"If it's an accident!" exclaimed Mr. Hardley, "I think it ought to be prevented. There have been too many happenings on this trip already. I thought you said your submarine was safe for underwater trips!" he fairly snapped at Tom.
The young inventor gave one look at the irate man who was coming out in his true colors. But it was no time to rebuke him. Too much yet remained to be done. Ned and Koku were still in the chamber and protected from some unknown sea monster by only a comparatively thin door. They must be inside to be perfectly safe.
Tom speeded up the pumps that were forcing the water from the chamber so the inner door could be opened. Eagerly he and his men watched the gauges to note when the last gallon should have been forced out by the compressed air. Not until then would it be safe to let Ned and Koku step into the interior of the craft.
The submarine had not ceased rolling from the force of the blow she had received when there came another, and this time on the opposite side. Once more she rolled to a dangerous angle.
"Bless my tea biscuit!" cried Mr. Damon, "what is it all about, Tom Swift?"
"I don't know," was the low-voiced answer, "unless a pair of monsters are attacking us on both sides alternately. But we'll soon learn. There goes the last of the water!"
The gauge showed that the diving chamber was empty. Quickly the inner doors were opened, and, with their suits still dripping from their immersion in the salty sea, Ned and Koku stepped forth. In another moment their helmets were loosed from the bayonet catches, and they could speak.
"What was it, Ned?" cried Tom.
"Big fish!" answered Koku.
"Two monster whales!" gasped Ned. "We barely got away from them! They're ramming the sub, Tom!"