What the maps call Lake No is merely the expanded mouth of the meeting waters. The current flowing from the south from the Bahr-el-Gebel passes along its apparent shores, which are projecting masses of papyrus. In order to reach the Gazelle it is necessary to bend westwards along the gradually narrowing lake-basin. At no season of the year is this water otherwise than shallow; even at the time of our retrograde voyage, when the floods were highest, we stranded more than once. Floating islands of papyrus of considerable extent were visible every here and there, and broke the uniformity of the expanse. The passage which leads to the Gazelle has the essential properties of running water, although the stream itself is in winter scarcely perceptible. The river, however, is surrounded by such a multiplicity of backwaters and waters remaining in old river-beds, that the united volume of such a number of streams as I saw emptying themselves into it, at various times, through some hundreds of miles, could not possibly find its exit through this single channel alone. Petherick, in 1863, at the period when the water-floods were as low as possible, estimated the volume of waters to be rolling on at the rate of 3042 cubic feet a second; but he must have referred simply to the navigable channel at the mouth, without intending to represent that the calculation referred to the entire mass of the waters. It remains still a matter of dispute which of the two currents should be considered as the main stream. According to analogy, as the Sobat is related to the Blue Nile, so the Bahr-el-Gebel is to the Bahr-el-Abiad, just as the Blue Nile is to the Nile of Egypt. [Sidenote: THE GAZELLE.]