Lessons in practical electricity; principles, experiments, and arithmetical problems; over four hundred illustrations; an elementary text book (1909)
Swoope, C. Walton (Coates Walton), d. 1901 · New York, D. Van Nostrand company · leaf 351
Fig. 302.—Connections of Transmitting and Receiving Stations for the Wire-less System of Telegraphy. The stations may be located miles apart with no metallic connections between them. circuit with a battery and a relay of several hundred ohmsresistance. One plug is also connected to a vertical…
Electricity · Magnetism
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