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Description and Use of the

r 57. The longitude of the stars and planetsis reckoned upon the ecliptic; the numbersbeginning at the first point of aries T, wherethe ecliptic crosses the equator, and increasingaccording to the order of the signs.

158. The latitude of the stars and planetsis determined by their distance from theecliptic upon a secondary or great circlepasting through its poles, and cresting it atright angles.

159. Twenty-four of these circular lines,which cross the ecliptic at right angles, beingfifteen degrees from each other, are drawnupon the surface of our celestial globe;which being produced both ways, those onone side meet in a point on the northernpolar circle, and those on the other meet ina point on the southern polar circle.

160. The points determined by the meet-ing of these circles are called the poles ofthe ecliptic, one north, the other south.

161. The longitude of the stars hath beenobserved to increase about a degree in 72years, which is called the precession of theequinox.

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