Lives of the electricians

by William T. Jeans

Charles Wheatstone was born at Gloucester in February 1802. His father was a music-seller in that town; and on removing afterwards to London he became a teacher of the flute, and was accustomed to boast that he had been engaged in connection with the musical education of the Princess Charlotte. His son, Charles, was educated at a private school in his native city. It is said that he early showed an aptitude for mathematics and physics; but not much is known of his youthful career. On his removal to London he became a manufacturer of musical instruments, the scientific principles of which formed with him the subject of profound studies. His practical ingenuity was displayed in the application of the scientific principles he discovered to new purposes, to the construction of philosophical toys and the improvement of musical instruments. “In 1823,” says a friend of his who wrote a notice of him in the Proceedings of the Royal Society, “at the age of twenty-one, we find him in conjunction with his brother, long since deceased, engaged in the manufacture and sale of musical instruments in London.” But there is unquestionable evidence of his having obtained distinction in London by his ingenuity at the age of nineteen.

Of his first notable achievement in London the following curious account was given in September, 1821, in the leading literary journal of that time: “We have been much gratified,” said the writer, “with an exhibition in Pall Mall of an instrument under the denomination of the enchanted lyre, the invention of a Mr. Wheatstone. The exhibition room presents a work of handsome construction in the form of an ancient lyre suspended from the ceiling. Its horns terminate in mouths resembling bugles. Its centre is covered on both sides with plates of a bright metallic lustre, and there is an ornamented keyhole, like that of a timepiece, which admits of its being wound up, but which is evidently a mere ruse, as the instrument certainly does not utter melodious sounds in consequence of that operation. Round it there is a slight hoop-rail, perhaps five feet in diameter, which is supported by equally slight fixtures in the floor. The inventor disclaims mechanism altogether (though he winds up the machine) and asserts that the performance of the enchanted lyre is entirely the result of a new combination of powers. Be that as it may, its execution is both brilliant and beautiful. The music seems to proceed from it; the tones are very sweet; the expression soft or powerful, and the whole really charming. We listened to Steibelt’s battle-piece with unfeigned pleasure, and were equally delighted with several other compositions of simple melody and of more difficult harmony. Mr. Wheatstone professes to be able to give a concert, producing by the same means an imitation of various wind and stringed instruments; the lovers of music will have a treat in hearing the enchanted lyre go through a half hour’s entertainment.”

Another contemporary account is more prescient, if not amusing. On the 1st of September, 1821, it was reported in the Repository of Arts that “Under the appellation of the enchanted lyre Mr. Wheatstone has opened an exhibition at his music shop in Pall Mall, which has excited considerable sensation among the votaries of the art. The form of a lyre of large dimensions is suspended from the ceiling apparently by a cord of the thickness of a goose-quill. The lyre has no strings or wires, but these are represented by a set of metal or steel rods, and it is surrounded by a small fence. The company being assembled, Mr. Wheatstone applies a key to a small aperture, and gives a few turns representative of the act of winding up, and music is instantly heard, and apparently from the belly of the lyre. The sceptical he invites to stoop under the fence, and hold their ears close to the belly of the lyre; and they, including ourselves, are compelled to admit that the sound appears to be within the instrument; but while making this admission, the attentive auditor is instantly convinced that the music is not the effect of mechanism (a fact indeed which Mr. Wheatstone not only concedes, but openly avows, even in his notice). It is quite obvious that the music is produced by a skilful player, or perhaps two, upon one or more instruments. The music seems to proceed from a combination of harp, pianoforte, and dulcimer; it certainly at times partakes of the character of these three instruments; and in point of tone, the difference sometimes is considerably in favour of the lyre; the piano and forte appear more marked, the crescendo is extremely effective, and the forte in the lower notes is inconceivably powerful in vibration. The performance lasts an hour: various pieces of difficult execution are played with precision, rapidity, and proper expression.”

“It is evident that some acoustical illusion, effected through a secret channel of some sort or other, is the cause of our hearing the sound in the belly of the lyre.... How then is sound thus conducted so as to deceive completely our sense of hearing? This seems to be the only question that can suggest itself on witnessing this singular experiment; it is a secret upon which Mr. Wheatstone rests the interest and merit of this invention; and to this question, no one, as far as we can learn, has yet been able to return an answer that could solve every difficulty. It is really a very ingenious invention, which the proprietor as yet wishes to keep a secret. It may be proper to add that Mr. Wheatstone represents the present exhibition to be an application of a general principle for conducting sound, which principle he professes himself to be capable of carrying to a much greater extent. According to his statement, it is equally applicable to wind instruments; and the same means by which the sound is conducted into the lyre will, when employed on a larger scale, enable him to convey in a similar manner the combined strains of a whole orchestra. This promised extension of the principle of conducting musical sounds from one place to another gives rise to some curious reflections on the progress which our age is constantly making in discoveries and contrivances of every description. Who knows but by this means the music of an opera performed at the King’s Theatre may ere long be simultaneously enjoyed at Hanover Square Rooms, the City of London Tavern, and even at the Horns Tavern at Kennington, the sound travelling, like gas, through snug conductors, from the main laboratory of harmony in the Haymarket to distant parts of the metropolis; with this advantage, that in its progress it is not subject to any diminution? What a prospect for the art, to have music ‘laid on’ at probably one-tenth the expense of what we can get it ourselves! And if music be capable of being thus conducted, perhaps words of speech may be susceptible of the same means of propagation. The eloquence of counsel, the debates in Parliament, instead of being read the next day only—But we really shall lose ourselves in the pursuit of this curious subject.”

