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，纪制作英格兰赫里福德教堂界地过是些绘在羔皮、或者说拉伸了犊皮上，没有使用托勒密几何方法。