FOREWORD By kind permission of Antenna, we reproduce below, in a more compact version, the article "The Telephon of Philipp Reis" by Basilio Catania, appeared on Antenna, Newsletter of the Mercurians, Vol. 17, No. 1, October 2004, p. 3-8. Read the full article at the Mercurians site.

The "Telephon" of Philipp Reis

Johann Philipp Reis (1834-1874)

Toward the end of 2003, news from the London Science Museum caused some excitement among the scientific community, when they revealed that successful tests on an 1863 Reis telephone conducted in 1947 by the British company Standard Telephones and Cables (STC) had been kept secret in order not to jeopardize negotiations then in course between Standard Telephones and Cables and American Telegraph & Telephone (AT&T) [1, 2, 3, 4]. The Standard Telephones and Cables' tests were said to have shown that Reis's Telephon (the inventor's term for his instrument) could transmit speech sufficiently well, and therefore Reis deserved to be recognized as the true inventor of the telephone, perhaps on a par with Antonio Meucci [1, 2, 4]. Having extensively investigated both Antonio Meucci and Philipp Reis, I wish to offer my fellow Mercurians my findings on this subject. An essay of my research on Antonio Meucci was given in Antenna some years ago [5, 6]. A full list of my publications on this subject is reported in http://www.esanet.it/chez_basilio/meucci.htm.

Tests on the Reis Telephon

Let me first point out that the above mentioned papers [1, 2, 3, 4] do not provide details about the nature of the tests performed by Standard Telephones and Cables engineers nor about the results obtained. Therefore, it is not possible to compare those tests, for instance, with tests conducted in 1932 by British Post Office researchers on the same subject. Contrary to the Standard Telephones and Cables tests, the results of the British Post Office tests were published [7], and later referred to by, among others, William Aitken in 1939 [8, p. 34] and Michael Woolley, International Telecommunications Union (ITU) General Secretary, in 1976 [9]. Here is an excerpt of the British Post Office study as reported by Aitken (italics added for emphasis):

«Recently it was suggested that the description of Reis' instruments in the Science Museum was hardly fair to Graham Bell, and the question was discussed by the Council of The Institution of Electrical Engineers.» As a result the Post Office experts tested these instruments and reported that: «When the platinum contacts were so adjusted as to be microphonic they would act as a fairly satisfactory microphone. This was verified by the P. O. Research Section, using a modern receiver and a step up transformer. When the adjustment was exactly right, speech was transmitted reasonably well, the volume being 20 db, or so below that of a carbon transmitter, but it was impossible to keep the adjustment right for long.»

Aitken also reported that Prof. David Hughes, universally recognized as the first inventor of the carbon microphone, tested a Reis telephone during his 1865 visit to St. Petersburg. Hughes later commented on those tests [8, p. 33] (italics added):

I was enabled to transmit and receive perfectly all musical sounds, and also a few spoken words, though these were rather uncertain, for at one moment a word could be clearly heard, and then from some unexplained cause no words were possible. This wonderful instrument was based upon the true theory of telephony, and it contained all the necessary organs to make it a practical success . . . . I also believe that the often successful transmission of words by Prof. Reis' transmitter was due to an accidental adjustment of his contacts to a true microphonic condition.

 In more recent times, Prof. Bernard S. Finn, Curator of the Division of Electricity and Modern Physics of the National Museum of American History (Smithsonian Institution) in Washington, D. C., stated [10] (italics added):

 . . . . if the sound entering a Reis transmitter is not too strong, contact between the metal point and the metal strip will not be broken. Instead, the pressure of the former on the latter will fluctuate with the sound, causing fluctuations in the electrical resistance and therefore in the current. Similarly, the receiver will respond to continuously fluctuating as well as to intermittent currents (but not by magnetostriction). The sensitivity, however, is extremely low, so low that it is not unreasonable to question the validity of the limited testimony regarding successful voice transmission in the 1860s.

 In other words, the ability of Reis' telephone transmitter to transmit speech with acceptable quality, though at a much lower level, was quite known both before and after the aforesaid Standard Telephone and Cable tests. As for Reis' telephone receiver, when operated by magnetostriction-- that is, on the principle on which it was designed and intended to operate -- it had inherent limitations that prevented its use for speech transmission, and was marginally acceptable for the mere transmission of tones. For this reason, the above experimenters generally used a regular electromagnetic receiver to evaluate the "microphonic" performance of the Reis transmitter.

