fully
guarded since Berg and Andy once sneaked in. I think it was just an
accident, but I have thought of a plan whereby such accidents can be
avoided in the future. It needs a simple device."

"Better patent it," suggested Mr. Sharp with a smile.

"Maybe I will," replied the young inventor. "But not now. We haven't
time, if we intend to get fitted out for our trip."

"No; I should say the sooner we started the better," remarked Captain
Weston. "That is, if you don't mind me speaking about it," he added
gently, and the others smiled, for his diffident comments were only a
matter of habit.

The first act of the adventurers, after tying the submarine at the
dock, was to proceed with the loading of the food and supplies. Tom and
Mr. Damon looked to this, while Mr. Swift and Mr. Sharp made some
necessary changes to the machinery. The next day the young inventor
attached his device to the pump valve, and the loading of the craft was
continued.

All was in readiness for the gold-seeking expedition a week later.
Captain Weston had carefully charted the route they were to follow, and
it was decided to move along on the surface for the first day, so as to
get well out to sea before submerging the craft. Then it would sink
below the surface, and run along under the water until the wreck was
reached, rising at times, as needed, to renew the air supply.

With sufficient stores and provisions aboard to last several months, if
necessary, though they did not expect to be gone more than sixty days
at most, the adventurers arose early one morning and went down to the
dock. Mr. Jackson was not to accompany them. He did not care about a
submarine trip, he said, and Mr. Swift desired him to remain at the
seaside cottage and guard the shops, which contained much valuable
machinery. The airship was also left there.

"Well, are we all ready?" asked Mr. Swift of the little party of
gold-seekers, as they were about to enter the conning tower hatchway of
the submarine.

"All ready, dad," responded his son.

"Then let's get aboard," proposed Captain Weston. "But first let me
take an observation."

He swept the horizon with his telescope, and Tom noticed that the
sailor kept it fixed on one particular spot for some time.

"Did you see anything?" asked the lad.

"Well, there is a boat lying off there," was the answer. "And some one
is observing us through a glass. But I don't believe it matters.
Probably they're only trying to see