coward! I'd just like to chase after him and get
my hands on him once!" was the thought that passed through his brain.

But he knew he could not. The scoundrel, no matter who it was, must be
allowed to escape in order that he turn his attention to the burning
shed and try to save the airship from destruction. Once the fire got
inside, there was enough of the dangerous gasoline about to insure the
speedy burning of the whole flimsy fabric, all but the motor itself.

So Frank kept headed straight for the hangar, trying to shut out the
sight of that crouching, fleeing figure. He continued to lift his sturdy
young voice in repeated shouts:

"Fire! Fire!"

Those in the house must hear; yes, and the neighbors, too. He might not
be able to master the flames alone and single handed, and would need
help. Besides, it was only right that Andy, being part owner in the
monoplane, should be made aware of its sudden peril.

As he thus drew near the low building he saw that the fire had already
gained considerable headway, just as if the incendiary might have used
kerosene or some other inflammable fluid, to hasten matters.

Frank's heart grew cold as ice as he contemplated the rapidity with
which those hungry flames were crawling up the dry boards that
constituted the side of the shed.

But he did not lose his head in this sudden crisis. It was
characteristic of Frank Bird that, no matter what the emergency, he was
always cool enough to think out the proper thing to be done or else jump
at it through instinct.

And Frank had foreseen just some such possible need as this. He even
kept several buckets of moist sand handy, where it could be snatched up
at a second's warning, knowing that most fires can be smothered, when
quenching them with water is out of the question.

"The buckets!" he gasped, as he arrived close to the building, one part
of which was now fairly covered with the creeping tongues of ruddy
fire. "I must use them on it!"

He had to turn the corner of the shed to get to where they stood. And as
he did so he ran plump into a figure that was coming toward him. Just in
time did Frank dodge a big fist that shot out. And in that second he
recognized in the other Shea, the Irishman who had been hired to keep
watch of the shed.

"Hold on, Shea!" shouted Frank. "It's me, Frank Bird. Somebody has set
fire to the shed! Grab up a bucket of sand and carry it around here. We
can put it out yet if we're busy!"

Shea had