Page:EB1911 - Volume 19.djvu/268

 result of harbour works, however, a channel has been cleared and steamers can ascend the river for 6 m.

The Pongola rises in the Transvaal in high ground N.E. of Wakkerstroom and flows E., forming, for the greater part of its course, the northern frontier of the province. After piercing the Lebombo Mountains, it turns N. and joins the Maputa, a river emptying into Delagoa Bay. The Umgeni, which rises in the Spion Kop hills some 30 m. S.E. of Giant’s Castle, passes through the central part of Natal and reaches the sea 4 m. N. of Durban. It flows alternately through mountainous and pastoral country, and is known for two magnificent waterfalls, both within 12 m. of Pietermaritzburg. The upper fall is close to the village of Howick. Here the Umgeni leaps in a single sheet of water down a precipice over 350 ft. high, more than double the height of Niagara, forming, when the river is swollen by the rains, a spectacle of rare magnificence. Some 12 m. below are the Karkloof or Lower Falls, where in a series of beautiful cascades the water descends to the plain. Other rivers of Natal which rise in the spurs of the Drakensberg or in the higher terraces are the Umvoti, which runs south of the Tugela and gives its name to a county division, the Umlaas (which gives Durban its main water supply, the Illovo, which traverse the country between the Umgeni and Umkomaas, and the Umtamvuna, noteworthy as forming the boundary between Natal and Pondoland. There are also seventeen distinct coast streams in the colony.

[Geology. —The general geological structure of Natal and Zululand is simple. It consists of a series of plateaus formed of sedimentary rocks which mainly belong to three formations of widely separated ages, and which rest on a platform of granitic and metamorphic rocks.

The geological formations represented include:—

Pre-Cape Rocks.—The granites and schists occur in close association. The series covers considerable areas in the lowest parts of the valleys and near the coast. The widest areas are in Zululand. In the Umzimkulu river and in the Tugela river below its junction with the Buffalo, metamorphic limestones are associated with schists, gneisses and granites. A group of highly inclined quartzites, altered conglomerates and jasperoid rocks which crop out on the Umhlatuzi river, between Melmoth and Nkandhla and on the White Umfolosi river above Ulundi Plains, is considered by Anderson to represent some portion of the Lower Witwatersrand series. The conglomerates are true “banket” and are auriferous, but the gold has not been met with in payable quantities.

Table Mountain Sandstone Series.—This rests unconformably on the pre-Cape rocks. Traced northwards, the series becomes thinner and finally dies out. As a rule denudation, which has acted on a magnificent scale, has removed all but a few hundred feet of the basement beds. The maximum thickness of 2000 ft. occurs near Melmoth. The beds are usually thin false-bedded sandstones with an almost complete absence of shales. A conglomerate at the base contains traces of gold. Griesbach mentions the occurrence of some small bivalves in the shales of Greytown, but Anderson failed to find any fossils.

Ecca Glacial Series.—A great unconformity separates the Table Mountain and Ecca series. In the Cape this gap is represented by the Witteberg and Bokkeveld series. The Dwyka conglomerate rarely attains any great thickness though forming wide outcrops. It is usually a hard compact rock containing striated stones. The Umgeni quarries, where the rock is used for road-metal, furnish the best exposures.

Ecca Series.—With the Beaufort series this occupies over two-thirds of the western portion of the province and has wide outcrops in Zululand and in the Vryheid districts. The Ecca shales contain some of the best coals of South Africa, but the seams contain much unmarketable coal. Around Dundee and Newcastle the coals are bituminous. In Zululand they are chiefly anthracitic. The fossils include several species of Glossopteris among them: Glossopteris browniana var indica; ''Bunb. Phyllotheca Zeilleri eth. fil.''; Estheria Greyii, Jones, indicating a Permo-Carboniferous age.

Beaufort Series.—The Ecca series graduates upwards into the highly coloured sandstones and shales of the Beaufort series. Fossil reptilian remains, chiefly Dicynodon, are abundant.

Stormberg Series.—This consists of sandstones and shales with thin seams of coal. The chief outcrops occur around Biggarsberg and along the upper slopes of the Drakensberg. The fossil flora—Thinnfeldia odontopteroides, Morr. and a Pterophyllum—indicate a Rhaetic age. No reptilian remains have been found.

Upper Karroo.—The Red beds and Cave sandstones occur along the eastern flanks of the Drakensberg.

