Having ascertained the site, depth, and value of the Sarra wells, Lieutenant Fouché, in accordance with his instructions, set himself to march back to Ounianga, but the return journey was particularly dramatic. For from the very first day his guide led him directly south, instead of marching south-south-west. One is justified in supposing that he meant to lead astray in the desert the detachment whose camels were so exhausted that everybody went on foot, and whose store of water was limited to a little less than a gallon a day per man. Astonished at this unaccustomed deviation, the lieutenant drew the guide’s attention to it, but the latter answered: “Do not be uneasy, we are on the right road.” But when he judged that the column was far enough from the tracks left by the outward journey, he replied to a fresh observation made by the lieutenant: “You are probably right, for I no longer see my usual landmarks; but if you would lend me a camel and a skin of water, I would go and find our tracks of the other day, and as soon as I had found them I would come back to look for you.” The lieutenant thought it wiser to turn guide himself, and, compass in hand, he put himself at the head of the caravan, with what anxiety may be guessed! An error of direction of a few degrees—quite a usual thing in marching by the compass with no natural landmarks—might work out at a matter of 15 miles in a distance of 180, that being the distance to Tekro. And the well had to be found, in the immensity of the desert, before the detachment’s scanty water- supply gave out! The black soldiers’ thirst was aggravated by the crushing heat; reduced to a daily ration of a little less than 4 quarts of water, they no longer ate any solid food. The camels, grown weak, slackened their pace. The men, uneasy at not coming across their traces of the outward journey, thought themselves hopelessly lost. Their feet, swollen with weariness and made painful by the burning sands, seemed incapable of carrying them to the end of that interminable plain, torrid and unchanging, where the air vibrated as it vibrates above an overheated stove, creating all along the route deceptive mirages, ceaselessly dissolving and reappearing. After a while some of them lost heart and wanted to stop, preferring to wait for death where they were rather than go on with an aimless march. The lieutenant tried to cheer them up by singing the praises of his compass, and promising them that on the morning of the seventh day the three familiar rocks near the well of Tekro should appear before them on the horizon. Incredulous, but respectful, they betook themselves again to their journey, advancing automatically behind the camels as exhausted as themselves, and by some miracle, on the promised day and at the promised hour, they saw faintly outlined against the far horizon the rocks of their salvation! A few hours later, bivouacked round the well of Tekro, the brave fellows who