Gramophone

Collier's New Encyclopedia (1921)

or "DISC TALKING MACHINE," a mechanism for reproducing sound , differing in construction, but not in principle, from the phonograph. aph. It was invented in 1888 by Emile Berliner, a German -American inventor, who was chief instrument inspector of the Bell Telephone Co., and also inventor of the telephone transmitter. The gramophone differs from the phonograph principally in that its records are engraved on discs instead of on cylinders. On the cylinder of the phonograph the vibrations reproducing the sounds are caused by winding grooves of uneven depths, the variation of depth causing the needle to vibrate up and down. The records on the discs of the gramophone are spiral grooves radiating outward from the center, and zig-zagging, so that the recording needle vibrates laterally, while the disc revolves in a horizontal position. In the gramophone, also, the needle, or stylus, is not propelled by a feed screw, the disc itself causing the stylus, or needle, to move, at the same time that it causes it to vibrate. Gramophone records were first made by photo-engraving sound tracings, or by direct etchings in copper or zinc. Later wax surfaces were employed. From the original record a disc, or matrix, was made, by electrotyping. This, in turn, is used for making impressions in celluloid, rubber or composition. Celluloid was first used, in a semi-heated state, but later it was found better to use hard rubber discs, on which the reversed records of the electrotypes were reproduced, in reverse, by heavy pressure. It was this improving process, perfected in 1895, which made the gramophone a commercial possibility. A further improvement