قراءة كتاب Development of the Phonograph at Alexander Graham Bell's Volta Laboratory Contributions from the Museum of History and Technology, United States National Museum Bulletin 218, Paper 5, (pages 69-79)
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Development of the Phonograph at Alexander Graham Bell's Volta Laboratory Contributions from the Museum of History and Technology, United States National Museum Bulletin 218, Paper 5, (pages 69-79)
href="@public@vhost@g@gutenberg@html@files@30112@[email protected]#fig7" class="pginternal" tag="{http://www.w3.org/1999/xhtml}a">Figure 7. The experimental Graphophone built from these plans is in the U. S. National Museum (cat. no. 287665).
An interesting exception has a horizontal 7-inch turntable (see figs. 7 and 8). This machine, although made in 1886, is a duplicate of one made earlier but taken to Europe by Chichester Bell. Tainter was granted U. S. patent 385886 for it on July 10, 1888.
The playing arm is rigid, except for a pivoted vertical motion of 90 degrees to allow removal of the record or a return to starting position. While recording or playing, the record not only rotated, but moved laterally under the stylus, which thus described a spiral, recording 150 grooves to the inch.
The Bell and Tainter records, preserved at the Smithsonian, are both of the lateral cut and "hill-and-dale" types. Edison for many years used the "hill-and-dale" method with both cylinder and disc records, and Emile Berliner is credited with the invention of the lateral cut Gramophone record in 1887. The Volta associates, however, had been experimenting with both types, as early as 1881, as is shown by the following quotation from Tainter:[9]
The record on the electro-type in the Smithsonian package is of the other form, where the vibrations are impressed parallel to the surface of the recording material, as was done in the old Scott Phonautograph of 1857, thus forming a groove of uniform depth, but of wavy character, in which the sides of the groove act upon the tracing point instead of the bottom, as is the case in the vertical type. This form we named the zig-zag form, and referred to it in that way in our notes. Its important advantage in guiding the reproducing needle I first called attention to in the note on p. 9-Vol 1-Home Notes on March 29-1881, and endeavored to use it in my early work, but encountered so much difficulty in getting a form of reproducer that would work with the soft wax records without tearing the groove, we used the hill and valley type of record more often than the other.
In 1885, when the Volta associates were sure that they had a number of practical inventions, they filed applications for patents. They also began to look around for investors. After giving several demonstrations in Washington, they gained the necessary support, and the American Graphophone Co. was organized to manufacture and sell the machines. The Volta Graphophone Co. was formed to control the patents.
The Howe sewing machine factory at Bridgeport, Connecticut, became the American Graphophone plant; Tainter went there to supervise the manufacturing, and continued his inventive work for many years. This Bridgeport plant is still in use today by a successor firm, the Dictaphone Corporation.
The work of the Volta associates laid the foundation for the successful use of the dictating machine in business, for their wax recording process was practical and their machines sturdy. But it was to take several more years and the renewed work of Edison and further developments by Berliner and many others, before the talking machine industry really got under way and became a major factor in home entertainment.[10]
