“ From the Mbomu-Welle confluence to the junction of the Ubangi with the Congo the river has a course of fully 700 m., while the Ubangi-Welle combined exceeds 1400 m. From its mouth to Zongo rapids, a distance of 350 m., the stream, is navigable by Steamers drawing 3 ft. of water. In general the Ubangi flows through a fertile and forested region. ”

“ The chief of the head streams of the Welle (known in its upper course as the Kibali) rises on the western slope of a hill about 40 m. west of Wadelai. It is joined by several small streams, the main river flowing in a W.N.W. direction. After a course of over 700 m. (during which it receives one large southern tributary—the Bomokandi—and other considerable affluents) the Welle joins the Mbomu in 4° 10′ N. 22° 37′ E. The Mbomu, which has two large northern tributaries, the Shinko and the Bale, rises in 4° 50′ N. 27° 12′ E. For some distance it runs parallel to and about 100 m. ”