Collins, A. Frederick (Archie Frederick), 1869- · New York, London, D. Appleton and company · leaf 98
ywhere on the Earth will swing round until it is inthe same direction as the lines of magnetic force. How to Make a Simple Com-pass.—Take a piece of watchspring about 3 inches long andstraighten it. Heat the middlered-hot and let it cool slowly,when the temper will be taken outof it at this point.… … STEEL SEWINGNEEDLE CORK Fig. 88. — Compassplete. Com- 78 THE BOOK OF THE STARS
Astronomy · Stars
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