. BEECHEY, 
 
 Telegraph Engineer. A Book for Beginners. Illustrated. Fcap. 8vo, 
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 Handr ailing: by the Square Cut. By JOHN JONES, 
 
 Staircase Builder. Fourth edition, with seven plates, 8vo, cloth, 3^. 6d. 
 
 Handrailing : by the Square Cut. By JOHN JONES, 
 
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 The Gas Consumer s Handy Book. By WILLIAM 
 
 RICHARDS, C.E. Illustrated. i8mo, sewed, 6d. 
 
 Steam Heating for Buildings ; or, Hints to Steam 
 
 Fitters, being a description of Steam Heating Apparatus for Warming 
 and Ventilating Private Houses and large Buildings ; with Remarks on 
 Steam, Water, and Air in their relation to Heating ; to which are added 
 miscellaneous Tables. By J. W. BALDWIN, Steam Heating Engineer. 
 With many illustrations. Second edition, crown 8vo, cloth, ics. 6d. 
 
PUBLISHED BY E. & F. N. SPON. 
 
 A Pocket-Book of Useful Formula and Memoranda 
 
 for Civil and Mechanical Engineers. By GUILFORD L. MOLESWORTH, 
 Mem. Inst. C.E., Consulting Engineer to the Government of India for 
 State Railways. With numerous illustrations, 744 pp. Twenty-first 
 edition, revised and enlarged, 32mo, roan, 6s. 
 
 SYNOPSIS OF CONTENTS: 
 
 Surveying, Levelling, etc. Strength and Weight of Materials Earthwork, Brickwork, 
 Masonry, Arches, etc. Struts, Columns, Beams, and Trusses Flooring, Roofing, and Roof 
 Trusses Girders, Bridges, etc. Railways and Roads Hydraulic Formulae Canals, Sewers, 
 Waterworks, Docks Irrigation and Breakwaters Gas, Ventilation, and Warming Heat, 
 Light, Colour, and Sound Gravity : Centres, Forces, and Powers Millwork, Teeth of 
 Wheels, Shafting, etc. Workshop Recipes Sundry Machinery Animal Power Steam and 
 the Steam Engine Water-power, Water-wheels, Turbines, etc. Wind and Windmills- 
 Steam Navigation, Ship Building, Tonnage, etc. Gunnery, Projectiles, etc. Weights, 
 Measures, and Money Trigonometry, Conic Sections, and Curves Telegraphy Mensura- 
 tion Tables of Areas and Circumference, and Arcs of Circles Logarithms, Square and 
 Cube Roots, Powers Reciprocals, etc. Useful Numbers Differential ar.d Integral Calcu- 
 lus Algebraic Signs Telegraphic Construction and Formulas. 
 
 Spons Tables and Memoranda for Engineers; 
 
 selected and arranged by J. T. HURST, C.E., Author of 'Architectural 
 Surveyors' Handbook,' ' Hurst's Tredgold's Carpentry, ' etc. Fifth edition, 
 64010, roan, gilt edges, I s. ; or in cloth case, is. 6d. 
 
 This work is printed in a pearl type, and is so small, measuring only 2t in. by if in. by 
 i in. thick, that it may be easily carried in the waistcoat pocket. 
 
 " It is certainly an extremely rare thing for a reviewer to be called upon to notice a volume 
 measuring but 2$ in. by if in., yet these dimensions faithfully represent the size of the handy 
 little book before us. The volume which contains 118 printed pages, besides a few blank 
 pages for memoranda is, in fact, a true pocket-book, adapted for being carried in the waist- 
 coat pocket, and containing a far greater amount and variety of information than most people 
 
 would imagine could be compressed into so small a space The little volume has been 
 
 compiled with considerable care and judgment, and we can cordially recommend it to our 
 readers as a useful little pocket companion." Engineering. 
 
 Analysis, Technical Valuation, Purification and Use 
 
 of Coal Gas. By the Rev. W. R. BOWPITCH, M.A. With wood engravings, 
 
 8vo, cloth, 12s. 6d. 
 
 Condensation of Gas Purification of Gas Light Measuring Place of Testing Gas 
 Test Candles The Standard for Measuring Gas-light Test Burners Testing Gas for 
 Sulphur Testing Gas for Ammonia Condensation by Bromine Gravimetric Method of 
 taking Specific Gravity of Gas Carburetting or Naphthalizing Gas Acetylene Explosions 
 of Gas Gnawing of Gaspipes by Rats Pressure as related to Public Lighting, etc. 
 
