"Use the machine gun!" he yelled. "That is our only hope!" The next second he fell to the deck, struck by a spear. CHAPTER XXIX THE ESCAPE "He's killed!" cried Andy. "Oh Perfessor! Perfessor!" exclaimed Washington. "I tole yo' not to go out." "Never mind! Start the machine gun!" yelled Andy. "We must fight off these human fiends!" "Call up the boys!" shouted Bill. "They'll be killed under the ship!" "I'm afraid it's too late," said Andy. "Here, Tom, you help Washington work the machine gun!" The weapon had been covered by canvas, and, fortunately, the snow had not harmed it. The canvas was yanked off, and, while Tom prepared to feed the cartridges down the hopper, Washington worked the crank. In a few seconds there was a fusillade that sounded like a small battery going into action. From the muzzle of the machine gun poured out a leaden hail. It struck the Esquimaux fairly and though they tried to stand against it they could not. Their arrows and spears dropped from their hands and they staggered back, many badly hurt or killed. "Why don't those pesky boys come up!" wondered Andy. His gun was again empty. He hastened into the cabin to reload the magazine. As he did so he heard a tapping on the plate glass window set in the floor of the car. "Who is there?" he cried. "It's us; Jack and Mark!" a voice answered. "Let us up! The ship is free!" Andy flung open the window. It was just large enough for a boy to squeeze through. In a moment Jack and Mark were in the cabin. In the meanwhile Bill had dropped his gun and carried the professor from the deck inside. The old man was unconscious, but a glance showed that the spear had made only a slight wound on the head, and not one that was likely to be dangerous. "Is he dead?" cried the boys. "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.