It was strangely unlike the usual desert-constancy. All day the grey-green expanse of stones and bushes quivered like a mirage with the movement of men on foot; and horsemen; men on camels; camels bearing the hunched black loads which were the goat-hair tent-cloths; camels swaying curiously, like butterflies, under the winged and fringed howdahs of the women; camels tusked like mammoths or tailed like birds with the cocked or dragging tent-poles of silvery poplar. There was no order nor control nor routine of march, other than the wide front, the self-contained parties, the simultaneous start, which the insecurity of countless generations had made instinctive. The difference was that the desert, whose daily sparseness gave value to every man, today seemed with their numbers suddenly to come alive.