The arimillary Sphere os an ancient instrument for astronomical observation,developed from the Huen-Tien astronomical theory.
The armillary sphere,in early eras,had a simpler structure.It was composed of a fixed equator ring and a movable Syh-Yo ring turning on its polar axis.After generations of modification,the armillary sphere became an accurate instrument by the Tang and Sung Dynastics.The armillary sphere an exhibit is in imitation of the style in the Ming Dynasty Built to a ratio of two to one.It¡¦s composed of three levels of rings designed to represent the positions of important circles of the celestial sphere.

