's new chemical extinguisher
in the airship when the door of the hangar was suddenly opened and a
very much excited man entered crying:

"Fire! Fire! Bless my kitchen sink, your meadow's on fire, Tom Swift!
It's blazing high! Fire! Fire!"

CHAPTER V

THE EXPLOSION

Tom and Ned were so startled by the entrance of the excited man with
his cry of "Fire!" that the young inventor nearly dropped the tank of
liquid extinguisher he was helping to hoist into the aeroplane. Then,
as he caught sight of his visitor, Tom exclaimed:

"Hello, Mr. Damon! We were wondering whether you'd be along to witness
our first experiment."

"Experiment, Tom Swift! Experiment! Bless my Latin grammar! but you'd
much better be calling out the fire department to play on that blaze
down in your meadow. What is it--your barns or one of your new shops?"

"Neither one, Mr. Damon," laughed Ned. "It's only a blaze that Koku and
Rad started."

"And the fire department is here," added Tom.

"Where?" inquired the eccentric man.

"Here," and Tom pointed to his airship--one of the smaller craft--into
which the tank of chemicals had been hoisted.

"Oh!" exclaimed Mr. Damon. "Something new, eh, Tom?" His eyes glistened.

"Yes. Fighting fires from the air. I got the idea after the fireworks
factory went up in smoke. Will you come along? There's plenty of room."

"I believe I will," assented Mr. Damon. It was not the first time, by
any means, that he had gone aloft with Tom. "I happened to be coming
over in my auto," he went on to explain, "when I happened to see the
fire down in the meadow. I was afraid you didn't know about it."

"Oh, yes," replied Tom. "I had Rad and Koku light a big pile of packing
boxes, to represent, as nearly as possible, on a small scale, a burning
building. I plan now to sail over it and drop the tins of chemicals.
They are arranged to burst as they fall into the blaze, and I hope the
carbon dioxide set loose will blanket out the fire."

"Sounds interesting," commented Mr. Damon. "I'll go along."

The airship was wheeled out of the hangar and was soon ready for the
flight. A big cloud of black vapor down in the meadow told Tom and Ned
that Koku and Eradicate had done their work well. The giant and the
colored man had poured oil over the wood to make a fierce blaze that
would give Tom's new chemical combination a severe test.

A mechanic turned the propeller of the airship until there was an
accumulation of gas i