He invented a mechanized water clock with the Tantric monk and mathematician Yi Xing (Chinese: 一行; pinyin: Yī Xíng; Wade–Giles: I-Hsing).
Water, flowing into scoops, turned a wheel automatically, rotating it one complete revolution in one day and night.
It permitted the exact determinations of the time of dawns and dusks, full and new moons, tarrying and hurrying.
All these motions were brought about by machinery within the casing, each depending on wheels and shafts, hooks, pins and interlocking rods, stopping devices and locks checking mutually.
He wrote The Five-Planet and Twenty-eight Constellation Deities (Chinese: 五星二十八宿神形; pinyin: wǔxīng èrshíbāxiù shénxíng), of which a Song dynasty copy resides in the collection of the Osaka City Art Museum.