om time to time in the wind-swept area to look for
the lost mine.

There were weary days that followed. Hour after hour was spent in the
air in the glider, the whole party being aboard. Observation after
observation was taken, sometimes a certain strata of wind enabling them
to get close enough to the earth to use their eyes, while again they
had to use the telescopes. They covered a wide section but as day after
day passed, and they were no nearer their goal, even Tom optimistic as
he usually was, began to have a tired and discouraged look.

"Don't you see anything like the place where you found the mine?" he
asked of the exile brothers.

They could only shake their heads. Indeed their task was not easy, for
to recognize the place again was difficult.

More than a week passed. They had been back and forth to their base of
supplies at the airship, often staying away over night, once remaining
aloft all through the dark hours in the glider, in a fierce gale which
prevented a landing. They ate and slept on board, and seldom descended
unless at or near the place where they had left the Falcon. Once they
completely crossed the zone of wind, and came to a calm place on the
other side. It was as wild and desolate as the other edge.

Nearly two weeks had passed, and Tom was almost ready to give up and go
back home. He had at least accomplished part of his desire, to rescue
the exile, and he had even done better than originally intended, for
there was Mr. Borious who had also been saved, and it was the intention
of the young inventor to take him to the United States.

"But the platinum treasure has me beat, I guess," said Tom grimly. "We
can't seem to get a trace of it."

Night was coming on, and he had half determined to head back for the
airship. Ivan Petrofsky was peering anxiously down at the desolate
land, over which they were gliding. He and his brother took turns at
this.

They were not far above the earth, but landmarks, such as had to be
depended on to locate the mine, could not readily be observed without
the glass. Mr. Damon, with a pair of ordinary field glasses, was doing
all he could to pick out likely spots, though it was doubtful if he
would know the place if he saw it.

However, as chance willed it, he was instrumental in bringing the quest
to a close, and most unexpectedly. Peter Petrofsky was relieving his
brother at the telescope, when the odd man, who had not taken his eyes
from the field glasses