sending up vast columns of vapour. Hence the native name Musi-oa-tunya, “Smoke does sound there,” The chasm extends the whole breadth of the river and is more than twice the depth of Niagara, varying from 256 ft. at the right bank to 343 ft. in the centre. Unlike Niagara the water does not fall into an open basin but is arrested at a distance of from 80 to 240 ft. by the opposite wall of the chasm. Both walls are of the same height, so that the falls appear to be formed by a huge crack in the bed of the river. The only outlet is a narrow channel cut in the barrier wall at a point about three fifths from the western end of the chasm, and through this gorge, not more than 100 ft wide, the whole volume of the river pours for 130 yds. before emerging into an enormous zigzag trough (the Grand Cañon) which conducts the river past the basalt plateau. The tremendous pressure to which the water is subjected in the confinement of the chasm causes the perpetual columns of mist which rise over the precipice.
The fall is broken by islands on the lip of the precipice into four parts. Close to the right bank is a sloping cataract 36 yds. wide, called the Leaping Water, then beyond Boaruka Island, about 300 yds. wide, is the Main Fall, 473 yds. broad, and divided by Livingstone Island from the Rainbow Fall 535 yds. wide. At both these falls the rock is sharp cut and the river maintains its level to the edge of the precipice. At the left bank of the river is the Eastern Cataract, a millrace resembling the Leaping Water. From opposite the western end of the falls to Danger Point, which overlooks the entrance of the gorge, the escarpment of the chasm is covered with great trees known as the Rain Forest, looking across the gorge the eastern part of the wall (the Knife Edge) is less densely wooded.
At the end of the gorge the river has hollowed out a deep pool, named the Boiling Pot. It is some 500 ft. across, its surface, smooth at low water, is at flood-time troubled by slow, enormous swirls and heavy boilings. Thence the channel turns sharply westward, beginning the great zigzag mentioned. This grand and gloomy canon is over 40 m. long. Its almost perpendicular walls are over 400 ft. high, the level of the escarpment being that of the lip of the falls. A little below the Boiling Pot, and almost at right angles to the falls, the cañon is spanned by a bridge (completed in April 1905) which forms a link in the Cape to Cairo railway scheme. This bridge, 650 ft. long, with a main arch of 500 ft. span, is slightly below the top of the gorge. The height from low-water level to the rails is 420 ft.
The volume of water borne over the falls varies greatly, the level of the river in the cañon sinking as much as 60 ft. between the full flood of April and the end of the dry season in October. When the river is high the water rolls over the main falls in one great unbroken expanse; at low water (when alone it is possible to look into the grey depths of the great chasm) the falls are broken by crevices in the rock into numerous cascades.
The falls are in the territory of Rhodesia. They were discovered by David Livingstone on the 17th of November 1855, and by him named after Queen Victoria of England. Livingstone approached them from above and gained his first view of the falls from the island on its lip now named after him. In 1860 Livingstone, with Dr (afterwards Sir John) Kirk, made a careful investigation of the falls, but until the opening of the railway from Bulawayo (1905) they were rarely visited. The land in the vicinity of the falls is preserved by the Rhodesian government as a public park.
See Livingstone's Missionary Travels and Researches in South Africa (London, 1857) for the story of the discovery of the falls, and the Popular Account of Dr Livingstone's Expedition to the Zambesi and its Tributaries 1858-1864 (London, 1894) for a fuller description of the falls and a theory as to their origin. How I crossed Africa, by Major Serpa Pinto (English trans., London. 1881), contains a graphic account of the visit paid to the falls by the Portuguese explorer. In the Geographical Journal for January 1905 is an article by A. J. C. Molyneux on “The Physical History of the Victoria Falls.” The article is illustrated by excellent photographs and gives a bibliography. Consult also “The Gorge and Basin of the Zambesi below the Victoria Falls,” by G. W. Lamplugh in the Geog. Jour. (1908), vol. xxxi. (F. R. C.)
