Chapter IV: Contemporary Documents (2)

“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
complementary telegraph to[29] the conducting screw (_s_). From
here it goes through the conducter 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 condensation 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 disturbing 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_[30] 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
sufficient to have a first try; afterward you will get on quite
alone.

“I am, Sir,
“Your most obediant Servant,
“Ph. Reis.

“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.]

TELEPHON.

Each apparatus consists, as is seen from the above illustration, of two parts: the Telephone proper, A, and the Reproduction 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, _b_, _in whose little concavity a 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 which there are perceived as a tone or combination of tones (chord). By imposing the little upper case (Oberkästchen) 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 triads (Dreiklänge) 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 oneself 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 = _b_.
3 " = _c_.
4 " = _d_.
5 " = _e_, &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 for every five beats a dactyl-beat (Dactylusschlag), and there results

for _e_.

and one beat for _f_, &c.

_z_, = 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. Reis,
Teacher at L. F. Garnier’s Institute for boys.
Friedrichsdorf, near Homburg-by-the-Height,
August 1863.

[The foregoing “Prospectus” was accompanied by a further document printed as a postscript by Reis, 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
[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. Reis,

“Teacher at L. F. Garnier’s Institute for Boys.”

[In September of the same year the telephone was shown by Prof. R Böttger 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 neighbouring University of Greifswald, has informed the author of this work that the Telephone there shown was of the form figured in Reis’s Prospectus (p. 86), and that Reis claimed at that time to be able to transmit words by his instruments. In the same autumn the following notice appeared in Böttger’s ‘Notizblatt,’ and was copied thence into Dingler’s ‘Journal,’ and other scientific papers.]

[=10.=] ON THE IMPROVED TELEPHONE.

[Translated from the original notice which appeared in
Böttger’s ‘Polytechnisches Notizblatt,’ 1863, No. 15, p. 225,
and in Dingler’s ‘Polytechnisches 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. Reis, of Friedrichsdorf, near Homburg-vor-der-Höhe, 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 Reis first gave publicity to his apparatus,[31] 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 Reis 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, and 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 experimenters 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,[32] which according 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. Röber 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 instrument, 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 ‘Gartenlaube,’ 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 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 (Fachmännern), the opportunity of witnessing with their own eyesight the efficiency of this apparatus,--lately, in fact essentially improved,--Professor Böttger of Frankfort-on-the-Main exhibited several experiments 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 Report 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 proceedings for the preceding years. Amongst those proceedings was a lecture by the late Professor Buff, at which Reis’s Telephone was shown, and at which Reis himself is believed to have been present.]

[=12.=] [EXTRACT FROM THE ‘TWELFTH REPORT OF THE UPPER-HESSIAN ASSOCIATION FOR NATURAL AND MEDICAL SCIENCE,’ (‘Oberhessische Gesellschaft für Natur und Heilkunde,’) Giessen, February 1867.]

P. 155. Report on the doings and condition of the Association 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 experiments,’ by Professor Buff.

EXHIBITION OF THE TELEPHONE TO THE NATURALISTS’ ASSOCIATION OF
GERMANY. (DEUTSCHE NATURFORSCHER VERSAMMLUNG.)

[By far the most important of all the public exhibitions given by Reis 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 assembled 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 (Göttingen), Prof. Plücker (Bonn), Prof. Quincke (Heidelberg), Prof. Dellmann (Kreutznach), Prof. Böttger (Frankfurt-a.-M. and Mainz), Prof. Kekule (Bonn), Prof. Gerlach (Erlangen), Dr. J. Frick (Carlsruhe), Dr. F. Kohlrausch (Würtzburg), Prof. Reusch (Tübingen), Prof. J. Müller (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 (Frankfurt-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 Nürnberg), 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. Reis came over from Friedrichsdorf 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 Reis himself, and by Prof. Poggendorff, the instrument was shown in action with great success. Reis expounded the story how he came to think of combining with the electric current interruptor 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. Böttger 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 REPORT OF THE GERMAN NATURALISTS’ 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. Reis 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 Reis’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 Reis 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 Müller-Pouillet’s ‘Textbook of Physics’ (Lehrbuch der Physik) edited by Professor J. Müller; in the ‘Technical Physics’ of Hessler, of Vienna, edited by Professor Pisko; in Pisko’s ‘Recent 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 MÜLLER-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.

