Willson, Robert Wheeler, 1853-1922 · Boston, New York Ginn & company · leaf 20
Fig. 9 radius, and a pair of compasses, d, whose legs may be bent and oneof which carries a hard pencil point. Determine by trial with the compasses the center of the base ofthe hemisphere, and mark two diameters by drawing straight linesupon the base at right angles through the center. Prolong… … hemisphere exactly central upon the circular protractor, by bring-ing the marked ends of one of the diameters upon those divisionsof the protractor which are numbered 0° and 180°, and the other onthe divisions numbered 90° and 270°. Determine and mark the o LABORATORY ASTRONOMT highest point of the…
Astronomy
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