OUGHTRED, WILLIAM (1575–1660), mathematician, son of the Rev. Benjamin Oughtred, and descended from an ancient family of the same name in the north of England, was born at Eton on 5 March 1574-5, and educated at the college. On 1 Sept. 1592 he entered at King's College, Cambridge, and while still an undergraduate devoted his attention to mathematics and composed his 'Easy Method of Geometrical Dialling,' This work, on being circulated in manuscript, attracted the notice of some eminent mathematicians : and Sir Christopher Wren in 1647, when a fellow-commoner of Wadham College, Oxford, translated it into Latin ; but his translation was not published until 1648. In 1595 Oughtred was admitted a fellow of his college. About 1600 he conceived the invention of a projected horizontal instrument for delineating dials upon any kind of plane, and for working most questions which could be performed by the globe. An account of this invention was translated into English and published in 1633, together with his ' Circles of Proportion,' by William Foster, who had been one of his pupils (Ward, Gresham, Professors, p. 88).
About 1603 he was ordained priest, and in 1605, on being presented to the living of Shalford in Surrey, quitted the university. Five years later he was presented to the rectory of Albury, near Guildford, in the same county, and here he appears to have been for the most part resident until his death. He occasionally visited London, although, according to his own statement, not oftener than once a year. 'As oft,' he says, 'as I was toiled with the labours of my own profession, I have allayed that tediousness by walking in the pleasant and more than Elysian fields of the diverse and various parts of human learning, and not of the mathematics only.' He also took pupils, and, according to Lloyd (Memoires, ed. 1668, p. 608), 'his house was full of young gentlemen that came from all parts to be instructed by him ; 'among these he names a son of Sir William Backhouse, Mr. Stokes, Dr. William Lloyd, and Mr. Arthur Haughton. For a time, too, he seems to have resided in the family of the Earl of Arundel as tutor to his second son, Henry Frederick Howard, afterwards third earl of Arundel [q. v.] During the first fourteen years of his incumbency the parish registers, with the entries in his beautiful clear hand, seem to have been regularly kept; but after that time only an occasional entry presents itself. About 1632 he seems to have been seeking pecuniary aid, and to have suffered from a consciousness of neglect (Rigaud, i. 16). According to Lloyd, he was frequently invited to reside in Italy, France, and Holland, and the list of his correspondents includes the names of the most eminent mathematicians of the time, by whom he was equally respected for his sobriety of judgment and modesty of disposition. The living was a good one; and Oughtred's known sympathy with the royalist party marked him out as an object of suspicion to the committee of sequestrations in 1645. Lilly says : 'Several inconsiderable articles were deposed and sworn against him, material enough to have sequestered him, but that, on his day of leaving, I applied myself to Sir Bulstrod Whitlock, and all my old friends, who in such numbers appeared in his behalf that, though the chairman and many other Presbyterian members were stiff against him, yet he was cleared by the major number' (Life and Times, ed. 1822, p. 136). It is probably in connection with this persecution that, writing in the same year, he describes himself as 'daunted and broken with these disastrous times' (Rigaud, i. 66). But, generally speaking, his life appears to have been spent peacefully in the conscientious discharge of the duties of his office, relieved by congenial studies and a not inconsiderable correspondence with learned friends. In 1618 he writes : ' I, being in London, went to see my honoured friend, Master Henry Briggs, who then brought me acquainted with Master Gunter [q.v.], with whom, falling into speech about his quadrant, I shewed him my horizontall instrument' ('Apologet. Epist.' in Ward's Lives, p. 78). In 1630 he was attacked by Richard Delamaine the elder [q. v.], and replied in a pamphlet entitled 'To the English gentrie . . . the just Apologie of W. Oughtred against the slanderous insinuations of Richard Delamain, in a pamphlet called "Grammelogia," ' 4to. The merits of the controversy may be gathered from the expressions of W. Robinson, who 'cannot but wonder at the indiscretion of R. D., who, being conscious to himself that he is but the pickpurse of another man's wit, would thus inconsiderably provoke and awake a sleeping lion' (Rigaud, i. 11). In 1631 appeared the 'Clavis Mathematics,' which Oughtred compiled while residing with the family of the Earl of Arundel. He was encouraged to publish the work by his friend, Sir Charles Cavendish, a younger brother of the Duke
