John Pell

John Pell (1 March 1611 – 12 December 1685) was an English mathematician and political agent abroad. Early life He was born at Southwick in Sussex. His father, also named John Pell, was from Southwick, and his mother was Mary Holland, from Halden in Kent. The second of two sons, Pell's older brother was Thomas Pell. By the time he was six, they were orphans, their father dying in 1616 and their mother the following year. John Pell the elder had a fine library, which proved valuable to the young Pell as he grew up. He was educated at Steyning Grammar School and entered Trinity College, Cambridge, at the age of 13. During his university career he became an accomplished linguist; even before taking a B.A. degree in 1629, he corresponded with Henry Briggs and other mathematicians. He was promoted by seniority to M.A. in 1630 and taught in the short-lived Chichester Academy set up by Samuel Hartlib. On 3 July 1632 he married Ithamaria Reginald (also rendered as Ithamara or Ithumaria, with the surname Reginolles), sister of the writer and polymath Bathsua Makin. They had four sons and four daughters. Ithumaria died in 1661. Some time before 1669 Pell remarried. Pell spent much of the 1630s working under Hartlib's influence, on topics in the area of pedagogy, encyclopedism and pansophy, combinatorics, and the legacy of Trithemius. By 1638 he had formulated a proposal for a universal language. In mathematics, he concentrated on expanding the scope of algebra in the theory of equations, and on mathematical tables. As part of a joint lobbying effort with Hartlib to find himself support to continue as a researcher, he had his short Idea of Mathematics printed in October 1638. It brought interested responses from Johann Moriaen and Marin Mersenne. Academic and diplomat His reputation and the influence of Sir William Boswell, the English resident, with the States-General procured his election in 1644 to the chair of mathematics in Amsterdam, after an earlier attempt immediately after Martin van den Hove left for Leiden had failed. From 1644 he worked on a polemical work, against Longomontanus. For this he put in a large effort soliciting help and testimonials: from Bonaventura Cavalieri, his patron Sir Charles Cavendish, René Descartes, Thomas Hobbes, Mersenne, Claude Mydorge, and Gilles de Roberval. It finally appeared as Controversy with Longomontanus concerning the Quadrature of the Circle (1647).