Gramophone
or "DISC TALKING MACHINE," a mechanism for reproducing sound , differing in construction, but not in principle, from the phonograph.
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 discs a composition of shellac, in which the records could be more sharply reproduced, resulting in clearer and more distinct sounds. Another substitute still is a fibrous die, faced with a thin layer of shellac on both sides. This gives a disc much lighter in weight, less susceptible to changes of climate or temperature and capable of harder usage. The motive power of the gramophone was at first applied by hand, but later a mechanism on the principle of a clock, driven by a spring, was invented by Eldridge R.
Johnson, which not only supplied motive power but acted as a speed regulator.
În more recent years the etching process of producing the records has been abandoned, the expiration of the regular gramophone patents enabling the various gramophone manufacturers to utilize the wax cutting process, while still retaining the principle of horizontal motion. This latter change, besides various other qualities of the phonograph, which were also incorporated, brought the phonograph to its present high degree of perfection. For the reproduction of singing and music the gramophone is considered the better instrument, the disc lending itself to infinite repetition, without deterioration of the records.