It has been said that the death of mystery is the grave of interest. Nevertheless, Charles Wheatstone did not keep secret the means by which this mysterious music was produced. In 1823 he contributed a paper to Thomson’s Annals of Philosophy in which he described the remarkably simple and original experiments that led him to the invention of this apparatus, and explained how molecular vibrations produced sound. With reference to phonic vibrations in linear conductors he said: “In my first experiments on this subject I placed a tuning-fork at the extremity of a glass or metallic rod five feet in length communicating with a sounding-board. The sound was heard as instantly as when the fork was in immediate contact, and it immediately ceased when the rod was removed from the sounding-board or the fork from the rod. From this it is evident that vibrations inaudible in their transmission, being multiplied by meeting with a sonorous body, become very sensibly heard. Pursuing my investigations on this subject, I discovered means of transmitting, through rods of much greater length, and of very inconsiderable thickness, the sounds of all musical instruments dependent on the vibrations of solid bodies and of many descriptions of wind instruments. One of the practical applications of this discovery has been exhibited in London for about two years under the appellation of the ‘Enchanted Lyre.’ So perfect was the illusion in this instance from the intense vibratory state of the reciprocating instrument and from the interception of the sounds of the distant exciting one, that it was universally imagined to be one of the highest efforts of ingenuity in musical mechanism.” It is a noteworthy evidence of the interest evoked by this article that it was reproduced in the leading French and German publications of that year.

This “Enchanted Lyre” has since been described by Mr. W. H. Preece as the first telephone. It was exhibited, he says, “to delighted crowds at the Adelaide Gallery; it was often used by Prof. Faraday, and has frequently since been produced by Prof. Tyndall at the Royal Institution. A large special box was placed in one of the cellars of the Institution, and a light rod of deal rested upon it. No sound was heard in the theatre until a light tray or other sounding-box was placed on the rod, whereupon its music pealed forth over the whole place. The vibrations of the musical box, with all their complexity and beauty, are imparted to the rod of wood and are thence given up to the sounding-box. The sounding-box impresses them upon the air, and the air conveys them to the ear, whence they are transmitted to the brain, imparting those agreeable sensations called music.”

Wheatstone’s invention of the Enchanted Lyre or the “first telephone” was no accidental discovery or lucky idea: it was the result of a profound and original investigation of the scientific principles of sound. He discovered and demonstrated by numerous experiments that sound was produced by the vibrations of the atmosphere; and in 1823 when he announced for the first time that “the loudness of sound is dependent on the excursions of the vibrations, volume or fulness of sound on the number of the coexciting particles put in motion,” he stated that he had just seen Fresnel’s paper, in which the same conclusions were arrived at with respect to light as he (Wheatstone) had proved with respect to sound. He added that “the important discoveries of Dr. Thos. Young have recently re-established the vibratory theory of light, and new facts are every day augmenting its probability. The new views in acoustical science which I have opened will, I presume, give additional confirmation to the opinions of these eminent philosophers.” Prophetic words!

The analogy between sound and light as results of wave-motions in air or ether is now part of the alphabet of science. Charles Wheatstone made an independent discovery of the principles of sound; but in this he was partly anticipated by Young. Nor was he alone in the original and practical experiments by which he demonstrated their accuracy. At the time he made these experiments (he was then only twenty years old), he thought he was the first who had indicated the phenomena of sound in that way; but Professor Oerstead, of Copenhagen, on seeing him perform these experiments, informed him of some similar ones he had previously made.

In the middle of the year 1827 he invented a small instrument consisting of a steel rod on the top of which a glass silvered bead was placed. By concentrating on it an intense light and making the rod to vibrate, beautiful forms were created. In this respect this philosophical toy resembled the Kaleidoscope which Brewster invented; and it was therefore called the kaleidophone. There is, however, no similarity between the construction or mode of action of the two instruments. In 1828 he devised the terpsiphone which made music by the reciprocal vibrations of columns of air. In 1833 he contributed to the Royal Society a paper on acoustic or Chladni figures, so called because Chladni in 1787 showed that by strewing sand on vibrating surfaces, and then throwing the particles into vibration by means of a violin bow, beautiful and varied symmetrical figures could be produced. Wheatstone showed that all the figures of vibrating surfaces result from very simple modes of vibration, oscillating isochronously, and superposed upon each other, the figures varying with the component modes of vibration, the number of the superpositions, and the angles at which they are superposed.

As indicating the variety of subjects that engaged his attention about the same time, a fact recorded by a friend may be quoted here. At one period Wheatstone’s attention was for a time directed to problems of mental philosophy, and especially to the quasi-mechanical solution of them which was hoped for by the followers of Gall and Spurzheim; he was an active member of the London Phrenological Society, then presided over by Dr. Elliotson, and in January 1832 he read a paper at one of the meetings on dreaming and somnambulism, which was published in extenso in the Lancet of that date. This paper is remarkable like all his writings for the extreme clearness with which known facts are stated and the deductions based upon them.