The standard electrical dictionary : a popular encyclopaedia of words and terms used in the practice of electrical engineering (1898)
Sloane, T. O'Conor (Thomas O'Conor), 1851-1940 · London : Crosby Lockwood and Son · leaf 382
f the points. The blocks are carriedon a standard and base D. The blocks are connected with two ter-minals ^, y, of a circuit, including a telephone and battery. Thereare two contacts to be disturbed. If delicately adjusted a fly walking over the base-board will dis-turb the contacts enough to… … Fig. 242. Microphone. Microphone Relay. A combined microphone and telephone.A microphone is placed close to the diaphragm of a telephone.The slight sound waves emitted by the telephone affect the micro-phone and are repeated in its circuit. The microphone circuitincludes a local battery and…
Electricity
Internet Archive · Medical Heritage Library · Public Domain Mark 1.0. Free to use for anything.
![An illustration from [Electric engineering.] (1902)](https://img.insideoutlibrary.com/img/200/ia-electricengineer04inte-206-68.webp)