Cretaceous.—Deposits of this age are confined to the littoral. They are exceedingly prolific in fossils which prove them to be of Upper Cretaceous age. A long list of fossils has been obtained from Umkivelane Hill, Zululand. W.G.*]

Climate.—With a rise in level (not reckoning the mountain tops) of 5500 ft. in a distance of 170 m., Natal possesses several varieties of climate but is nowhere unhealthy. The climate is comparable to that of north Italy. The valleys and coast belt, though practically free from malarial fever, are hot and humid, and fires in dwelling houses are seldom required even in the coolest months; the lower plateaus are cool and the air dry; the uplands are bracing and often very cold, with snow on the ground in winter. The year is divided into two seasons, summer, which begins in October and ends in March, and winter, which fills up the rest of the year. Summer is the rainy season, and May, June and July the driest months of the year. The mean temperature at Durban, records taken at 260 ft. above the sea, is 70° F., varying from 42° in winter to 98° in summer. The average summer humidity is 76%, that of winter 74%. At Pietermaritzburg, 41 m. inland and 2200 ft. above the sea, the temperature is about 64°. In the uplands the heat of summer is often greater than on the coast, but the air is less humid and the nights are generally cool. Both the humidity and the temperature are increased by the great mass of water, the Mozambique current, flowing south from the equatorial regions. At Durban the annual rainfall is about 40 in., at Pietermaritzburg 38. The average for the province is believed to be about 30 in. In 1893, the year of highest recorded rainfall, 70 in. fell on the coast districts. Thunderstorms, averaging nearly one hundred in the year, and violent hailstorms, occur in summer, being most severe in the interior. The storms serve to modify the intense heat, though the lightning and hail cause considerable damage. The prevailing winds on the coast are north-east, warm and humid, and south-west, cool and bracing, though in summer the south-west wind brings rain. Inland, chiefly in early summer, a hot dry wind, often accompanied by a dust storm, blows from the north. These winds, which blow on an average twenty-five days in the year, seldom reach the coast and are generally followed by rain. Inhabitants of Natal are practically exempt from chest diseases.

Flora.—Botanically, Natal is divided into three zones: (1) the coast belt, extending from the sea inland to heights of 1500 ft., and in some cases to 1800 and 2000 ft.; (2) the midland region, which rises to 4000 ft.; (3) the upper regions. In these zones the flora varies from sub-tropical to sub-alpine. The heaths and proteads common at the Cape peninsula, in Basutoland and other parts of South Africa, are rare in Natal, but almost any species of the flora of semi-tropical and temperate countries introduced attains perfection. The trees and plants characteristic of each zone are not always confined to that zone, but in several instances, when common to the coast belt and the midlands, their character alters according to the elevation of the land. The dense bush or jungle of evergreen trees, climbers and flowering shrubs, which up to the middle of the 19th century covered the greater part of the coast belt, has largely disappeared. There are still, however, in the coast belt woods of leguminous evergreens bearing bright-coloured flowers. The trees in these woods are generally from 20 to 50 ft. in height and include the knob-thorn, water-boom, kafir-boom (with brilliant scarlet flowers), the Cape chestnut and milk woods (Mimusops). But the most striking of the coast-belt flora are the tropical forms—the palm, mangrove, wild banana (Strelitzia augusta), tree-ferns, tree euphoria, candelabra spurge and Caput medusae. Of palms there are two varieties, the ilala (Hyphaene crinita), found only by the sea shore and a mile or two inland, and the isundu (Phoenix reclinata), more widespread and found at heights up to 2000 ft. or even higher. The amatungulu or Natal plum, found chiefly near the sea, is one of the few wild plants with edible fruit. Its leaves are of a glossy dark green, its flower white and star-shaped and its fruit resembles the plum. Other wild fruits are the so-called Cape gooseberry (not native to Natal) and the kaw apple or Dingaan apricot, which grows on a species of ebony tree.

The midland region is characterized by grass lands (the Natal grasses are long and coarse) and by considerable areas of flat-topped thorn bush mimosa. The bush is not as a rule dense, nor is it of any great height. A tree peculiar to this zone is the Alberta magna. It has dull pink flowers, succeeded by seed vessels, each of which is crowned by two scarlet-coloured leafy lobes. A grass belt separates the thorn bush from the districts carrying heavy timber, found mainly in the upland zone, along the sides of the mountains exposed to the rains and in kloofs. The indigenous timber trees are