ON THE LOADSTONE, BK. VI.
239
The true and natural motion of the axis or pole of the
Earth directed to the Arctick circle of the Zodiack.
A I is part of the Arctick circle of the Zodiack, in which one period of obliquity is performed; from A to E is the period of the anomaly of the præcession of the æquinoxes; A I is the shape of the curved line which the pole of the Earth describes by a true motion compounded of the three motions, that is to say, of the æquable motion præcessional, of that of the anomaly of the præcessions, and that of obliquity.
The
