﻿Vol. 6 1.] NORTH-EASTERN TERRITORIES OF THE CONGO FREE STATE. 647 



but slightly undulating. To show the slight difference of eleva- 

 tion in that part, the altitudes of the different stations may be 

 quoted, as follows : — Niangara, 2360 feet; Bafuka, 2460 ; Ndoruma, 

 2500 ; Yakuluku camp, 2430 ; and it may be here mentioned 

 that the three last-named places are almost on the apex of the 

 watershed between the Nile and Congo Basins. This divortium 

 aquarum does not present, however, the aspect of a more or less 

 definite ridge, but rather of a monotonous plain or level plateau, where 

 the many tributaries of both basins intermingle their springs and 

 courses into an inextricable network. 



According to the seasons, which here become well defined, the 

 country, in the dry period of the year, is so parched and dry, as to 

 be often waterless over large tracts ; while, in the rainy part of the 

 year, it becomes extremely marshy, on account of the predominantly- 

 argillaceous character of its subsoil, and the watercourses, having 

 very little fall, are then expanded into enormous swamps. 



Little geological information is to be gleaned from this zone, clay 

 appearing to constitute most of the subsoil, but being frequently 

 overlain in its higher parts by limonitic rocks. Near Bafuka 

 two ridges of the limonitic formation, were seen striking north and 

 south. 



Towards Tambura, to the north of Ndoruma, the country becomes 

 hilly again, and the watershed is more distinctly defined by large 

 outcrops of gneiss of markedly-foliated structure, apparently 

 dipping south-eastward at a low angle. In these gneisses I have 

 noted, as accessory minerals, garnets, a little tourmaline, and some 

 pale-green crystals of kyanite ; black flakes of mica were also 

 abundant. 



The Mount-Bundukwa Group of Hills. 



Travelling eastward from Ndoruma, a little to the south of the 

 border, we reached the knot of hills, situated near long. 29° 10' 

 east and lat. 4° 23' north, comprising Mount Baghinze in the Bahr-el- 

 Ghazal, and Mounts Bundukwa, Nangango, and Tambili, on the 

 Congo side of the frontier. Between Ndoruma and here, the inter- 

 vening country presents no hills, only large undulations, forming 

 the shallow valleys of the tributaries of the Uelle. 



Clay and limonitic puddingstone were here the only rocks met 

 with, as far as Yakululu. Some 12 miles east of that place, appears 

 the group of the Bundukwa Hills, a possible remnant of what may 

 have been once a mountain-chain, ranging north-west and south-east, 

 and perhaps connected with hills of a similar nature situated in 

 the -Nile Territory. 



Looking eastward from the top of those hills, one can see that 

 the country resumes its monotonous aspect of a level plain without 

 any noticeable elevations. 



Mount Bundukwa (3225 feet above sea-level) itself is about 

 a mile and a half in length in a north-westerly and south-easterly 



