Phonograph, an instrument for mechanically recording and reproducing articulate human speech, song, &c. The phonograph was Copyright 1851 in U.S. invented by Mr T. A. Edison by J. B. Lippincott (q.v.) in the spring of 1877, at his Company. Menlo Park Laboratory, New Jersey, and came into existence as the result of one of the many lines of experiment he was then engaged upon. Following up some of his telegraphic inventions, he had developed a machine, which by reason of the indentations made on paper, would transfer a message in Morse characters from one circuit to another automatically, through the agency of a tracing-point connected with a circuit-closing device. Upon revolving with rapidity the cylinder that carried the indented or embossed paper Mr Edison found that the indentations could be reproduced with immense rapidity through the vibration of the tracing-point. He at once saw that he could vibrate a diaphragm by the sound-waves of the voice, and, by means of a stylus attached to the diaphragm, make them record themselves upon an impressible substance placed on the revolving cylinder. The record being made thus, the diaphragm would, when the stylus again traversed the cylinder, be thrown into the same vibrations as before, and the actual reproduction of human speech, or any other sound, would be the result. The invention thought out in this manner was at once tried, with paraffined paper as the receiving material, and afterwards with tinfoil, the experiment proving a remarkable success, despite the crudity of the apparatus. In 1878 Mr Edison made a number of phonographs, which were exhibited in America and Europe, and attracted universal attention. The records were made in these on soft tinfoil sheets fastened around metal cylinders. For a while Mr Edison was compelled to suspend work on this invention, but soon returned to it and worked out the machine as it exists practically to-day. It occupies about the same space as a hand sewing-machine. A light tube of wax to slide on and off the cylinder is substituted for the tinfoil, which had been wrapped around, and the indenting stylus is replaced by a minute engraving point. Under the varying pressure of the sound-waves, this point or knife cuts into the tube almost imperceptibly, the wax chiselled away wreathing off in very fine spirals before the edge of the little blade, as the cylinder travels under it. Each cylinder will receive about a thousand words. In the improved machine Mr Edison at first employed two diaphragms in 'spectacle' form, one to receive and the other to reproduce; but he has since combined these in a single efficient attachment. The wax cylinders can be used several hundred times, the machine being fitted with a small paring tool which will shave off the record previously made, leaving a smooth new surface. The machine has also been supplemented by the inventor with an ingenious little electric motor with delicate governing mechanism, so that the phonograph can be operated at any chosen rate of speed, uniformly. This motor derives its energising current either from an Edison-Lalande primary battery, a storage battery, or an electric-light circuit.
The new and perfected Edison phonograph has already gone into very general use, and hundreds of thousands are distributed in American business offices, where they facilitate correspondence in a variety of ways. They are also employed by stenographers as a help in the transcription of their shorthand notes. Heretofore these notes have been slowly dictated to amanuenses, but they are now frequently read off to a phonograph, and then written out at leisure. The phonograph is, however, being used for direct stenograph work, and it reported verbatim 40,000 words of discussion at one convention held in 1890, the words being quietly repeated into the machine by the reporter as quickly as they were uttered by the various speakers. A large number of machines are in use by actors, clergymen, musicians, reciters, and others, to improve their elocution and singing. Automatic phonographs are also to be found in many places of public resort, equipped with musical or elocutionary cylinders, which can be heard upon the insertion of a small coin; and miniature phonographs have been applied to dolls and toys. The value of the phonograph in the preservation of dying languages has been perceived too, and records have already been secured of the speech, songs, war-cries, and folklore of American tribes now becoming extinct. It is also worthy of note that several voice records remain of distinguished men, who 'being dead yet speak.' Their tones can now be renewed at will, and their very utterances, faithful in accent and individuality, can be heard again and again through all time.
Improvements are being made in the wholesale reproduction of phonographic cylinders, by electrolyzing and other processes; and the machine, in a more or less modified form, is being introduced as a means of furnishing a record of communications through the telephone. Phonographic clocks, books, and other devices have also been invented by Mr Edison, whose discovery is evidently of a generic nature, opening up a large and entirely new field in the arts and sciences. See also TELEPHONE.