 A Practical Treatise on Natural and Artificial 
 
 Concrete, its Varieties and Constructive Adaptations. By HENRY REID, 
 Author of the ' Science and Art of the Manufacture of Portland Cement.' 
 New Edition, with 59 woodcuts and $ plates, 8vo, cloth, 15^. 
 
 Hydrodynamics : Treatise relative to the Testing of 
 
 Water- Wheels and Machinery, with various other matters pertaining to 
 Hydrodynamics. By JAMES EMERSON. With numerous illustrations, 
 360 pp. Third edition, crown 8vo, cloth, 4.5-. 6d. 
 
CATALOGUE OF SCIENTIFIC BOOKS 
 
 The Gas Analyst's Manual. By F. W. HARTLEY, 
 
 Assoc. Inst. C.E., etc. With numerous illustrations. Crown 8vo, 
 cloth, 6s. 
 
 Gas Measurement and Gas Meter Testing. By 
 
 F. W. HARTLEY. Fourth edition, revised and extended. Illustrated, 
 crown 8vo, cloth , 4^. 
 
 The French- Polisher s Manual. By a French- 
 Polisher; containing Timber Staining, Washing, Matching, Improving, 
 Painting, Imitations, Directions for Staining, Sizing, Embodying, 
 Smoothing, Spirit Varnishing, French- Polishing, Directions for Re- 
 polishing. Third edition, royal 32ino, sewed, &d. 
 
 Hops, their Cultivation, Commerce, and Uses in 
 
 various Countries. By P. L. SiMMONDS. Crown 8vo, cloth, 4^. 6d. 
 
 A Practical Treatise on the Manufacture and Distri- 
 bution of Coal Gas. By WILLIAM RICHARDS. Demy 410, with numerous 
 wood engravings and 29 plates, cloth, 28s. 
 
 SYNOPSIS OF CONTENTS : 
 
 Introduction History of Gas Lighting Chemistry of Gas Manufacture, by Lewis 
 Thompson, Esq., M.R.C.S. Coal, with Analyses, by J. Paterson, Lewis Thompson, and 
 G. R. Hislop ; Esqrs. Retorts, Iron and Clay Retort Setting Hydraulic Main Con- 
 densers Exhausters Washers and Scrubbers Purifiers Purification History of Gas 
 Holder Tanks, Brick and Stone, Composite, Concrete, Cast-iron, Compound Annular 
 Wrpught-iron Specifications Gas Holders Station M eter Governor Distribution- 
 Mains Gas Mathematics, or Formulae for the Distribution of Gas, by Lewis Thompson, Esq. 
 Services Consumers' Meters Regulators Burners Fittings Photometer Carburization 
 of Gas Air Gas and Water Gas Composition of Coal Gas, by Lewis Thompson, Esq. 
 Analyses of Gas Influence of Atmospheric Pressure and Temperature on Gas Residual 
 Products Appendix Description of Retort Settings, Buildings, etc., etc. 
 
 Practical Geometry and Engineering Drawing ; a 
 
 Course of Descriptive Geometry adapted to the Requirements of the 
 Engineering Draughtsman, including the determination of cast shadows 
 and Isometric Projection, each chapter being followed by numerous 
 examples ; to which are added rules for Shading Shade-lining, etc., 
 together with practical instructions as to the Lining, Colouring, Printing, 
 and general treatment of Engineering Drawings, with a chapter on 
 drawing Instruments. By GEORGE S. CLARKE, Lieut. R.E., Instructor 
 in Mechanical Drawing, Royal Indian Engineering College. 20 plates^ 
 4to, cloth, 15^. 
 
 The Elements of Graphic Statics. By Professor 
 
 KARL VON OTT, translated from the German by G. S. CLARKE, Lieut. 
 R.E., Instructor in Mechanical Drawing, Royal Indian Engineering 
 College. With 93 illustrations , crown 8vo, cloth, $s. 
 
 The Principles of Graphic Statics. By GEORGE 
 
 SYDENHAM CLARKE, Lieut. Royal Engineers. With 112 illustrations. 
 4to, cloth, 12s. 6d. 
 
PUBLISHED BY E. & F. N. SPON. 
 
 The New Formula for Mean Velocity of Discharge 
 
 of Rivers and Canals. By W. R. KUTTER. Translated from articles in 
 the ' Cultur-Ingenieur,' by Lowis D'A. JACKSON, Assoc. Inst. C.E. 
 8vo, cloth, I2J. 6ct. 
 
 Practical Hydraulics ; a Series of Rules and Tables 
 
 for the use of Engineers, etc., etc. By THOMAS Box. Fifth edition, 
 numerous plates, post 8vo, cloth, 5>r. 
 
