6^ DISCOVERIES OF THE PORTUGUESE. 
than the Tagus and Mondego of his native coun- 
try ; and he conceives it to be the mere ilhision 
of distance which led his countrymen to seek, 
through toils and perils, on the shores of these 
barbarous rivers, what a diligent search would 
easily have enabled them to discover at home in 
equal abundance. 
The great desert is also described. It is repre- 
sented as beginning at Cape Blanco, whence, 
spreading like a robe, with the river Senegal for 
its border, it is wrapped round the continent till 
it comes to drink the waters of the Nile, which 
communicate to it some portion of moisture. The 
territory, however, is not so wholly barren, but 
that it is peopled in spots called Abeses (oases). 
Of this territory, there are three kinds : That 
which is poorly covered with grass and shrubs, is 
called Azagar ; that composed of fine sand with- 
out verdure, Sahel ; that formed of small stones 
in the form of gravel, Sahara. 
Meanwhile, the progress of discovery was car- 
ried on rapidly in another direction.* The castle 
of Mina, upon the Gold Coast, had been establish- 
ed as the centre of the Portuguese power, and as 
the point whence all further advances were to be 
made. It was now a long time since the sovereign 
pontiff had granted to the kings of Portugal the 
* Di Barros, III. 3. 
