The elements of theoretical and descriptive astronomy, for the use of colleges and academies (1901)
White, Charles J. (Charles Joyce), 1839-1917 · New York, J. Wiley & sons; · leaf 49
e lines AD andi>Cbe drawn perpendicular to the reflecting surfaces, and pro*long AD until it meets BC. The angle DCB is equal to theangle which the two surfaces make with each other. We havethen to prove that the angle SEB is double the angle DCB. Now since the angle of incidence always equals… … Fig. 16. we wish to measure the angular distance between two celestialbodies, A and B (Fig. 16). The instrument is so held that itsplane passes through the two bodies, and the fainter of them, which in this case we suppose tobe B, is seen directly through thehorizon-glass and the telescope.B is so…
Astronomy
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