Other authors, among them Silvanus P. Thompson -- considered to be the utmost Reis biographer and supporter -- have gone so far as to state that Reis transmitter was "fundamentally similar" to the carbon microphones later patented by Thomas Edison, Francis Blake and Emile Berliner.

Let us now delve a little more into the birth and development of the Reis' Telephon.

Invention and Development of the Reis Telephon

It has been said justly that the telephone is the son of the telegraph. The success of this great precursor was so overwhelming and so escalating that many inventors began to wonder what else could they do by applying the same marvelous principle of the telegraph, namely the "make-and-break" of the electric current to transmit other types of signals, such as music or speech.

It is recognized unanimously that the first to envisage speech transmission by such a technique was the French Charles Bourseul who, on August 18, 1854, sent a letter to the Parisian journal L'Illustration [11], in which he stated ( italics added):

I have asked myself . . . . if the spoken word itself could not be transmitted by electricity. . . . The thing is practicable in this way:--
. . . . Suppose that a man speaks near a movable disk, sufficiently flexible to lose none of the vibrations of the voice; that this disk alternately makes and breaks the connection with a battery; you may have at a distance another disk which will simultaneously execute the same vibrations. It is true that the intensity of the sounds produced will be variable at the point of departure, at which the disk vibrates by means of the voice, and constant at the point of arrival, where it vibrates by means of electricity; but it has been shown that this does not change the sounds. It is, moreover, evident that the sounds will be reproduced at the same pitch. The present state of acoustic science does not permit us to declare a priori if this will be precisely the case with syllables uttered by the human voice. . . . However this may be, observe that the syllables can only reproduce upon the sense of hearing the vibrations of the intervening medium. Reproduce precisely these vibrations, and you will reproduce precisely these syllables.

There is no doubt that Charles Bourseul would have gone beyond the mere description of a principle, if he were not discouraged by both his managers (he was then working in a telegraph office in Paris), and the scientists of the Paris Académie des Sciences, the latter harshly criticized by the editor of L'Illustration [11]. The Paris article was picked up shortly afterward in September 1854 by the German paper Didaskalia of Frankfurt-am-Main [12]. There it appears to have met with greater appreciation. Many writers ([8, p. 17-18]; [13]) reported that Johann Philipp Reis, professor of Physics at the Garnier Institute of Friedrichsdorf, had read it and decided to embark on a practical realization of Bourseul's ideas.

Philipp Reis essentially devised three different models of his Telephon, all of which were based on the same principle, namely the "make-and-break" of the current in the transmitter and the "magnetostriction" or "galvanic music" in the receiver. The latter was first discovered by Prof. Charles Grafton Page in 1837 [14].

Reis built his first telephone model in 1858, four years after Bourseul's paper, as related in detail by Silvanus Thompson [15]. The transmitter consisted of an ear-like acoustic structure, that terminated in a tympanum whose oscillations caused the make-and break of an electric current through a slender S-shaped rod glued at one end to the center of the tympanum. The receiver consisted of a six-inches long coil, wound on a knitting needle, similar to that shown in Figure 1 below, but set perpendicularly on top of a violin case, which acted as a sounding board.

Figure 1. Reis telephone ( third version) on sale by Wilhelm J. Albert, Frankfurt, from Comte Théodose Du Moncel, Le Téléphone (Paris: Librairie Hachette et Cie., 1882), p. 15

Reis made his second telephone model in 1861 and demonstrated it before the Physikalischen Vereins (Physical Society) of Frankfurt-am-Main on October 26, 1861 [16]. This time the transmitter (Figure 2) consisted of a hollow conical cavity bored in a block of wood which terminated in an animal membrane upon which was glued a thin strip of platinum that connected to one pole of the battery. Another thin strip of metal, holding at a right angle a platinum wire, was placed in such a manner as to have the end of the wire very near but not touching the other strip at the center of the membrane, in order to make-and-break the current according to the pressure of the sounds channeled into the cone. The screw (h in Figure 2) served to adjust the distance between the aforesaid platinum wire and the strip glued on the membrane.

