Western union. (City of Hannibal, Mo.) 1850-1851, 1850-11-28
From the Dol. Newspaper.
CHIMNEY5.

A subscriber To your paper asks "how &c
prevent chimneys from smoking without
pulling them downl" We will suggest Q
lew facts in regard to this subject, knowing
al the same time that they are known to Il
large number OF your readers. In the first
place, the reason why smoke is carrie 4
through the chimney into the air above is
that the fire creates partial vacuum in it,
and the air below rushing in below to sup.
ply the void, produces curren: which car
ries out the smoke and watcrv vapor; for
the ascent of smoke is entirely mechan.
ica, and not owing, as some imagine. to its
being lighter than air The draft OF a
chimney is influenced BY several things
Long chiinneys have stronger draugh,
than short ones, because they have n long.
er column of warm air. But here observe
that they may be SO long as TO cool the air
before it has reached the top, and the
smoke then will fall down. owing to its
weight. A narrow throat opening into n
large pipe makes strong draught. Bu,
the throat must be wide enough to allow all
the smoke, vapor, rariiied air, &c, to ascend
freely. Small pipes are more easily rari-
fled than large ones, and hence are to be
preferred. But il they are too small, they
cause so much resistance to friction. as to
impede the action of the draught. The size
OF the chimney ought to be regulated by
the kind OF fuel used--grcen wood requiring
a larger aperture than dry. and bituminous
coal more than anthracite. A fire place
with a low front causes n stronger draught
because none but rarliied air is then per-
mitted to enter the chimney, and thus it is
kept constantly warm. One thing in con-
structng chimneys is to exclude all air
from entering that has not first passed thro'
the fire, ard keep all air ou, that IS no, nee.
essary to support combustion. These things
if properly attended to-, will obviate any
necessity Of n smoky chimney; but some di.
rections TO those who have such nuiSances
will. not be amiss, in order that they may in
part, If not entirely avoid all inconvenience
arising from them.
|. Your chimney may be too large, so
large indeed, ,ha, descending currents oi
air meet the smoke and drive it down; il
so, this is obvia;cd hy putting long, mar
row crock on the top Oft, plan follow
ed in many places.
=. The breast may be too high. This is
quickly remedied by placing piece OF sheet
iron so rs to cover over part OF the ori-
fee.
3. One plan followed by an old gentle
man we have heard of, was to knock out
the corner bricks in the chimney, about
two-lhirds of the way up from the fire
place to the top so us to afford room to in
sert in each corner cows horn, having
first sawed them of so as to allow n free
passage OF air through them. and having
placed them in, little end foremost, and
turned up at an angle of about 80 ;; then
secure with plaster all orifces around them.
This is from very scientific man, who
knew the plan TO succeed, from whom we
obtained all our inform,ion in regard to
chimncyS.
The last thing is to cut Your wood, and
have it thoroughly dry, and very probably
your chimney, which has so long smoked
from using green wood, will be eiiectually
cured. NV.