The result of it all, however, is that he believes the Lukuga was formerly a tributary of the lake, the bed of which at some former time was lifted up to a higher level; that the whole stretch of land here has been sunk lower by some convulsion of nature, taking the Lukuga with it, and thus making a sort of dam of the land at the foot, which accounts for the steady rise of the river year by year; and that in three years the lake will rise above this dam, and, gathering force, will tear like a resistless torrent through all this mud and vegetation, and roaring on, as the Nile does where it leaves the Victoria Nyanza, will sweep through the country till it pours its accumulated waters into the Lualaba, and thus swell the Congo into a still larger Amazon of Africa. This seems to be the only plausible solution of the mystery attached to Tanganika. The only objection to it is, no such convulsion or change of the bed of the Tanganika seems to have occurred during this generation, and what has become, then, for at least seventy years, of all the waters these hundred rivers have been pouring into the lake? We should like the estimate of some engineer of how many feet that lake would rise in fifty years, with all its tributaries pouring incessantly such a flood into it. We are afraid the figures would hardly harmonize with this slow rise of the lake. It may be that there is a gradual filtering of the water through the ooze at the foot, which will account for the slow filling up of the great basin--a leakage that retards the process of accumulation. But if Stanley's explorations and statements can be relied upon, the mystery will soon solve itself, and men will not have to hunt for an outlet long. He makes the length of Tanganika three hundred and twenty-nine geographical miles, and its average breadth twenty-eight miles.