 A Practical Treatise on the Construction of Hori- 
 zontal and Vertical Waferwheels, specially designed for the use of opera- 
 tive mechanics. By WILLIAM CULLEN, Millwright and Engineer. With 
 ii plates. Second edition, revised and enlarged, small 4to, cloth, \2s.6d. 
 
 Aid Book to Engineering Enterprise Abroad. By 
 
 EWING MATHESON, M. Inst. C.E. The book treats of Public Works 
 and Engineering Enterprises in their inception and preliminary arrange- 
 ment ; of the different modes in which money is provided for their 
 accomplishment ; and of the economical and technical considerations by 
 which success or failure is determined. The information necessary to 
 the designs of Engineers is classified, as are also those particulars by 
 which Contractors may estimate the cost of works, and Capitalists the 
 probabilities of profit. Illustrated, 2 vols., 8vo, I2J. 6d. each. 
 
 The Essential Elements of Practical Mechanics; 
 
 based on the Principle of Work, designed for Engineering Students. By 
 OLIVER BYRNE, formerly Professor of Mathematics, College for Civil 
 Engineers. Third edition, with 148 wood engravings, post 8vo, cloth, 
 7s. 6d. 
 
 CONTENTS : 
 
 Chap. I. How Work is Measured by a Unit, both with and without reference to a Unit 
 of Time Chap. 2. The Work of Living Agents, the Influence of Friction, and introduces 
 one of the most beautiful Laws of Motion Chap. 3. The principles expounded in the first and 
 second chapters are applied to the Motion of Bodies Chap. 4. The Transmission of Work by 
 simple Machines Chap. 5. Useful Propositions and Rules. 
 
 The Practical Millwright's and Engineers Ready 
 
 Reckoner; or Tables for finding the diameter and power of cog-wheels, 
 diameter, weight, and power of shafts, diameter and strength of bolts, etc, 
 By THOMAS DIXON. Fourth edition, I2mo, cloth, 3.?. 
 
 Breweries and Mailings : their Arrangement, Con- 
 struction, Machinery, and Plant. By G. SCAMELL, F.R.I.B.A. Second 
 edition, revised, enlarged, and partly rewritten. By F. COLYER, M.I.C.E., 
 M.I.M.E. With 20 plates, 8vo, cloth, i8j. 
 
 A Practical Treatise on the Manufacture of Starch, 
 
 Glucose, Starch-Sugar, and Dextrine, based on the German of L. Von 
 Wagner, Professor in the Royal Technical School, Buda Pesth, and 
 other authorities. By JULIUS FRANKEL ; edited by ROBERT HUTTER, 
 proprietor of the Philadelphia Starch Works. With 58 illustrations, 
 344 pp., 8vo, cloth, 18^. 
 
io CATALOGUE OF SCIENTIFIC BOOKS 
 
 A Practical Treatise on Mill-gearing, Wheels, Shafts, 
 
 Riggers, etc. ; for the use of Engineers. By THOMAS Box. Third 
 edition, with II plates. Crown 8vo, cloth, 'js. (id. 
 
 Mining 1 Machinery: a Descriptive Treatise on the 
 
 Machinery, Tools, and other Appliances used in Mining. By G. G. 
 ANDRE, F.G.S., Assoc. Inst. C.E., Mem. of the Society of Engineers. 
 Royal 4to, uniform with the Author's Treatise on Coal Mining, con- 
 taining 182 plates, accurately drawn to scale, with descriptive text, in 
 2 vols., cloth, 3/. 12s. 
 
 CONTENTS : 
 
 Machinery for Prospecting, Excavating, Hauling, and Hoisting Ventilation Pumping 
 Treatment of Mineral Products, including Gold and Silver, Copper, Tin, and Lead, Iron, 
 Coal, Sulphur, China Clay, Brick Earth, etc. 
 
 Tables for Setting out Curves for Railways, Canals, 
 
 Roads, etc., varying from a radius of five chains to three miles. By A. 
 KENNEDY and R. W. HACKWOOD. Illustrated, 32mo, cloth, 2s. 6d. 
 
 The Science and Art of the Manufacture of Portland 
 
 Cement, with observations on some of its constructive applications. With 
 66 illustrations. By HENRY REID, C.E., Author of 'A Practical 
 Treatise on Concrete,' etc., etc. 8vo, cloth, i8j. 
 
 The Draughtsman's Handbook of Plan and Map 
 
 . Drawing-, including instructions for the preparation of Engineering, 
 Architectural, and Mechanical Drawings. With numerous illustrations 
 in the text, and 33 plates (15 printed in colours}. By G. G. ANDRE, 
 F.G.S., Assoc. Inst. C.E. 4to, cloth, 9*. 
 
