THE AFRICAN ASSOCIATION. .311 
horsemen to enter the city one by one, determines 
the levy to be complete, when the tree is worn 
through the middle. The articles of commerce 
exported from Bornou are gold-dust, slaves, hor- 
ses, salt, and civet. The complexion of the na- 
tives of Bornou is black, but their features are dif- 
ferent from those of the negroes. 
On the north of the Niger, to the south-west of 
Bornou, lies the extensive and powerful empire of 
Cassina. On the north it is bounded by the moun- 
tains of Eyre, which separate it from Fezzan, and 
on the cast by Zanfara and Bornou. Cassina, the 
capital, is situated five journeys to the north of the 
Niger, in N. lat. 16° 20', and W. long. 11° 45'. 
Cassina is not mentioned by Edrisi, being proba- 
bly at that period subject to Ghana, which has now, 
in its turn, become one of its provinces. After the 
power of Tombuctoo was reduced by the arms of 
Marocco, it was long considered as the most pow- 
erful central empire in Africa ; but, at present, 
though the Sultan of Cassina still enumerates a 
thousand towns and villages in his extensive do- 
mains, he is reckoned much inferior in power to 
the Emperor of Bornou. The territories of Cas- 
sina consist of a large proportion of land of amaz- 
ing fertility, interspersed with arid wastes, where 
the rays of the sun, reflected from the sand, glow 
like an immense furnace with intense and suffocat- 
ing heat, and sandy heaths, where the odoriferous 
