It was the voice of the earthquake. Nat had heard it once before in California.
As the boys’ knives fell on the ropes, the Discoverer shot upward. Up and up into the lightning-riven sky she arose, while beneath them the earth shook and rocked and rumbled.
“Great Scott!” cried a voice,—it was Nat’s,—“if ever we get struck by a flash of that lightning,—good-bye!”
The words sounded flippant, but the danger was real. The boy recalled reading of the fatal disaster to the great Zeppelin dirigible in a thunder-storm. But still they could not seek a refuge on the earth, at any rate not on the island. The air was the only place for them to seek safety.
The noise all about was nothing less than terrific. Voices could not be heard unless raised to a shout. The rigging of the dirigible creaked and groaned as the great bag swayed, and added to the distracting turmoil.
Paralyzed by the very suddenness and utter unexpectedness of it all, the adventurers for a time merely clung to the rails of their swaying, madly careening craft. How that night passed, none on board was exactly able to tell in after days.
They got the engine going, and held the big cloud cruiser as close to the earth as they dared, using the descending planes to steady her under the wild swaying of the great gas bag. A furious wind accompanied the earthquake, and when the lightning died away it seemed as if there was to be fresh and even more deadly peril, from the possibility of the great gas container being ripped bodily from the substructure.
But the rigging held tightly, and dawn found the disturbance almost at an end. It was a shaken, white-faced crew that regarded one another in the gray light. The night had been one to try the nerves of a man of iron, and the Motor Rangers were only youths.
However, the storm died out almost as swiftly as it had come, and breakfast and hot coffee heartened them wonderfully. Even old Matco plucked up his spirits, although, during the night, he was certain that they were bound to perish in the anger of the old gods of his country.
After the morning meal they began to look about them. They found that, during the night, they had been blown far to the southward of the site of the lost city, but they could still make out the ragged peaks that marked its locality.