be mistaken on such a point. But whether this outflow is permanent or not, is a totally different question, which unfortunately has not been answered. In his book, now published, Lieutenant Cameron has not expressed any doubt on this point, and has spoken of the Lukuga as a permanent out-flowing stream; but in his earlier letters to the Geographical Society, he did express great doubt, and was inclined "to think that in the dry season, or when the lake is at its lowest level, little or no water leaves it."
He had intended to examine the Lukuga more closely. On the 9th of May, 1874, he wrote from Ujiji: "I propose buying three canoes, which will hold all I intend to take, and then, wherever that river goes, d.v., I go too." But six days later he had to write: "I have abandoned the idea of proceeding down the Lukuga, as such a journey would be most expensive, and require a very long time, as cutting the grass for a way would be hard work, and we should most likely require the assistance of the natives, for which one would have to pay heavily." Those who remember the account which Sir Samuel Baker has given of the obstruction which stopped his passage up the Nile, in 1870, or have read Colonel Long's account of how, in 1874, the "putrid mass of vegetable matter" was cut through by a battalion of Soudan soldiers, after a sickly and deadly work of three weeks, will the better under- stand the decisive nature of the obstacle which stopped Cameron.
As a matter of fact, then, the Lukuga was not examined. There is no proof that it is anything more than an overflow into an adjoining swamp; and there is, equally, no proof that it is not a river, and a very important branch of a great river system. Whatever conviction Lieutenant Cameron now has, it is not the result of observation, but is based on native testimony; as such it is, after all, still a matter of opinion; and on that there is little to be said, for mere opinion can never decide a point of geography.
The sluggishness of the stream might, indeed, seem to be proof that the Lukuga cannot be the outflow of such a body of water; but it is rightly enough answered that the outlet of great lakes is often extremely sluggish. On a smaller scale, we have already referred to the outlet of Derwentwater; and Mr. Clements Markham has instanced two similar cases—the Kirkaig and the Inver, on the west coast of Sutherland shire. The Niagara itself issues from Lake Erie with a current almost imperceptible, and it is difficult to observe the flow of the Nile as it leaves the Albert Nyanza; so that from the sluggishness of the stream no argument can fairly be drawn one way or the other.
If the natives' testimony is to be accepted, the Lukuga, flowing into the Lualaba, Is a main branch of that river which, near the sea, we know as the Congo; and one piece of evidence in support of this, one to which perhaps sufficient weight has not been given, is that a Portuguese map, dated 1623, and now in the British Museum, shows one large lake—clearly Nyassa and Tanganyika combined, a pardonable enough mistake—with an outlet to the south-east, which we may identify with the Shire, flowing towards the Indian Ocean, and another outlet to the west, shown as a head stream of the Congo. We are perhaps too prone to refuse the very loose testimony of an inexact and unscientific age; but when we bear in mind that seventeen hundred years ago Ptolemy described the Nile as issuing from two lakes lying east and west of each other, lakes which we now know as the Victoria and Albert Nyanzas; and that the old map of two hundred and fifty years ago shows, with fair accuracy, what we know to be the course of the Shire, we cannot but attach some importance to its testimony as regarding the origin of the Congo.
But if the Lukuga is to be accepted as a veritable outlet of Tanganyika, does it necessarily follow that there is no outlet to the north, no connection with the Albert Nyanza, the lake so near, and so exactly on the same level? If there is no connection, the correspondence of level is an extraordinary freak of nature; and if there is a connection, then Tanganyika presents to us the very remarkable phenomenon of a lake with two outlets.
The opinion held by many geographers is that a lake with two outlets is absolutely unknown; but this opinion is certainly too sweeping, too comprehensive. There are, beyond doubt, lakes which, on authority more or less good, are said to have a double outlet—Lake Masanga (Colonel Long's Lake Ibrahim Pasha) is one of these; and the bifurcation of a river is by no means the very rare thing which it was long maintained to be. Strictly speaking, a river bifurcates at every island or eyot which lies in its stream: it is the mere accident of position which permits it to close again. Signor Gessi, an officer on the staff of
