"We might as well use that in the diving suit reservoirs," remarked the professor. "We will feel better, at least for a little while."
The helmets of the suits were brought in, and the vapor released from the small tanks. A change was at once noticed. The old stale air in the cabin was forced out of the exhaust pipes, and the fresh took its place. Every one felt better.
Faster and faster revolved the big screw. The ship vibrated more and more. Yet it did not move, nor did it rise. The crew were still prisoners beneath the water.
For an hour or so conditions were fairly comfortable. Then the same unpleasantness was experienced as was noticed before.
"If we could only open a window," sighed Mark, "and let in a lot of fresh air, how nice it would be."
The air rapidly became more foul. Soon Washington was gasping for breath. Tom and Bill showed signs of uneasiness.
"Lie down on the floor," counseled the professor. "You will find the air a little fresher down there."
They all did as he advised, the inventor himself stretching out at full length. A little relief was experienced.
They knew it could not last long. Even the professor seemed to have given up hope. The engine was not going to free the ship in time to save the lives of those on board.
Washington crawled to the engine room, as some of the bearings needed oiling. The professor seemed in despair. He opened one of the slides that covered the glass bulls eye windows. Then he turned off the electric lights. The opening was black, showing that the sea of grass still surrounded them. With a groan Mr. Henderson turned aside. The last hope was gone. He sank down on the floor of the darkened cabin.