Electrical engineer's pocket-book: a hand-book of useful data for electricians and electrical engineers (1901)
Foster, Horatio A. (Horatio Alvah), 1858-1913 · New York, D. Van Nostrand co.; London, E.& F.N. Spon, ltd. · leaf 670
Bboards to the A boards, and an order-wire connects the A boardoperator with the B board operators. When a subscriber calls, the B operator on the section on which the calling subscribers line-drop happensto be situated merely plugs a trunk-line into the subscribers spring-iackThe A operator… … Fig. 22c, I W P-HHIi SubscribersLines. a* :7Tb ° that operator to plug a trunk-line in on the number required, which shedoes, and answers back giving the number of the trunk-line she proposes touse ; and the A operator then connects the ends of the two trunk-linesby a multiple cord, as on the…
Electrical engineering
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