per floors
communicate with the vertical flues, and these highways and byways for
rats and mice, for fire and smoke, for odors from the kitchen, noises
from the nursery and dust from the furnace and coal-bin, are also
strewn with builders' rubbish, which carries flame like stubble on a
harvest-field.

[Illustration: MINED AND COUNTERMINED.]

"Brick houses, as usually built, are not much better, but that is not
the fault of the bricks--_they_ are tougher than good intentions; they
have been burned once and fire agrees with them. In fact, there is no
building material so thoroughly reliable, through thick and thin, in
prosperity and in adversity, as good, honest, well-burned bricks. But
the ordinary brick house is double--a house within a house--a wooden
frame in a brick shell. Like logs in a coal-pit, the inner house is
well protected from outside attacks, but the flames, once kindled
within, will run about as freely as in a wooden building, and laugh at
cold water, which, however abundantly it is poured out, can never reach
the heart of the fire till its destructive work is accomplished. Thrown
upon the outer walls, it runs down the bricks or clapboards; poured
over the roof, it is carried promptly to the ground, as it ought to
be; shot in through the windows, it runs down the plastering, washes
off the paper, soaks the carpets, ruins the merchandise and spoils
everything that water can spoil, while the fire itself roars behind the
wainscot, climbs to the rafters and rages among the old papers, cobwebs
and heirlooms in the attic till the roof falls in, the floors go down
with a crash and an upward shower of sparks, and only the tottering
walls, with their eyeless window sockets, or the ragged, blackened
chimney's, remain."

"One road leads to fire and the other to combustion; that's plain
enough," said Jack; "but where do the merits come in? I thought we were
to learn the relative merits of bricks and wood."

"Wood has one conspicuous merit, a virtue that covers a multitude of
sins--it is cheap; but let me first arrange the fire-escapes."

"By all means. Otherwise we shall be cremated before morning."

"If you understand my sketch you will see that but one thing is needful
to retard the progress of hidden fire, even in a wooden building, long
enough at least for one to go up the hill and fetch a pail of water.
This remedy consists simply in choking the flues and stopping the
draught, which can easily be done by f