At the beginning of the 19th century, geography is still in a process of being created as a proper discipline. One man especially takes place in that process : Alexander von Humboldt. Among his contributions, he gives pictures an important part in the production of geographical knowledge. Pictures, and moreover maps, are never used only as simple illustrations, but they are included in and as a scientific program. The creation of a new cartographical way, the pasigraphy, is a clue of the importance of pictures in his career. This article aims to show how pictures in the Humboldtian research help to build his conception of the world.