The heart of Africa, Vol. 1 (of 2)

by Georg August Schweinfurth

The southern limit of Nganye’s territory is reached at the river Sway, which flows through the desert land which bounds alike his territories and Aboo Sammat’s. Just one league before we arrived at the river we passed the hamlets of Marra, who was a “behnky” of Nganye’s. The Sway is the upper Dyoor, and according to the uniform representations of the Niam-niam, it is considered as the main stream. I came across its source at the mountain of Baginze, where, although it is but a little brook, it is called by the same name. The proofs that I can adduce for the identity of the Dyoor and Sway are conclusive enough to establish it for a certainty, and they appear worthy of some special notice here, since they may serve to throw some light upon the question of the independence of the Welle, as a system distinct from that of the Nile basin.

1. There is no doubt that the length of the river’s course between the two points where I crossed it, the one in Marra’s district and the other in Bongo-land, near Manganya, amounts to 145 miles; but the positions, which I accurately determined, of the south Bongo Seribas, belonging to Ghattas and Kurshook Ali, and the assertion of these two men that the Dyoor flows due north from a distance of at least 70 miles above the fording-place near Manganya, virtually reduce the portion of the course that I did not explore to one-half.

2. At Marra, the Sway was already a stream with a volume of water sufficient to have an important share in the formation of the Dyoor.

3. All the Niam-niam that were questioned by me in Kurkur and Dangah, and who came from parts of their native land adjacent to these places, plainly and uniformly called the Dyoor by the name of the Sway; and without ever having been to Marra they were quite aware that the river came from the parts intermediate between the lands of Nganye and Wando.

4. Upon the road which the roving ivory companies of Mundo take over what was formerly Tombo’s territory, the Sway is crossed near Fomboa, at a place that corresponds to the curve which the river describes in my map.

5. The most important river flowing towards the north and east that must be crossed by expeditions proceeding southwards from Dem Bekeer in Dar Ferteet, is the Nomatilla or Nomatina, which according to all accounts is identical with the upper course of the Wow or Nyenahm, and is at all events the largest tributary of the Dyoor. From Solongoh’s residence, past which it flows, the Nubians have followed the course of the Nomatilla right down into the lands of the Bongo and Dyoor. There are no other important tributaries that the Dyoor can possibly receive upon the left; the Sway must, therefore, necessarily be the whole and entire upper course of the Dyoor.

To myself it was a great satisfaction thus to have placed beyond a doubt the origin of at least one of the principal source streams of the region of the upper Nile; and thus definitely to have assigned its geographical position to Mount Baginze.

HYDROGRAPHY OF THE SWAY.

The Sway flows past Marra along a level steppe, which on account of the rapid flow and deep channel of the river can only rarely, and that at the time of the rainfall, be under water. At this time the banks were perpendicular, rising to a height of some 18 or 20 feet, and being cut through layers of alluvial soil very much reminded one of the Nile “guefs.” The distance between bank and bank was 40 feet, but the actual river was now about 25 feet wide. Its depth was about 4 feet, and it was flowing at the rate of 120 feet a minute. The volume of water which passed was thus 200 cubic feet in a second, whilst the Dyoor, before its union with the Wow, at the dry season in the end of December, did not roll onward a volume of more than 1176 cubic feet. In the middle of June again the Sway had a volume of 1650 cubic feet to the second; whilst the Dyoor in the rainy season, at the point I have just mentioned, exhibited a volume of 8800 to 14,800 cubic feet.

This apparent discrepancy between the proportions of water of the two rivers at the opposite seasons of the year, is nevertheless quite in accordance with physical laws, and is consequently adapted to the purposes of demonstration. The drainage of the land outwards from its springs takes place in definite channels. These channels are represented by the great rivers which take their rise in the highest districts. The rain, uniformly spread throughout the country, makes its escape to its destination by the courses which are periodically opened in the smaller streams which become tributary to the larger. Compared, therefore, to what they are in the winter, the great rivers are not during the rainy season proportionately increased to the same extent as the smaller.