fl. 700s

Chinese Buddhist Monk, Mathematician, and Astronomer

I-Hsing is most known for his contributions to the development of a water clock with an escapement to control the speed and regularity of the clock's movements. This advancement allowed more accurate timekeeping correct to within 15 minutes a day.

Records on the life of I-Hsing, also known as I-Xing, are scarce and center on his association with the construction of a water clock in eighth century China. Early in the K'ai-Yuan reign of 713-741, the crown recruited Buddhist monk I-Hsing to work with administrative official Liang Ling-Tsan (Liang Ling-Zan) and lead the building of a bronze astronomical instrument, a water clock that would tell time and indicate the movements of the constellations.

Water clocks date back to around 3,000 B.C. in China. This type of clock relies on the constant drip of water from one vessel into another to provide...