Wentworth, G. A. (George Albert), 1835-1906 · Boston, Ginn & company · leaf 226
ing at each end asolar lens having its focus on a silvered plate on the other end.The arc of the declination limb turns on an axis, and one orthe other solar lens is used, according as the sun is north orsouth of the equator. Fig. 15 shows the position of the decli-nation arc when the sun is south;… … Fig. 15. Burts Solar Compass FIELD INSTRUMENTS 239
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