In the reign of the Tang emperor Xuanzong (ruled 712-755), Buddhist Master Yixing (673-727), another outstanding astronomer, improved on Zhang Heng's instrument by making a bronze armillary sphere which revolved through one degree a day and one full revolution per year, and also had two wooden mannikins which beat a drum and a bell to mark the time of day.
唐玄宗時，也有一位出色的天文學家一行法師，他改良張衡的渾天儀為「渾天銅儀」，銅儀每天轉一度，每年轉一圈，還有兩個木人，按時擊鼓、敲鐘。