Anna-Dorothee von den Brincken:
Concept of the world by the Irish seafarer Saint Brendan as seen from the 12th century
Cartographica Helvetica 21 (2000) 17–21
The museum in Bischofszell (Canton of Thurgovia) has a unique world map on display which is otherwise unknown in this combination: One side of the parchment shows the map image. The archetype of this world map is an illustration to the 13th book of the Etymologiae by Isidore of Seville (died 636). There is a 'perspective' suggestion as to the spherical form of the Earth. An additional element, however, does not appear in Isidore's work: in the lower part, i.e. to the north, outside of the cosmos, there is a rectangular object containing the four rivers of Paradise, thus an unmistakable reference to Paradise.
On the other side of the manuscript the beginning of the Navigatio Sancti Brendani is written by hand in a sophisticated script. The text tells the legend of Saint Brendan of Ireland (6th century), who sailed to a paradise island in the Atlantic during a period of seven years with 17 companions. The writing and decorations could be a 12th-century carolino-gothica from southern Germany. A careful comparison of the script and lettering shows without doubt that text and map match.