John, an erudite mathematician, was the son of a clergyman, and was born at Southwick in Sussex in 1610. His youth was full of high mental promise. At the school of Steyning he soon became a proficient in Latin, Greek, and Hebrew; by the age of thirteen he was ready to enter Trinity College, Cambridge; during his university course he made himself an accomplished linguist; and in 1630, the year in which he took the degree of M.A., he was holding a learned correspondence with several eminent mathematicians. This promise soon began to be fulfilled; for Pell, from this time till his death, devoted all his attention to the promotion of mathematical science. He occupied the chair of mathematics at Amsterdam from 1643 to 1646, and the same chair at Breda from 1646 to 1652. It is true that after this he was employed by Cromwell in the political office of agent to the Protestant cantons of Switzerland. It is true, also, that after the Restoration he took holy orders, and was presented by Sheldon, Bishop of London, to several rich benefices. Yet all the while the single-minded bookworm was immersed in his favourite study, publishing several works, and writing those almost innumerable letters and pamphlets which are now preserved in nearly forty folio volumes in the British Museum. He even carried his mathematical abstraction to the extent of altogether neglecting his personal affairs. His friends cozened him out of the profits of his benefices, and then left him a prey to merciless creditors. He lived in extreme indigence till his death in 1685. Dr Pell's principal works are—A Controversy with Longomontanus concerning the Quadrature of the Circle, 4to, Amsterdam, 1646; An Idea of the Mathematics, 12mo, London, 1650; Branker's Translation of Rhonnius' Introduction to Algebra, much altered and augmented, 4to, London, 1668; and A Table of Ten Thousand Square Numbers, fol., London, 1672.