《宋史·志·卷一》
此后虽然有璇玑王衡，却不是因为历法而制作；制作历法的人也不再用仪器来考核自己的历法，云气吉凶、每月初一、星象和谶纬，都没有人知晓它们必定相当的计算根据。
其后虽有玑衡，而不为历作。为历者亦不复以器自考，气朔星纬，皆莫能知其必当之数。
After this there were the Xuanyi and Wang Heng [instruments], but they were not made forcalendars. Nor did calendar-makers continue to use machines to check their calendars; no one knew of any basis for unequivocal calculations related to auspicious or inauspicious clouds and vapours, the first day of each month, the constellations, and the prophetic classics.