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. In Benguela the plains are healthy and cultivated. More to the north, one encounters nothing but monotonous savannahs and forests with gigantic trees. The soil, at a great number of points, is saturated with water, and, so to speak, enveloped in a shroud of pestilential vapour, which the breeze never scatters. The low plains of Biafra and Benin, and especially the Delta of the Niger, are unwholesome, rank, and foul-smelling marshes. In their mangrove swamps lurks fever, and a legion of deadly diseases. "Macies et nova febrium Terris incubuit cohors."--(_Horace._) Until the early years of the present century very little was known of the interior of Southern Africa. At this epoch some native merchants traversed the country from one sea to another--from St. Paul de Loanda to the coast of Mozambique and Zanzibar. This exploit was repeated and outstripped by Dr. Livingstone, who, from 1850 to 1856, accomplished a marvellous journey of six thousand miles, through regions never before trodden by the white man's foot.