Shen Kuo (1031–1095) was a Song-dynasty statesman and polymath whose Dream Pool Essays of 1088 first described the magnetic compass for navigation, discovered magnetic declination toward true north, and recorded Bi Sheng's invention of movable-type printing — centuries before Europe knew any of it.
A finance minister, astronomer-royal and general who fell from political favor, he spent his retirement writing one of the most wide-ranging scientific works ever produced: geology, optics, astronomy, cartography, hydraulics, archaeology and medicine.
