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 198
ion of the mirror; thedeflections of the spot of lighton the scale, however, arepractically proportional to thestrength of currents through the instrument. When a telescope issubstituted for the lamp, as in Fig. 164, a dark room is not required. The scale readings are reflectedin the mirror and… … Fig. 164.— DArsonval Mirror-Reflecting Galra-nonieter with Scale and Reading Telescope.
Electricity · Magnetism
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
