joined the pipe. If it had not been for the automatic cut-off all the
gas in the holder would have poured out in a great volume, and the
ship would have fallen like a shot.

"Can we do nothing to save those on the burning vessel?" asked Mark,
pointing to where a cloud of smoke hung over the ocean.

"I fear not, now," answered the professor. "We are in a bad plight
ourselves."

"Are we in any danger?" asked Jack.

"Not specially," Mr. Henderson replied. "But we must find a means of
lowering ourselves gradually."

"Then it will be too late to save any of those on the ship," observed
Mark.

"I'm afraid so," the scientist made reply.

The Mermaid rested some distance above the surface of the waters. She
moved slightly to and fro with the wind, and rocked gently. The
professor was examining the broken machinery.

"I have a plan!" suddenly cried Mark.

"What is it?" asked Mr. Henderson.

"Can't we bore a hole in the tank, insert a small faucet or tap, and
let the gas out that way gradually?" asked the boy. "When we get down