HARRIOT, or HARRIOTT, Thomas, mathematician, born in Oxford, England, in 1560; died in London, 2 July, 1621. After studying at St. Mary's hall, Oxford, where he took his bachelor's degree in 1579, he became tutor to Sir Walter Raleigh, who in 1585 appointed him geographer to the second expedition to Virginia with Sir Richard Grenville. He remained there about two years. On his return he resumed his mathematical studies, and afterward received a yearly pension of £120 from Henry Percy, Earl of Northumberland, who was distinguished for his patronage of men of science. Harriot's death was caused by a cancer in the lip, occasioned, it is supposed, by his habit of holding in his mouth instruments of brass. From papers discovered in 1784, it would appear that he had either procured a telescope from Holland, or divined the construction of that instrument, and that he coincided in point of time with Galileo in discovering the spots on the sun's disk. On his return from this country he published "A Briefe and True Report of the New Found Land of Virginia, etc." (London, 1588). It was afterward translated into Latin, French, and German, and is contained in volume iii. of Hakluyt's "Voyages." After his death his "Artis Analyticae Praxis" was published (London, 1631). In this he discloses the important algebraical discovery that every equation may be regarded as formed by the product of as many simple equations as there are units in the number expressing its order. Besides this, Harriot made several changes in the notation of algebra.