Once she nose-dived, flattened out, and made straight for a sheer wall of rock that a few seconds previously she ought to have cleared with a thousand feet to spare. Vainly Peter put the vertical rudders hard over. It seemed as if a collision was inevitable and that the shattered debris of the flying-boat would fall headlong into the fathomless chasm, when a side gust of terrific force hurled her, like a leaf, crab-fashion, so that she just scraped clear with a few feet between her port wing-tips and the pitiless face of the peak.
Then, propelled upwards by a freak air-current of irresistible strength, the flying-boat was hurled, like a sheet of paper up a tall chimney, between the perpendicular walls of a deep defile. So near did she scrape the summit of one of the twin peaks, that the rush of air dislodged a mass of snow, sending it thundering into the abyss, with a roar plainly audible within the supposedly sound-proof pilot's cabin.
Suddenly the roseate snow peaks gave place to a void of intense darkness. The crossing of the Sierras was accomplished. Ahead lay miles of country, sloping towards the Caribbean Sea, with nothing higher than three thousand feet to be encountered—at least, so the map read.
"We're over!" exclaimed Peter thankfully, as the flying-boat settled down to her normal even style of flight.
"More by luck than by anything else," thought Uncle Brian, who felt bruised and shaken all over.
"I'll take her down to eight thousand feet," continued Peter briskly. "Then I'll get you to stand by, Uncle. There's nothing to be done except to watch the altimeter and the compass. There's no need to bust along now. We've ten hours of darkness in front of us and we don't want to find ourselves miles out over the Atlantic when day breaks. I'll cut out the after motors."
In spite of the fact that the interior of the fuselage was heated by pipes connected with the exhausts, the air within the cabins was bitterly cold, and the temperature fell yet lower after the rear pair of motors was shut down.
Peter was now feeling very sleepy. Lack of proper rest, the excitement of the last two days, and the effect of the rarefied atmosphere all combined to reduce him to a state of resistless drowsiness.
"You turn in," said his uncle peremptorily. "I'm good for another ten hours, if needs must. If there's anything requiring your attention, I'll wake you."
The elder man "took on". Since the flying-boat was built largely after his designs, he was well acquainted with the technical part of the mechanism and construction, but he was quite a novice in the art of actual flight. As long as things went right, there was little for him to do.