The signs of the ecliptic took their names from 12 constellations mentioned in the Introduction to be situated in the Heavens near those places. It is to be observed, that the signs are not to be confounded with the constellations of the same name: For the _Sign of Aries_, is not the same with the _Constellation_ Aries; the latter is a system of Stars digested into the figure of a _Ram_, but the sign of _Aries_ is only 30 degrees of the ecliptic, counted from the equinoctial point ♈, (which is reckoned the first point in the ecliptic) to the beginning of _Taurus_: Or, it is sometimes taken for all that space upon the Celestial Globe contained between the two circles passing through the first points of ♈ and ♉. What has been here said of _Aries_, is to be noted of all the rest of the signs. The constellations above-mentioned were formerly situated within the signs which now bear their names; but by a slow motion of the equinoctial points, being one degree in 72 years, the constellation _Aries_ has now got into the sign ♉, and so of the rest. So that _Pisces_ is now got into the Sign of ♈; this slow motion in the Heavens is called the _Precession of the Equinoctial Points_. [Sidenote: _Poles of the Ecliptic._] The _Poles of the Ecliptic_ are both situated in the Solstitial Colure, at 23 degrees, 29 minutes distance from the Pole of the world; and they take their denomination from the Hemisphere wherein they are placed, _viz._ that which lies in the (Northern/Southern) Hemisphere, is called the (North/South) Pole of the ecliptic. The arctic and antarctic circles, are described by the Poles of the ecliptic in the diurnal motion of the Earth round its axis, whence it seems these two circles are called _Polar_. [Sidenote: _Circles of Longitude._] 8. All great circles passing through the Poles of the ecliptic, and consequently intersecting it at right angles, are called _Circles of Longitude_: So that, [Sidenote: _Longitude of any Point in the Heavens._] [Sidenote: _Place of a Star._] 9. The _Longitude_ of any _Point_ in the Heavens (as a _Star_ or _Planet_, _&c._) is an arch of the ecliptic contained between the circle of longitude passing thro’ that point, and the equinoctial point ♈. And that degree of any sign which lies under the circle of longitude, passing thro’ any Star or Planet, is called the _Place_ of that Star or Planet. _Note_, The _Sun_ never goes out of the ecliptic, and it is not usual to say the Sun’s longitude, but we commonly express it the _Sun’s Place_, which is that sign, degree, minute, _&c._, of the ecliptic, which he at any time passes. 10. All circles conceived to be drawn parallel to the ecliptic, are called _Parallels of Latitude_: So that, [Sidenote: _Latitude of a Star, &c._]