Читать книгу Philipp Reis: Inventor of the Telephone - Silvanus P. Thompson - Страница 8

Fig. 8.

The third form, also preserved in the collection in Garnier’s Institute, is given in Fig. 8, which, with the preceding, is taken by permission from the pamphlet of the late Professor Schenk, consists of a round tin box, the upper part of which fits upon the lower precisely like the lid of a collar-box. Over this lid b, which is 15 centimetres in diameter, was formerly stretched the vibrating membrane, there being also an inner flange of metal. Into a circular aperture below opened an auditory tube a, with an embouchure representing the pinna. The precise arrangements of the contact-parts of this apparatus are not known. Mr. Horkheimer, who aided Reis in his earlier experiments, has no knowledge of this form, which he thinks was made later than June 1862. This is not improbable, as the design with horizontal membrane more nearly approaches that of the tenth form, the “Square-box” pattern.