horrible prison barrack with the cruel guards--you do not
call that much? My friend," spoke the Russian solemnly, "no one on
earth has done so much for me as you have, and if it is the power of
man to show you where that lost mine is, my brother and I will do so!"

"Agreed," spoke Ivan quietly.

"Then what plans shall we make?" asked Tom, after a little more talk.
"Are we to go about indiscriminately, or is there any possible way of
getting on the trail?"

"My brother and I will try and decide on a definite route," spoke Ivan
Petrofsky. "It is some time since I have seen him, and longer since we
accidently found the mine together, but we will consult each other,
and, if possible make some sort of a map."

This was done the next day, the present maps aboard the Falcon being
consulted, and the brothers comparing notes. They began to lay out a
stretch of country in which it was most likely the lost mine lay. It
took several days to do this, for sometimes one brother would forget
some point, and again the other would. But at last they agreed on
certain facts.

"This is the nearest we can come to it," said Ivan Petrofsky to Tom.
"The lost platinum mine lies somewhere between the city of Iakutsk and
the first range of the Iablonnoi mountains. Those are the northern and
southern boundaries. As for the western one, it is most likely the Lena
river, and the eastern one the Amaga river. So you see you have quite a
large stretch of country to search, Tom Swift."

"Yes, I should say I had," agreed the young inventor. "But I have had
harder tasks. Now that I know where to head for I'll get there as soon
as possible."

"And what will you do when you arrive?" asked Ned.

"Fly about in the Falcon, in ever-widening circles, starting as near
the centre of that area as possible," replied Tom. "And as soon as I
run into a steady hurricane I'll know that I'm at the place of the big
winds, and I'll get out my glider, for I'll be pretty sure to be near
the place."

"Bless my gas meter!" cried Mr. Damon. "That's the talk!"

Tom put his plan into operation at once, by heading the nose of his
craft for the desolate region mapped out by the Russian brothers.

The days that followed were filled with weary searching. It was like
the time when they had sought for the plain of the great ruined Temple
in Mexico, that they might locate the underground city of gold. Only in
this case they had no such landmark as a great Aztec ruin to guide