On the armillary sphere there was also a large gear wheel which connected it to the drive system of the entire clock tower. Thus the officers of the Ministry of Astronomy, which was charged with making astronomical observations, could use the sphere to follow the movements of the sun and stars.
渾儀上面還有一個大齒輪，和整座儀象台的傳動系統連結，所以負責觀測天象的司天監，可以用渾儀來同步追蹤太陽或恆星的移動。