th sparks of fire, surged into their faces.

"Back, Mary! Back!" cried Mr. Keith, and he dragged the impetuous girl
with him to their own corridor, and back into his offices which, for
the time being, were comparatively free from the choking vapor.

"We must try the windows, Uncle Barton! We must!" cried Mary. "Surely
there is some way down--maybe by dropping from ledge to ledge!"

Her uncle shook his head. Then he opened the window and looked out. As
he did so there arose from the streets below the cries of many voices,
mingled with the various sounds of fire apparatus--the whistles of
engines, the clang of gongs, and the puffing of steamers.

"The firemen are here! They'll save us!" cried Mary, as she heard the
noises in the street below. "We can leap into the life nets."

"There isn't a life net made, nor men who could retain it, to hold up a
person jumping from the tenth story," said her uncle. "Our only chance
is to wait for them to subdue the fire."

"Isn't there a back way down, Uncle Barton?" "No, Mary!" He closed the
window for, open as it was, the draft created served to suck smoke into
the office, and Mary was coughing.

Uncle and niece faced each other. Trapped indeed they were, unless the
fire, which was now raging all through the building, with the stairs
and elevator shafts as a center, could be subdued. That the city fire
department was doing its best was not to be doubted.

"We can only wait--and hope," said Mr. Keith solemnly.

Mary gave a gasp. Her uncle thought she was going to burst into tears,
but she bravely conquered herself and faced him with what was meant to
be a smile. But it is difficult to smile with quivering lips, and Mary
soon gave up the attempt.

Mr. Keith went over to the water cooler--one of those inverted large
glass bottles--and looked to see how much water it contained.

"It's nearly full," he said.

"What good will it do?" asked Mary. "This fire is beyond a little water
like that."

"Yes, but it will serve to keep our handkerchiefs wet so we can breathe
through them if the smoke gets too thick," was his reply.

"It begins to look as if we'd need to try that soon," said Mary, and
she pointed to thick smoke curling in under the door.

"Yes," agreed her uncle. "It's getting worse." Hardly had he spoken
when there came a rush of feet in the corridor outside his office door.
Then a voice exclaimed:

"We're trapped! We can't get down either the stairs or the elevato