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. "De gas machine am gone on a rampage ag'in!" Then, all at once, the airship began to sink. All rushed to the engine room. The gas generator had ceased working and the craft was settling toward the ocean, there being nothing to keep it aloft. Frantically the professor and Washington worked at the apparatus. It could not be adjusted. Despair was on every face. Faster and faster sunk the _Monarch_. "Will we sink?" asked Andy. "I can't swim." "We may float," said the professor. "The bottom part of the ship is water tight. We may float long enough to fix the machinery." Then, with a splash, the _Monarch_ settled into the ocean, the gas bag falling limply on top of the cabins. "Get out the life preservers!" shouted the professor. "They are in the forward part. Put them on, while Washington and I try to fix the gas machine!" The airship had now become a water ship. It rose and fell on the waves, rocking from side to side. "Get ready to jump!" yelled Jack, running in from the conning tower. "What now?" asked Professor Henderson, "Haven't we troubles enough?" "There's a big whale and he's headed right this way!" yelled Jack. "He's coming on like a locomotive, to ram us!"