Jakob Steiner, unschooled until age 18, was one of the founders of and greatest contributors to the field of projective or modern geometry. Building on the work of such greats as Gerard Desargues and Gaspard Monge, the Swiss geometer discovered both the Steiner surface and the Steiner theorem, and extrapolated the work of the French geometer, Jean Poncelet, to develop the Poncelet-Steiner theorem, all of which helped to build the developing field of synthetic or projective geometry. A firm believer in the power of geometry, he pronounced that the calculations involved in algebra and analysis simply replaced real thinking, while geometry stimulated it. Made wealthy by his lectures on geometry, at his death Steiner bequeathed a third of his fortune to the Berlin Academy to establish the Steiner Prize.

Steiner was born on March 18, 1796, in the village of Utzensdorf, near Bern, Switzerland. The last of eight children of Niklaus...