Lessons in astronomy including uranography. A brief intoductory course without mathematics (1896)
Young, Charles A. (Charles Augustus), 1834-1908 · Boston, London, Ginn and company · leaf 335
r the arc Q F,will measure the time which has elapsed since m was on themeridian PQ. The angle mPQ is called the hour-angle of thestar m. It is the angle at the pole between the meridian andthe hour-circle which passes through the body. Having now this definition of the hour-angle, we may… … Fig. 93. — Hour-Angle. mean solar time (Art. 89) is the hour-angle of a fictitious sunwhich moves around the heavens uniformly, once a year, in the equator, keeping itsright ascension equal to themean longitude of the realsun. For some purposes,as in dealing with the tides,it is convenient to use…
Astronomy
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
