Page:Africa by Élisée Reclus, Volume 3.djvu/522

 known as Stanley Pool, which is about 80 square miles in extent, with a depth of 200 feet. On the north or right side this island-studded basin is skirted by a line of eroded rocks clothed on top with verdure, which from their resemblance to the chalk cliffs on the south coast of England have been named the Dover Cliffs. A little below Stanley Pool begins the

A little below Stanley Pool begins the long line of rapids by which the navigation is entirely interrupted between the middle and lower course of the Congo, and to which Stanley has applied the collective name of Livingstone Falls. For a space of about 165 miles from Brazzaville to Matadi there follow thirty-two cascades besides numerous rapids, with a total approximate fall of 850 feet. Some are separated by intervals of smooth water without perceptible incline, while others are connected by continuous slopes, where the current rises and falls in long seething billowy waves. At several points the Congo, pent up between its rocky walls, is no more than 1,000 or 1,500 feet broad, and below Isangala it rushes through a gorge said to be scarcely 250 yards wide. Here the aspect of the stream changes incessantly. Everywhere sharp angular bends in the gloomy defiles, rocky cirques filled with boiling waters, cascades, opposing currents, raging whirlpools, vast liquid masses tearing along at tremendous speed, tranquil bays with unruffled surface, followed by fresh rapids, where the mighty stream again plunges into the wild gorges of its rocky bed. Here depth and velocity have to compensate for a broader channel, the whole body of the Congo rushing along in some places at the fearful rate of 30 miles Villages. an hour, with a depth of over 300 feet. In the region of the rapids it is joined only by a few rivulets from the north, and from the southern plateaux by some larger streams, such as the Lu-Lu, Nkissi, Kwilu,Lu-Fu, and Mposo.

For some 30 miles below the Yellala Falls, last of the series, the fluvial valley still preserves the aspect of a defile hollowed out by the slow action of running waters. The jagged cliffs rise on both sides over 300, and in some places fully