 CONTENTS : 
 
 The Drawing Office and its Furnishings Geometrical Problems Lines, Dots, and their 
 Combinations Colours, Shading, Lettering, Bordering, and North Points Scales Plotting 
 Civil Engineers' and Surveyors' Plans Map Drawing Mechanical and Architectural 
 Drawing Copying and Reducing Trigonometrical Formula, etc., etc. 
 
 7^ he B oiler-maker s andiron Ship-builder s Companion, 
 
 comprising a series of original and carefully calculated tables, of the 
 utmost utility to persons interested in the iron trades. By JAMES FODEN, 
 author of ' Mechanical Tables,' etc. Second edition revised, with illustra- 
 tions, crown 8vo, cloth, 5-r. 
 
 Rock Blasting: a Practical Treatise on the means 
 
 employed in Blasting Rocks for Industrial Purposes. By G. G. ANDRE, 
 F.G.S., Assoc. Inst. C.E. With 56 illustrations and 12 plates, 8vo, cloth, 
 los. 6d. 
 
 Surcharged and different Forms of Retaining Walls. 
 
 By J. S. TATE. Illustrated, 8vo, sewed, 2s. 
 
PUBLISHED BY E. & F. N. SPON. u 
 
 A Treatise on Ropemaking as practised in public and 
 
 private Rope-yards, with a Description of the Manufacture, Rules, Tables 
 of Weights, etc., adapted to the Trade, Shipping, Mining, Railways, 
 Builders, etc. By R. CHAPMAN, formerly foreman to Messrs. Huddart 
 and Co., Limehouse, and late Master Ropemaker to H.M. Dockyard, 
 Deptford. Second edition, I2mo, cloth, 3^. 
 
 L ax tori s Builders and Contractors Tables ; for the 
 
 use of Engineers, Architects, Surveyors, Builders, Land Agents, and 
 others. Bricklayer, containing 22 tables, with nearly 30,000 calculations. 
 4to, cloth, 5-r. 
 
 Laxtoris Builders and Contractors Tables. Ex- 
 cavator, Earth, Land, Water, and Gas, containing 53 tables, with nearly 
 24,000 calculations. 4to, cloth, 5-r 
 
 Sanitary Engineering: a Guide to the Construction 
 
 of Works of Sewerage and House Drainage, with Tables for facilitating 
 the calculations of the Engineer. By BALDWIN LATHAM, C.E., M. Inst. 
 C.E., F.G.S., F.M.S., Past-President of the Society of Engineers. Second 
 edition, with numerous plates and woodczits, 8vo, cloth, I/. ioj. 
 
 Screw Cutting Tables for Engineers and Machinists, 
 
 giving the values of the different trains of Wheels required to produce 
 Screws of any pitch, calculated by Lord Lindsay, M.P., F.R.S., F.R.A.S., 
 etc. Royal 8vo, cloth, oblong, 2s. 
 
 Screw Cutting Tables, for the use of Mechanical 
 
 Engineers, showing the proper arrangement of Wheels for cutting the 
 Threads of Screws of any required pitch, with a Table for making the 
 Universal Gas-pipe Threads and Taps. By W. A. MARTIN, Engineer. 
 Second edition, royal 8vo, oblong, cloth, is., or sewed, 6d. 
 
 A Treatise on a Practical Method of Designing Slide- 
 
 Valve Gears by Simple Geometrical Constrtiction, based upon the principles 
 enunciated in Euclid's Elements, and comprising the various forms of 
 Plain Slide- Valve and Expansion Gearing ; together with Stephenson's, 
 Gooch's, and Allan's Link-Motions, as applied either to reversing or to 
 variable expansion combinations. By EDWARD J. COWLING WELCH, 
 Memb. Inst. Mechanical Engineers. Crown 8vo, cloth, 6s. 
 
 Cleaning and Scouring : a Manual for Dyers, Laun- 
 dresses, and for Domestic Use. By S. CHRISTOPHER. i8mo, sewed, 6d. 
 
 A Handbook of House Sanitation ; for the use of all 
 
 persons seeking a Healthy Home. A reprint of those portions of Mr. 
 Bailey-Denton's Lectures on Sanitary Engineering, given before the 
 School of Military Engineering, which related to the "Dwelling," 
 enlarged and revised by his Son, E. F. BAILEY-DENTON, C.E., B.A. 
 With 140 illustrations, 8vo, cloth, 8*. 6d. 
 
12 CATALOGUE OF SCIENTIFIC BOOKS 
 
 Treatise on Valve-Gears, with special consideration 
 
 of the Link-Motions of Locomotive Engines. By Dr. GUSTAV ZEUNER. 
 Third edition, revised and enlarged, translated from the German, with the 
 special permission of the author, by MORITZ MULLER. Plates, 8vo, 
 cloth, I2s. 6d. 
 
