And then, as seen by a distant observer, a singular spectacle was unfolded.  The straggling train suddenly seemed to resolve itself into a large widening circle of horsemen, revolving round and partly hiding the few heavy wagons that were being rapidly freed from their struggling teams.  These, too, joined the circle, and were driven before the whirling troopers.  Gradually the circle seemed to grow smaller under the “winding-up” of those evolutions, until the horseless wagons reappeared again, motionless, fronting the four points of the compass, thus making the radii of a smaller inner circle, into which the teams of the wagons as well as the troopers’ horses were closely “wound up” and densely packed together in an immovable mass.  As the circle became smaller the troopers leaped from their horses,—­which, however, continued to blindly follow each other in the narrower circle,—­and ran to the wagons, carbines in hand.  In five minutes from the time of giving the order the straggling train was a fortified camp, the horses corralled in the centre, the dismounted troopers securely posted with their repeating carbines in the angles of the rude bastions formed by the deserted wagons, and ready for an attack.  The stampede, if such it was, was stopped.

And yet no cause for it was to be seen!  Nothing in earth or sky suggested a reason for this extraordinary panic, or the marvelous evolution that suppressed it.  The guide, with three men in open order, rode out and radiated across the empty plain, returning as empty of result.  In an hour the horses were sufficiently calmed and fed, the camp slowly unwound itself, the teams were set to and were led out of the circle, and as the rays of the setting sun began to expand fanlike across the plain the cavalcade moved on.  But between them and the sinking sun, and visible through its last rays, was a faint line of haze parallel with their track.  Yet even this, too, quickly faded away.

Had the guide, however, penetrated half a mile further to the west he would have come upon the cause of the panic, and a spectacle more marvelous than that he had just witnessed.  For the illimitable plain with its monotonous prospect was far from being level; a hundred yards further on he would have slowly and imperceptibly descended into a depression nearly a mile in width.  Here he not only would have completely lost sight of his own cavalcade, but have come upon another thrice its length.  For here was a trailing line of jog-trotting dusky shapes, some crouching on dwarf ponies half their size, some trailing lances, lodge-poles, rifles, women and children after them, all moving with a monotonous rhythmic motion as marked as the military precision of the other cavalcade, and always on a parallel line with it.  They had done so all day, keeping touch and distance by stealthy videttes that crept and crawled along the imperceptible slope towards the unconscious white men.  It was, no doubt, the near proximity of one of those watchers that had touched the keen scent of the troopers’ horses.