Clock-driven celestial globe, Chinese, 1830.

This celestial globe was made by Qi Mei-lu in Wuyuan, China. The metal globe depicts Chinese star patterns and is labelled in Chinese script. Inside the globe a clockwork mechanism turns the sphere in time with the Earth's rotation. The celestial globe is a three-dimensional model of the heavens on which the stars are plotted on the outside of a sphere. Originating in the Ancient World, it was probably inspired by the discovery that the Earth was round. The globe could be used to teach and demonstrate various astronomical principles.