Figure 2. Reis transmitter (second version) of 1861, from [Theodor Stein, letter to the editor] "Can Speech be Transmitted with the Bored-Block Transmitter of Philipp Reis?" The Electrician and Electrical Engineer (July 1887): 281-2

The receiver was very similar to that shown in Figure 1 , differing from the former model in that the violin case was replaced by a regular (parallelepided-shaped) sounding box on which the solenoid (still wound on a knitting needle) was placed horizontally . The operator put his ear on top of the wood cover (which was normally closed) for better reception of the sounds.

A variation of Reis' second model was built in the second half of 1862 by Wilhelm von Legat, inspector of the Royal Prussian Telegraphs, on the basis of information gathered from the available literature [18]. Some authors consider this one to be Reis's third model, while others--more appropriately--refer to it as "Reis-Legat" model. Legat's transmitter differed from Reis' second transmitter in that he used an hollow conical tube (instead of a hollow bored into a block of wood), and the make-and-break device resembled more Reis' first model's S-shaped rod, held in place by a spring. Although Legat based his receiver on magnetostriction, it differed quite substantially in construction from Reis' first and second receiver models. It utilized a horseshoe electromagnet (featuring an iron core much larger in diameter than the Reis's knitting needle) placed upon a sounding board, but equipped additionally with a light armature that was kept in contact with the poles of the electromagnet by means of a spring and attached to a plate "suspended in the manner of a pendulum." The purpose of this alteration was to improve the communication of the vibrations of the core--caused by magnetostriction--to the surrounding air.

 Philipp Reis continued his experiments and developed a third model of his Telephon (Figure 1). He first demonstrated it to the Physical Society in Frankfurt-am-Main on July 4, 1863 [20]. The third was the most known and widely available Reis model. It was built initially by J. Wilhelm Albert of Frankfurt, and later by the Hauck firm of Vienna, and it sold in Europe and the United States at a price of 14 or 21 florins, depending on the finishing. Among the most renowned examples of Reis' third model are:

• that of the London Science Museum , said to be the property of the Institution of Electrical Engineers;
• that bought by William Ladd of London, who demonstrated it before the British Association for the Advancement of Science on August 28, 1863 [21];
• that exhibited by Prof. Clifton on November 10, 1864, before the Manchester Literary and Philosophical Society [22];
• that demonstrated by Mr. Shearer, dealer of the shop "Messrs. Kemp & Co." of Edinburgh (where Bell was living) in December of 1862 and afterward put on sale in the same shop [23, 24];
• that acquired from Mr. Ladd by Stephen M. Yeates of Dublin in the Fall of 1863 and demonstrated to the British Association at Newcastle-on-Tyne in December 1863, as well as, in a modified version, to the Dublin Philosophical Society in December 1865 ([8], p. 39-40);
• that seen and tested by Prof. David Hughes in St. Petersburg, Russia;
• that acquired by the Smithsonian Institution, Washington, DC, which Prof. Joseph Henry showed to Alexander Graham Bell on March 1 or 2, 1875 [25];

The same model was also demonstrated in September 1863 to both the Emperor of Austria, Franz Joseph, and the King Max of Bavaria, on the occasion of their visit to the Goethe's birthplace (which became the head office of the Freies Deutscher Hochstift) in Frankfurt-am-Main ([8], p. 21).

The most remarkable innovation of Reis' third model was in the transmitter, which was now housed in a cube-shaped box of wood (Figure 1), with the upper face holding the membrane and its make-and-break device. Two lateral faces held, respectively, the speaking tube and a simplified Morse apparatus, to be used for signaling. A tripod, clamped at one edge and holding the platinum wire in the middle, replaced the corresponding platinum strip employed in the first two models. Also, Reis suggested putting a drop of mercury in a small bowl at the center of the tympanum to facilitate the intermittent contact with the platinum wire.

Conclusions

Reis third model met with an exceptional success, all over the world.

It is worth pointing out that the United States, in its case against Alexander Graham Bell, cited Antonio Meucci and Philipp Reis as the precursors of the electromagnetic telephone and the variable resistance telephone, respectively [26]. An impressive list of 61 articles concerning Reis's telephone (plus 5 concerning Bourseul), was appended to the printed version of the "Deposition of Antonio Meucci" available at the New York Public Library.

