Tinfoil phonograph, c 1885.
© Science Museum / Science & Society Picture Library
Tinfoil phonograph made by the London Stereoscopic Company. Thomas Edison (1847-1931) invented sound recording in 1877. A sheet of tinfoil, moving under a needle attached to a diaphragm which vibrated in response to sound, became indented with a pattern which could be played back. Edison's first instrument had separate recording and reproducing diaphragms, but the model shown here has a single diaphragm for both functions. Also shown is the flywheel added by Edison to smooth out variations in speed inevitable with hand-turned machines.