from a sunken treasure ship, off the coast of Uruguay, South
America. They sailed beneath the seas for many miles, and were in
great peril at times. One reason for this was that a rival firm
of submarine builders got wind of the treasure, and tried to get
ahead of the Swifts in recovering it. How Tom and his friends
succeeded in their quest, how they nearly perished at the bottom
of the sea, how they were captured by a foreign war vessel, and
sentenced to death, how they fought with a school of giant sharks
and how they blew up the wreck to recover the money is all told
of in the book.

On their return to civilization with the gold, Mr. Swift, Tom,
and their friends deposited the money in the Shopton Bank, where
Ned Newton worked. Ned was a bright lad, but had not been
advanced as rapidly as he deserved, and Tom knew this. He asked
his father to speak to the president, Mr. Pendergast, in Ned's
behalf, and, as a result the lad was made assistant cashier, for
the request of a man who controlled a three hundred thousand
dollar deposit was not to be despised.

In building the submarine Tom and his father rented a large
cottage on the New Jersey seacoast, but, on returning from their
treasure-quest they went back to Shopton, leaving the submarine
at the boathouse of the shore cottage, which was near the city of
Atlantis. That was in the fall of the year, and all that winter
the young inventor had been busy on many things, not the least of
which was his storage battery. It was now spring, and seeing the
item in the paper, about the touring club prize for an electric
auto, had given him a new idea.