 A Pocket-Book for Boiler Makers and Steam Users, 
 
 comprising a variety of useful information for Employer and Workman, 
 Government Inspectors, Board of Trade Surveyors, Engineers in charge 
 of Works and Slips, Foremen of Manufactories, and the general Steam- 
 using Public. By MAURICE JOHN SEXTON. Second edition, royal 
 32mo, roan, gilt edges, $s. 
 
 The Strains upon Bridge Girders and Roof Trusses, 
 
 including the Warren, Lattice, Trellis, Bowstring, and other Forms of 
 Girders, the Curved Roof, and Simple and Compound Trusses. By 
 THOS. CARGILL, C.E.B.A.T., C.D., Assoc. Inst. C.E., Member of the 
 Society of Engineers. With 64 illustrations, drawn and worked out to scale, 
 8vo, cloth, 12s. 6d. 
 
 A Practical Treatise on the Steam Engine, con- 
 taining Plans and Arrangements of Details for Fixed Steam Engines, 
 with Essays on the Principles involved in Design and Construction By 
 ARTHUR RIGG, Engineer, Member of the Society of Engineers and of 
 the Royal Institution of Great Britain. Demy 4to, copiously illustrated 
 with woodcuts and 96 plates, in one Volume, half-bound morocco, 2.1. 2s. ; 
 or cheaper edition, cloth, 2$s. 
 
 This work is not, in any sense, an elementary treatise, or history of the steam engine, but 
 is intended to describe examples of Fixed Steam Engines without entering into the wide 
 domain of locomotive or marine practice. To this end illustrations will be given of the most 
 recent arrangements of Horizontal, Vertical, Beam, Pumping, Winding, Portable, Semi- 
 portable, Corliss, Allen, Compound, and other similar Engines, by the most eminent Firms in 
 Great Britain and America. The laws relating to the action and precautions to be observed 
 in the construction of the various details, such as Cylinders, Pistons, Piston-rods, Connecting- 
 rods, Cross-heads, Motion- blocks, Eccentrics, Simple, Expansion, Balanced, and Equilibrium 
 Slide-valves, and Valve-gearing will be minutely deali with. In this connection will be found 
 articles upon the Velocity of Reciprocating Parts and the Mode of Applying the Indicator, 
 Heat and Expansion of Steam Governors, and the like. It is the writer's desire to draw 
 illustrations from every possible source, and give only those rules that present practice deems 
 correct. 
 
 Barlow s Tables of Sqiiares, Cubes, Square Roots, 
 
 Cube Roots, Reciprocals of ail Integer Numbers ^lp to 10,000. Post 8vo, 
 cloth, 6s. 
 
 Caimis (M.) Treatise on the Teeth of Wheels, demon- 
 strating the best forms which can be given to them for the purposes of 
 Machinery, such as Mill-work and Clock-work, and the art of finding 
 their numbers. Translated from the French, with details of the present 
 practice of Millwrights, Engine Makers, and other Machinists, by 
 ISAAC HAWKINS. Third edition, with \% plates, 8vo, cloth, 5*. 
 
PUBLISHED BY E. & F. N. SPON. i3 
 
 A Practical Treatise on the Science of Land and 
 
 Engineering Surveying, Levelling, Estimating Quantities, etc., with a 
 general description of the several Instruments required for Surveying, 
 Levelling, Plotting, etc. By H. S. MERRETT. Third edition, 41 plates 
 with ilhistrations and tables, royal 8vo, cloth, I2J. 6d. 
 
 PRINCIPAL CONTENTS : 
 
 Part i. Introduction and the Principles of Geometry. Part 2. Land Surveying; com- 
 prising General Observations The Chain Offsets Surveying by the Chain only Surveying 
 Hilly Ground To Survey an Estate or Parish by the Chain only Surveying with the 
 Theodolite Mining and Town Surveying Railroad Surveying Mapping Division and 
 Laying out of Land Observations on Enclosures Plane Trigonometry. Part 3. Levelling 
 Simple and Compound Levelling The Level Book Parliamentary Plan and Section 
 Levelling with a Theodolite Gradients Wooden Curves To Lay out a Railway Curve 
 Setting out Widths. Part 4. Calculating Quantities generally for Estimates Cuttings and 
 Embankments Tunnels Brickwork Ironwork Timber Measuring. Part 5. Description 
 and Use of Instruments in Surveying and Plotting The Improved Dumpy Level Troughton's 
 Level The Prismatic Compass Proportional Compass Box Sextant Vernier Panta- 
 graph Merrett's Improved Quadrant Improved Computation Scale The Diagonal Scale- 
 Straight Edge and Sector. Part 6. Logarithms of Numbers Logarithmic Sines and 
 Co-Sines, Tangents and Co-Tangents Natural Sines and Co-SinesTables for Earthwork, 
 for Setting out Curves, and for various Calculations, etc., etc., etc. 
 
