. Collection of United States patents granted to Thomas A. Edison, 1869-1884 . one-instrument having a diaphragm and electro-magnet, aswingingleverplacedwithitsmovingend in contact with the receiving-diaphragm,and a switch or key for increasing the elec-tric current and operating the lever as asounder or call upon the diaphragm, substan-tially as set forth. 2. In combination with the telephone-trans-mitter B and receiver A, the induction-coilC D, battery Q, local circuit, switch S, and a 203,01? circuit-connections, substantially as and/for |the purposes set forth. 3. In combination with the m
. Collection of United States patents granted to Thomas A. Edison, 1869-1884 . one-instrument having a diaphragm and electro-magnet, aswingingleverplacedwithitsmovingend in contact with the receiving-diaphragm,and a switch or key for increasing the elec-tric current and operating the lever as asounder or call upon the diaphragm, substan-tially as set forth. 2. In combination with the telephone-trans-mitter B and receiver A, the induction-coilC D, battery Q, local circuit, switch S, and a 203,01? circuit-connections, substantially as and/for |the purposes set forth. 3. In combination with the main-line cir-cuit and local circuit, and the telephonic in-strument, the induction-coil composed of twowires, the largest of which is surrounded bya finer insulated wire wound helically, thetwo being then wound into a helix to formthe induction-coil, substantially as set forth. Signed by me this 28th day of February,.. D. 1878. - THOS. A. EDISOK Witnesses: Geo. T. Pinckney,Chas. H. Smith. T. A. or Speaking-Telegraph. No. 203,018. Patented April 30, 1878.
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Keywords: ., boo, bookcentury1800, booksubjectinventions, booksubjecttelephone
