. Mechanical appliances, mechanical movements and novelties of construction; a complete work and a continuation, as a second volume, of the author's book entitled "Mechanical movements, powers and devices" ... including an explanatory chapter on the leading conceptions of perpetual motion existing during the past three centuries. TRANSMISSION OF POWER. 31. S3. ACOUSTIC TELEPHONE. The mouthpiece, a, has a cen-tral aperture for the passage of sound waves to the diaphragm, c, whose edges are secured within arabbet of the mouthpiece. Thediaphragm is about 7 inches indiameter and is made of sprucew
. Mechanical appliances, mechanical movements and novelties of construction; a complete work and a continuation, as a second volume, of the author's book entitled "Mechanical movements, powers and devices" ... including an explanatory chapter on the leading conceptions of perpetual motion existing during the past three centuries. TRANSMISSION OF POWER. 31. S3. ACOUSTIC TELEPHONE. The mouthpiece, a, has a cen-tral aperture for the passage of sound waves to the diaphragm, c, whose edges are secured within arabbet of the mouthpiece. Thediaphragm is about 7 inches indiameter and is made of sprucewood, which possesses great sono-rousness combined with strengthsufficient to sustain the tension ofthe line wire. The mouthpiece and diaphragm are held to the wallon a bed piece, l>, by the tension of the line wire. The bed piece isrecessed at both sides, /g, and centrally apertured for the passage ofthreads connecting the line wire to the diaphragm. The front recess,/, affords a space between the diaphragm and the center of the bedpiece for free action of the diaphragm, promoting clearness of enun-ciation when the instrument is used as a receiver, and the rear recess,g, secures a small marginal support for the transmitter, thereby avoid-ing a large contact with the wall and preventing excessive vibration. To avoid indistinct articulation and th
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Keywords: ., bookauthorhiscoxgardnerdexter18, bookcentury1900, bookdecade1910
