The medieval Mappa Mundi in England's Hereford cathedral, for example, is little more than drawings on vellum, or stretched calfskin, and it lacks Ptolemy's geometric method.

比如，中世纪制作的英格兰赫里福德教堂世界地图过是些绘在羔皮、或者说拉伸了的犊皮上的图案，没有使密的几何方法。