Elementary lessons in electricity and magnetism (1906)
Thompson, Silvanus P. (Silvanus Phillips), 1851-1916, Schwetzky, Otto H. L. [from old catalog] · Chicago, Thompson & Thomas · leaf 130
28-64 2 89 •999 57-29 I 90 I •000 Infin. 0 Cosine. Co-tangent. Arc. 112 ELEMENTARY LESSONS ON [chap. ii. Lesson XI L—Terrestrial Magnetism. 134. Tlie Mariners Compass.— It was mentionedin Art. 79 that the compass sold by opticians consists ofa magnetised steel needle balanced on a fine point abovea… … Fig. 65. card, divided out into the 32 points of the Compass, isitself attached to the needle, and swings round with it sothat the point marked N on the card always points tothe north. In the newest and best ships compassesseveral magnetised needles are placed side by side, as itis found that the…
Electricity · Magnetism
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