It is also worth recalling that Reis's Telephon was studied, tested and modified by scores of scientists, including Stephen Yeates, Peter Van der Weyde, the brothers Cecil and Leonard Wray ([8], p. 39 et seq.), and Silvanus P. Thompson [26], to name a few.

Philipp Reis would have improved his Telephon and offered us more creations from his ingenious mind, if he had not died prematurely on January 14, 1874, just one week after his fortieth birthday.

Reis must be admired not only because of his inventive genius, but also for his generosity and modesty, since he gave his invention to the world. In fact, not only did he not file an application for a patent, but he also disclosed all details of construction and operation of his Telephon both orally and in writing to anyone wishing to know them. In the circular accompanying the apparatus sold by W. J. Albert he stated "I am now able to offer an apparatus with which every physicist will succeed in repeating these interesting experiments regarding the reproduction of tone at distant stations." He therefore followed the noble tradition of physicists who used to freely exchange knowledge, instruments and ideas all over the world, without caring about making money out of them.

Very probably because there were no royalties to be paid to Philipp Reis or his successors for his invention (as was the case of Meucci), many competitors of the Bell Company in the United States in the 1880s maintained Reis' priority in the invention of the telephone. They tried to stretch the "make-and-break" transmitter principle into a "loose contact" principle, thence to a "variable pressure" principle, and later to a "variable resistance" principle. Similarly, the Reis receiver as improved by Legat was gradually transformed to work with a "nonzero" air gap, thus obtaining a regular electromagnetic receiver. Lawyers argued for these stretched interpretations and claimed that Reis had anticipated Bell, Edison, Blake, and Berliner. In other words they maintained that Reis invented everything! God save the physicists from the lawyers (as well as from the physicists who supported the lawyers)!

Unfortunately, trying to put Reis on a higher pedestal, they ended up damaging his public image, since they unfairly exposed him to the counterattack of Bell's supporters. Nonetheless, Philipp Reis must remain in our hearts and minds as a superb man and scientist, deserving an everlasting recognition for his outstanding contribution to the progress of telecommunications.

