Illustrious natural philosopher, born in Woolsthorpe, near Grantham, in Lincolnshire; entered Trinity College, Cambridge, in 1661, where he applied himself specially to the study of mathematics, invented the method of fluxions, and began to theorise on gravitation, graduating in 1667, and becoming professor of Mathematics in 1669; failing at first, from a mistaken measurement given of the earth's diameter, in his attempts to establish the theory referred to, he set himself to the construction of telescopes, and discovered the composition of light; shortly after this, hearing of a correction of the measurement required, he renewed his study of gravitation, and made his theory good in a series of papers communicated to the Royal Society, though it was not till 1687, encouraged by Halley, he gave the complete demonstration in his "Principia" to the world; in 1695 he was made Warden of the Mint, and afterwards Master, a post he held till his death; his works were numerous, and he wrote on prophecy as well as treatises on science (1642-1727).