. Automatic telephony; a comprehensive treatise on automatic and semi-automatic systems . Toll Line Circuit-1 Toll Line Circuit-?. Toll Board Toll Board Fig. 252.—Automatic toll lines (scheme). into the jack, the operator throws the calling device key, she can put thecall through automatically. After dialing the number, the operatorrings with the regular ringing key. This operation holds no matterwhether she is switching toll lines only, or if she automatically completesthe connection to the called subscriber. Inter-city Scheme.—For the sake of simplicity, this is illustrated bytwo small excha
. Automatic telephony; a comprehensive treatise on automatic and semi-automatic systems . Toll Line Circuit-1 Toll Line Circuit-?. Toll Board Toll Board Fig. 252.—Automatic toll lines (scheme). into the jack, the operator throws the calling device key, she can put thecall through automatically. After dialing the number, the operatorrings with the regular ringing key. This operation holds no matterwhether she is switching toll lines only, or if she automatically completesthe connection to the called subscriber. Inter-city Scheme.—For the sake of simplicity, this is illustrated bytwo small exchanges, for the principles do not depend on the size. Thetoll lines (Fig. 252) terminate at each end in toll selectors, and in jacksand lamps on the toll board. The trunks from local selector banks alsorun to the toll board. When a subscriber in B desires to call a subscriber in A, he dials thetoll operator according to the number given in the directory. This giveshim a trunk terminating in a lamp and jack as shown at the right in theillustration. The toll operator answers in the usual way. She has acalling device which ma
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttelephone, bookyear19