References

[1] Liam McDougall, "Official: Bell didn't invent the telephone--'Top secret' file reveals that businessmen suppressed the identity of the telephone's real inventor," Sunday Herald Online, November 23, 2003, http://www.sundayherald.com/38216
[2] "Bell 'did not invent telephone' -- Claims that a German scientist invented the telephone 15 years before Alexander Graham Bell are supported by evidence from newly surfaced archive papers," BBC News Online, http://news.bbc.co.uk/go/pr/fr//2/hi/science/nature/3253174.stm, 1 December, 2003
[3] Roger Highfield, "Debate over who invented first phone hushed up for 50 years," The Daily Telegraph of London, December 1, 2003, available from http://www.telegraph.co.uk/ upon registration.
[4] "Who Invented the Telephone?" Antenna, Vol. 16, No. 2 (April 2004): 14
[5] Basilio Catania, "Antonio Meucci Revisited," Antenna, Vol. 9, No. 1 (November 1996): 4-5
[6] Basilio Catania,"Truth & Myth & 'Firsts'", Antenna, Vol. 13, No. 1 (November 2000): 2 & 11
[7] "The First Telephone," Post Office Electrical Engineers Journal, Vol. 25 (July 1932): 116-117
[8] William Aitken, Who invented the telephone? (London: Blackie and Son Limited, 1939)
[9] Michael Woolley, "The Telephone, its Invention, and Development," Telecommunication Journal, Vol. 43 (III/1976): 175-183.
[10] Bernard S. Finn, "Telephone," in Encyclopaedia Britannica, 15th Edition, 1990, 495-499
[11] Charles Bourseul, "Transmission électrique de la parole" (avec préface de la rédaction), L'Illustration, Journal Universel, Vol. XXIV, N. 600 (August 26, 1854): 139.
[12] "Elektrische Telephonie," Didaskalia, Blatter für Geist, Gemüth und Publicität, Vol. 32, No. 232 (September 28, 1854).
[13] [ Emile Berliner], "The History of The Telephone," The Telegraphic Journal and Electrical Review (June 28, 1884): 537-8
[14] Charles Grafton Page, "The Production of Galvanic Music," Sillimans Journal, V. XXXII, (July, 1837): 354 &396; vol. XXXIII (1838): 118.
[15] Silvanus P. Thompson, "Le premier téléphone," L'Électricien, Vol. 6, No. 54 (July 1, 1883): 60-67. A beautiful animation of Reis' first telephone (a facsimile of human ear carved in wood) is posted on the Internet by Columbia University at http://www.ilt.columbia.edu/projects/bluetelephone/html/part8.html.
[16] "Reproduktion des Schalles durch den galvanischen Strom" [Reproduction of sound by the galvanic current], Frankfurter Konversationsblatt, November 29, 1861.
[17] [Theodor Stein] "Can Speech be Transmitted with the Bored-Block Transmitter of Philipp Reis?" , The Electrician and Electrical Engineer (July 1887): 281-282.
[18] Wilhelm Von Legat, "[On the Reproduction of Sounds by means of Galvanic Current]" Zeitschrift des Deutsche-Österreichischen Telegraphen Vereins [Journal of the Austro-German Telegraph Union] Vol. IX (1862): 125. Dingler's Polytechnisches Journal, Vol. CLXIX (1863): 23 reproduced the article. An English translation appears in the "Deposition of Antonio Meucci," Part III, p. 29, copy in the New York Public Library. A beautiful animation of Reis-Legat transmitter is posted on Internet by Columbia University at http://www.ilt.columbia.edu/projects/bluetelephone/html/part9.html.
[19] Comte Théodose Du Moncel, Le Téléphone (Paris, Librairie Hachette et C.ie, 1882), 15
[20] Jahresbericht der Physikalischen Vereins zu Frankfurt am Main, für das Rechnungs Jahr 1862-1863, p. 35
[21] William Ladd, "An Acoustic Telegraph," [lecture on the Reis telephone before the British Association for the Advancement of Science, 28 August 1863], The Civil Engineer and Architect's Journal, London, Vol. XXVI (1863): 307-308.
[22] "Minutes of the Meeting of the Physical and Mathematical Section, November 10, 1864," Proceedings of the Literary and Philosophical Society of Manchester (1865) [Communication of Prof. Clifton, who exhibited an "acoustical electric telegraph"].
[23] "Invention of the Telephone," The Telegraphic Journal and Electrical Review, January 15, 1886, 59. Dealt with demonstrations of Reis' telephone in Edinburgh in December 1862.
[24] Lawson Tait "Invention of the Telephone" [Letter to the Editor, about Bell having seen Reis telephone in Edinburgh], Scientific American, January 2, 1886, 6.
[25] The Deposition of Alexander Graham Bell in the suit brought by the United States to annul the Bell patents, rendered April-July, 1892 (Boston, MA: American Bell Telephone Co. 1908; Reprinted in New York, NY: Arno Press, 1974), Answer No. 54. The 61 articles appeared in the "Deposition of Antonio Meucci," in the trial instituted by the American Bell Telephone Co. et al. vs. the Globe Telephone Co. et al, Part III: "Documentary Evidence," and amounted to 112 pages of the same.
[26] Basilio Catania, "The U. S. Government Versus Alexander Graham Bell: An Important Acknowledgment for Antonio Meucci," Bulletin of Science, Technology & Society, Vol. 22, No. 6 (December 2002): 426-442.
[27] "Silvanus Thompson's Telephonic Apparatus," The Telegraphic Journal and Electrical Review, November 3, 1883, 341-343

Acknowledgements

The author is indebted to Dr. Erika Dittrich, curator of the "Philipp Reis Museum" in Friedrichsdorf, Germany, for providing extended and useful documentation on Philipp Reis.

The author is also indebted to Andrew Butrica, Editor of Antenna, for his useful suggestions, kind editing and additions to the original manuscript.

Notes about Magnetostriction

Magnetostriction is a property encountered in magnetic materials--typically, ferromagnetic materials-- where the material changes its shape upon application of a magnetic field. More precisely, as the material is magnetized, it exhibits a change in length accompanied by an inverse change in girth and, when demagnetized, it suddenly regains its original shape [1]. The change in shape of the magnet, subsequent to magnetization or demagnetization occurs very fast, the lag time being typically less than 1 microsecond [2].

