American telegraphy and encyclopedia of the telegraph; systems, apparatus, operation (1909)
Maver, William, jr. [from old catalog] · New York, Maver publishing company · leaf 592
le under the roof of the box. The actual connections ofthe telephone apparatus, with the condenser omitted, are shown in the Pearce and Jonessystem, next described. The signal box with inside door closed is illustrated in Fig. 360. The pulling ofthe lever k, shown on the outside of the door v>,… … CHICAGO POLICE PATROL BOX. 482 AMERICAN TELEGRAPHY. Special signals are transmitted by the police officer, or others having access to theboxes, by moving the pointer p. Fig. 359, to the designated point on the dial; which FIG. 360.
Telegraph
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
