Mathematician, born in Hertfordshire; was educated at Oxford for the Church, but his natural bent was towards mathematical science, and in 1619 he became professor of Astronomy in Gresham College, London, a position he held till his death; his "Canon Triangulorum" (1620) was the first table of logarithmic sines and tangents drawn up on Briggs's system; amongst other of his inventions was the surveying chain, a quadrant, Gunter's scale, and he was the first to observe the variations of the compass (1581-1626).