Miller, Kempster Blanchard, 1870-1933 · New York : McGraw publishing company · leaf 425
he calling plug embraces thewindings of the usual common battery repeating coil between thecenter points of which is bridged the private branch storage battery.When, however, the relays A and B are actuated the repeating coilis cut out entirely, the tip of the answering cord being then con-nected… … > t \ n^SSo
Telephone
Internet Archive · Cornell University Library · Public Domain Mark 1.0. Free to use for anything.
