in the book, entitled, "Tom
Swift in the City of Gold," I related his adventures.

How he and his friends were followed by the Fogers, how they eluded
them, made their way to the ruined temple in a small dirigible balloon,
descended to the secret tunnel, managed to turn aside the underground
river, and reach the city of gold with its wonderful gold statues--all
this is told in the volume.

Then, after pulling down, in the centre of the underground city, the
big golden statue, the door of rock descended, and made our friends
prisoners. They almost died, but Andy Foger and his father, in league
with some rascally Mexicans and a tribe of head-hunters, finally made
their way to the tunnel, and most unexpectedly, released Tom and his
friends.

There was a fight, but our hero's party escaped with considerable gold
and safely reached Shopton. Now, after a winter spent in work, fixing
over an old aeroplane, we again meet Tom.

"Would you mind telling me something about where this platinum comes
from, and if you can get any more of it?" asked Tom, after a pause,
following the strange statement made by the Russian.

"I will gladly tell you the story," spoke Mr. Petrofsky, "for I am much
interested in inventions, and I formerly did something in that line
myself, and I have even made a small aeroplane, so you see I know the
need of platinum in a high power magneto."

"But where did you get such pure metal?" asked Tom. "I have never seen
it's equal."

"There is none like it in all the world," went on the Russian, "and
perhaps there never can be any more. I have only a small supply. But in
Siberia--in the lost mine--there is a large quantity of it, as pure as
this, needing only a little refining.

"Can't we get some from there?" asked the young inventor eagerly. "I
should think the Russian government would mine it, and export it."

"They would--if they could find it," said Ivan Petrofsky dryly, "but
they can't--no one can find it--and I have tried very hard--so hard, in
fact, that it is the reason for my coming to this country--that and the
desire to find and aid my brother, who is a Siberian exile."

"This is getting interesting," remarked Ned to Tom in a low voice, and
the young inventor nodded.

"My brother Peter, who is younger than I by a few years, and I, are the
last of our family," began Mr. Petrofsky, motioning Tom and Ned to take
chairs. "We lived in St. Petersburg, and early in life, though we were
of the no