Rätsel der mittelalterlichen Seekarten: ein Diskussionsbeitrag

Abstract

"Of all the illustrations depicting a section of the earth's surface, the first to resemble the actual circumstances closely are Medieval sea charts known as Portolan charts. These depictions appeared quite suddenly in the thirteenth century and exhibit a conspicuous chordal network, a linear system based on the point of the wind. Mathematical investigations of the coastlines shown on these sea charts have revealed an astonishing degree of precision in comparison to modern charts. It is not known what methods were used to determine the geodetic foundations for the Portolan works. The question of authorship leads back to Roman and Hellenistic antiquity, and it is not impossible to imagine a set of circumstances that could have allowed these mysterious documents to survive ancient times and be handed down through the generations to the Medieval period." (author's abstract)