The telephone, the microphone & the phonograph

Strictly speaking, the telephone is merely an instrument adapted for the transmission of sound to a distance, and this idea of transmitting sound is as old as the world itself. The Greeks made use of means which might effect it, and there is no doubt that these means were sometimes used for the pagan oracles. But such transmission of sound was within somewhat narrow limits, and certainly did not exceed those of a speaking-tube. Mr. Preece considers that the earliest document in which this transmission of sound to a distance is distinctly formulated, dates from 1667: he refers to a paper by one Robert Hooke, who writes to this effect: ‘It is not impossible to hear a whisper at a furlong’s distance, it having been already done; and perhaps the nature of the thing would not make it more impossible, though that furlong should be ten times multiply’d. And though some famous authors have affirm’d it impossible to hear through the thinnest plate of Muscovy glass; yet I know a way, by which ’tis easie enough to hear one speak through a wall a yard thick. It has not yet been thoroughly examin’d how far otacousticons may be improv’d, nor what other wayes there may be of quickning our hearing, or conveying sound through other bodies than the air; for that is not the only medium I can assure the reader, that I have, by the help of a distended wire, propagated the sound to a very considerable distance in an instant, or with as seemingly quick a motion as that of light, at least incomparably quicker than that which at the same time was propagated through the air; and this not only in a straight line or direct, but in one bended in many angles.’

This plan for the transmission of sound is the principle of the string telephones which have attracted attention for some years, and it remained in the stage of simple experiment until 1819, when Sir Charles Wheatstone applied it to his magic lyre. In this instrument, sounds were transmitted through a long strip of deal, with one end in connection with a sounding board: one step more led to the use of the membrane employed in string telephones. It would be difficult to say with whom this idea originated, since it is claimed, as if beyond dispute, by several telephone-makers. If we may believe some travellers, it has long been used in Spain for the correspondence of lovers. However this may be, it was not to be found among the scientific appliances of some years ago, and it was even supposed by many persons that the cord consisted of an acoustic tube of slender diameter. Although the instrument has become a child’s toy, it has great scientific importance, for it proves that vibrations capable of reproducing speech may be extremely minute, since they can be mechanically transmitted more than a hundred yards.

From the telegraphic point of view, however, the problem of transmitting sounds to a distance was far from being solved in this way, and the idea of applying electricity to this mode of transmission naturally arose as soon as the wonderful effects of electric telegraphy were observed, that is, in the years subsequent to 1839. A surprising discovery made in America by Mr. Page, in 1837, and afterwards investigated by MM. Wertheim, De la Rive, and others, must also have led up to it: for it was observed that a magnetic bar could emit sounds when rapidly magnetised and demagnetised, and these sounds corresponded with the number of currents which produced them. Again, the electric vibrators devised by MM. Macaulay, Wagner, Neef, etc., and adapted to produce musical sounds, between 1847–1852, by MM. Froment and Pétrina, showed that the problem of transmitting sounds to a distance was not insoluble. Yet, up to 1854, no one had ventured to admit the possibility of transmitting speech by electricity, and when M. Charles Bourseul published in that year a paper on the electric transmission of speech, the idea was regarded as a fanciful dream. I confess that I myself thought it incredible, and when I produced the paper in the first edition of my account of the applications of electricity, published in 1854, I felt bound to add that the scheme seemed more than doubtful. Yet, as the paper was thoughtfully written, I had no hesitation in publishing it, affixing the signature of CH. B. Events justified this daring idea, and although it did not include the only principle which could lead to the reproduction of articulate sounds, yet it was the germ of the fertile invention which has made the names of Graham Bell and Elisha Gray famous. For this reason I will again quote M. Charles Bourseul’s paper.

‘After the telegraphic marvels which can reproduce at a distance hand-writings, or even more or less complicated drawings, it may appear impossible to penetrate further into the region of the marvellous. Yet we will try to advance a few steps further. I have, for example, asked myself whether speech itself may not be transmitted by electricity—in a word, if what is spoken in Vienna may not be heard in Paris. The thing is practicable in this way:—

‘We know that sounds are made by vibrations, and are adapted to the ear by the same vibrations which are reproduced by the intervening medium. But the intensity of the vibrations diminishes very rapidly with the distance: so that it is, even with the aid of speaking-tubes and trumpets, impossible to exceed somewhat narrow limits. Suppose that a man speaks near a moveable disk, sufficiently flexible to lose none of the vibrations of the voice, that this disk alternately makes and breaks the currents from 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 à priori if this will be precisely the case with syllables uttered by the human voice. The mode in which these syllables are produced has not yet been sufficiently investigated. It is true that we know that some are uttered by the teeth, others by the lips, and so on; but this is all.

‘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.

‘It is, at all events, impossible in the present condition of science to prove the impossibility of transmitting sound by electricity. Everything tends to show, on the contrary, that there is such a possibility. When the application of electro-magnetism to the transmission of messages was first discussed, a man of great scientific attainments treated the idea as utopian, and yet there is now direct communication between London and Vienna by means of a simple wire. Men declared it to be impossible, but so it is.

‘It need not be said that numerous applications of the highest importance will immediately arise from the transmission of speech by electricity. Any one who is not deaf and dumb may use this mode of transmission, which would require no apparatus, except an electric battery, two vibrating disks, and a wire. In many cases, as for example in large establishments, orders might be transmitted in this way, although transmission by electricity will not be used while it is necessary to go from letter to letter, and to make use of telegraphs which require use and apprenticeship. However this may be, it is certain that in a more or less distant future, speech will be transmitted by electricity. I have made some experiments in this direction: they are delicate, and demand time and patience, but the approximations obtained promise a favourable result.’

