Endnote 50
Part II, §18.  Instead of reckoning a star's right ascension by referring it to the equator, it was reckoned by observing the degree of the zodiac which southed along with it.  This is expressed in the first `Table of fixed stars' in MS. Camb. Univ. Lib. Ii. 3. 3 (fol. 70, back) by the phrase `cum gradibus, quibus celum mediant'; the other co-ordinate of position was the star's declination from the equator, as in the modern method.  The ancients also used the co-ordinates of longitude and latitude of a star, the longitude being reckoned along the ecliptic, and the latitude along great circles through the poles of the ecliptic; as appears from the second Table in the same MS.