The Probert Encyclopaedia of Science & Technology

GRAMAPHONE

A gramaphone is a now almost obsolete device for replaying sound recordings made on plastic disks. A disk was engraved with a spiral pattern of grooves, and the recording reproduced by a blunt stylus of sapphire or diamond which transmitted the bumps of travelling over the grooves to a sensitive material, originally glass or mica which then vibrated reproducing the original sound waves. The sound was then passed to an amplifier, originally a horn and later an electronic amplifier. The recordings for a gramaphone were made by a phonograph, the original invented in 1877 by Thomas Edison which recorded the sound on tinfoil, and later improved by Tainter to engrave wax disks instead.
Research Gramaphone