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 310
must alwaysbe used in toll line jacks, regardless of whether the operator is answeringor calling; and the plug marked Auto must always be used in the trunksto the automatic switchboard or in pay-station lines. When a line To20-*/n-•Ji su la tingTrans. Make cutoff Relay 1000uj forToll Lines,… … Fig. 243.- -A typical cord circuit for connecting toll lines to local automatic switchboard lines. operator has received an order for a connection to one of her toll lines,she picks up the toll plug of an idle cord circuit and inserts it into thejack of the line on which the desired party is to be…
Telephone
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