Celestial globe

The earliest celestial globe was dated back to 52 BC in the West Han[?] dynasty by the astronomers Geng Shou-chang (耿壽 昌) and Luo-xia Hong (落下 閎). The first water powered celestial globe was created by Zhang Heng in the East Han dynasty.

Then Li Chun-feng (李淳風) of the Tang dynasty created one in 633 AD with three spherical layers to calibrate multiple aspects of astronomical observations.

In 723 AD, Tang dynasty buddhist monk Yi-xing (一行) and government official Liang Ling-zan (梁令瓚) combined Zhang Heng's water powered celestial globe with an escapement device. The result was allegedly the world's first water powered mechanical clock.

See also: celestial sphere, Chinese constellation, Chinese zodiac