to the N.W.  But when we came to the Southern Lotembwa, we were informed by Shakatwala that the river we had crossed flowed in an opposite direction—­not into Dilolo, but into the Kasai.  This phenomenon of a river running in opposite directions struck even his mind as strange; and, though I did not observe the current, simply from taking it for granted that it was toward the lake, I have no doubt that his assertion, corroborated as it was by others, is correct, and that the Dilolo is actually the watershed between the river systems that flow to the east and west.

I would have returned in order to examine more carefully this most interesting point, but, having had my lower extremities chilled in crossing the Northern Lotembwa, I was seized with vomiting of blood, and, besides, saw no reason to doubt the native testimony.  The distance between Dilolo and the valleys leading to that of the Kasai is not more than fifteen miles, and the plains between are perfectly level; and, had I returned, I should only have found that this little lake Dilolo, by giving a portion to the Kasai and another to the Zambesi, distributes its waters to the Atlantic and Indian Oceans.  I state the fact exactly as it opened to my own mind, for it was only now that I apprehended the true form of the river systems and continent.  I had seen the various rivers of this country on the western side flowing from the subtending ridges into the centre, and had received information from natives and Arabs that most of the rivers on the eastern side of the same great region took a somewhat similar course from an elevated ridge there, and that all united in two main drains, the one flowing to the north and the other to the south, and that the northern drain found its way out by the Congo to the west, and the southern by the Zambesi to the east.  I was thus on the watershed, or highest point of these two great systems, but still not more than 4000 feet above the level of the sea, and 1000 feet lower than the top of the western ridge we had already crossed; yet, instead of lofty snow-clad mountains appearing to verify the conjectures of the speculative, we had extensive plains, over which one may travel a month without seeing any thing higher than an ant-hill or a tree.  I was not then aware that any one else had discovered the elevated trough form of the centre of Africa.

I had observed that the old schistose rocks on the sides dipped in toward the centre of the country, and their strike nearly corresponded with the major axis of the continent; and also that where the later erupted trap rocks had been spread out in tabular masses over the central plateau, they had borne angular fragments of the older rocks in their substance; but the partial generalization which the observations led to was, that great volcanic action had taken place in ancient times, somewhat in the same way it does now, at distances of not more than three hundred miles from the sea, and that this igneous action, extending along both sides of the continent, had tilted up the lateral rocks in the manner they are now seen to lie.  The greater energy and more extended range of igneous action in those very remote periods when Africa was formed, embracing all the flanks, imparted to it its present very simple literal outline.  This was the length to which I had come.