Lessons in practical electricity; principles, experiments, and arithmetical problems, an elementary text-book (1902)
Swoope, Coates Walton. [from old catalog] · New York, D. Van Nostrand company · leaf 347
e contact resistance between the buttons,and thus vary the current strength in the telephone circuit.The induced currents in the telephone cause the disc toreproduce the original sounds. The telephone may be locatedat a considerable distance from the microphone, when thereproduced sound, as the…
Electricity · Magnetism
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
