Theory and practice of the electric telegraph; a manual for operators and students (1875)
Churchill, Charles Henry, d. 1904. [from old catalog] · Oberlin, Ohio, Sherman & bros. · leaf 68
a very small space. An ebonite button at A is used to depress the levertill it strikes the small platinum anvil, which is the oppositeelectrode, and insulated from the frame. This closes the cir-cuit. A spring raises it when the pressure is withdrawn thusopening the circuit. When the key is not in… … 48 MANUAL OF TELEGRAPHY. wires attached to binding screws at A. Above the electro-magnet is the armature C which carries a lever having asmall vertical motion between set screws at B. The other endof the lever carries a steel point P. A strip of paper is carriedover the steel point and between two…
Telegraph
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
![An illustration from [Graphophone patents] (1878)](https://img.insideoutlibrary.com/img/200/ia-graphophonepaten20unit-577-258.webp)
![An illustration from [Graphophone patents] (1878)](https://img.insideoutlibrary.com/img/200/ia-graphophonepaten15unit-175-108.webp)
![An illustration from [Graphophone patents] (1878)](https://img.insideoutlibrary.com/img/200/ia-graphophonepaten02unit-572-245.webp)