Page:Popular Science Monthly Volume 12.djvu/586

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568
THE POPULAR SCIENCE MONTHLY.

that they may be left unnoticed; and we proceed now to describe one of a different character, designed to test the telephone itself. At a distance of about half a mile, access was obtained to a Morse instrument in private use, and joined to the office by 'overhouse' wire. Dividing our party and arranging a programme of operations, two remained with a telephone in the office, while other two, of whom the writer was one, proceeded with the second telephone to the distant instrument. By an arrangement which a practical telegraphist will understand, the key of the Morse was kept in circuit, so that signals could be exchanged in that way. It may be noticed, however, that this was hardly necessary, as the diaphragm of the telephone can be used as a key, with the linger or a blunt point, so that dot and dash signals are interchangeable, should the voice fail to be heard. As the wire in this instance traveled almost alone over part of its course, we were in hopes that induced currents would be conspicuous by their absence. In this we were, however, disappointed, for the pot was boiling away, rather more faintly, but with the 'plop-plop-plop' distinctly audible, and once more a sharp masterful Morse click was heard coming in now and again. The deadly ABC was, however, absent, so that our experiment proved highly successful. For some reason or another—probably an imperfect condition of the wire, or the effects of 'induction' over and above what made itself audible to us—the spoken sounds were deficient in distinctness; but songs sung at either end were very beautifully heard, and, indeed, the sustained note of sung words had always a better carrying-power than rapidly-spoken words. Every syllable and every turn of melody of such a song as 'My Mother bids me bind my Hair,' sung by a lady at one end, or 'When the Heart of a Man,' sung at the other, could be distinctly heard, but with the effect before noticed, that the voice was muffled or shut in, as if the singer were in a cellar, while it was not always possible to say at once whether the voice was that of a man or a woman.

"In the course of some domestic experiments it was remarked that, in playing the scale downward from C in alt. on the piano, the result to the listener was a 'tit' only for the four upper notes, although all below that had a clear 'ting,' and the octaves below were mostly distinct, although at the low notes of the piano the sound was again lost. The ringing notes of a musical-box were not so successful, but, with close attention, its rapid execution of 'Tommy Dodd' could be well enough made out. An endeavor was made to catch the ticking of a watch, but this was not successful, and the experiment is not recommended, as the near presence of a watch to a magnet is not desirable; and the watch exposed to it in this instance was, it is thought, affected for a short time thereafter, although it received no permanent damage.

"The observations made in the course of these experiments convinced those present that the telephone presents facilities for the