"We hope not," answered Andy. "But we have no time to lose. Can one of you start the ship?"
"I can!" exclaimed Jack.
"Then do it, while I help hold the enemy at bay!"
The Esquimaux, in spite of their losses, were returning to the attack. Closer and closer they pressed to the ship. The machine gun was making great gaps in their ranks, but they did not seem to mind. They were bent on recapturing their former captives, whose track they had followed from the ice cavern.
Jack ran to the engine room. He saw that everything was in readiness for sending the ship aloft. But little gas more was needed in the bag. He turned on the full supply. The noise of the guns, the shouts and yells of the natives, made the place resound with wild noises. It was a battle such as the arctic regions had never before witnessed.
A tremor shook the Monarch. The ship shivered. Jack ran to the conning tower. He grasped the lever that started the propeller. Then came a sudden lurch. The airship tore loose from the ice and rose swiftly in the air. Jack set the screw to working and turned the steering wheel so that the Monarch's nose was pointed due south, away from the land of perpetual ice and snow.
A wild yell of disappointed rage burst from hundreds of throats as the Esquimaux saw their captives escape. They filled the air with arrows and spears, but to no purpose. Andy sent the last shots in his rifle at the savages, and, as the ship rose a hundred feet in the air, the remaining cartridges in the machine gun were exploded.
"Hurrah!" cried the old hunter. "We're off!"
On and on sped the Monarch, every second putting the frozen north behind her. Jack had all the engines going at full speed.
"What has happened? Where are we?" asked Professor Henderson, suddenly recovering consciousness.