Steiner, Jakob (yä'kôp shtī'nur) [key], 1796–1863, Swiss mathematician. He was largely self-taught and was professor of geometry at the Univ. of Berlin from 1834. A pioneer in the development of synthetic, or pure, geometry (i.e., deduced by axiomatic methods, as Euclid's geometry), particularly projective geometry, he was considered by many the greatest geometer since Apollonius of Perga and exerted an important influence on his students, who included Bernhard Riemann.
