For a moment longer he watched it; then, what it was he knew, or felt by such strong instinct as makes knowledge; and, like the blast of a clarion, his alarm rang over the unarmed and slumbering camp.

An instant, and the hive of men, so still, so motionless, broke into violent movement; and from the tents the half-clothed sleepers poured, wakened, and fresh in wakening as hounds.  Perfect discipline did the rest.  With marvelous, with matchless swiftness and precision they harnessed and got under arms.  They were but fifteen hundred or so in all—­a single squadron of Chasseurs, two battalions of Zouaves, half a corps of Tirailleurs, and some Turcos; only a branch of the main body, and without artillery.  But they were some of the flower of the army of Algiers, and they roused in a second, with the vivacious ferocity of the bounding tiger, with the glad, eager impatience for the slaughter of the unloosed hawk.  Yet, rapid in its wondrous celerity as their united action was, it was not so rapid as the downward sweep of the war-cloud that came so near, with the tossing of white draperies and the shine of countless sabers, now growing clearer and clearer out of the darkness, till, with a whir like the noise of an eagle’s wings, and a swoop like an eagle’s seizure, the Arabs whirled down upon them, met a few yards in advance by the answering charge of the Light Cavalry.

There was a crash as if rock were hurled upon rock, as the Chasseurs, scarce seated in saddle, rushed forward to save the pickets; to encounter the first blind force of attack, and, to give the infantry, further in, more time for harness and defense.  Out of the caverns of the night an armed multitude seemed to have suddenly poured.  A moment ago they had slept in security; now thousands on thousands, whom they could not number; whom they could but dimly even perceive, were thrown on them in immeasurable hosts, which the encircling cloud of dust served but to render vaster, ghastlier, and more majestic.  The Arab line stretched out with wings that seemed to extend on and on without end; the line of the Chasseurs was not one-half its length; they were but a single squadron flung in their stirrups, scarcely clothed, knowing only that the foe was upon them, caring only that their sword-hands were hard on their weapons.  With all the elan of France they launched themselves forward to break the rush of the desert horses; they met with a terrible sound, like falling trees, like clashing metal.

The hoofs of the rearing chargers struck each other’s breasts, and these bit and tore at each other’s manes, while their riders reeled down dead.  Frank and Arab were blent in one inextricable mass as the charging squadrons encountered.  The outer wings of the tribes were spared the shock, and swept on to meet the bayonets of Zouaves and Turcos as, at their swift foot-gallop, the Enfants Perdus of France threw themselves forward from the darkness.  The cavalry was enveloped in the overwhelming numbers of the center, and the flanks seemed to cover the Zouaves and Tirailleurs as some great settling mist may cover the cattle who move beneath it.