Joseph Liouville was a French mathematician and engineer.
Joseph Liouville
Title page of the first volume of Journal de Mathématiques Pures et Appliquées in 1836.
Saint-Omer is a commune and sub-prefecture of the Pas-de-Calais department in France.
The theater « le moulin à café » (the coffee grinder)
Cathedral
19th century Cavaillé-Coll organ in the cathedral
Main square and theater (the old town hall)