"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 them.