“Figure 348[33] exhibits Reis’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 communication with the clamping-screw _a_ by means of a quite thin little strip of metal _f_ (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 _l_, while a little platinum spike fastened upon its under-side at _i_, dips into the hollow of the little metal pillar _k_, containing some quicksilver. The clamping-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 connected by a wire with _b_, 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 connexion 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 downwards, the tin-piece _h 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 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 distinctly perceptibly_, and indeed Reis found that this is the case for all tones between F and _f''_.

“In Reis’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, Reis gave to his apparatus the name _Telephone_ (Jahresbericht des physikalischen Vereins zu Frankfurt-a.-M. für 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 Gewerbeschule in Vienna, was published at Vienna in 1865. At that time the novelties in acoustics were König’s apparatus for the graphic study of sounds, König’s manometric flames, Schaffgotsch’s singing flames, Helmholtz’s ‘Researches on the Quality of Sounds,’ Duhamel’s Vibrograph, Scott and König’s Phonautograph, and Reis’s Telephone. The account given of the latter is more detailed in some respects than any other published at the time.]

Page 94.--PRINCIPLE OF THE “TELEPHON” OF REIS.

51. (_a._) Allied to the Membrane Phonautograph is the “Telephon” of Reis[34] (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 established 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;[35] though, obviously, it cannot inform _what_ is being spoken.

(_b._) 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 longitudinal or transverse or both together. Such an iron wire, lying in a multiplying wire-coil, _G_, Reis inserted at the second [receiving] station, _C_. The wire emitted sounds when the membrane was set into vibrations by singing or speaking (at _S_, Fig. 33) into the hollow cubical piece _A_. In the investigations 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 transmitter) at _S_. Usually the air of the song that was sung could be recognised by its rhythm.[36] 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 Reis is certainly a “Telephone” but not a “Phonic Telegraph.” The single means of transmission for song and speech--and that only for moderate distances--remains the old familiar speaking-tube. Nevertheless, the experiment of Reis must ever be reckoned amongst the most beautiful and interesting of school-experiments. And since the means for this are so simple, the apparatus of Reis 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 Reis 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 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.

(_b._) 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, _x x_, of which measures 9 centimetres, and its height, _u x_, 2·8 centimetres.

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, _m m_, by means of a silk thread lying in the shoulder of the same. This circular membrane is surrounded by a wider circular aperture, _b 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 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 projecting 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 0·9 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 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 correspondence 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 corresponding 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 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. Reis 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. Professor Boettger
brought the apparatus before the Naturforscher-Versammlung 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 ignorant of Reis’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 Reis’s name,[37] and speaks of him as “Reuss.”]

[=17.=] KUHN’S ‘HANDBOOK OF APPLIED ELECTRICITY,’

(‘Handbuch der Angewandten Elektricitätslehre,’ von Carl Kuhn), being vol. xx. of Karsten’s ‘Universal Encyclopædia of Physics’ (Karsten’s ‘Allgemeine Encyclopädie der Physik’).

[Karsten’s ‘Encyclopædia 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 Royal Lyceum of Munich, and member of the Munich Academy. Kuhn’s volume on ‘Applied Electricity,’ published in 1866, is to be found on the shelves of almost every library of any pretensions in Great Britain. The account given therein of Reis’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 Report (p. 70), and from Reis’s Prospectus (p. 87). The extract translated below includes all the matter that is of importance.]

