Modern practice of the electric telegraph. A handbook for electricians and operators (1872)
Pope, Frank L. (Franklin Leonard), 1840-1895 · New York : D. Van Nostrand · leaf 53
e-ment is found extremely useful in connecting batter-ies as well as instruments. At a way station it ispreferable to a simple cut-out, for the reason that theapparatus is entirely disconnected from the circuit whenthe wedge is withdrawn (59). 65. THE UNIVERSAL SWITCH, for the use of officeshaving… … the arrangement most generally used, which is knownas the Culgan Switch, from the name of its inventor.The upright straps of brass, A, B, C, D, E, F, are fixedupon a slab of hard wood, or other non-conducting ma-terial, and provided with binding screws at their upperextremities, for the reception…
Telegraph
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