 Saws: the History, Development, Action, Classifica- 
 tion, and Comparison of Saws of all kinds. By ROBERT GRIMSHAW. 
 With 220 illustrations, 410, cloth, I2J. 6d. 
 
 A Sitpplement to the above ; containing additional 
 
 practical matter, more especially relating to the forms of Saw Teeth for 
 special material and conditions, and to the behaviour of Saws under 
 particular conditions. With 120 illustrations, cloth, 9-r. 
 
 A Guide for the Electric Testing of Telegraph Cables. 
 
 By Capt. V. HOSKICER, Royal Danish Engineers. With illustrations, 
 second edition, crown 8vo, cloth, 4^. 6d. 
 
 Laying and Repairing Electric Telegraph Cables. By 
 
 Capt. V. HOSKICER, Royal Danish Engineers. Crown 8vo, cloth, 
 3J. 6d. 
 
 A Pocket- Book of Practical Rules for the Proportions 
 
 of Modern Engines and Boilers for Land and Marine purposes. By N. P. 
 BURGH. Seventh edition, royal 32mo, roan, 45-. 6d. 
 
 Table of Logarithms of the Natural Numbers, from 
 
 i to 108,000. By CHARLES BABBAGE, Esq., M.A. Stereotyped edition, 
 royal 8vo, cloth, 7.5-. 6d. 
 
 To ensure the correctness of these Tables of Logarithms, they were compared with Callett's, 
 Vega's, Mutton's, Briggs', Gardiner's, and Taylor's Tables of Logarithms, and carefully read 
 by nine different readers ; and further, to remove any possibility of an error remaining, the 
 stereotyped sheets were hung up in the Hall at Cambridge University, and a reward offered 
 to anyone who could find an inaccuracy. So correct are these Tables, that since their first 
 issue in 1827 no error has been discovered. 
 
14 CATALOGUE OF SCIENTIFIC BOOKS 
 
 The Steam Engine considered as a Heat Engine : a 
 
 Treatise on the Theory of the Steam Engine, illustrated by Diagrams, 
 Tables, and Examples from Practice. By JAS. H. COTTERILL, M.A., 
 F.R.S., Professor of Applied Mechanics in the Royal Naval College. 
 8vo, cloth, I2J-. 6d. 
 
 The Practice of Hand Turning in Wood, Ivory, Shell, 
 
 etc., with Instructions for Turning such Work in Metal as may be required 
 in the Practice of Turning in Wood, Ivory, etc. ; also an Appendix on 
 Ornamental Turning. (A book for beginners.) By FRANCIS CAMPIN. 
 Second edition, with wood engravings, crown 8vo, cloth, 6s. 
 
 CONTENTS : 
 
 On Lathes Turning Tools Turning Wood Drilling Screw Cutting Miscellaneous 
 Apparatus and Processes Turning Particular Forms Staining Polishing Spinning Metals 
 Materials Ornamental Turning, etc. 
 
 Health and Comfort in Hoiise Building, or Ventila- 
 tion with Warm Air by Self-Acting Suction P(nver, with Review of the 
 mode of Calculating the Draught in Hot- Air Flues, and with some actual 
 Experiments. By J. DRYSDALE, M.D., and J. W. HAYWARD, M.D. 
 Second edition, with Supplement, with plates, demy 8vo, cloth, 'js. 6d. 
 
 Treatise on Watchwork, Past and Present. By the 
 
 Rev. H. L. NELTHROPP, M.A., F.S.A. With 32 illustrations, crown 
 8vo, cloth, 6s. 6d. 
 
 CONTENTS : 
 
 Definitions of Words and Terms used in Watchwork Tools Time Historical Sum- 
 mary On Calculations of the Numbers for Wheels and Pinions;, their Proportional Sizes, 
 Trains, etc. Of Dial Wheels, or Motion Work Length of Time of Going without Winding 
 up The Verge The Horizontal The Duplex The Lever The Chronometer Repeating 
 Watches Keyless Watches The Pendulum, or Spiral Spring Compensation Jewelling of 
 Pivot Holes Clerkenwell Fallacies of the Trade Incapacity of Workmen How to Choose 
 and Use a Watch, etc. 
 
