is catching!" shouted Mr. Swift,
pointing to where a little spurt of flame showed on the roof of a
distant building.

"It's from sparks!" Tom said.

"Any danger of using water there?" Ned wanted to know.

"No, use all you like! That's the only thing to do. Come on, you with
the hose!" Tom yelled. "Save the other buildings!"

"But are you going to let the red shed burn?" asked Mr. Swift. "You
know what it means, Tom."

"Yes, Father, I know. And I'm going to fight that fire in a new way.
But we must save the other buildings, too. Play water on all the other
sheds and structures!" ordered the young inventor. "I'll tackle this
one myself. Oh, Ned!" he called.

"Yes," answered his chum. "What is it?"

"You take charge of protecting the place where the new aerial warship
is stored. Will you? I can't afford to lose that."

"I'll look after it, Tom. No harm in using water there, though; is
there?"

"Not if you don't use too much. Some of the woodwork isn't varnished
yet, and I wouldn't want it to be wet. But do the best you can. Take
Koku and Eradicate with you. They can't do any good here."

"Do you mean to say you're going to give up and let this burn?"

"Not a bit of it, Ned. But I have another plan I want to try. Lively
now! The wind's changing, and it's blowing over toward my aerial
warship shed. If that catches--"

Tom shook his head protestingly, and Ned set off on the run, calling to
the colored man and the giant to get out another line of hose.

"I wonder what Tom is going to do?" mused Ned, as he neared the big
shed he and the others had left on the alarm of fire.

Tom, himself, seemed in no doubt as to his procedure With one look at
the blazing red shed, as if to form an opinion as to how much longer it
could burn without getting entirely beyond control, Tom set off on a
run toward another large structure. Ned, glancing toward his chum,
observed:

"The dirigible shed! I wonder what his game is? Surely that can't be
in danger--it's too far off!"

Ned was right as to the last statement. The shed, where was housed a
great dirigible balloon Tom had made, but which he seldom used of late,
was sufficiently removed from the zone of fire to be out of danger.

Meanwhile several members of the fire-fighting force that had been
summoned from the various shops by the alarm, had made an effort to
save from the red shed some of the more valuable of the contents. There
were some machines in there, as we