Page:A short history of astronomy(1898).djvu/97

§ 42] then he found that was equal to the former, but that ♈︎ ' was greater than the former ♈︎ , or that '

was slightly to the east of. This change ' being nearly the same for all stars, it was simpler to attribute it to an equal motion in the opposite direction of the point ♈︎, say from ♈︎ to ♈︎' (fig. 22), i.e. by a motion of the equator from ♈︎ to ♈︎' ', its inclination ' ♈︎'  remaining equal to its former amount  ♈︎. The general effect of this change is shewn in a different way in fig. 23, where ♈︎ ♈︎' ♎︎ ♎︎' being the ecliptic, represents the equator as it appeared in the time of Timocharis,  (printed in red) the same in the time of Hipparchus, ♈︎, ♎︎ being the earlier positions of the two equinoctial points, and ♈︎', ♎︎' the later positions.