IN NORTHERN MISTS 



seems to be founded upon a map of this kind. In St. Augustine 

 we first find the division of the T-map clearly expressed. This 

 dogmato-schematic form was fixed by Isidore, according to 

 whom the round disc of the earth surrounded by the outer 

 ocean was to be corripared to a wheel (or an O), divided into 

 three by a T.^ Mechanical map-forms after this prescription 



Beatus map, from Osma, 1203. The east is at the top. 



(cf. Vol. I, pp. 125, 150) were common during the whole of the 

 first part of the Middle Ages until the fourteenth century ; indeed 

 they circulated and exercised influence far into the sixteenth; 

 but sometimes, in accordance with the four corners of the earth 

 in the Bible, the maps were given a square form instead of a 



iPor this reason they were also called OT-maps, which corresponded to 

 the initial letters of " orbis terrarum." 

 184 



