Читать книгу Philipp Reis: Inventor of the Telephone - Silvanus P. Thompson - Страница 13

Fig. 14.

The Transmitter described with so much minuteness by Inspector von Legat in his Report on Reis’s Telephone in 1862 (see p. 70), differs from the earliest and latest forms, so much so that some have doubted whether this form was really invented by Reis. It is not described anywhere else than in Legat’s Report (in the “Zeitschrift” of the Austro-German Telegraph Union, reprinted also in Dingler’s Journal), except in Kuhn’s Handbook, where, however, the description is taken from Legat. Nevertheless a comparison of this instrument (Fig. 14) with the original model of the ear, from which Reis started, will show that it embodies no new point. There is, first, a conical tube to receive the sound, closed at its end with a tympanum of membrane. There is next a curved lever, c d, the lower end of which rests against the centre of the membrane. Thirdly, there is a vertical spring, g, which makes contact lightly against the upper end of the curved lever. Lastly, there is an adjusting screw. It may be further pointed out that in each case the current enters (or leaves, as the case may be) the lever at its middle point. This form of transmitter is so closely allied indeed to the primitive “ear” as to be alike in every feature save the external form of the sound-gathering funnel. The only reasonable doubt is not whether it be, as Legat asserts, Reis’s transmitter, but whether it ought not in chronological order to rank second. Legat’s paper was not published, however, till 1862, whilst the fourth form was described by Reis in 1861. No trace of any instrument corresponding in form to Fig. 14, save modern reproductions from Legat’s drawing, has been found. The instrument held by Reis in his hand in the photograph (Fig. 12) is so strikingly like the form described by Legat, that it furnishes an additional reason for accepting Legat’s statement that this transmitter really is Reis’s invention.

Fig. 15.

Fig. 16.