next year he became foreign member. In 1889, he was appointed professor of differential and integral calculus at Toulouse University. Research Stieltjes worked on almost all branches of analysis, continued fractions and number theory, and for his work, he is sometimes called "the father of the analytic theory of continued fractions". His work is also seen as important as a first step towards the theory of Hilbert spaces. Other important contributions to mathematics that he made involved discontinuous functions and divergent series, differential equations, interpolation, the gamma function and elliptic functions. He became known internationally because of the Riemann–Stieltjes integral. Awards Stieltjes' work on continued fractions earned him the Ormoy Prize of the Académie des Sciences. See also Chebyshev–Markov–Stieltjes inequalities Lebesgue–Stieltjes integral Laplace–Stieltjes transform Riemann–Stieltjes integral Heine–Stieltjes polynomials Stieltjes–Wigert polynomials Stieltjes polynomials Stieltjes constants Stieltjes matrix Stieltjes moment problem Stieltjes transformation (and Stieltjes inversion formula) Annales de la Faculté des Sciences de Toulouse co-founded by Stieltjes Montel's theorem References External links Œuvres complètes de Thomas Jan Stieltjes, pub. par les soins de la Société mathématique d'Amsterdam. (Groningen: P. Noordhoff, 1914–18) (PDF copy at UMDL, text in Dutch, French and German) 1856 births 1894 deaths French mathematicians Academic staff of the Delft University of Technology Members of the Royal Netherlands Academy of Arts and Sciences People from Zwolle 19th-century Dutch scientists 19th-century Dutch mathematicians