Phonograph cylinder
= Phonograph cylinder
{wiki=Phonograph_cylinder}
A phonograph cylinder is an early medium for recording and reproducing sound. Invented by Thomas Edison in 1877, it consists of a cylindrical shell, typically made of wax or a similar material, onto which sound waves are inscribed in a spiral groove. The cylinder is mounted on a phonograph machine, which uses a needle to trace the grooves, converting the physical variations into sound.