Leybourn, William

, who was originally a printer in London, published several of the mathematical works of Samuel Foster, astronomical professor in Gresham college. He afterwards became an eminent author himself, and appears to have been the most universal mathematician of his time. He published many mathematical treatises in the seventeenth century. Among these his “Cursus Mathematicus” was esteemed the best system of the kind extant. His “Panarithmologia; or, Trader’s sure Guide,” being tables ready cast up, was long in use. It was formed upon a plan of his own, and has been adopted by Mr. Bareme in France. The seventh edition was published in 1741. We have no account of his birth or death. 3