Automatic telephony; a comprehensive treatise on automatic and semi-automatic systems (1921)
Smith, Arthur Bessey, b. 1875, Campbell, Wilson Lee · New York : McGraw-Hill · leaf 339
OMA TIC TELEPHON Y them, rendering it unnecessary to have any person switch toll lines at theother places. For example, A, B, C, D, and E may be five exchanges on one line ofrailroad. At C may be located the toll board. An operator there canreach out over the toll line, dial up any desired… … String of exchanges. It is better if traffic is large enough to have two toll lines along thesame route. One can be restricted to through service and can not becalled by the subscribers, it is under the control of the operator at C.The other is the local line and can be called by any subscriber at…
Telephone
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