Preceptory
a religious house of the Knights Templars, subordinate to the Temple, or principal house of the order in London, under the government of an eminent knight. The preceptories of each province were subject to a provincial superior, three of whom ranked above all the rest, viz., those of Jerusalem, Tripolis, and Antioch. subject to a pro- PRECESSION OF THE EQUINOXES, in astronomy, the going forward of the equinoxes. The arrival of the sun at the point Aries a little earlier than he might be expected to reach it was first observed by Hipparchus about 150 в. c.
Depending, as the phenomenon does, for its explanation, on the law of gravity, Hipparchus could not account for it.
Sir Isaac Newton was the first who did so, and that his newly discovered law of gravitation explained the precession of PREFECT the equinoxes was a confirmation of the accuracy with which he had read the law itself. Excepting only at the two equinoxes, the the plane i in which the sun moves in his orbit and that in which the earth rotates do not coincide. By the law of gravitation one body does not attract another in mass, but acts on its separate particles. The sun then does not attract the earth as a whole, but tends to pull the parts nearest it away from those in proximity to the center, and the center again away from those on the other side. The bulged-out equatorial zone is specially liable to be thus acted upon, and, but for the rotation of the earth, would be so drawn down toward the ecliptic that it and the equator would ultimately be in one plane. The earth's rotation, however, modifies this action, and simply causes the points at which the earth's equator intersects the plane of the ecliptic to move slowly in a direction opposite to that in which the earth rotates. This is what is denominated the precession of the equinoxes. It is generally associated with the sun, but the moon is twice as potent in producing it; owing to her comparative nearness to the earth she is able to produce a greater differential effect on the nearer and more remote portions of our planet.