Hawkins electrical guide ... : questions, answers & illustrations : a progressive course of study for engineers, electricians, students and those desiring to acquire a working knowledge of electricity and its applications ; a practical treatise (1914)
Hawkins, N. (Nehemiah), 1833-1928 · New York : T. Audel & Co. · leaf 32
the main station but the extension can talk, and throwing the listening key cuts off themain and allows the extension bell only to ring. The ringing key must be thrown toring the extension station from the main, whch makes the system intercommunicating.Each station is fed by its own battery and… … LX TENDONKINlilN6 KEY £
Electrical engineering
Internet Archive · Brigham Young University · Public Domain Mark 1.0. Free to use for anything.
