Su Song

Su Song (1020-1101) was a Song dynasty Chinese polymath who served as a government minister while working as an astronomer, horologist, engineer and pharmacologist. He is best known for designing and building a large water driven astronomical clock tower completed in Kaifeng in 1092, which combined an armillary sphere, a celestial globe and a mechanical timekeeping and striking mechanism incorporating an early escapement like device, regarded by historians of technology as one of the most sophisticated pre-modern mechanical clocks known. He also compiled the Bencao Tujing, an illustrated pharmacological treatise cataloguing medicinal plants, minerals and animal substances used in Chinese medicine of his era, drawing on submissions gathered from across the empire. His detailed written descriptions of the clock tower's construction survive and have allowed later scholars to reconstruct its mechanism in detail.