 Spons Engineers' and Contractors Illustrated Book 
 
 of Prices of Machines, Tools, Ironwork, and Contractors' Material; 
 and Engineers* Directory. Third edition, 410, cloth, 6s. 
 
 Algebra Self-Taught. By W. P. HIGGS, M.A., 
 
 D.Sc., LL.D., Assoc. Inst. C.E., Author of 'A Handbook of the Differ- 
 ential Calculus,' etc. Second edition, crown 8vo, cloth, 2s. 6d. 
 
 CONTENTS : 
 
 and Proportionate Parts Transformation of System of Logarithms Common Uses of 
 Common Logarithms Compound Multiplication and the Binomial Theorem Division, 
 Fractions, and Ratio Continued Proportion The Series and the Summation of the h'eries 
 Limit of Series Square and Cube Roots Equations List of Formulae, etc. 
 
PUBLISHED BY E. & F. N. SPON. 
 
 JUST PUBLISHED. 
 
 tn super-royal 8vo, 1168 pp., with 2400 illustrations, in 3 Divisions, cloth, price 13*. 
 each ; or i vol., cloth, a/. ; or half-morocco, a/. 8,r. 
 
 A SUPPLEMENT 
 
 SPONS' DICTIONARY OF ENGINEERING, 
 
 Cifril, fpcdjmtiral, UKlitarg, mtb |takl 
 
 EDITED BY ERNEST SPON, MEMB. Soc. ENGINEERS. 
 
 THE success which has attended the publication of ' SPONS' DICTIONARY OF 
 ENGINEERING' has encouraged the Publishers to use every effort tending to 
 keep the work up to the standard of existing professional knowledge. As the 
 Book has now been some years before the public without addition or revision, 
 there are many subjects of importance which, of necessity, are either not 
 included in its pages, or have been treated somewhat less fully than their 
 present importance demands. With the object, therefore, of remedying these 
 omissions, this Supplement is now being issued. Each subject in it is treated 
 in a thoroughly comprehensive way ; but, of course, without repeating the 
 information already included in the body of the work. 
 The new matter comprises articles upon 
 
 Abacus, Counters, Speed 
 Indicators, and Slide 
 Rule. 
 
 Agricultural Implements 
 and Machinery. 
 
 Air Compressors. 
 
 Animal Charcoal Ma- 
 chinery. 
 
 Antimony, 
 
 Axles and Axle-boxes. 
 
 Barn Machinery. 
 
 Belts and Belting. 
 
 Blasting. Boilers. 
 
 Brakes. 
 
 Brick Machinery. 
 
 Bridges. 
 
 Cages for Mines. 
 
 Calculus, Differential and 
 Integral. 
 
 Canals. 
 
 Carpentry. 
 
 Cast Iron, 
 
 Cement, Concrete, 
 Limes, and Mortar. 
 
 Chimney Shafts. 
 
 Coal Cleansing and 
 Washing. 
 
 Coal Mining. 
 
 Coal Cutting Machines. 
 
 Coke Ovens. Copper. 
 
 Docks. Drainage. 
 
 Dredging Machinery. 
 
 Dynamo - Electric and 
 Magneto-Electric Ma- 
 chines. 
 
 Dynamometers. 
 
 Electrical Engineering, 
 Telegraphy, Electric 
 Lighting and its prac- 
 ticaldetails,Telephones 
 
 Engines, Varieties of. 
 
 Explosives. Fans. 
 
 Founding, Moulding and 
 the practical work of 
 the Foundry. 
 
 Gas, Manufacture of. 
 
 Hammers, Steam and 
 other Power. 
 
 Heat. Horse Power. 
 
 Hydraulics. 
 
 Hydro-geology. 
 
 Indicators. Iron. 
 
 Lifts, Hoists, and Eleva- 
 tors. 
 
 Lighthouses, Buoys, and 
 Beacons. 
 
 Machine Tools. 
 
 Materials of Construc- 
 tion. 
 
 Meters. 
 
 Ores, Machinery and 
 Processes employed to 
 Dress. 
 
 Piers. 
 
 Pile Driving. 
 
 Pneumatic Transmis- 
 sion. 
 
 Pumps. 
 
 Pyrometers. 
 
 Road Locomotives. 
 
 Rock Drills. 
 
 Rolling Stock. 
 
 Sanitary Engineering. 
 
 Shafting. 
 
 Steel. 
 
 Steam Navvy. 
 
 Stone Machinery. 
 
 Tramways. 
 
 Well Sinking. 
 
NOW COMPLETE. 
 
 With nearly 1500 illustrations, in super-royal 8vo, in 5 Divisions, cloth. 
 Divisions I to 4, 13^. 6d. each ; Division 5, I'js.dd. ; or 2 vols., cloth, ,3 IQJ. 
 
