not--at first."

"Come on then, Ned and Mr. Damon. Mr. Petrofsky and Rad can cast off
the ropes."

The wind, if anything, was stronger than ever. It was a terrific gale,
and just what was needed. But how would the air glider act? That was
what Tom wanted very much to know.

"Cast off!" he cried to the Russian and Eradicate, and they slipped the
ropes.

The next moment, with a rush and whizzing roar, the air glider shot
aloft on the wings of the wind.

CHAPTER IX

THE SPIES

"We're certainly going up!" yelled Ned, as he sat beside Tom in the
cabin of the air glider.

"That's right!" agreed the young inventor rather proudly, as he grasped
two levers, one of which steered the craft, the other being used to
shift the weights. "We're going up. I was pretty sure of that. The next
thing is to see if it will remain stationary in the air, and answer the
rudder."

"Bless my top knot!" cried Mr. Damon. "You don't mean to tell me you
can stand still in a gale of wind, Tom Swift."

"That's exactly what I do mean. You can't do it in an aeroplane, for
that depends on motion to keep itself up in the air. But the glider is
different. That's one of its specialties, remaining still, and that's
why it will be valuable if we ever get to Siberia. We can hover over a
certain spot in a gale of wind, and search about below with telescopes
for a sign of the lost platinum mine.

"How high are you going up?" demanded Ned, for the air glider was still
mounting upward on a slant. If you' ever scaled a flat piece of tin, or
a stone, you'll remember how it seems to slide up a hill of air, when
it was thrown at the right angle. It was just this way with the air
glider--it was mounting upward on a slant.

"I'm going up a couple of hundred feet at least," answered Tom, "and
higher if the gale-strata is there. I want to give it a good test while
I'm at it."

Ned looked down through a heavy plate of glass in the floor of the
cabin, and could see Mr. Petrofsky and Eradicate looking up at them.

"Bless my handkerchief!" cried Mr. Damon, when his attention had been
called to this. "It's just like an airship."

"Except that we haven't a bit of machinery on board," said Tom. "These
weights do everything," and he shifted them forward on the sliding
rods, with the effect that the air glider dipped down with a startling
lurch.

"We're falling!" cried Ned.

"Not a bit of it," answered Tom. "I only showed you how it worked. By
slidi