“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.

“We’s on de Monarch an’ we’s done left dem cantankerous conglomerated disputatious Mosquitoes down on de ice!” exclaimed Washington, coming in to see how his master was.  “Are yo’ much hurted, Perfessor?”

“It’s only a scratch,” replied the inventor.  “I’m all right,” and he insisted on getting up and seeing how the engines were running.  He was a little weak, but some medicine which Washington fixed at his master’s direction soon brought him around.

The airship was working beautifully in spite of being frozen up in the terrible cold.  On and up she went until she had left the vicinity of the savages far behind.  After about an hour’s flight the professor had Jack lower the craft to within half a mile of the surface, as he said he wanted to see what was below.

The boy, who was in charge of the conning tower, set the necessary machinery, while the professor went to the window in the bottom of the ship to watch.

“We’re over the sea!” he exclaimed.  “There is no land or ice in sight!”

“Come here quick!” cried Washington, from the engine room.

“What’s the matter?” exclaimed the professor.