 : SPONS' ENCYCLOPEDIA 
 
 OF THE 
 
 INDUSTRIAL ARTS, MANUFACTURES, AND COMMERCIAL 
 PRODUCTS. 
 
 EDITED BY C. G. WARNFORD LOCK, F.L.S. 
 
 Among the more important of the subjects treated of, are the 
 following : 
 
 Acids, 207 pp. 220 figs. 
 Alcohol, 23 pp. 1 6 figs. 
 Alcoholic Liquors, 13 pp. 
 Alkalies, 89 pp. 78 figs. 
 Alloys. Alum. 
 
 Asphalt. Assaying. 
 Beverages, 89 pp. 29 figs. 
 Blacks. 
 
 Bleaching Powder, 1 5 pp. 
 Bleaching, 5 1 pp. 48 figs. 
 Candles, 18 pp. 9 figs. 
 Carbon Bisulphide. 
 Celluloid, 9 pp. 
 Cements. Clay. 
 Coal-tar Products, 44 pp. 
 
 14 figs. 
 Cocoa, 8 pp. 
 Coffee, 32 pp. 13 figs. 
 Cork, 8 pp. 17 figs. 
 Cotton Manufactures, 62 
 
 pp. 57 figs. 
 Drugs, 38 pp. 
 Dyeing and Calico 
 
 Printing, 28 pp. 9 figs. 
 Dyestuffs, 16 pp. 
 Electro-Metallurgy, 13 
 
 pp. 
 
 Explosives, 22 pp. 33 figs. 
 Feathers. 
 Fibrous Substances, 92 
 
 pp. 79 figs. 
 Floor-cloth, 1 6 pp. 21 
 
 figs. 
 
 Food Preservation, 8 pp. 
 Fruit, 8 pp. 
 
 Fur, 5 pp. 
 
 Gas, Coal, 8 pp. 
 
 Gems. 
 
 Glass, 45 pp. 77 figs. 
 
 Graphite, 7 pp. 
 
 Hair, 7 pp. 
 
 Hair Manufactures. 
 
 Hats, 26 pp. 26 figs. 
 
 Honey. Hops. 
 
 Horn. 
 
 Ice, 10 pp. 14 figs. 
 
 Indiarubber Manufac- 
 tures, 23 pp. 17 figs. 
 
 Ink, 17 pp. 
 
 Ivory. 
 
 Jute Manufactures, 1 1 
 pp., ii figs. 
 
 Knitted Fabrics 
 Hosiery, 15 pp. 13 figs. 
 
 Lace, 13 pp. 9 figs. 
 
 Leather, 28 pp. 3 1 figs. 
 
 Linen Manufactures, 16 
 pp. 6 figs. 
 
 Manures, 21 pp. 30 figs. 
 
 Matches, 17 pp. 38 figs. 
 
 Mordants, 13 pp. 
 
 Narcotics, 47 pp. 
 
 Nuts, 10 pp. 
 
 Oils and Fatty Sub- 
 stances, 125 pp. 
 
 Paint. 
 
 Paper, 26 pp. 23 figs. 
 
 Paraffin, 8 pp. 6 figs. 
 
 Pearl and Coral, 8 pp. 
 
 Perfumes, 10 pp. 
 
 Photography, 13 pp. 20 
 
 figs. 
 
 Pigments, 9 pp. 6 figs. 
 Pottery, 46 pp. 57 figs. 
 Printing and Engraving, 
 
 20 pp. 8 figs. 
 Rags. 
 Resinous and Gummy 
 
 Substances, 75 pp. 16 
 
 figs. 
 
 Rope, 1 6 pp. 17 figs. 
 Salt, 31 pp. 23 figs. 
 Silk, 8 pp. 
 Silk Manufactures, 9 pp. 
 
 II figs. 
 Skins, 5 pp. 
 Small Wares, 4 pp. 
 Soap and Glycerine, 39 
 
 pp. 45 %s. 
 Spices, 1 6 pp. 
 Sponge, 5 pp. 
 Starch, 9 pp. 10 figs. 
 Sugar, 155 pp. 134 
 
 figs. 
 
 Sulphur. 
 Tannin, 1 8 pp. 
 Tea, 12 pp. 
 Timber, 13 pp. 
 Varnish, 15 pp. 
 Vinegar, 5 pp. 
 Wax, 5 pp. 
 Wool, 2 pp. 
 Woollen Manufactures, 
 
 58 pp. 39 figs. 
 
 London: E. & F. N. SPON, 16, Charing Cross. 
 
 New York : 44, Murray Street. 
 
 

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