It passed through the oases of El-Maia and Methlili to Ouargla, at that time the last outpost of French authority. At Ouargla it rested for a week; and there, renewing its supplies, penetrated southwards to survey the desert country of the Touaregs for the construction of the oft-mooted trans-Saharan railway. South of Ouargla all the difficulties of the advance were doubled. The companies went down through the archipelago of oases in the dangerous Touat country amongst a sullen people, who had little food to supply, and would hardly supply it. Tavernay led his men with care, neither practising a discipline needlessly strict, nor relaxing into carelessness. But he was under-officered, and his officers even so were inexperienced. Lieutenant Laurent, a man irritable and unjust, was his second in command, and there were but two _sous-lieutenants_ besides. In spite of all Tavernay's care the convoy diminished. One day a camel would stumble on the slippery bottom of a salt marsh, fall, and break its limbs; the next another would fail, and die through a long-untended wound, caused by the rough saddle upon its back. In the ranks of the soldiers, too, there was trouble, and Laurent was not the man to deal with it. There was hardly a company of the Legion, recruited, as it so largely was, from the outcasts and the men of sorrows, in which there were not some of disordered minds, some whom absinthe had brought to the edge of insanity. Upon these the severity of the expedition bore heavily. Tents had been perforce discarded. The men slept under the stars. They woke from freezing nights to the bitter winds of dawn, and two hours after dawn they were parched by a burning sun, and all the day they suffered under its pitiless and blinding glare. Storms whelmed them in lofty spirals of whirling, choking sand. For a week they would toil over high red mountainous ground of loose stones; then would follow the monotony of bare round plains, piled here and there with black rocks, quivering and glittering in the heat; the sun rose day after day upon their left hand in scarlet, and set in scarlet upon their right, and they themselves were still the tiny centre of the same empty inhospitable space; so that only the difference of the ground they trod, the feel of soft sand beneath their feet, where a minute before they had marched on gravel, told them that they progressed at all. The worst of the men became prone to disobedience, eager for change; and every now and then a soldier would rise upon his elbow in the night time, gaze furtively about over his sleeping comrades, watch the sentries until their backs were turned, and then crawl past them into the darkness. Of these men none ever returned. Or some mania would seize upon them and fix a strange idea in their brains, such as that which besieged Barbier, the fusilier, who had once stepped out of the railway carriage in his evening dress. He leaned over towards Stretton one evening, and said in a hoarse,