The figure below, taken from [3], shows how the orientation of magnetic domains, occasioned by the application of a magnetic field H, provokes the elongation e of the material. Philipp Reis clearly explained this mechanism in his lecture of October 26, 1861 at the Physical Society in Frankfurt-am-Main [10]: "At each closing of the circuit, the atoms of the iron wire inside the distant spiral are moved away from each other (Pouillet Müller, p. 304, Vol. II., fifth edition); on breaking the circuit, these atoms seek to regain their position of equilibrium".

Orientation of magnetic domains caused by magnetization provokes the elongation e of the material [3]

In the case of an electromagnet, magnetostriction occurs each time the coil is traversed by an electric current, upon connection to a battery. As soon as the connection with the battery is broken, the magnet's length and girth return normal.

Magnetostriction can be quantified by the magnetostrictive coefficient, l, which is the fractional change in length as the magnetization of the material increases from zero to the saturation value [4]. Ferromagnetic materials exhibit a positive coefficient, of the order of 40÷50 ppm, that is, the magnet length increases by between 1/25,000 and 1/20,000 of its rest value, upon magnetization [1, 5].

The magnetostrictive effect was first identified in 1842 by James Prescott Joule, who observed that a bar of nickel changed in length when it was magnetized [1, 4, 6].

However, prior to Joule's observations, Charles Grafton Page of Salem, MA, had discovered, in 1837, that an electromagnet gives forth a sharp sound (often referred to as a "tick," or "click") when it is suddenly magnetized or demagnetized. Page also noted that "when the contact is made, the sound is very feeble; when broken it may be heard at two or three feet distance" [7, 8]. As also noted by A. Graham Bell [9], "when the circuit upon which it [the electromagnet] is placed is rapidly made and broken, a succession of explosive noises [clicks] proceeds from the magnet." The ear will therefore perceive a continuous sound similar to a musical note, with a pitch depending upon the number of clicks per second. Thence the name of "Galvanic Music" given by Page to the phenomenon. Page gave public demonstrations of his "Galvanic music," and these were deemed as kicking off research on the speaking telephone [8, 9].

The frequency of the free longitudinal vibration of the knitting needle used by Reis in his receiver affects the frequency response in a regime of forced oscillations. For this reason, Peter Van der Weyde [11] instead of a knitting needle used a bundle of five knitting needles with different length--hence with different free longitudinal vibration frequency--thus obtaining a more uniform reproduction of audible sounds.

References

[1] "Magnetostriction," by Magnetics Group, Department of Physics, University of Hull, Kingston upon Hull, GB, posted at http://www.physics.hull.ac.uk/magnetics/Research/Facilities/Magnetostriction/magnetostriction.html.
[2] Perucca, E. (Filippi, F., Editor), "Magnetostrizione," Dizionario d'Ingegneria [Dictionary of Engineering] in 13 vols., UTET - Unione Tipografico-Editrice Torinese, Torino, Italy, 1977.
[3] "Magnetostriction and Magnetostrictive Materials," Active Material Laboratory, University of California, Los Angeles, http://aml.seas.ucla.edu/research/areas/magnetostrictive/mag-composites/Magnetostriction and Magnetostrictive Materials.htm.
[4] "Magnetostriction," The Brainy Encyclopedia, http://www.brainyencyclopedia.com/encyclopedia/m/ma/magnetostriction.html.
[5] Amos E. Dolbear, The Telephone, Boston, Lee & Shepard, 1877, p. 109.
[6] James P. Joule, Philosophical Magazine, vol. XXV, 1844, p. 76, 225.
[7] Charles G. Page, [Galvanic music], Benjamin Silliman's Journal, April 5, 1837, p. 307.
[8] "C. G. Page Creates Galvanic Music," http://www.ilt.columbia.edu/projects/bluetelephone/html/part4.html.
[9] A. Graham Bell, "Researches in Electric Telephony" [Lecture given on October 31, 1877], Proceedings Society of Telegraph Engineers, London, 1877.
[10] J. Philipp Reis, "On telephony by means of the galvanic current," Jahresbericht des Physikalischen Vereins zu Frankfurt-am-Main, für das Rechnungs Jahr 1860-1861, p. 57-64 (published in 1862).
[11] Peter H. Van der Weyde, "The Telephone" [Reis], The Manufacturer and Builder, New York, Vol. I, No. 5, May 1869, p. 129-130.

• Date last modified: 8 November 2004