ed back into the shop again, though Frank had looked
after him as though inclined to wonder what ailed his cousin to be so
mysterious in his actions.

"Forgot to take his change out of the pockets of those wet clothes?"
suggested Larry, noticing the upraised eyebrows of Frank.

"I don't know about that," returned the other, stepping back a pace to
where he could glance through the open door. "He's gone straight to
the drawer where we keep some of our stuff. There, he's taken out the
marine glasses that I just put away. What under the sun do you suppose
Andy wants with them? He doesn't look up at the summit of Old Thunder
Top, where we landed from our monoplane last summer, being the first
human being ever to step there above the big cliffs. No, Andy has gone
to a window with the glass. He seems to want to keep out of sight.
Now, I wonder why?"

"Three to one he just saw your sister Janet going along the further
road; and couldn't keep from wanting to admire her at close range,"
chuckled Larry.

"But now he's elevating the glasses," Frank went on. "He seems to be
interested in that old mill you can see yonder above the trees. I
declare, I did see something moving then in one of the upper windows.
That beats everything. To think of Andy having such sharp eyes."

"Oh! the boys used to play there last summer," ventured Elephant;
"though since then nobody goes near the old place. I was told it had
become the haunt of hoboes this summer. Anyway, the boys fight shy of
it right along now."

"Here comes Andy; now we'll know," said Nat, just as smartly as any of
them could have spoken, for his hurry spell was over, and he had
command of his vocal chords once more.

"Wondering what took you inside to get the glasses," remarked Frank, as
the other joined them, a frown marked on his usually placid face. "And
then, what made you go to a window instead of standing outside openly,
and looking?"

"I'll tell you," returned Andy, solemnly. "I didn't want 'em to see me
peeking."

"You mean the fellows in the old deserted mill?" asked Larry.

"No other," came the quick reply, "I don't know how it came to strike
me, because you know as a rule I ain't suspicious; but something about
the way those two men in the touring car looked so greedily at our new
aeroplane gave me an idea it might be them."

"Goodness gracious!" gasped Elephant, his eyes round with wonder and
excitement.

"And was it?" demanded Frank, hastil