Edison phonographIn 1877, Thomas Alva Edison, though this date is often given as the date of a finished model of his first phonograph, may have actually only made a sketch. Some correspondence in Sep 1877 suggests Edison was at work on his ideas for what became his cylinder phonograph, though construction of a working model may not have begun until 4 Dec, according to the diary of one of Edison's aides. Indeed, Edison did not file for the patent until 24 Dec 1877. The idea came to him while working on a telegraph transmitter, when he noticed that when the tape of the machine was played at high speed, it gave off a noise resembling spoken words. After experimenting with a needle attached to the diaphragm of a telephone receiver to prick paper tape to record a message, his idea evolved to using a stylus on a tinfoil cylinder.«[Image: Sketch dated 20 Nov 1877 given to machinist John Kruesi to make the world's first cylinder phonograph.] |
