Furthermore, it is a mistake to regard accuracy as the goal and ideal of the medieval map maker. To gain a sympathetic understanding of his work we must see what purposes he intended it to fulfill. He drew maps to accompany and clarify the written texts to which they were usually subsidiary. The maps were more or less in the nature of diagrammatic sketches on which the features of the earth’s surface were shown in a general way, and the draftsman understood perfectly well that all he could hope to give was a rough approximation to relative positions. The medieval scribe and map maker was an artist who took pride in the beauty of his work. The same motives which impelled him to enliven his manuscript with a multitude of miniatures led him to relieve the coldly geometrical outlines of his map by lines and colors pleasing to the eye, by entertaining sketches and readable legends. He was creating something very different from the modern cartographic or topographic sheet that stands on its own merits as an independently useful, scientific document and from which we can get precise information about distances, heights, positions, and terrain. He would have branded any man a fool who thought that one could hope to determine from his map the distance from Jerusalem to England or from the mouth of the Ganges to the mouth of the Nile. In other words, most medieval maps—including wall maps—were nothing more than rough diagrams converted into works of art. When, during the latter years of the thirteenth century, the sailors of the Mediterranean, driven by the necessity of securing reliable aids to navigation, began piece by piece to construct marine charts upon which the contours of the coasts were shown with an approach to modern correctness, we have indeed a revolution in cartographic art and geographical science. Bearing in mind these considerations, we see that the major inaccuracies of medieval maps are (1) exaggeration in the scale of particular regions at the expense of others and (2) distortion, often amounting to a complete failure to show places in their proper relative positions. The first of these inaccuracies was usually deliberate, the second more or less unavoidable. Both are well-known characteristics of our modern American railway folder maps. EXAGGERATION