Studies of the cosmos and astrology were popular in early China, and artisans used many symbols to picture the universe, as on the back of this bronze mirror. The raised designs on the outer rim represent mountain ranges that circumscribe the world and reach the sky. The central field contains constellations of rising and setting stars and planets while the central knob represents the polar star. In ancient Chinese texts, raised circular star motifs are given various names, including “star and cloud” (xing yun), “strung pearls” (lian zhu), or “hundred nipples” (bai ru). In ancient China, a round shape usually referred to Heaven while a square shape referred to Earth. However, mirrors were typically round without necessarily having a celestial meaning.