Flow Maps

Flow maps are a representation of a flow chart mixed with cartographic information. They usually show the movement of something such as goods or people and how it is distributed. The wider the flow out of the origin, the larger the value. This is a map of french wine exports in 1864.

http://upload.wikimedia.org/wikipedia/commons/6/62/Minard’s_map_of_French_wine_exports_for_1864.jpg