VICTORIA NYANZA, the largest lake in Africa and chief reservoir of the Nile, lying between 0° 20′ N to 3° S and 31° 40′ to 34° 52′ E. Among the fresh-water lakes of the world it is exceeded in size by Lake Superior only and has an area of over 26,000 sq. m., being nearly the size of Scotland. In shape It is an irregular quadrilateral, but its shores, save on the west, are deeply indented. Its greatest length, taking into account the principal gulfs, N to S. is 250 m., its greatest breadth 200 m. Its coast-line exceeds 2000 m. It fills a depression in the central part of the great plateau which stretches between the western (Albertine) and eastern rift-valleys (see Africa, § 1), and has an elevation of about 3720 ft. above the sea.[1] Its greatest ascertained depth is some 270 ft., which compares with soundings of 2000 ft. on Tanganyika and 2500 ft. on Nyasa. Victoria Nyanza is remarkable for the severe and sudden storms which sweep across it, rendering navigation dangerous. It contains many groups of islands, the majority being near the coast-line. The lake is full of reefs, many just below the surface of the water, which is clear and very fresh. It is abundantly stocked with fish. Geological research shows that the land surrounding the lake consists of gneiss, quartz and schistose rocks, covered, in the higher regions, with marl and red clay, and in the valleys with a rich black loam.
Shores and Islands.—The shores of the lake present varied aspects. The western coast, which contains no large indentations, is, in its southern part, backed by precipices of 300 or more ft. high, behind which rise downs to thrice the height of the cliffs. Going north, the hills give way to papyrus and ambach swamps, which mark the delta of the Kagera. Beyond the mouth of that river the hills reappear, and increase in height, till on reaching the N.W. corner of the nyanza they rise some 500 ft. above the water. This western shore is marked by a continuous fault line which runs parallel to the lake at a short distance inland. The northern coast of the lake is very deeply indented and is marked throughout its length by rocky headlands jutting into the waters. This high land is very narrow, and the streams which rise on its northern face within a mile or two of the nyanza drain north away from the lake. On a promontory about 30 m. east of the Katonga (see below) is Entebbe, the port of Uganda and seat of the British administration. The chief indentations on the north side are Murchison Bay and Napoleon Gulf, the entrance to the last named being partly filled by the triangular-shaped island of Buvuma or Uvuma (area 160 sq. m.). Napoleon Gulf itself is deeply indented, one bay, that of Jinja, running N.W. and being the outlet of the Nile, the water here forcing its way through the rock-bound shore of the lake. The north-east corner of the lake is flat and bare. A narrow channel, partly masked by islands, leads into Kavirondo Gulf, which, with an average width of 6 m., extends 45 m. E. of the normal coast-line—a fact taken advantage of in building the railway from Mombasa to the lake. A promontory, 174 ft. above lake-level, jutting into the small bay of Ugowe, at the north-east end of Kavirondo Gulf, is the point where the railway terminates. The station is known as Port Florence. On the south side of the gulf tall hills approach, and in some cases reach, the water's edge, and behind them towers the rugged range of Kasagunga with its saw-like edge. Proceeding south the shore trends generally south-west and is marked with many deep inlets, the coast presenting a succession of bold bluffs, while inland the whole district is distinctly mountainous. At the S.E. corner of the lake Speke Gulf projects eastward, and at the S.W. corner Emin Pasha Gulf pushes southward. Here the coast is barren and hilly, while long ridges of rock run into the lake.
The largest island in the lake, Ukerewe, on the S.E. coast, immediately north of Speke Gulf, is almost a peninsula, but the strip of land connecting it with the shore is pierced by two narrow channels about ¾ of a mile long. Ukerewe is 25 m. long, and 12 broad at its greatest width. It is uninhabited, wooded and hilly, rising 650 ft. above the lake. At the N.W. corner of the nyanza is the Sessé archipelago, consisting of sixty-two islands. The largest island in this group, namely, Bugala, is narrow, resembling the letter S in shape, and is almost cut in two in the middle. Most of these islands are densely forested, and some of them attain considerable elevation. Their scenery is of striking beauty. Forty-two were inhabited.[2] Buvuma Island, at the entrance of Napoleon Gulf, has already been mentioned. Between it and as far as the mouth of Kavirondo Gulf are numerous other islands, of which the chief are Bugaia, Lolui, Rusunga and Mfwanganu. In general characteristics and the beauty of their scenery these islands resemble those of the Sessé archipelago. The islands are of ironstone formation overlying quartzite and crystalline schists.
Rivers—The Kagera, the largest and most important of the lake
