he exclaimed. "It is bad. There's not enough oxygen in it. I notice it, now that I've stopped working. The gage indicates it, too. The automatic air-changer must have stopped working. I'll fix it."
He hurried to the machine which was depended on to supply fresh air to the submarine.
"Why, the air tanks are empty!" the young inventor cried. "We haven't any more air except what is in the ship now!"
"And we're rapidly breathing that up," added Captain Weston solemnly.
"Can't you make more?" cried Mr. Damon. "I thought you said you could make oxygen aboard the ship."
"We can," answered Mr. Swift, "but I did not bring along a supply of the necessary chemicals. I did not think we would be submerged long enough for that. But there should have been enough in the reserve tank to last several days. How about it, Tom?"
"It's all leaked out, or else it wasn't filled," was the despairing answer. "All the air we have is what's in the ship, and we can't make more."
The treasure-seekers looked at each other. It was an awful situation.
