Elements of descriptive astronomy, a text-book (1897)
Howe, Herbert A · New York, Silver · leaf 100
77 THE EARTH. perpendicular to the plane of the floor. The earth's axis swings around a perpendicular to the plane of the ecliptic, as shown in Fig. 74. CA is perpendicular to the ecliptic ; PC, the earth's axis, takes successively the positions PC, P'C, P"C, etc., 25,800 years being required for a… … Fig. 74. — THE PRECESSIONAL MOTION OF THE EARTH'S EQUATOR. The point where the equator cuts the plane of the ecliptic likewise moves around, taking the positions V' and V" successively. On extending the planes of the equator and the ecliptic to the sky, the point V, where the celestial equator and…
Astronomy
Internet Archive · Gerstein - University of Toronto · Public domain (published before 1931). Free to use for anything.
