FIFTEENTH-CENTURY WORLD MAPS 61 



shown that two main causes of the confused representation of 

 north-east Africa are the ignorance of the cartographer about 

 the existence of the eastern Sudan, so that he telescoped Egypt 

 and Abyssinia together, and the failure to reahze that much of 

 the hydrographic detail available applied to one river only, the 

 Abbai, and not to a number of distinct streams. 



The Coptic Church of Ab^^ssinia was in touch with Cairo 

 and Jerusalem, and it was doubtless from emissaries of the 

 Church that Fra Mauro obtained his information. Near Lake 

 Tana he has the name 'Ciebel gamar', literally 'mountain of 

 the moon'. Mr. O. G. S. Crawford suggests that this was the 

 origin of the legend about the source of the Nile, and that it 

 was only later that the site was transferred to the Equator.^ 



The suggestion is partly retained of a 'western Nile' flow- 

 ing from a great marsh, no doubt Lake Chad; beyond this 

 marsh a river flows westwards to enter the ocean by two 

 branches to the north of Cape Verde, no doubt the Senegal 

 and perhaps the Gambia. Fra Mauro tells us that he was 

 supplied v/ith Portuguese charts and had spoken with those 

 who had navigated in these waters. Actually the only con- 

 temporary names he has are 'C. Virde' and C. Rosso, im- 

 mediately north of the great gulf; the small river in the vicinity 

 may be the Rio Grande. The drawing of the coastline does not 

 show much correspondence with reality. The Portuguese are 

 stated to have reached the meridian of Tunis and perhaps even 

 that of Alexandria. Curiously enough, on the map the eastern 

 end of the gulf may be said to be on the meridian of Tunis, 

 as in fact the eastern terminus of the Gulf of Guinea is. (To 

 have crossed the meridian of Alexandria, however, would have 

 entailed rounding the Cape of Good Hope.) By 1459 the 

 Portuguese navigators had probably not passed beyond Sierra 

 I Leone, and it is disputed whether at that date the Cape Verde 

 Islands had been discovered. The delineation of the great 

 gulf can scarcely rest on first-hand knowledge possessed by the 

 Portuguese. The lack of the latest information on the map has 

 been criticized, especially as Bianco was employed in its 

 production, but it is scarcely justifiable to argue from this that 



^Crawford, O. G. S., 'Some medieval theories about the Nile* {Geogr. 

 Joum., 114, 1949, 6-29.) 



