The southern end of this lake is ten days northeast of the town of Cazembe; and as that is probably more than five days from Shinte, we can not have been nearer to it than 150 miles.  Probably this lake is the watershed between the Zambesi and the Nile, as Lake Dilolo is that between the Leeba and Kasai.  But, however this may be, the phenomena of the rainy season show that it is not necessary to assume the existence of high snowy mountains until we get reliable information.  This, it is to be hoped, will be one of the results of the researches of Captain Burton in his present journey.

The original valley formation of the continent determined the northern and southern course of the Zambesi in the centre, and also of the ancient river which once flowed from the Linyanti basin to the Orange River.  It also gave direction to the southern and northern flow of the Kasai and the Nile.  We find that between the latitudes, say 6 Deg. and 12 Deg.  S., from which, in all probability, the head waters of those rivers diverge, there is a sort of elevated partition in the great longitudinal valley.  Presuming on the correctness of the native information, which places the humid region to which the Nile and Zambesi probably owe their origin within the latitudes indicated, why does so much more rain fall there than in the same latitudes north of the equator?  Why does Darfur not give rise to great rivers, like Londa and the country east of it?  The prevailing winds in the ocean opposite the territory pointed out are said to be from the N.E. and S.E. during a great part of the year; they extend their currents on one side at least of the equator quite beyond the middle of the continent, and even until in Angola they meet the sea-breeze from the Atlantic.  If the reader remembers the explanation given at page 109,* that the comparative want of rain on the Kalahari Desert is caused by the mass of air losing its humidity as it passes up and glides over the subtending ridge, and will turn to the map, he may perceive that the same cause is in operation in an intense degree by the mountains of Abyssinia to render the region about Darfur still more arid, and that the flanking ranges mentioned lie much nearer the equator than those which rob the Kalahari of humidity.  The Nile, even while running through a part of that region, receives remarkably few branches.  Observing also that there is no known abrupt lateral mountain-range between 6 Deg. and 12 Deg.  S., but that there is an elevated partition there, and that the southing and northing of the southeasters and northeasters probably cause a confluence of the two great atmospheric currents, he will perceive an accumulation of humidity on the flanks and crown of the partition, instead of, as elsewhere, opposite the Kalahari and Darfur, a deposition of the atmospheric moisture on the eastern slopes of the subtending ridges.  This explanation is offered with all deference to those who have made meteorology their special study,