I had taken a short walk previously on the left shore. The very same appearances of water remaining behind were visible, and I found muscles on the dry ground, amongst which were the Erethria ovata. Long traces of little deposits of earth, which, on closer examination, I discovered to be dams against the high water on the shore itself; and the alluvial reeds in conjunction with the muscles, make me conjecture that the Sobàt ascends over its shores here, as in many other places. Behind these low deposits lay an unlimited stubble-field on the other side of the village which lies on a gently ascending hill, elevated perhaps by the remains of clay walls, and stretching far beyond the horizon. The better kind of tokuls have frequently a roof, but the eaves only project inconsiderably: the smaller ones have a round form of roof, low sleeping places and reed-hedges being between them. Dinkas are said to dwell there; but not a person, not a living creature, is to be seen. Thermometer, sunrise, 17°; noon, 28°; sunset, 26°.
19th March.—We all dine together in the open air, after an antelope-hunt. The island on which we are, is, properly speaking, a large broad sand-bank, about a quarter of an hour long: its somewhat elevated back is covered with verdure, and is connected with the shore on the right at low water-mark. Purslane (Arabic Rigli) is found very commonly upon it; we see also numerous birds fishing in the many tongue-shaped segments of the upper part, and, in fact, sharing among themselves the narrow lake on the high right shore, close to which is a village, from whence the people have likewise fled. These feathered occupants seem to remove very seldom from this happy place. The antelopes presented themselves in great numbers; but Suliman Kashef’s body-guard, though generally good shots, did not know the huntsman’s custom of dividing and forming a chain, so as to catch the herd in the middle. I had no inclination, either, to join in such a surrounding of the game; for these Turks fire as if they were shooting in files, and their guns carry far, and are always recommended to the care of the supreme Allàh.
20th March.—Departure at a quarter after nine o’clock, with a favourable north-east wind, without sails, S.S.W. and S.W. by W., where, on the right, behind the high shore, a village lies in the bend to the left, and below it a broad sand-bank, on which some long-legged water-fowls are wandering about. We leave at the right side another sand-bank exactly similar to the former, throwing its shallows far beyond the middle of the river, and halt, S.S.E. at the right shore at half-past ten o’clock. Suliman Kashef’s halberdiers bring eight antelopes, one of which I procure, being the largest of the Tete species. This specimen is now in the Zoological Museum at Berlin as a nova species.
The shores have widened here, and fall off in an angle of 45° to 50°: though they appear on this account lower, yet it is plainly visible by the steeper places, that they always become higher. It is only below in the places where the river beats against, that the bluish clay is seen: the remaining part of the shores has, apparently, merely constituents of the same, as is the case in most places where the high water has not washed away the crust of humus crumbling from above and covering the base of the surface; for the original soil discloses itself immediately under the covering of earth, as is seen in precipices, and clefts in rocks caused by water. The river has also thrown or deposited thick layers on the shores. We must not be deceived here by observing various strata of earth mixed above and below with sand; this is a later alluvial deposit.
A pure layer of clay is never to be seen, however, in these tracts of strata, so far as I have remarked here and on the Nile. If it does appear, it lies either as the foundation of the whole, below on the banks of the water, as on the Nile; for all the ground there is alluvial and earthy deposits, gained when the high water is drawn off; or it rises, as in the Sobàt, with the talus of the shores to the surface, which is covered with a crust of humus. The Sobàt dug a bed for itself in firm clay-ground that resisted the water, and remained tolerably constant in the trench opened by it, without having altered its course, for no gohrs are seen on dry ground; but perhaps, in some places, it has flowed over its bed, and formed channels. On the contrary, the White Stream wallowed for a long time in the deep slime of an emptied lake, before it threw up solid dams, on which there are marshy forests, as on the old shores. This long valley-basin lies also on a layer of clay.
