The path of the Sun, called the Ecliptic, is based on the annual revolution of the Earth around the Sun. Taking this apparent path of the Sun as a circumference, you have at right angles thereto the North and South poles of the Ecliptic: connected by vertical circles of Longitude measured in degrees Eastward from the Vernal Equinox. Circles parallel to the Ecliptic are measured in degrees of Latitude North or South.
Stretching for some 8 degrees on either side of the Ecliptic is a belt in which lie the orbits of all the solar system bodies, each inclined in various degrees to the Earth's orbit. Since Hipparchus (q.v.), the greatest of the ancient astronomers, this belt has been divided into twelve 30° arcs, or signs, measured from the Vernal Equinox; the signs named from the constellations which once coincided with these arcs, but which because of the Precession of the Equinoxial point now no longer coincide. The statement that this disproves astrology is sheer ignorance, for no modern astrologer ascribes the sign influences to their background of stars, but to conditions of momentum and gravitation within the earth by virtue of its annual revolution around the Sun. (v. Zodiac; Precession; Galactic Center.) Many of these terms are loosely used by some astrologers, largely because they lack complete astronomical understanding of the factors on which their map of the heavens for a given moment is erected. (v. Map of the Heavens.)
