Page:Popular Science Monthly Volume 16.djvu/510

rivers. This kind of map was mainly used for military purposes, and was regarded as a map of the world, for the vast extent of the Roman Empire comprised nearly all that was then known of the habitable world.

Fig. 5.—Claudius Ptolemy. (From an Old Map.)

Great progress was effected in map-making by Marinus of Tyre, who lived during the second century of our era. He studied with great