燕肃
宋代博学科学家画家诗人
Yan Su(燕肃) (961–1040), courtesy name Muzhi(穆之), also styled Zhongmu(仲穆), originally from Shanggu(上谷), with ancestral home in Yidu, Qingzhou (now part of Shandong), later settled in Caozhou (formerly in present-day southwest Dingtao, Shandong). He was a famous scientist, painter, and poet of the Northern Song Dynasty. Yan Su was orphaned and poor as a child but had exceptional talent. He passed the imperial examination during the Dazhong Xiangfu era of Emperor Zhenzong and served in various posts including magistrate of Kaicheng County, assistant prefect of Henan Prefecture, and governor of Yuezhou and Mingzhou. During the Tianxi era, he was promoted to Zhixueshi at the Longtu Pavilion, earning the nickname “Yan Longtu.” He was highly knowledgeable, skilled in astronomy and physics, and invented instruments like the south-pointing chariot, remembrance drum, and lotus-shaped water clock. He authored 'Treatise on Ocean Tides' and created the 'Ocean Tide Chart' to explain the principles of tides.