BARROW, IsAAc (1630-77)- An eminent English theologian and mathematician. He was born in London and was educated at the Charterhouse and the University of Cambridge. Although lie acquired fame in several distinct lines, it is as a mathematician, perhaps, that he made his greatest success. Ile was appointed professor of geometry at Gresham College in 1662, and in the following year wasmade Lucasian pro fessor of geometry at Cambridge. He resigned the latter appointment in 1669 in favor of his pupil, Isaac Newton. In 1672 he became master of Trinity College, and to his efforts is due the foundation of the valuable library of that insti tution. In 1675 he was nominated vice-chancel lor of the university. Ile died two years later at the age of forty-seven. Of his original mathe matical works, the principal are his Lectiones Geometricce (London, 1669) and Lectiones Op ticw (Cambridge, 1674). Noteworthy are also his Euclidis Elementa ( 1655 ) ; A rch inlet/is Op era. (1675) ; and Apollonii Conieorum lib. ir.
(1675). A Latin edition of his mathematical works, some of which exist also in English translations, was prepared in 1860 by Whe well. The best edition of the Theological Works of Barrow, including his Latin poems and a notice of his life by Whewell, has been pre pared by the Rev. A. Napier (9 vols., Cambridge, (1859). The Davy Manuscripts in the British Museum contain another excellent biography of Barrow. The mathematical' contributions of Bar low paved the way for the introduction of the differential calculus, his treatment of tangents approaching closely the methods of the fluxion al calculus of Newton. In another field, his Treatise on the Pope's Supremacy (posthumousl is generally recognized as one of the very best works of its kind: and no less celebrated are his sermons.