Chinese Astrolabe, 19th century, wood, 3.37 inches diameter, Frederick Venditti, 1988.11.21.
A circular astrolabe with a recessed enter and 12 Chinese cycle characters carved around the flat rim. An early astrolabe was invented during the Hellenistic period (c. 150 B.C.E.), supposedly by Hipparchus of Nicaea, and further developed around the world. It was used by astronomers, navigators, and astrologers to locate and predict the positions of the Sun, Moon, planets, and stars, among other functions.