p the whole pile down on their
heads, and make them wish they'd stayed away from this place."

"Good!" exclaimed Ned, chuckling. "Give me a broom. There's another one
for you."

The two lads in the loft peered down. The red-headed, squint-eyed bully
and his chums had their knives out, and were about to cut some of the
important guy wires, when, at a signal from Tom, Ned, with a sweep of
his broom, sent a big pile of the dirt, sawdust and lampblack down upon
the heads of the conspirators. The young inventor did the same thing,
and for an instant the lower part of the shed looked as if a dirtstorm
had taken place there. The pile of refuse went straight down on the
heads of the trio, and, as they were looking up, in order to see to cut
the wires, they received considerable of it in their faces.

In an instant the white countenances of the lads were changed to
black--as black as the burnt-cork performers in a minstrel show. Then
came a series of howls.

"Wow! Who did that!"

"I'm blinded! The shed is falling down!"

"Run fellows, run!" screamed Andy. "There's been an explosion. We'll be
killed!"

At that moment the big doors of the shed were thrown open, and Mr.
Sharp came in. He started back in astonishment at the sight of the
three grotesque figures, their faces black with the soot, and their
clothes covered with sawdust and shavings, rushing wildly around.

"That will teach you to come meddling around here. Andy Foger!" cried
Tom.

"I--I--you--you--Oh, wait--I--you--" spluttered the bully, almost
speechless with rage. Sam and Pete were wildly trying to wipe the stuff
from their faces, but only made matters worse. They were so startled
that they did not know enough to run out of the opened doors.

"Wish we had some more stuff to put on 'em," remarked Ned, who was
holding his sides that ached from laughter.

"I have it!" cried Tom, and he caught up a bucket of red paint, that
had been used to give the airship its brilliant hue. Running to the end
of the loft Tom stood for an instant over the trio of lads who were
threatening and imploring by 'turns.

"Here's another souvenir of your visit," shouted the young inventor, as
he dashed the bucket of red paint down on the conspirators. This
completed the work of the dirt and soot, and a few seconds later, each
face looking like a stage Indian's ready for the war-path, the trio
dashed out. They shed shavings, sawdust and lampblack at every step,
and from their clo