Shen Kuo (born 1031, Qiantang [nowHangzhou, Zhejiang province], China—died 1095, Jingkou [nowZhenjiang,Jiangsu province]) was a Chinese astronomer, mathematician, and high official whose famous workMengxi bitan (“Brush Talks from Dream Brook” [Dream Brook was the name of his estate in Jingkou]) contains the first reference to the magneticcompass, the first description ofmovable type, and a fairly accurate explanation of the origin offossils. TheMengxi bitan also contains Shen’s observations on such varied subjects asmathematics,astronomy, atmospheric phenomena,cartography,optics, andmedicine. Shen produced a number of works, including commentaries on theConfucian Classics, atlases,diplomatic reports, and a variety of monographs. HisMengxi bitan was written relatively late in life, after he had been removed from office on a trumped-up charge and banished after troops under his titular command suffered a severe defeat by Tangut warriors; some 60,000 Chinese perished in the battle. He retired to Dream Brook in 1088 and lived out the remainder of his years there.