The principal drainage of the snowy range is to the west, down into the Semliki River, and south to the Albert Edward Lake. The Katonga flowing into Lake Victoria, and the Kafur into the Victoria Nile, are both fed from the eastern face of Ruwenzori. The Mississi River, emptying into Lake Albert direct, rises from the northern extremity of the mountains.
During our journey southward, through the Semliki Valley and along the shores of the Albert Edward, I counted sixty-two streams which descended from Ruwenzori alone, the most important being the Rami, Rubutu, Singiri, Ramilulu, Butahu, Rusirubi, Rwimi rivers, descending to the Semliki River; and the Ruverahi, Nyamagasani, Unyamwambi, Rukoki, Nsongi and Rusango rivers, pouring into the Albert Edward.
By boiling point the upper lake was ascertained to be at an altitude of 3,307 feet, and Lake Albert at 2,350 feet above the sea; thus making a difference of level of 957 feet for about 150 miles of river. Therefore, besides a strong current which we observed, and rapids, the Semliki River must have a considerable number of great cataracts in its course from lake to lake.
The Semliki Valley is noted for its hot-house character only for some forty miles. That portion of it exposed to the sweep of the gales from Lake Albert seems to have but a sour soil, for the yield of it is an acrid grass, rejected by cattle, and thin forests of acacia; but between this and the portion of exposed lake to the upper end is a soil so rich and so productive that would rival the best soils in the world. The natives have long ago discovered this fact, for they have gathered in multitudes of small tribes to clear the thick forest and plant their banana and plantain stalks. One can scarcely travel a mile in any direction without coming across a luxuriant, heavy-fruited plantain grove. In no part of Africa may be seen such abundance of food, not even in Uganda. Ten such columns as I led might have revelled in abundance. The plantain fruit, when mature, measured from twelve to eighteen inches in length, and thick as the fore-arm of an ordinary man.
It occupied us sixteen days to traverse this rich forest region, generally distinguished by the name of Awamba, after the tribe, and during that time we had ten separate rainfalls, several of them lasting over nine hours, while it thundered daily. Besides this, when we issued out of the forest, and clung to the grassy foot of the range, at a few hundred feet of altitude above it, we observed that, as far as we could see, the forest extended unbroken, except by the numerous banana plantations. There were many lateral depressions, marking the courses of the streams, but few elevations of any importance, but over the whole slowly sailed the snow-white mist in broad, irregular streams; these, in a few moments, became joined into a universal mass, which to us, looking down upon it, resembled an inverted sky. All this was very annoying to us as curious sightseers, anxious to know the strange world we were in; but it furnished suggestions as to the reason why this part was so especially prolific, and why Ruwenzori was so coy. No winds could cool this portion of the valley, or waft the vapours away and clear the atmosphere from an entire corner of the compass, owing to the extent and great height of Ruwenzori. The great mountain intercepted every breeze from east round to south, and prevented the everlasting exhalations of the valley from being blown in that direction, but, on their reaching the intense cold above, distilled them, and rediffused them in copious showers of rain. From north to west the northern range of mountains obstructed the free passage of the winds, and assisted to maintain that equable heat of the valley that was necessary for the fostering of that marvellous vegetation. In every camp of this region the smoke hung over us like a pall, smarting the eyes and half suffocating us. In such a Nature’s conservatory as the Semliki Valley, buried under its own perpetual warm exhalations, vegetation, as a matter of course, finding every favourable element therein necessary for its growth and nourishment, grows in riotous profusion. Where the humus is deep we find a tall and stately forest, with an impervious underwood of young trees, bound together and sometimes altogether hidden by countless climbing vines and robust plants; where the humus is thinner, as near the foot of the range, dense crops of cane-grass, from ten to fifteen feet in height, flourish luxuriant and impenetrable. Every tree-stem has its green robe of soft moss, dripping with dew, and each tree-fern or horizontal branch has its orchids, or broad elephant-eared plant. Every rock is clothed with lichens, and if but the slightest hollow is found in it, there will be seen a multitude of tropic plants crowding every inch. In short, everywhere, except upon the perpendicular face of a late-moved boulder, vegetation thrives of every variety of greenness, form, and character.
About a day before we finally issued out of the forest region we were made still further aware what curious novelties in plants a natural conservatory can produce. Between Mtarega and Ulegga we were astonished at the huge girth of the wild banana plant, some of them being eighteen inches in diameter two feet above the ground. The fronds were gathered at the top of the stalk like an artificial bouquet, but presently spread out, two feet wide and ten feet in length, forming graceful curves and a most cooling shade, the leaves circling the flowers, which were like great rosettes with drooping tassels. There seemed to be no limit to the altitude at which these wild bananas grew, though we observed that their number on the mountain slopes became more limited above 8,000 feet. The tree-ferns, reaching as high as thirty feet from the ground, presented themselves in a series of narrow groves along the moist hollows or near banks of streamlets, while an untold variety of smaller ferns grew in their neighbourhood, as though they were determined to prove their relationship to the giants of the fern family. Then the calamus, climbing from one tall tree to another with resolute grasp, next attracted our attention. In the neighbourhood of such fern-groves the trees were veritable giants, the orchids in their forks were most numerous, and the elephant-eared lichen studded the horizontal branches, while every tree was draped with soft green moss, beaded with dew, and seemed sodden through excess of moisture.