Lessons in practical electricity; principles, experiments, and arithmetical problems, an elementary text-book (1903)
Swoope, Coates Walton. [from old catalog] · New York, D. Van Nostrand company · leaf 64
EARTHS MAGNETISM. 45 … Fig. 62.—Mariners Compass. permit the needle to come to rest pointing N and S, and thengently twist the box around until the point marked N on thescale, is directly under theN-pole of the needle. Thetrue geographical northwill then be so many de-grees east, or west of theposition the needle…
Electricity · Magnetism
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
