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Rhodesia
that only a small portion of Southern Rhodesia is under 3000 ft. The eastern boundary, along Portuguese East Africa, forms the edge of the tableland; the height of the edge is accentuated by a series of ridges, so that the country here assumes a mountainous appearance, the grass-clad heights being reminiscent of the Cheviot Hills of Scotland or the lower Alps of Switzerland.
Geology.—The geology of this region is very imperfectly known. Metamorphic rocks extend over immense areas, but these and the other formations are to a great extent hidden beneath superficial deposits. Conglomerates and banded ironstone rocks are found in the metamorphic areas around Bulawayo and the borders of Katanga; but to what extent these represent the different formations older than the Karroo and newer than the Swaziland schists (see Transvaal) has not been satisfactorily determined. Certain gold-bearing conglomerates, are regarded as the equivalents of the Witwatersrand series, but the main sources of gold are the veins of quartz and igneous rocks developed in the metamorphic series. The Karroo formation is well represented, and covers extensive areas in the Zambezi basin. The Dwyka conglomerate appears to be developed in the Tuli district. The coal-bearing strata of Tuli and Wankies are certainly of Karroo age. They have yielded the fossil remains of fishes Acrolepis molyneuxi, the fresh-water mollusc Palaeomutela, a few reptilian bones, and species of Glossopteris among plants.
The age of a widely distributed series of red-white sandstones, named by Molyneux the Forest Sandstone, remains uncertain. Molyneux considers them Tertiary, but it is not improbable that sandstones of various ages from Karroo to those of Recent date are represented. They contain numerous interbedded sheets of basalt, but it is doubtful if any of these are of so recent a date as Tertiary. Rocks of Karroo age occur round Lake Bangweulu, and contain numerous fossil plants and a few small shells. The age of the wide, thick sheet of basalt, through which the Zambezi has cut the Batoka gorge between the Victoria Falls and Wankies, remains uncertain.[1]
Climate.—As Southern Rhodesia extends between 16° S. and 22° S., and is thus within the tropics, it might be expected that the climate would be trying for Europeans, but owing to the elevation of the country the temperature is rarely too high for comfort. Another factor that renders the climate equable is that the rainy season coincides with the summer months, and the winter months are dry. The nights are always cool, so that the climate approximates to the ideal. On the high tableland which forms the great proportion of the country the temperature in the shade rarely reaches 100° and there is just sufficient frost in the winter to be useful to farmers. The winter months are June, July and August, and the hottest months are the spring months of September, October and November, just before the rains begin. A temperature of 110° is sometimes reached in the low-lying district of Tuli (elevation 1890 ft.) and in the Zambezi valley. There is a striking difference between the minimum temperatures on the ground and those registered 4 ft. from the ground. The latter rarely reach freezing-point, but the ground temperature is sometimes as low as 24°. Hoar frost is most noticeable in the vleis and low-lying areas. The period known as the rainy season extends from September to March, but the greatest amount falls in the last three months of that period. The mean annual rainfall for various stations in the eastern half of Rhodesia ranges from 24 to 44 in., the greatest rainfall being along the eastern border. For the western half the mean ranges from 19 to 27 in., but in the south-west corner it is much drier, the rainfall so far recorded never reaching 18 in. There is a sufficiency of rain for all summer crops, but winter crops, such as wheat, must be assisted by irrigation. Malaria is prevalent in certain districts during the wet season, but this is now preventable and the country is very healthy, children, especially in towns and on the high veld, growing sturdily. The death-rate amongst Europeans is only about 15 per 1000.
Fauna.—Rhodesia is rich in the larger gramivorous animals, especially in antelope, which number about twenty-five varieties, including kudu, eland, hartebeeste, roan, sable, wildebeeste and impala. The most common are the duiker, the steenbok and the rietbok. Other herbivorous animals found in the country are the buffalo, giraffe, zebra, elephant, hippopotamus, rhinoceros (black and white), warthog, and various baboons and monkeys. The buffalo is now rare, having been almost exterminated by the rinderpest in 1896. The carnivora include the lion, leopard, cheetah, and various wild cats, foxes, wolves, jackals and dogs. There are at least five varieties of the mongoose. Amongst the rodents are squirrels, dormice, rats (eleven kinds), the porcupine, the Cape hare and the rock hare. Of insectivora the ant-eater, the ant-bear, the hedgehog and various shrews may be mentioned. Bats number eleven varieties. Snakes are numerous, the most important being the python, the puff-adder and the cobra. Crocodiles and iguanas are found in most of the rivers, and chameleons and lizards are very common. Rhodesia abounds in beetles, butterflies and moths, and new varieties are frequently discovered in the wet season. Mention ought to be made of white ants (termites) and locusts. The ants are a serious pest, attacking all cut timber resting in or on the ground. They gradually envelop the dead wood in a mound of earth and, consume it wholly, so that all poles and house-timber have to be carefully protected either by chemical preparations or by raising them clear from contact with the earth. The mounds which the white ants erect often reach a height of many feet. There are several kinds, the black-headed nipper ant, chiefly found in the west, being the most destructive. Locusts are particularly dreaded in their wingless state, when they clean off every green leaf, every bit of vegetation, as they march on in their hundreds of thousands. The rivers are not very plentiful in fish, but occasional sport is afforded by barbel, bream and tiger-fish.
Birds to the number of about 400 varieties have been found in Rhodesia. The largest of these are the ostrich, the secretary-bird, the paauw, the koorhaan, cranes (three varieties), storks (four), vultures (six) and eagles (eight). The chief birds that attract sportsmen, besides the paauw and the koorhaan already mentioned, are the guinea-fowl (three kinds), partridge and francolin (seven kinds), wild goose, duck and teal. Some of the most interesting birds are the weaver-birds (eighteen), the ox-peckers, which find their food on the backs of cattle, the kingfishers (eight), the hornbills (five), the parrots, lovebirds, the polygamous widow birds—whose females are of insignificant appearance, but whose males develop a brilliant plumage and lengthy tails during the
- ↑ For geology see F. H. Hatch, “Notes on the Geology of Mashonaland and Matabeleland,” Geol. Mag., 1895; A. J. C. Molyneux, “The Sedimentary Deposits of Rhodesia,” Quart. Journ. Geol. Soc., vol. lix. (1903); F. P. Mennel, “Geology of Rhodesia,” British Association Handbook (Cape Town, 1905); G. W. Lamplugh, British Assoc. Rep., South African Meeting, 1905.