P. 1017. The researches established by Reis on the 26th of October, 1861, in Frankfurt[38] have already shown that if the current interruptions follow one another almost continuously and very rapidly, in a spiral arranged with a thin iron core, the iron wire can be set into longitudinal vibrations, 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 Reis of Friedrichsdorf, before the Physical Society, and the meeting of the Free German Institute in Frankfort-on-the-Main,” relate to similar arrangements. “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 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 (récepteur). The tone-indicator (Fig. 34, p. 109) 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 indifferent, 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_, being held by a support, remains in connection with the metallic circuit. This lever, the arm, _c e_, 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, _f_, 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 communicating 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 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 _l_ 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 following:--By speaking into, singing, or conducting the tones of an instrument into the tube, _a b_, 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 rarefaction of the enclosed air. In consequence of these actions, the electro-magnet, _m m_ (Fig. 13), is correspondingly demagnetised 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 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 astonishing (?) 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 Reis’s Prospectus, and adds nothing to
the information already published.]

[This is the last of the contemporary documents bearing upon the performance of Reis’s instruments. From the prominent notice obtained at the time by the inventor, it is clear that his invention was even then accorded an honourable place amongst the acknowledged conquests of science. A critical examination of this body of evidence proves not only the substantial nature of Reis’s claim, but that the claim was openly recognised and allowed by the best authorities of the time. The thing was not done in a corner.]

FOOTNOTES:

[15] [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.

[16] [The three plates or tables with which Reis accompanied his Memoir, containing a variety of undulatory curves corresponding to various combinations 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 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 Reis’s Table I. Fig. 2 of Plate 1, was in like manner copied by Legat from the first figure of Reis’s Table II., and Fig. 3 of Plate I., which represents the curves of a non-harmonious combination 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.

[17] [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.

[18] [This is the fundamental principle, not only of the telephone, but of the phonograph; and it is wonderful with what clearness Reis had grasped his principle in 1861.]--S. P. T.

[19] [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.

[20] [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.

[21] [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 produced 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, and has found iron, steel, and cobalt wires varying from 4 to 10 inches in length, including some used by Reis himself 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 articulation transmitted surpasses that obtainable with any of the ordinary magnetic 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.

[22] [This limit is a mistake of Professor Böttger’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.

[23] [Professor Böttger had not to wait long for the fulfilment to a very large degree of this anticipation; for within six months Dingler’s Journal, in which this article appeared, contained Legat’s report on Reis’s instruments, 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.]

[24] [Compare ‘_Die Geschichte und Entwickelung des Fernsprechwesens_,’ a pamphlet issued officially in 1880 from the Imperial German Post-Office in Berlin, p. 6.]

[25] [Plate VIII. of the original in Vol. IX. of the Zeitschrift.]

[26] [Plate IX. of the original Memoir.]

[27] [This word, as the context and ending of the paragraph shows, should have been spelled _tones_. The letter, written in English by Reis 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 “_tönen_,” 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.]

[28] [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.]

[29] [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.]

[30] [This word is underscored in Reis’s original letter.]

[31] [Compare Böttger Polyt. Notizbl. 1863, p. 81, the notice translated at p. 61 preceding.]--S. P. T.

[32] [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 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.

[33] [Fig. 30 of this book.]

[34] [References.] _Telephon von Reis_ im Jahresbericht des physikalischen Vereins zu Frankfurt-a.-M. für 1860-1861, pag. 57 bis 64. _Müller-Pouillet_, Physik, 1863, 6. Auflage, II pag. 352, Fig. 325. _Berl. Ber._ für 1861, xvii. pag. 171 bis 173. Der Musiktelegraph in der “Gartenlaube” 1863, Nr. 51, pag. 807 bis 909. Aus der Natur 1862, xxi. pag. 470 bis 484; _König’s_ Catalog, 1865, pag. 5.

[35] [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; for 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 electromagnetic 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.

[36] [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.]

[37] 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 Electricity,’ 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 “Reuss,” 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:--“_If 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.

[38] Ueber Fortpflanzung der Töne auf wilkührlich weite Entfernungen, mit Hülfe der Elektricität (Telephonie). Polyt. Journ. clxviii. 185; aus Böttger’s Notizbl. 1863, Nr. 6. [See translation on page 61.]