Louis-Léger Vauthier [SEP] native language
Louis-Léger Vauthier
Louis-Léger Vauthier (6 April 1815 – 5 October 1901) was a French engineer who designed bridges and roadways and was elected to the National Assembly of France in May 1849, as a member for the departement of Cher.
Vauthier was born in Bergerac in the Dordogne department. Although deported for his revolutionary ideas, he became a civil engineer in Spain and then Switzerland before returning to Paris in 1861. He also spent several years in Recife, Brazil.
He is known to have
Louis-Léger Vauthier (1815–1901) developed the population contour map, a map that shows the population density of Paris in 1874 by contours or isolines.
Uses.
Thematic maps serve three primary purposes. 
1. They provide specific information about particular locations.
2. They provide general information about spatial patterns.
3. They can be used to compare patterns on two or more maps.
Common examples are maps of demographic data such as population density. When designing a thematic map, cartographers must balance