American telegraphy and encyclopedia of the telegraph; systems, apparatus, operation (1909)
Maver, William, jr. [from old catalog] · New York, Maver publishing company · leaf 588
FIG. 354. … MULTIPLE TRANSMITTER OR BREAK WHEEL. Gamewell police telegraph boxes.—The Gamewell police telegrapli box isshown in its three positions in Figs. 355, 356 and 357: namely,with both doors closed,with the outer door open, and with both doors open. 478 AMERICAN TELEGRAPHY. In the practical operation…
Telegraph
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