_A Bird’s-eye View of the Country._—When on leaving the shores of Lake Chad we proceeded towards the north-east, we first entered into a sandy region, with parallel valleys running between grassy downs that rose to a height of not more than 300 feet: this was Kanem, the country of corn and cattle, where subterranean water abounds and where it is easy to live. After marching for about 100 miles, we left this fertile country and dropped quite suddenly into the desert itself, with its dull, empty, vague horizons, so monotonous that the slightest details interested us, such as a line of stones on the sand, the sight of a crescent of sand- dunes, or a poor, solitary, half-dead shrub; also our passing through a meagre pasturage of dusty _had_ was quite an event, or the discovery in the distance of a few green bushes of _siwak_, till we reached the wells, where we were to rest all day long, to lead the camels to drink, and renew our own provision of water, which was often brackish and evil- smelling. This was the deceptive desert of the Lowlands of the Chad, the region I mentioned above as being lower in level than Lake Chad itself. After a further march of about 250 miles we entered the country of rocks; at first scarcely visible above the sands, they soon rose in sharp peaks that looked like mediæval ruins, and then shot up into long steep cliffs bordering rugged plateaux, that formed ledges one above the other to the foot of the mountains: this was the region of Borkou, Tibesti, and Ennedi, the very heart of the desert, situated at almost the same distance from the shores of Lake Chad, the Nile, and the Mediterranean. This rocky belt forms, from the Tripolitain to Dar Four, a long broken wall, encircling on the north-east the basin of the Chad, which it divides from the dismal and unexplored waste of the Lybian Desert. Tibesti and Ennedi form the highest and almost inaccessible parts of this region, while another part, Borkou, consists of a wide depression between the basins of the Chad and of the Nile. =4. The Oasis of Borkou.= _Faya._—The _zawia_ of Faya had been chosen as the military and administrative centre of French Borkou, in preference to those of the Senoussists (Ain Galakka and Gouro), because it offers the least unfavourable lines of communication with the garrisons of Gouro, Fada, and Ounianga, and the best position for joining Borkou by wireless telegraphy to the nearest post of the Chad territory, 350 miles to the south.