The Yellala of the Congo. 289 
stone (“ First Expedition,” p. 284), has a steeper 
declivity than some other great rivers, reaching 
even 7 inches per mile. With 3 to 4 inches, the 
Ganges, the Amazonas, and the Mississippi flow at 
the rate of three knots an hour in the lowest season 
and five or six during the flood : what, then, may 
be expected from the Nzadi ? 
According to the people, beyond the small upper 
fall where projections shut out the view, the 
channel smoothens for a short space and carries 
canoes. Native travellers from Nkulu usually 
take the mountain-path cutting across an easterly 
bend of the bed to Banza Menzi, the Manzy of 
Tuckey’s text and the Menzi Macooloo of his map. 
It is situated on a level platform 9 miles north of 
Nkulu, and they find the stream still violent. The 
second march is to Banza Ninga, by the First 
Expedition called “ Inga,” an indirect line of 
five hours =15 miles. The third, of about the 
same distance, makes Banza Mavunda where, 20 
to 24 miles above the Yellala, Tuckey found the 
river once more navigable, clear in the middle and 
flowing at the rate of two miles an hour—a retar¬ 
dation evidently caused by the rapids beyond : 
I have remarked this effect in the Brazilian 
“Cachoeiras.” 1 Above it the Nzadi widens, and 
canoeing is practicable with portages at the two 
1 “ Lowlands of the Brazil,” chap. xvii. Tinsleys, 1875. 
II. 
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