But now, with the arrival of Bugeaud, the war in Africa was changed; hitherto it had been a mere war of occupation,--a holding of the ground already French against the attacking Arabs; now it was to be a duel, a war of devastation; thus only could France hope to tame the indefatigable Abd-el-Kader, and permanently hold her own. The trouble was not so much to fight him as to get near enough to fight him; for he pursued a truly Fabian policy, and being lighter armed, was consequently swifter than the invaders. Under Marshal Clausel, the French, drawing with them the heavy wagons and munitions of European warfare, were obliged to follow the high-roads, and the Arabs could never be taken by surprise; scouts gave information of their numbers, and after harassing marches they would find that the foe had either retreated to unknown fastnesses or assembled on the spot in prodigious force. Now Lamoricière proposed a plan, in the execution of which he was eminently successful. Bugeaud's design was, to follow the Arabs into the desert, to climb the steep mountains, to plunge into their chasms, to storm every hill-fort, and to drive, step by step, the swift Abd-el-Kader far from the land which his presence so troubled; but how? for swift troops are light-armed, carry no luggage, and but little provision; and to follow without food the Arabs who concealed food in _silos_, _caches_ in the ground, seemed hopeless. Lamoricière required but his Zouaves, who carried only four days' provisions, and no baggage of any sort; when they drew near any of these _silos_, which were always, of course, in the vicinity of the deserted villages, he spread out his troops in a long crescent, and they advanced slowly, rooting up the ground with their bayonets till some one struck on the stone or pebbles covering the precious deposit. Thus, without wagons, trained to tireless activity, they could follow the Arabs from _douar_ to _douar_ with little delay, and with fatal effect.