fl. c. 52 B.C.

Chinese astronomer who built an early armillary sphere or equatorial ring to show the positions of important circles in the heavens. Some 130 years later, in A.D. 84, Fu An and Chia Kuei added a second ring to show the ecliptic, and in 125 Change Heng added two more rings for the meridian and horizon, thus constituting the first complete armillary sphere.