Ned reached above his head, and turned a valve, which, by an ingeniously simple arrangement, opened the exhaust valve by which the bad air was driven out and admitted a fresh supply at the same time.
“I did begin to notice the air getting a little stale,” commented Herc; as he did so, “Ah-h-h-h-h!” he exclaimed the next instant, throwing out his chest and inflating his lungs with the fresh air which, as if by magic, flooded the place, “that’s as good as a sea breeze.”
And so they all agreed. The air had been getting fouler than they had really noticed in their intense concentration on the running of the boat.
“Well,” said the lieutenant below, “there’s no doubt about that device working as well as everything else about the Lockyer. And now let us see about getting to the surface. We must, according to my calculations, be not far off the light by this time.”
“Very well, then,” said Mr. Lockyer, with a confident smile. “It’s ho! for the surface. And here, gentlemen,” he said, producing a long, shiny bit of metal with a slot on one end, “is the means by which we are to get there.”
So saying, he stepped to the side of the cabin where, against the wall, appeared the top of a valve. Fitting the slot of the wrench over this projection, he gave a gentle twist. Instantly a swishing sound followed, not unlike the loud screaming hiss of escaping steam from the safety valve of a locomotive.
“The biggest air pumps we have are now at work driving out the water from all the tanks simultaneously,” he explained; “the water is being expelled at the rate of hundreds of gallons a minute.”
“Queer we don’t feel that we are rising,” commented the naval officer; “the balance in this boat seems to be better preserved than in the present type. She does not tip or tilt at all on her upward way.”
“Yet we are rising,” said the inventor. He pointed to the depth indicator.