John Wallis (1616-1703), English mathematician. Wallis was educated at Cambridge, where he studied medicine and mathematics, then entering the priesthood in the 1640s. He was chief cryptographer for Parliament and the royal court from 1643 to 1689. He made contributions in calculus, trigonometry and geometry, and the concept of infinity. From 1649 until his death in 1703 he was Savilian Professor of Geometry at the University of Oxford. Both this and Wallis' Royal Society fellowship are mentioned in the Latin inscription. This is the frontispiece portrait of the author from Wallis's A Treatise of Algebra (1685).