_From Borkou to Wadai._—I left the oasis of Faya on 25 April 1917 in an east-south-easterly direction, skirting the foot of the western spurs of the high tablelands of Ennedi. In ten days I reached the post of Fada, where Captain Châteauvieux presented to me the chiefs Gaëdas and Mourdias, whom two long years of incessant struggles had constrained to submit; we discussed and settled in concert the conditions on which the “aman” should be granted them. After which, turning my back on the picturesque rocks of Ennedi, I went on my way towards the south-west, across the desert of Mortcha, to reach the wells of Oum Chalouba. These wells, situated in the Wadi Hachim, belong to the Nakazzas, one of the principal Toubou tribes of Borkou, who are masters, under our control, of the oasis surrounding the post of Fada, but whose submission to our authority did not prevent them from entertaining with our enemies relations as cordial as they were clandestine, that gave us endless trouble. The judgment-seat of the native court over which I presided was heaped high with complaints and claims for damages against their chiefs, Allatchi and Djimmi. Their low cunning and double-dealing exasperated me; but since my return to Europe it has become evident to me that, like many other reputable persons, they were simply engaged in politics. [Illustration: The author’s routes between Tibesti and the Nile] The wells of Oum Chalouba are very important, both because of their position at the extreme southern limit of the Sahara and because they never run dry. Accordingly, the caravans that go and come between Wadai and the Mediterranean by Ounianga and Koufra all pass through this station, where, it may be added, their sojourn is usually brief owing to the high price of food. It is 140 miles from Oum Chalouba to Abéché, the capital of Wadai, in a general direction from north to south, across a region of great plains intersected by valleys running from east to west in which a few wooded galleries bear witness to the annual passage of ephemeral torrents that come down from the granitic hills and tablelands of Zagawa and Tama. The summer rains are not sufficient to permit the cultivation of native cereals, but they produce extensive and abundant pasturage, where Mahamid tribes graze fine herds of oxen and flocks of sheep and goats.