Elementary astronomy; a beginner's text-book (1899)
Holden, Edward Singleton, 1846-1914 · New York, H. Holt and company · leaf 43
re to be spoken of.If they are not thoroughly understood some points will notbe as clear as they should be. Axgles: Their Measurement. — An angle is theamount of divergence of two lines. For example, the angle between the two lines S1Eand S2E is the amount of diver-gence of these lines. The… … Fig. 5. —Angles : theirMeasurement. In order to compare them and to obtain their numerical ratio, wemust have a unit-angle. The unit-angle is obtained in this way ; The circumference of anycircle is divided into 360 equal parts. The points of division arejoined, with the centre. The angles between…
Astronomy
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
