derground city. It's impossible Tom, my boy!"

"Well, that may be," agreed Tom. "I'm not saying it's true. Mr.
Illingway is telling only what he heard."

"Go on! Tell some more," begged Mr. Damon. "Bless my shirt studs,
this is getting exciting!"

"He says that the traveler told of this underground city of gold,"
went on Tom, "though he had never been there himself. He had met a
native who had located it, and who had brought out some of the gold,
including several of the images, and one he gave to the white man in
return for some favor. The white man took it to Africa with him."

"But where is this underground city, Tom?" asked Mr. Swift. "Doesn't
Mr. Illingway give you any idea of its location."

"He says it is somewhere in Mexico," explained the lad. "The
Africans haven't a very good idea of geography, but some of the
tribesmen whom the white traveler taught, could draw rude maps, and
Mr. Illingway had a native sketch one for him, showing as nearly as
possible where the city of gold is located."

"Tom Swift, have you got that map?" suddenly cried Mr. Damon. "Bless
my pocketbook, but--"

"I have it!" said Tom quietly, taking from the envelope a piece of
paper covered with rough marks. "It isn't very good, but--"

"Bless my very existence!" cried the excitable man. "But you're not
going to let such a chance as this slip past; are you Tom? Are you
going to hunt for that buried city of gold?"

"I certainly am," answered the young inventor quietly.

"Tom! You're not going off on another wild expedition?" asked Mr.
Swift anxiously.

"I'm afraid I'll have to," answered his son with a smile.

"Go? Of course he'll go!" burst out Mr. Damon. "And I'm going with
him; can't I, Tom?"

"Surely. The reason Mr. Illingway sent me the letter was to tell me
about the city of gold. He thought, after my travels in Africa, that
to find a buried city in Mexico would be no trouble at all, I
suppose. Anyhow he suggests that I make the attempt, and--"

"Oh, but, Tom, just when I am perfecting my gyroscope!" exclaimed
Mr. Swift. "I need your help."

"I'll help you when I come back, dad. I want to get some of this
gold."

"But we are rich enough, Tom."

"It isn't so much the money, dad. Listen. There is another part to
the letter. Mr. Illingway says that in that underground city,
according to the rumor among the African natives, there is not only
gold in plenty, and a number of small gold statues, but one immense
big one--o