. Collection of United States patents granted to Thomas A. Edison, 1869-1884 . speaking-telegraph, the combination,with a diaphragm, of a rheostat or resistance-coils and a conductor vibrated by the dia-phragm and acting to short-circuit more orless of the rheostat in proportion to the ampli-tude of the vibrations, substantially as setforth. 2. In combination with a diaphragm actu-ated by sound-vibrations and a metallic con-ductor, an elastic cushion, /, interposed be-tween the diaphragm and said metallic con-ductor, to move the latter in proportion to themovement of the diaphragm, substantial
. Collection of United States patents granted to Thomas A. Edison, 1869-1884 . speaking-telegraph, the combination,with a diaphragm, of a rheostat or resistance-coils and a conductor vibrated by the dia-phragm and acting to short-circuit more orless of the rheostat in proportion to the ampli-tude of the vibrations, substantially as setforth. 2. In combination with a diaphragm actu-ated by sound-vibrations and a metallic con-ductor, an elastic cushion, /, interposed be-tween the diaphragm and said metallic con-ductor, to move the latter in proportion to themovement of the diaphragm, substantially asset forth. 3. In aspeakiug-telegraph, the combination,with the diaphragm and rheostat, of a localcircuit and au induction-coil, substantially asset forth. 4. Inaspeaking-telegraph,an induction-coil,a rheostat, and a battery in a local circuit, anda main-line circuit passing through a secondinduction-coil and also through the battery,substantially as set forth. Signed bv me this 8th day of December, 1877. THOS. A. EDISON. Witnesses: Geo. T. Pinckney,Chas. H. 2 Sheets—Sheet i T. A, 203,014, Patented April 3a, 1878.
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Keywords: ., boo, bookcentury1800, booksubjectinventions, booksubjecttelephone
