Читать книгу Philipp Reis: Inventor of the Telephone - Silvanus P. Thompson - Страница 10

Another form, a mere variety of the preceding, is described as follows by Professor Böttger in his “Polytechnisches Notizblatt” (see p. 61):—

“A little light box, a sort of hollow cube of wood, has a large opening at its front side and a small one at the back of the opposite side. The latter is closed with a very fine membrane (of pig’s smaller intestine) which is strained stiff. A narrow springy strip of platinum foil, fixed at its outer part to the wood, touches the membrane at its middle; a second platinum strip is fastened by one of its ends to the wood at another spot, and bears at its other end a fine horizontal spike, which touches the other little platinum strip where it lies upon the membrane.”