"You forget the leak in the gas bag," spoke up Andy. "That will have to be mended before we can escape." "With quick work we can do it!" exclaimed the inventor. "Hurry on, Dirola!" Dirola needed no urging. With fierce words she hurried on the dogs, her whip sounding like a revolver as it snapped and cracked. But fast as the escaping ones went, the pursuers seemed to come faster. Now they were so close that they could be seen brandishing their spears, bows and arrows. Their shouts, too, were borne forward on the cold wind. At last the adventurers were at the side of the airship. Hastily they dismounted from their sleds turning the dogs loose. The Esquimaux in pursuit were about half a mile to the rear and would soon be upon them. "Quick, Dirola! Into the ship with you!" called Andy. "We'll take you with us if we go at all!" "We must mend the tear first!" exclaimed the professor, scrambling up the icy slope toward the cabin of the _Monarch_ in a fashion that would have done credit to a much younger man. "Andy, you and the boys, with Tom and Bill, hold the enemy at bay until Washington and I get the ship in readiness for a start!" "All right!" cried Andy, now in his element. "I'll make those Esquimaux wish they had let us alone!" Dirola had disappeared inside the cabin. In a few minutes the professor and Washington were hard at work setting the machinery in motion. First, after having seen that none of the apparatus was disarranged, Amos Henderson started the gas generating machine. Next, leaving Washington in charge of this and the engine room, the inventor prepared a big patch with some cement on it. This he gave to Mark, who quickly found the place where the old patch had come off the silk bag, and covered the opening. Already the bag was beginning to swell with the gas. But now with loud yells the Esquimaux came rushing up. Leaping off their sleds, they began throwing their spears and shooting their arrows. CHAPTER XVIII NORTHWARD ONCE MORE "Repel boarders!" sung out Andy. "Where are the guns?" "Here!" shouted Tom, handing out the rifles fully loaded. The old hunter seized a weapon, as did Bill, Jack, and Mark. Tom also leveled his gun at the savages. Bang! Crack! Bang! went the guns. It was like a skirmish in battle. As Andy directed, each one fired low. So heavy a fusillade as the adventurers were able to fire had its effect. Many of the Esquimaux fell, none badly hurt, but disabled so they could not attack. Still the main body advanced up the slope with angry cries, determined to capture the airship and regain their captives.