he turned it. The portal swung back, and
Tom and his friend found themselves inside the shed which, of late, had
been such an object of worry and conjecture to the young inventor. What
would he find there?

"Flash the light," he called to Mr. Damon in a hoarse whisper.

The eccentric man drew it from his packet He pressed the spring switch,
and in an instant a brilliant shaft of radiance shot out, cutting the
intense blackness like a knife. Mr. Damon flashed it on all sides.

But to the amazement of Tom and his companion, it did not illuminate
the broad white wings and stretches of canvas of an aeroplane It only
shone on the bare walls of the shed, and on some piles of rubbish in
the corners. Up and down, to right and left, shot the pencil of light.

"There's--there's nothing here!" gasped Tom.

"I--I guess you're right!" agreed Mr. Damon "The shed is empty!"

"Then where is Andy Foger building his aeroplane?" asked Tom in a
whisper; but Mr. Damon could not answer him.

Chapter Nine

A Trial Flight

For a few moments after their exclamations of surprise Tom and Mr.
Damon did not know what else to say. They stared about in amazement,
hardly able to believe that the shed could be empty. They had expected
to see some form of aeroplane in it, and Tom was almost sure his eyes
would meet a reproduction of his Humming Bird, made from the stolen
plans.

"Can it be possible there's nothing here?" went on Tom, after a long
pause. He could not seem to believe it.

"Evidently not," answered Mr. Damon, as he advanced toward the center
of the big building and flashed the light on all sides. "You can see
for yourself."

"Or, rather, you can't see," spoke the youth. "It isn't here, that's
sure. You can't stick an aeroplane, even as small a one as my Humming
Bird, in a corner. No; it isn't here."

"Well, we'll have to look further," went on Mr. Damon. "I think--"

But a sudden noise near the big main doors of the shed interrupted him.

"Come on!" exclaimed Tom in a whisper. "Some one's coming! They may see
us! Let's get out!"

Mr. Damon released the pressure on the spring switch, and the light
went out. After waiting a moment to let their eyes become accustomed to
the darkness, he and Tom stole to the door by which they had entered.
As they swung it cautiously open they again heard the noise near the
main portals by which Andy had formerly taken in and out the Anthony,
as he had named the aeroplane in which