. Damon. "Right in the center of
the city, too. There's one big building there--the Landmark."

"Looks as if that was afire," said Ned quickly. "Hasn't some relative
of Mary's an office there, Tom?"

"Yes. Mr. Keith. And her other uncle, Jasper Blake, is also interested
in the building. It's the Landmark all right!" cried Tom, as his craft
rose higher and advanced nearer the blaze.

"What are you going to do?" yelled Mr. Damon, as he saw the young
inventor head directly toward a spouting mushroom of flame, which
showed that the fire had broken through the roof. "What are you going
to do?"

"Go to the rescue!" answered Tom Swift. "I couldn't ask a better
opportunity to try my new extinguisher! Sit tight, every one!"

CHAPTER XXIV

A STRANGE DISCOVERY

Once it became evident to the occupants of the airship what Tom Swift's
plans were, they all prepared to help him. Previous to the trip certain
duties had been assigned to each one, duties which were to be exercised
when Tom gave the exhibition of his new aerial fire-fighting apparatus
at the set fire before the fire department of Denton.

This preparation now stood the young inventor in good stead, for there
was no confusion aboard the Lucifer when she winged her way toward the
burning Landmark Building, where the flames were continually spouting
higher and higher as they rushed through the roof, directly above the
stairway well and elevator shafts.

So far the flames had confined themselves to this central part of the
big structure, but it was only a question of time when they would
spread out on all sides, licking up the remainder of the pile. And, for
the most part, the firemen on the ground were at a great disadvantage.

They had run in lines as near as they could get to the center of the
blaze, and had also attached hose to the standpipes inside the
building. But this last effort was wasted, as developed later, for
there was no one in the building to direct the nozzle ends of the hose
attached to the standpipes on the different floors. Also the fierce
heat fairly melted the pipes themselves in the vicinity of the elevator
shafts, and there was no automatic sprinkling system in the building.

This was the situation, then, when Tom in his airship loaded with
fire-extinguishing chemicals headed for the blaze. And this, also, was
the desperate situation that confronted Mary Nestor and her uncle,
Barton Keith, as well as Amos Field and Jason Melling.