saw what looked like fine rain dropping from the lower part of
the balloon straight into the flames.

"He can't be dousing water on from up above there," reasoned
Ned. "Pouring water on carbide from a height is just as bad as
spurting it on from a hose, though perhaps not so dangerous to
the persons doing it. But it can't be--"

"By Jove!" suddenly exclaimed Ned, as he had a better view of
what was going on. "It's sand, that's what it is! Tom is giving
battle to the flames with sand from the ballast bags of the
dirigible! Hurray? That's the ticket! Sand! The only thing safe
to use in case of an explosive chemical fire.

"Fine for you. Tom Swift! Fine!"



CHAPTER IV
SUSPICIONS


High up aloft, over the blazing red shed, with its dangerous
contents that any moment might explode, Tom Swift continued to
hold his big dirigible balloon as near the flames as possible.
And as he stood outside on the small deck in front of the
pilot-house, where were located the various controls, the young
inventor pulled the levers that emptied bag after bag of fine
sand on the spouting flames that, already, were beginning to die
down as a result of this effectual quenching.