John Greaves

John Greaves (1602 to 1652) was an English mathematician, astronomer and antiquarian. Educated at Balliol College, Oxford, he became a Fellow of Merton College in 1624 and was chosen Gresham Professor of Geometry at Gresham College, London, in 1630; he later held the Savilian chair of astronomy at Oxford. He studied Persian and Arabic, collected manuscripts for Archbishop William Laud, and travelled in Italy and the Levant from 1636 to 1640, where he made a survey of the Great Pyramid of Giza. He was particularly interested in weights and measures and wrote on the Roman foot and denarius, and in 1645 he attempted a reform of the Julian calendar that was not adopted. A supporter of Charles I in the English Civil War, he lost his Oxford positions in 1647.