The practical telephone handbook and guide to the telephonic exchange (1906)
Poole, Joseph · New York, Macmillan Co. · leaf 539
r 0. This dial isconnected to a wheel with 10 teeth to correspond, and asingle tooth apart from the others, which serves a specialpurpose. The connections are shown in Fig. 471, whichshows the instrument in the normal condition. Each timeany one of the 10 teeth passes a certain spring whenmoving in… … Fig. 471.—Connections of Subscribers Instrument on the other wire of the loop. The first wire is called thevertical line, and the second the rotary line, forreasons which will be presently explained. Selecting.—To call a number, say 5679, the receiver is firstremoved from the prong, then a finger…
Telephone
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