FIRST FRENCH PUBLICATION OF BELL'S PHOTOPHONE

BELL, M. A. GRAHAM.

De la production du son par l'energie radiante.

Paris, Imprimerie Gauthier-Villars, 1881. 8vo. Contemporary half calf, raised bands, gilt spine. Light wear along edges. Two small stamps on verso of title-page, and one on verso of last plate. In "Annales de Chimie et de Physique", Cinquiéme Series - Tome XXIII. 576 pp. + 3 plates. G. Bell's paper: pp. 397-432, pp. and 14 figures of experimental apparatus etc. The entiree volume offered. Fine and clean copy.

First publication of the first French translation of Bell's "On the Production and Reproduction of Sound by Light: the Photophone", originally published in 1880. The device allowed for the transmission of sound on a beam of light, and Bell himself regarded this, not the telephone, to be his most important invention.
"In the importance of the principles involved, I regard the photophone as the greatest invention I have ever made; greater than the telephone." Bell said in a 1921 interview. The photophone was the world's first wireless telephone communication and thereby anticipated Marconi's invention with several years.

The first successful attempts were based upon the properties of selenium: "The electric resistance of which varies with the degree of illumination to which it is exposed. Hence, given a transmitting instrument, such as a flexible mirror, by which the vibrations of a sound could throw into vibrations a beam of light, a receiver, consisting of sensitive selenium, forming part of an electric circuit with a battery and a telephone, should suffice to translate the varying intensities of light into corresponding varying intensities of electric current, and finally into vibrations of the telephone disk audible once more as sound." (Prescott, George. Bell's Electric Speaking Telephone. 313 p.).

Bell was so excited by his invention and its possibilities that he proposed that his second daughter should bear the name of the invention: Photophone. Fortunately for her, her mother was not quite as enthusiastic about the invention.

Order-nr.: 43072