“When Cameron was here in 1874, there was a spit of dry sand lined with grass or cane, projecting from the south side, and a similar one from the north side, the two being separated by a narrow channel, but to-day both spits are covered with a line of wild breakers. The spot where Cameron camped is no longer tenable, but is exposed to the billows of the Tanganika, which at this season are driven in by the south-east monsoon. “Take it any way you please, such conflict of opinions among people who ought to know what an outlet or an outflowing river is—many of them having seen the Luapula flow out from Bemba lake, others having seen the Lualaba plunge down from Mweru lake—makes it clear that there is either a crisis approaching in nature or that it has lately taken place, or is occurring—one cannot say which until the Lukuga is explored, and this work I propose to begin to-morrow.” Cameron says, on p. 304, in vol. i. of his ‘Across Africa’:— “Its entrance was more than a mile across, but closed by a _grass- grown sandbank_ with the exception of a channel 300 or 400 yards wide, and _across the channel there is a sill_ where the surf breaks heavily at times, although there is more than a fathom of water at its most shallow part.” An inflowing river meeting the billows of the Tanganika might be supposed to form a “surf,” or a sandy sill, it being only natural that there should be a conflict between the opposing forces. To this struggle then must be attributed the formation of the “sill of sand” which Cameron said ran across the channel. _July 16._—On the 16th we sailed up the creek. The mouth of the Lukuga, which was about 2500 yards wide, narrowed after a mile to 800 yards, and after another mile to 400 or 500 yards. Upon rounding the point of land on which Mkampemba stands, and where there is a considerable tract under tillage, I observed that the water changed its colour to a reddish brown, owing to the ferruginous conglomerate of which the low bluffs on either side are composed. This was also a proof to me that there was no outflowing river here. Clear water outflowing from the Tanganika, only two miles from the lake, ought never to be so deeply discoloured. As we proceeded on, the chief told us to stop, and threw a stick into the water, asking us to note how, despite the ripple and wind from lakeward, the stick and the water-bubbles persisted in struggling against them towards the lake. His face was triumphant as he thought he had completely proved one part of his statement, that water came into the lake. It only remained now, as he thought, to prove that water flowed out towards the west. Wherever there were indentations in the bluffs that banked it in, or a dip in the low grass-covered débris beneath, a growth of Mateté or water-cane and papyrus filled up these bits of still water, but mid- channel was clear and maintained a breadth of open white water ranging from 90 to 450 yards.