Philadelphia, merely to see if I was going to compete. There
is something strange about it, something that I can't
understand."

The time was to come when Mr. Swift and his son were to
get at the bottom of Mr. Berg's reasons, and they learned to
their sorrow that he had penetrated some of their secrets.

Before going to bed that night Tom and Mr. Sharp paid a
visit to the shed where the submarine was resting on the
ways, ready for launching. They found Mr. Jackson on guard
and the engineer said that no one had been around. Nor was
anything found disturbed.

"It certainly is a great machine," remarked the lad as he
looked up at the cigar-shaped bulk towering over his head.
"Dad has outdone himself this trip."

"It looks all right," commented Mr. Sharp. "Whether it
will work is another question."

"Yes, we can't tell until it's in the water," con ceded
Tom. "But I hope it does. Dad has spent much time and money
on it."

The Advance was, as her name indicated, much in advance of
previous submarines. There was not so much difference in
outward construction as there was in the means of propulsion
and in the manner in which the interior and the machinery
were arranged.