John Churchill. See Marlborough, Duke of.
John Clayton, an American botanist, born at Fulham, England, about 1090, died in Virginia, Dec. 15,1773. When about 20 years old he emigrated to Virginia, of which province his father had been appointed attorney general. He was educated as a physician, and was indefatigable in his botanical researches, addressing papers on the natural history of Virginia to the royal society of London, which were published in the " Philosophical Transactions." He also forwarded dried specimens of the flora of Virginia to Gronovius, who in conjunction with Linnaaus published an account of a portion of them (Flora Virginica, parts i. and ii., Leyden, 1739-43). The remainder were described in a third part by the son of Gronovius. Gronovius gave the name Clayto-nia to a genus of purslanes.
John Cleves Symmes, an American soldier, born in New Jersey about 1780, died at Hamilton, Butler co., Ohio, May 28, 1829. He entered the army as ensign in 1802, fought in the war of 1812, settled at Newport, Ky., and wrote and lectured on his theory that the earth is hollow, open at the poles, and capable of being inhabited within. He published " Theory of Concentric Spheres" (12mo, Cincinnati, 1826). For an abstract of Symmes's theory and arguments, see the "Atlantic Montlily" for April, 1873.
John Clowes, an English clergyman, born at Manchester, Oct. 31, 1743, died at Leamington, Mav 29, 1831. He was a fellow of Trinitv college, Cambridge, and in 1769 was made rector of St. John's church, Manchester. Having become in 1773 one of the first English disciples of Swedenborg, he was thenceforward earnest in promoting his doctrines, although he retained his rectorship for nearly 60 years. He translated Swedenborg's Arcana Calestia and other works, and published "Restoration of Pure Religion," two volumes of sermons, etc.
John Cockerill, an English engineer, born in Lancashire, Aug. 3,1790, died in Warsaw in 1810. He was the youngest son of an English machinist who had been employed in Belgium. John, with his brother James, also went to that country at an early age. After some preliminary experience, the former in 1816 established a machine shop at Seraing, which became one of the largest in Europe. In the height of his prosperity 2,000 workmen were employed there. This immense establishment belonged one half to the king of Holland, and one half to Cockerill; but at the revolution of 1830 the latter bought the king's share and remained sole proprietor. In 1839 he failed.
John Constable, an English landscape painter, born at East Bergholt, Suffolk, in 1776, died in London, March 30, 1837. In 1800 he was admitted a student of the royal academy. He had a thorough contempt for the conventionalities of the art, and when asked by Sir George Beaumont what style he intended to adopt, replied, "None but God Almighty's style." His subjects were rural landscapes with figures, and he was fond of depicting all the phenomena connected with rain storms, the effects of dew on the grass or foliage, and other transient minutiae. Among the best of his works are the "Valley Farm," in the Vernon gallery, and the "Corn Field," in the national gallery. In 1829 he was elected a royal academician. - See "Memoirs of John Constable, R. A., chiefly from his Letters," by C. R. Leslie, R. A. (enlarged ed., 1845).