here was no need, however, of remaining under water for any great
stretch of time, it was their practice to rise every day and renew the
air supply, also to float along on the surface for a while, or speed
along, with only the conning tower out, in order to afford a view, and
to enable Captain Weston to take observations. But care was always
exercised to make sure no ships were in sight when emerging on the
surface, for the gold-seekers did not want to be hailed and questioned
by inquisitive persons.

It was about four days after the disabling of the rival submarine, and
the Advance was speeding along about a mile and a half under water. Tom
was in the pilot house with Captain Weston, Mr. Damon was at his
favorite pastime of looking out of the glass side windows into the
ocean and its wonders, and Mr. Swift and the balloonists were, as
usual, in the engine-room.

"How near do you calculate we are to the sunken wreck?" asked Tom of
his companion.

"Well, at the calculation we made yesterday, we are within about a
thousand miles of it now. We ought to reach it in about four more days,
if we don't have any accidents."

"And how deep do you think it is?" went on the lad.

"Well, I'm afraid it's pretty close to two miles, if not more. It's
quite a depth, and of course impossible for ordinary divers to reach.
But it will be possible in this submarine and in the strong diving
suits your father has invented for us to get to it. Yes, I don't
anticipate much trouble in getting out the gold, once we reach the
wreck of course--"

The captain's remark was not finished. From the engine-room there came
a startled shout:

"Tom! Tom! Your father is hurt! Come here, quick!"

"Take the wheel!" cried the lad to the captain. "I must go to my
father." It was Mr. Sharp's voice he had heard.

Racing to the engine-room, Tom saw his parent doubled up over a dynamo,
while to one side, his hand on a copper switch, stood Mr. Sharp.

"What's the matter?" shouted the lad.

"He's held there by a current of electricity," replied the balloonist.
"The wires are crossed."

"Why don't you shut off the current?" demanded the youth, as he
prepared to pull his parent from the whirring machine. Then he
hesitated, for he feared he, too, would be glued fast by the terrible
current, and so be unable to help Mr. Swift.

"I'm held fast here, too," replied the balloonist. "I started to cut
out the current at this switch, but there's a short circuit