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 286
aving a continuous ring magnet and manually operatedcontrol switch. In either figure both the relay and bell could be mountedon one frame, or mounted separately; when both are mounted togetherthe combination is properly called a relay bell, but when mountedseparately, it should be called a relay…
Electrical engineering
Internet Archive · Brigham Young University · Public Domain Mark 1.0. Free to use for anything.
![An illustration from [Electric engineering.] (1902)](https://img.insideoutlibrary.com/img/200/ia-electricengineer02inte-275-147.webp)