The Sobàt may be considered as a further boundary of the peninsula of Sennaar, and have given to the latter the name of Gesira. Certainly it has been, like the Blue Nile, a main-road for the tribes of the highlands of Ethiopia to the valleys of these countries; and this must have been especially the case because it has no accompanying marsh-lakes. Such nations could not have wound down from the mountains of Bari and the highlands there, by reason of the many marshes; for we are not to suppose that nomadic tribes can provide themselves and families with a stock of provisions for a long journey, or stow entire herds in their hewn-out trunks of trees (canoes); and it is impossible that the cattle could have been driven along the shore for their use.
The further I ascend the Sobàt, the plainer I perceive why the right shore just behind Khartùm appears higher than the left, and why I could not get rid of the idea that this oblique inclination of the land was in opposition to the course and the mouth of the Nile, but still might be explained. The deposit of particles of earth and sand can only come from above, and will always try to level and equalise the tracts of land which the Nile covers with showers of rain, brooks, and rivulets. It is clear that the surface is elevated by that means, and that, where these washed-away and liquid particles of earth reach a stream like the White Nile, they are carried down by it, without the other shore (the left side of the Nile here) deriving naturally any advantages therefrom.
The high mountain chain of Fàzogl and Habesh mixed, as I conjecture, its collective waters, owing to a breach in its partition-walls, and their slime and morasses, and perhaps entire hills of decayed and corrupted matter connected therewith, filled depths in the lower valley on the side of the Nile up to the Delta—its most famous memorial,—and levelled the mountains of the neighbourhood, when Bertat, Dinka, and the country between the Sobàt and Bari rivers might have shot up in indomitable strength like artesian wells. Such catastrophes roll mountains and masses like a brook does its little pebbles, and throw up the water released from confinement in the cavities of heights which attract and collect it. A flood of liquid earth rolled then far and wide from the mountains without order and with numerous arms, but conformably to nature, the heavy particles sank. The water itself washed away, smoothed and levelled the ground. Therefore now we perceive those immeasurable plains on the Sobàt, whereon beasts cannot hide themselves, and which would be without shelter in the rainy season, if there were not mountains and forests in the neighbourhood.
Though it be mathematically proved that the great Nile runs in a channel as upon an ass’s back, yet we find just the contrary in the White Nile; but the Sobàt even displays that phenomenon, although not at this moment, for its shores are emptied, except in the lowermost grade. They lie and stretch higher than the adjacent land, being heaped up by the waves of the river; they are, however, generally narrow dams, only appearing wide in the places where there are shallow lakes behind in distant connection, or overgrown gohrs, the grass border of which more easily withstands that deep washing away than these immeasurable plains, which might be called beautiful from their splendid soil, if Ceres waved her golden ears, and Pomona offered shade and fruit. They shew, indeed, but little declination to the Nile, for which the Sobàt itself affords the best standard, being stagnant, and its shores only increasing in height here and there. The shores become higher, as on the great Nile itself; the less precipitous ones (although this is only local) are deceptive, as I have remarked several feet difference on the disrupt shore, and still more on the return voyage. I cannot divest myself of the idea that a lake has stood here also, or it may be that the surface of the earth from the region above to this, has been laid flat by the inundation, similar to the level fields of Egypt.
There is an incredible number of deer on the shores of the Sobàt, for I can add from my own conviction, so far as my eyes and ears do not deceive me, that I saw herds of antelopes at least a thousand strong—the Turks say from three to four thousand. About evening they shew themselves in immense lines on the bare horizon of the steppe, stand still, and approach—their tread sounds, in truth, like the evolutions of distant cavalry; at last, as soon as it is dark, they separate in the little bushes on the margin of the shore, to descend to the water. Hitherto I have not been able to seize this opportunity, because no one would remain with me on account of the lions and other savage beasts prowling about here, and it did not seem to me exactly safe, by reason of my close acquaintance with the lion and his just revenge, to lie alone behind a bush, and shoot some of the animals at a few paces off. My cook, however, has promised to accompany me on such sport, when we come again to a suitable place.