This description is certainly not full enough to enable us to discern from it the arrangement which would lead to the solution of the problem, and if the vibrations of the disk at the receiving station were to follow from making and breaking the current at the sending-station, under the influence of vibrations caused by the voice, they would only produce musical, and not articulate sounds. Yet the idea was magnificent, as Mr. Preece said, even when he thought it impossible to realise it. Besides, it is easy to see that M. Bourseul himself was not deceived as to the difficulties of the problem, as far as articulate sounds are concerned, for he points out, as we have seen, the difference existing between the simple vibrations which produce musical sounds, and the complex vibrations which cause articulate sounds; but, as he justly said: ‘Reproduce at the one end of the line the vibrations of air caused at the other, and speech will be transmitted, however complex the mechanism may be by which it is effected.’ We shall presently see how the problem was solved, and it is probable that some attempts had already enabled M. Bourseul to anticipate the solution of the question; but there is nothing in his paper to show what were the means he proposed, so that the discovery of the electric transmission of speech cannot reasonably be ascribed to him, and we do not understand why we should be reproached for having at that time failed to appreciate the importance of a discovery which seemed to be then only within the range of fancy.

It was not until 1876 that the problem of the electric transmission of speech was finally solved, and the discovery has lately given rise to an interesting controversy as to priority between Mr. Elisha Gray, of Chicago, and Mr. Graham Bell, on which we must say a few words.

As early as 1874 Mr. Elisha Gray was occupied with a system of musical telephone, which he wished to apply to manifold telegraphic transmissions, and the investigations which he made, in order to establish this system under the best possible conditions, gave him a glimpse of the possibility of transmitting articulate words by electricity. While carrying on his experiments on the telegraphic system, he arranged in fact, about the 15th January, 1876, a system of speaking telephone, and he deposited the specification and drawings in the American Patent Office, in the form of a caveat or provisional specification. The deposit was made on the 14th February, 1876: on the very same day, Mr. Graham Bell also deposited, in the American Patent Office, a request for a patent in which he spoke of an instrument of the same kind, but with special application to simultaneous telegraphic transmissions by means of a telephonic apparatus; and the few words which could, in this specification, refer to a telephone with articulate sounds, applied to an instrument which, by Mr. Bell’s own admission, had not produced any satisfactory results. In Mr. Gray’s caveat, on the contrary, the application of the instrument to the electric transmission of speech alone is indicated, the description of the system is complete, and the drawings which accompany it are so exact, that a telephone made from them would work perfectly: this was proved by Mr. Gray himself, when, some time afterwards, he finished his instruments, which differed in no respect from the one described in Mr. Bell’s statement as worked by a battery. On these grounds Mr. Elisha Gray would certainly have obtained the patent, if the expiration of his caveat had not been the result of an omission of form in the Patent Office, which, as we know, decides the priority of inventions in America. An action on the ground of this omission has lately been brought against Mr. Bell, in the Supreme Court of the American Patent Office, to set aside the patent granted to him. If Mr. Gray did not appeal before, it was because he was then wholly occupied with experiments on the system of harmonic telephone, applied to telegraphic communication, and he had no time to attend to the matter.

However this may be, Mr. Bell did not begin to give serious attention to the speaking telephone until he had obtained his patent, and his efforts were soon crowned with success: a few months later, he exhibited his speaking telephone at Philadelphia, which has from that time attracted so much public attention, and which, when perfected in a practical point of view, reached Europe in the autumn of 1877 under the form we know.

To complete this summary account of the telephone, we ought to say that since its success a good many claims of priority have arisen, as if by enchantment. Mr. John Camack, of English origin, has among others claimed the invention of the telephone, not merely relying on the description he gave of the instrument in 1865, but on the drawings he executed; he even adds, that if he had not lacked means for its construction, this would have been the date of the discovery of the telephone. A similar pretension has been put forward by Mr. Dolbear, a fellow countryman of Mr. Bell, of whose claim we shall speak presently.

Signor Manzetti, of Aosta, says the same thing, asserting that his telephonic invention was described in several newspapers of 1865, among others in ‘Le Petit Journal,’ of Paris, on the 22nd November, 1865; ‘Il Diritto’ at Rome, 16th July, 1865; ‘L’Echo d’Italia,’ New York, 9th August, 1865; ‘L’Italia,’ Florence, 10th August, 1865; ‘La Comuna d’Italia,’ Genoa, 1st December, 1865; ‘La Verità,’ Novara, 4th January, 1866; ‘Il Commercio,’ Genoa, 6th January, 1866. It is true that no description of the system was given, and that the journals in question only asserted that experiments had been made, which proved that the practical solution of the problem of transmitting speech by electricity became possible by this system. At any rate M. Charles Bourseul must still have the credit of the priority of the idea, and, in our opinion, all claims made after the fact only merit slight consideration.

Before considering Bell’s telephone, and the different modifications which have been applied to it, it seems worth while, in order to make the reader perfectly familiar with these kinds of instruments, to study the electro-musical telephones which preceded it, and especially that of M. Reiss, which was made in 1860, and became the starting point of all the others. We shall find that these instruments have very important applications, and that telegraphy will probably be one day much advanced by their use.