Yet these regions, deprived of springs and running waters, are not always sterile deserts, are not always desolate plains. In the dry season, the soil, a yellow ferruginous clay, acquires the hardness of brick, just as if it had been exposed to the fire of a furnace; but the roots and bulbs, protected by a ligneous covering, resist the devouring heat. The first rains revive them; they put forth their stems and branches; a myriad flowers reveal their sparkling colours; and the country which, a day or two before, had shown to the eye a bare and dreary surface, shines out in a panoply of splendour, as if a magician’s spell had suddenly transformed it into a terrestrial paradise! But as the days lengthen, and the sun’s power increases, the bloom and the beauty vanish, and the curse of fire once more descends upon the gloomy scene.
In several districts north of the Cape Colony whole years pass by without the sight or sound of running water rejoicing the wistful wanderer. Dr. Livingstone, while residing among the Bakouans, in the Bechuana country, saw the natives excavating the bed of the Kolobeng to extract a few drops of water. A centigrade thermometer, sunk two and a half inches in the earth, at noon, marked 56°. Insects placed on the surface of the ground died in a few seconds. The grass was so dry that it crumbled into powder when plucked.
The coast of Natal is rich in trees and herbage. The Zambesi, and other rivers which descend from the central plateau, refresh the plains of Mozambique and Zanzibar. But from the 4th parallel of north latitude to Cape Guardafui extends an almost continuous desert. The southern extremity of the Lupata chain also presents a vast naked country, where the presence of gold has encouraged the Portuguese to found some establishments.
The neighbouring zone of Kaffraria consists of great far-spreading, gently-undulating plains, characterized by extreme aridity. The western districts are much less broken than the central, and exhibit no undulations except in the vicinity of the ocean. There an immense level territory exists under the name of the Kalihari Desert, whose southern boundary is marked by the Gariep or Orange River, which drains rather than waters it. To the north this awful wilderness stretches as far as the Lake Ngami, thus covering the area comprised between the 29th and 30th parallels of south latitude. The pastoral country of Namaqua and Damaras bounds it on the west. Eastward it extends to the 24th meridian of west longitude.
Moisture is not wholly wanting in this vast region. The Kalihari has been called a desert, says Livingstone,[80] because it contains no running water, and very little in wells. Far from being destitute of vegetation, it is covered with grass and creeping plants, and there are large patches of bushes, and even trees. It is remarkably flat; and prodigious herds of antelopes roam over its trackless plains. The soil is composed in general of a fine soft sand, lightly coloured—that is, of a nearly pure silica. In the ancient beds of dried-up rivers lie immense patches of alluvial soil, which, hardened by the sun, form great reservoirs, retaining the rain-water for several months of the year. The quantity of grass flourishing in this region is remarkable. It grows generally in thick tufts, occasionally intermingled with spaces where the earth is naked or closely overgrown with creeping plants. These, deeply rooted in the soil, suffer but little from the effects of the excessive heat. Most of them have tubercular roots, and are so organized as to furnish both food and liquid during the long droughts—an epoch when one vainly seeks elsewhere anything which can appease one’s hunger or one’s thirst.
The rich vegetation of the Kalihari is due to its geological constitution. It consists of a great valley, or rather of a vast basin, whose bottom is formed of a diluvial earth, and which is encircled by a belt of rocks, cloven at several places. It follows that where the rain is abundant, the slope of the hills directs it towards the centre of the basin, and this rain filters and deposits itself beneath the surface of the soil. And it appears to be a proof of this statement, that on digging in the sand cisterns are formed, or “sucking-places,” which are filled with water supplied by subterraneous conduits.
This so-called Desert is not without its utility. Not only does it nourish innumerable multitudes of animals of every kind, but it has become the asylum of fugitive tribes. Here at first the Bakalabaris found a refuge; and then, in their turn, other peoples of the Bechuana, whose territories had been invaded by the Kaffirs.
The Kalihari has its mirage and its sirocco. During the excessive drought which precedes the rainy season, a burning wind traverses this desert from north to south, and during its three or four days’ duration it withers and dries up everything in its path. It is so loaded with electricity that a bundle of ostrich feathers, which remained exposed to it for a few seconds, was itself charged as if it had been in contact with a powerful electrical machine, and produced a lively disturbance, accompanied by cracking noises, when taken in the hand. As often as this wind prevails, the electricity of the atmosphere is so abundant that every movement of the natives causes sparks to be given off their karosses, or cloaks made of the skin of beasts.
The contrast is striking between the well-watered east coast of South Africa and the arid western coast. After the scarped mountains of the Cape, which ascend northward to the ocean, come the less lofty chains—the hills of sand which separate the interior sandy desert from the equally sandy district of the littoral. With the exception of the Walvish Bay, the coast for eight hundred miles—from the great Orange River to Cape Negro—has not a stream of water.
At Cape Negro commences a series of terraces, separated from one another by long bands of sunken ground. This ensemble describes a curve towards the interior, and leaves on the coast a level plain of about 110 miles in breadth.