Thomas Harriot

Timeline

1. 1577–1584Oxford · OxfordHe entered St Mary Hall, Oxford in 1577 and went to London after graduating in 1580. From about 1583 he was employed by Walter Raleigh, teaching navigational mathematics at Durham House to sailors bound for the New World, and wrote the unpublished treatise Arcticon. He improved latitude determination by sun and Pole Star, used the sun's amplitude to find magnetic declination, and gave a practical numerical solution to the Mercator problem, giving Raleigh's fleet the strongest navigational support in England at the time.
2. 1585–1588Roanoke Island · RoanokeHe arrived at Roanoke in 1585 with Ralph Lane's expedition, recording products, farming, diet, and Algonquian vocabulary, and fixing position by eclipse observation. The colony did not last; in summer 1586 he withdrew hastily with Drake amid storms and Spanish threats. In 1588 he published A Briefe and True Report of the New Found Land of Virginia, describing land and resources to investors and introducing the smoking of tobacco he had learned locally; a fuller sea journal did not survive.
3. 1595–1600Syon House · MiddlesexAfter Raleigh became entangled in charges of atheism, Harriot gradually transferred his allegiance to Henry Percy, 9th Earl of Northumberland. He obtained Durham estates in 1595 and then established a residence and laboratory at Syon House on the Thames. By 1597 he was deep in optics, studying the Alhazen problem; at the same time he computed projectile ranges for Raleigh and developed algebraic notation capable of handling both negative and imaginary roots. In 1599–1600 he also conducted chemical experiments with experimental precision. The complete statement of the law of refraction came only in July 1601.