Up this way, then."

On the second floor they found themselves in a big room that looked like
a forest of sewing machines, humming and clicking so fast that at first
the twins were fairly bewildered. Girls who, it seemed, could hardly be
older than Betty were bending over their machines, sewing away as if for
dear life. Most of them did not even look up from their work as the
visitors came through.

"The young man's trousers are in this next room," said the tailor,
leading the way to a heavy iron door which separated the two rooms on
that floor.

"What's the idea of this iron door?" asked Uncle Jack. "To keep a fire
from spreading from one department into the other?"

"Exactly so. That big, thick fire wall goes straight through the
building from top to bottom--cuts it in two. Suppose a fire breaks out
here on the piecework side: the foreman just opens this fire door and
shoos the boys and girls right through, like a lot of chickens. Then he
shuts the fire door tight, and they are safe. That big fire we had here
four years ago taught us something. So when the owner rebuilt it for us,
he built it right."

The big room on the other side of the fire wall was crowded almost as
full of workers as the first one. The main difference was that there
were more boys and men, and that more sewing was being done by hand.
Bob's khaki trousers were quickly found and tried on--a perfect fit.

"We'll give Bob a Patrol Leader's arm badge--two white bars of braid
below his left shoulder," said Uncle Jack. "Betty will get one bar for
the present, I understand. There are some badges yet to come, Colonel
Sure Pop says."

Bob and Betty looked at each other, too pleased to talk.

The four were walking downstairs for a look at the other floors of the
big tailor shop when the noon whistle blew. R-r-rip--slam--bang! A
torrent of rattle-brained boys came tearing pell mell down the stairs
like a waterfall over a dam. Most of them came pelting down three steps
at a jump, but on one of the landings somebody stumbled, and the yelling
boys piled up in a squirming, kicking heap.

"Hey! WAIT!" No one would ever have suspected the mild-mannered tailor
of having such a foghorn of a voice! The rush from the upper floors
slowed up at once, and Uncle Jack and Bob helped the fallen lads pick
themselves up. But the boy at the bottom, a little fellow with a thin,
pinched face that looked as if he had never had half enough to eat, nor
even enough fresh