Pierre Ossian Bonnet

Pierre Ossian Bonnet was a French mathematician who made important contributions to the differential geometry of surfaces, including the Gauss-Bonnet theorem. He was born in Montpellier on 22 December 1819, attended the Collège there, entered the École Polytechnique in Paris in 1838 and also studied at the École Nationale des Ponts et Chaussées. He turned down an engineering post for a career in teaching and research, and accepted a position at the École Polytechnique in 1844, the year he began his work on differential geometry. He was elected to the Academy of Sciences in 1862, in 1878 succeeded Le Verrier to the chair at the Sorbonne, and in 1883 succeeded Liouville as a member of the Bureau des Longitudes. He died in Paris on 22 June 1892.