GREGORY, JAMES (1638-1675), Scottish mathematician and astronomer, was educated at the grammar school of Aberdeen and at Marischal college of that city. In 1663 he published his treatise Optica promota, in which he described his great invention, the Gregorian reflecting telescope. About 1665 he went to the university of Padua, where he studied for some years, and in 1667 published Vera circuli et hyperbolae quadratura, in which he discussed infinite convergent series for the areas of the circle and hyperbola. In 1668 he published also at Padua Geometriae pars universalis, in which he gave a series of rules for the rec tification of curves and the mensuration of their solids of revolu tion. He was elected F.R.S., and was professor of mathematics successively at the universities of St. Andrews (1669-74) and Edinburgh (1674-75)•