Karl Heinrich Gräffe

Karl Heinrich Gräffe (1799 to 1873) was a German mathematician who became a professor at the University of Zurich. His father emigrated to North America and left him the family jewellery business, yet he studied at night, entered the Carolineum in Brunswick in 1821, and from 1823 studied at the University of Göttingen under Gauss and Thibaut, taking his doctorate in 1825. In 1828 he was appointed to the Zurich Institute of Technology and from 1833 he was associate professor at the newly founded University of Zurich, while also teaching at the Obere Industrieschule. He is known as the first to set out a method for approximating the roots of any polynomial, today called the Dandelin-Gräffe method, a procedure later studied in detail by Alexandre Ostrowski.