《明史·志·卷七》
嘉靖二年，华湘进言说： 古今善于制定历法的有三家，汉《太初历》用音律，唐《大衍历》用蓍草占卜，元《授时历》用日晷测影，最为接近真实。
嘉靖二年，湘言： 古今善治历者三家，汉《太初》以钟律，唐《大衍》以蓍策，元《授时》以晷景为近。
In the second year of Jiajing, Hua Xiang said: There are three schools that are good at formulating calendars in ancient and modern times. The Han "Taichu Calendar" uses musical notes, the Tang "Dayan Calendar" uses yarrow divination, and the Yuan "Shoushi Calendar" uses sundial shadow measurement., the closest to reality.