124 
AFRICA AND ITS EXPLORATION. 
Congo, for in June, after the “ Malka ” or fourteen days 
of incessant rain, the author speaks of whirlpools, not of 
a regular break. 
O 
I thus make the distance of the Yellala from the 
mouth between 116 and 117 miles and the total fall 
390 feet, of which about one half (195) occurs in the 
.sixty-four miles between Boma and the Yellala : of this 
figure again 100 feet belong to the section of five miles 
between the Vivi and the Great Rapids. The Zambeze, 
according to Dr. Livingstone (“ 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 
nutting 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 
nine 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 dis- 
tance, makes Banza Mavunda where, twenty to twenty- 
four 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 retardation evidently caused 
by the rapids beyond : I have remarked this effect in the 
Brazilian “ Cachoeiras.” * Above it the Nzadi widens, 
and canoeing is practicable with portages at the two 
Sangallas. The southern feature, double like the Yellala, 
shows an upper and a lower break, separated by two 
miles, the rapids being formed as usual by sunken ledges 
of rock. Two days’ paddling lead to the northern or 
highest Sangalla, which obstructs the stream for twenty - 
* “ Lowlands of the Brazil,” chap. xvii. Tinsleys, 1875. 
