Modern practice of the electric telegraph : a handbook for electricians and operators (1874)
Pope, Frank L., 1840-1895 · New York : D. Van Nostrand · leaf 52
63. Fig. 20 represents a Ground Switch (58). The lever THE MORSE, OR AMERICAN TELEGRAPHIC SYSTEM. 39 A is attached to a wire leading to the earth, and the twostuds, B, C, are connected to the line wire on each sideof the instruments. … . ^L
Telegraph
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