Below the aeroplanes lay a great peak extending four thousand feet above the level of the sea. To the west the Pacific beat fiercely against its side. To the south the Sierra raised its lofty crags, apparently, straight out of the ocean. To the north a succession of summits lifted above the range. Off to the east lay a faint trail connecting, by devious turns and twists through the mountain wilderness, with the Southern Pacific railroad. The beacon fire rose straight from a headland which jutted for some distance out into the ocean. The beat of the waves against the breakers at the foot of the headland came dimly up to the boys like the stir and rustle of a crowded street. There had been a fog, but it was lifting now, and here and there traces of green might be seen wherever the flames revealed the surface of the ground. After a time Ben turned back with the _Bertha_ and signaled to the others to help in the search for a safe landing-place. This was by no means an easy task, as it was deep twilight now on the lower stretches of the mountain, and most of the canyons seemed mere yawning pits whose open mouths gaped eagerly for the prey in the air. The boys turned to north and south in their machines and, sailing low, scrutinized the dim country in the hope of discovering some level spot where the flying machines could be brought to the ground with safety. At last, perhaps two miles to the south of the headland, where the beacon light still sent its red flames into the air, Ben came upon a canyon or gully which had evidently once been the bed of a rushing mountain torrent. The wash of water from the steep surfaces, however, had, in distant years, filled the narrow slit between the summits with fine white sand. It was by no means a large place, but was quite sufficient for the purpose. Ben felt his way carefully down, dropping into what seemed to him to be a fathomless pit between peaks until the white, hard floor below came faintly into view. After examining the place as thoroughly as possible with an electric searchlight, he volplaned down, much to Kit’s amazement, and soon had the satisfaction of feeling the rubber-tired wheels beneath the machine running evenly over a smooth surface. It had been a great risk, however, this dropping down into the darkness between two mountain peaks, and Ben was not certain, even after landing, that he had done the correct thing. His light showed a level surface for only a short distance. The opening of the canyon faced the Pacific. To left and right were almost perpendicular walls. To the east a great crag was worn far under a shelving side by the action of the waves which at some distant time must have forced their way through the split in the mountains.