American telegraphy and encyclopedia of the telegraph; systems, apparatus, operation (1909)
Maver, William, jr. [from old catalog] · New York, Maver publishing company · leaf 595
n the manner of the ordinary Morse keys, signals may be tapped out.As, however, expert operators are not available, this key is only used for the purpose ofsending in code signals, according to a printed blank attached to the inside of the doorof the box. The bell b is operated by the central… … PEARCE AND JONES SIGNAL BOX, PEARCE AND JONES POLICE TELEGRAPH. 485 transmitter battery tb. Usually the telephone receiver is suspended from a hook h, atwhich time the telephone battery is out of the circuit, being open at .r, and thebell, B, is then in the circuit, but, when the telephone receiver…
Telegraph
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