Ned was silent a moment, considering Tom's daring plan and
project. Then, as it became clearer, the young banker cried:

"Blamed if I don't think that's just the thing, Tom! It ought
to work, and, if it does, it will save a lot of lives, to say
nothing of property! A fire in a sky-scraper ought to be fought
from above. Then the extinguisher element, whether chemicals or
water, could be dropped where they'd do the most good. As it is
now, with water, a lot of it is wasted. Some of it never reaches
the heart of the fire, being splashed on the outside of the
building. A lot more turns to steam before it hits the flames,
and only a small percentage is really effective."

"That's my notion," Tom said.

"Then go ahead and do it!" urged his friend. "You have my
permission!"

"Thanks," commented Tom dryly. "But there are several things to
be worked out before we can start. I've got to devise some scheme
for carrying a sufficient quantity of chemicals, and invent some
way of releasing them from an airship over the blaze. But that
last part ought to be easy, for I think I can alter my warfare
bomb-dropping attachment to serve the purpose.

"What I really need, however, is some new chemical combination
that will quickly put a really big blaze out of business. There
are any number of these chemicals, but most of them depend on the
production of carbon dioxide. This is the product of some
solution of a carbonate and sulphuric acid, and I suppose,