Читать книгу Philipp Reis: Inventor of the Telephone - Silvanus P. Thompson - Страница 17

Fig. 19.

The first form of apparatus used by Reis for receiving the currents from the transmitter, and for reproducing audibly that which had been spoken or sung, consisted of a steel knitting-needle, round which was wound a spiral coil of silk-covered copper-wire. This wire, as Reis explains in his lecture “On Telephony,” was magnetised in varying degrees by the successive currents, and when thus rapidly magnetised and demagnetised, emitted tones depending upon the frequency, strength, etc., of the currents which flowed round it. It was soon found that the sounds it emitted required to be strengthened by the addition of a sounding-box, or resonant-case. This was in the first instance attained by placing the needle upon the sounding-board of a violin. At the first trial it was stuck loosely into one of the f-shaped holes of the violin (see Fig. 19): subsequently the needle was fixed by its lower end to the bridge of the violin. These details were furnished by Herr Peter, of Friedrichsdorf, music-teacher in Garnier’s Institute, to whom the violin belonged, and who gave Reis, expressly for this purpose, a violin of less value than that used by himself in his profession. Reis, who was not himself a musician, and indeed had so little of a musical ear as hardly to know one piece of music from another, kept this violin for the purpose of a sounding-box. It has now passed into the possession of Garnier’s Institute. It was in this form that the instrument was shown by Reis in October 1861 to the Physical Society of Frankfort.