Siméon Poisson
was born 231 years ago
21st June 1781

Siméon Poisson's most important works were a series of papers on definite integrals and his advances in Fourier series. This work was the foundation of later work in this area by Dirichlet and Riemann.

Find out more at:
http://www-history.mcs.st-andrews.ac.uk/Mathematicians/Poisson.html