“Of course, unless we wish to remain here below till the craft above us up-anchors, which may not be for days or may take place in an hour.”

In rejoinder to Mr. Dancer, Jack’s father said:

“That is too uncertain. By the way, Dancer, how long will the air remain pure in the White Shark?

“For twenty-four hours. I have an emergency oxygen device which increases that supply by some five hours, but the quality of air would be bad.”

“It does not seem any too good right now,” said Jack, aside to Tom. Then he added:

“How are we caught, sir?” addressing his query to Mr. Dancer.

“I think that a projection on the observation tube has become entangled in the rope.”

“In that case we are in a bad fix?”

“About as bad as it can be,” was the reply; “there’s no way of getting out there and cutting the obstruction loose, even if we had diving dresses, which we haven’t.”

Mr. Dancer looked about him despairingly as he spoke.