Yi Xing

Yi Xing was an eighth century Tang dynasty Buddhist monk, born Zhang Sui, who became one of the most significant scientific and religious figures of his era. Working with the engineer Liang Lingzan, he built a water powered celestial globe fitted with an escapement mechanism, the first in a long tradition of Chinese astronomical clockworks, a design that would influence timekeeping devices for centuries afterward. He also directed an astrogeodetic survey across the Tang empire, establishing thirteen observation sites stretching from Vietnam to Lake Baikal to improve the accuracy of astronomical data and the calendar. Within Buddhism he helped transmit Esoteric Buddhism to China, working with the Indian master Subhakarasimha on a translation of the Mahavairocana sutra and writing a commentary that later shaped Shingon Buddhism in Japan. He served as a trusted advisor to Emperor Xuanzong until his death in 727. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/