Belgian ] Congo 61 ROADS ; RIVERS (c) The Ubanghi, the greatest tributary of the Congo, and the boundary between French and Belgian terri tory, broken in places by rapids, but otherwise navi gable for steamers as far as Mokoange, and during the high -water period as far as Banzyville.

The first steamer to reach the great central water way of the Congo was the En Avant, a small paddle boat, 43 ft. long by 8 ft. beam . It was brought out by Stanley in 1879, and by strenuous exertions lasting for two years was dragged in three sections from Vivi, below the cataracts, to Stanley Pool, 250 miles up-stream. The navigation of the rivers of the Congo basin is by no means easy, being hampered by shoals, rocks, snags, and floating vegetation . Much has been done to improve matters by marking the banks and buoying the channels. Sandbanks also impede navigation. These, however, occur less frequently than in other great rivers such as the Niger, since the current of the lower and middle Congo is too sluggish and the riparian vegetation too luxuriant to favour their formation. The islands and the river banks are covered by a dense growth of swamp- grass or tangled forest which tends to fix their limits. The naviga tion of the tributary Kasai -Sankuru is somewhat more difficult than that of the Congo , owing to its being a swifter stream . Above the central basin of the Congo, where the altitude rises and streams are swifter, navigation is greatly affected by season and rainfall.

The administration possesses seventeen steamers, besides a number of shallow-draught barges on the lower Congo, and forty -four smaller steamers on the upper river and its branches. Within the last five years private firms-- Lever Brothers, the “ Citas ' Company (see p. 103 ), and others—have put steamers on the river.

As a result of the opening of the Colony to free 6