It was obvious to all three occupants of the aeroplane that the only means of thoroughly searching the comparatively open country at which they had now arrived was to rise to a greater height and sail about in widening circles. Bob therefore adjusted his elevator; and as the machine swept round, the other two peered over on opposite sides, using their glasses to scan the ground beneath. The fugitives being presumably mounted on the stolen ponies could hardly be otherwise than conspicuous; and when, after more than half an hour’s careful observation, nothing had been seen of them, the pursuers came to the conclusion that the men could not yet have quitted the valley. This was a very reasonable inference, considering that they had covered in less than an hour a distance of nearly fifty miles, which the fugitives, even on horseback, must take many hours to traverse. The natural conclusion was that the horsemen, warned by the whirring of the propeller, if not by the actual sight of the aeroplane, had taken shelter in one of the more rugged or more thickly wooded places until the pursuers had passed. There was nothing for it but to turn back and hunt up the valley again. The aeroplane was crossing the plateau obliquely towards the opening of the gorge when Lawrence suddenly caught sight of a number of round objects resembling bee-hives, clustered in a secluded dell. He pointed them out to Mr. Appleton, who examined them through his glass. "They are akois," he said: "the portable huts used by the nomad tribes in these parts, made of a circular wooden framework covered with felt. But I’ve never before seen so many in a group." As they looked, the intervals between the akois became filled with a dense crowd of men, who stood gazing up in astonishment at the strange machine flying high above their heads. The airmen had no particular interest in wheeling about to make a careful inspection of the camp, for it was inconceivable that Nurla and his man had come so far and joined their compatriots, if such these people were. They had soon left it far behind, and descending gradually as they neared the gorge, they re-entered this at an altitude of not more than a hundred feet above the river to renew their search.