Rensselaer Journal, Volume 11, Number 23, Rensselaer, Jasper County, 14 November 1901 — PHOTOGRAPHING SOUND. [ARTICLE]

PHOTOGRAPHING SOUND.

The invention of the telegraphone, says the Electrical Review, seems to have stimulated tesearch upon the possibilities of reproducing sounds. Among the various methods of making records of sound vibrations none is more accurate or sensitive than that employing photography, but hitherto no method of reproducing sounds from these records has been described. In a German mechanical Journal, Herr E. Rohmer describes a method of astonishing originality and beauty. He photographs upon a continuous moving roll of sensitive film a “speaking arc,” or arc containing a telephone transmitter circuit in shunt, and reproduces the sound by projecting light through this fl.m on a selenium cell in circuit with a telephone receiver and a battery Of course, every variation produced in the transmitter circuit and affecting the light emanating from the arc is photographed as alternate shadings and tightenings on the film, and these light variations impinging upon the sensitive selineutn cause corresponding fluctuations in its resislan. e and reproduce the sound in the receiving telephone with great accuracy. It is stated that the reproduction of sensitiveness and dearness !r superior to that rendered by the Poulsen telegraphone. As the Aim can be made very long without reaching a considerable weight, it pobsess s great portability, and has advantage over either the wax cylinder or the cross magnetized steel wire. Another striking advantage is found in the fact that any desired number of reproductions can easily and cheaply be made from the original film.