“I think we will wait,” said Mr. Sheldon.

“Yes, and I have also changed my mind,” added Professor Snodgrass. “There are no hermit crabs in these waters, anyhow.”

“No,” assented Dr. Klauss, with a smile. “Well, some other time I hope to have the pleasure of taking you to the bottom of the sea with me.”

The commander seemed so pleasant and affable that it was hard to realize his mood of a short time before.

“We could have a dandy time here, if he was only all right,” thought Jerry. “If we could go when we pleased, and could send word to our folks, I’d like a submarine voyage.”

But, under the circumstances, the very lives of Jerry and his chums might be in danger.

“Get ready!” called the inventor to his three engineers. “Sink the boat!”

There was a hissing as more water was pumped into the ballast tanks, and the forward motion of the craft ceased, to give place to a downward one. For a moment the visitors felt a queer sensation as when an elevator drops suddenly, but they soon grew used to this. In a few minutes the boat came to a rest with a slight shock.

“We are now on the bottom of the sea,” explained Dr. Klauss. “I shall now don my diving suit, and go out of the boat. Probably you have anticipated how this is done.