American telegraphy and encyclopedia of the telegraph; systems, apparatus, operation (1909)
Maver, William, jr. [from old catalog] · New York, Maver publishing company · leaf 584
tral office and operates the relay k, in whoselocal circuit, controlled by lever l\ is a register kg. This register is provided withchemically prepared paper which records the number of the box as received. If thecentral office should desire to speak to the policemen sending in an on duty sig-nal,… … 474 AMERICAN TELEGRAPHY. opens the main circuit, which actuates the call bell in the signal box. The act offorming a new circuit around the relay R avoids operating the register uselesslywhile the policeman is being signaled. Upon hearing the bell, after sending in an<on duty signal, the…
Telegraph
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
