CHAPTER VIII.
THE TSAD BASIN.
General Survey.
HE geographical centre of the African continent is not an Alpine range, as in Europe and Asia, but on the contrary a deep depression largely flooded by marsh waters, and in its relief inclining rather towards the Niger and the western regions. East and south this basin is encircled by mountains and uplands, north and west by disconnected hills and terraces, falling in the south-west to open, low-lying plains, through which the great lacustrine depression almost merges in the Benue hydrographic system. Thus the central region is almost everywhere easily accessible, and also contains a relatively dense population, estimated at certainly more than seven millions in a total area exceeding 280,000 square miles. Thanks to the fertility of the soil and its rich vegetation, the Tsad basin promises to become perhaps the most flourishing region in the whole of Africa.
But this inland basin has not yet been brought into direct and regular communication with the civilised world. Years pass before the echo reaches Europe of the events of which it is the scene, and the great movements of migration, wars and conquests remain unknown. Hitherto its direct relations have mainly been through the Dar-For and Wadai routes with the east, whence it has received its Mohammedan religion, its foreign culture and knowledge of the outer world. The highway connecting the Tsad basin with the Mediterranean seaboard has been of far less historic importance, although in recent times more frequented by traders from the north, and consequently now better known. But this more direct route is, in its turn, being gradually replaced by the much longer but easier south-western waterway of the Benue and Lower Niger.
The Tsad basin has hitherto been visited by few European explorers, and this dangerous journey has proved fatal to several of those who have attempted it. Bornu was first reached in 1823 by the Fezzan route and Kawar oasis by Denham, Clapperton, Oudney, Hillman, and Toole; but two of these English pioneers never returned to their native land. Over a quarter of a century passed before the next expedition was undertaken in 1851 by Richardson, Overweg, and Barth, but the
