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)Newville, Leslie J.
History
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)
Newville, Leslie J.
Phonograph
A cutting style A., secured to the end of a lever B was then
adjusted over the cylinder, as shown. Lever B was pivoted at the
points C-D, and the only pressure exerted to force the style into
the wax was due to the weight of the parts.
Upon the top of A was fixed a small brass disk, and immediately
over it a sensitive water jet adjusted, so that the stream of water
at its sensitive part fell upon the center of the brass disk.
The Phonograph cylinder E, was rotated while words and sounds were
shouted to the support to which the water jet was attached, and a
record that was quite visible to the unaided eye was the result.
The tape recorder, an unusual instrument which recorded mechanically on
a 3/16-inch strip of wax-covered paper, is one of the machines described
and illustrated in U. S. patent 341214, dated May 4, 1886 (see fig. 4).
The strip was coated by dipping it in a solution of beeswax and
paraffine (one part white beeswax, two parts paraffine, by weight), then
scraping one side clean and allowing the other side to harden.
[Illustration: Figure 7.--ORIGINAL PLANS FOR A DISC GRAPHOPHONE PATENTED
BY SUMNER TAINTER IN 1888, U. S. PATENT 385886.]
The machine of sturdy wood and metal construction, is hand powered by
means of a knob fastened to the fly wheel. From the fly-wheel shaft
power is transferred by a small friction wheel to a vertical shaft. At
the bottom of this shaft a V-pulley transfers motion by belts to
corresponding V-pulleys beneath the horizontal reels.
The wax strip passes from one 8-inch reel around the periphery of a
pulley (with guide flanges) mounted above the V-pulleys on the main
vertical shaft, where it comes in contact with the recording or
reproducing stylus. It is then taken up on the other reel.
The sharp recording stylus, actuated by a vibrating mica diaphragm, cuts
the wax from the strip. In reproducing, a dull, loosely mounted stylus,
attached to a rubber diaphragm, carried sounds through an ear tube to
the listener.
Both recording and reproducing heads, mounted alternately on the same
two posts, could be adjusted vertically so that several records could be
cut on the same 3/16-inch strip.
While this machine was never developed commercially, it is an
interesting ancestor of the modern tape recorder, which it resembles
somewhat in design. How practical it was or just why it was built we do
not know. The tape is now brittle, the heavy paper reels warped, and the
reproducing head missing. Otherwise, with some reconditioning, it could
be put into working condition.
Most of the disc machines designed by the Volta associates had the disc
mounted vertically (see figs. 5 and 6). The explanation is that in the
early experiments, the turntable, with disc, was mounted on the shop
lathe, along with the recording and reproducing heads. Later, when the
complete models were built, most of them featured vertical turntables.
Public-domain text, read in full here on John Shaqi.
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