&4 . Description and Use of the

from each other, so that the whole breadthof the zodiac is 16 degrees.

164. Amongst these parallels, the latitudeof the planets is reckoned ; and in their ap-parent motion they never exceed the limits-of the zodiac.

165. On each side of the zodiac, as wasobserved, other constellations are distinguish-ed ; those on the north side are called nor-thern, and those on the south side of it,southern constellations.

166. All the stars which compose theseconstellations, are supposed to increase theirlongitude continually ; upon which suppo-sition, the whole starry firmament has a stowmotion from west to east; insomuch thatthe first star in the constellation of Aries,which appeared in the vernal intersection ofthe equator and ecliptic in the time of Metonthe Athenian, upwards of 1900 years ago,is now removed about 30 degrees from it.

To represent this motion upon the ce-lestial globe, elevate the north pole, so that itsaxis may be perpendicular to the plane ofthe broad paper circle, and the equator willthen be in the same plane; let these repre-sent