Geometria by Rene Descartes. This work, by the French philosopher and mathematician Rene Descartes (1596-1650), was published in 1637 as an appendix to his earlier work 'Discourse on Method'. Geometria introduced the now-famous Cartesian co-ordinate system, and proposed the key idea of reducing geometry to a form of algebra. This is the cover of the 1639 edition, published in Leiden, the Netherlands. The title page shows a Latinized form of Descartes' name, and mentions Florimond de Beaune (who wrote an introduction to this work), and Franciscus van Schooten (the Elder), and the Dutch printer Joannis Maire. Van Schooten's son, also Franciscus, would later publish a 1649 commentary on Geometria.