702 / 868
S 1\1 O
607
S
1\'1
O
froOl
the
ca.rthy.
fiony,
and other P!\rt$, Sec
C UEMI -
ST R Y.
pllJlim.
Sl"IlLAX.
in
botany, a p,enus of the (rccC"i"
hex:moria
cl.Js. 1 'he cahx both ni male j:lnd
rem~lc
c<,otitls
of
fix
Jcav('s; nune of lhem havc: :lny corollA. ; lhe Ity lus of the
fc:m:\k is (riJi ..'
j
and
lhe
be.
n
v has three cel!s ,
cnht.un–ing (wa ft!cds.
1 iH!re
are
I
i
rpecic:s,
none 01 thc:m na–
tivl's
nr
Bri tain.
Sr.llTH E RY,
a
mam,,1 art, by whieh , n irregul" lump
of iron is wrollght ioto any
intt:nucd n'¡¡pe, hy
mLans
of
lire ha,nmcring. fi ling.
cre.
SMOKE ,
a
dr nf( el:tlbe \'apour, arifing from burning ba·
dies. As this \'apour Is
c:~tr(:m. ly
d,(agree",(,le
to
d lC
fo!n rc~,
and
Orten
prejudicial
tu
lhe
htahh , nunklnd have
falk n upon fc:veral
c->ntnVd.nces lo
c:r.joy
lhe
bl:lwfi t
of
Jire, wlthout bcing anno)'cd
~y
fmokc. T he
md t
u·
niverfal of lhefe contrin nce5 15 a tllbe lead,og Iro01 Ihe
ch<tmber
in
whlch
lhe
li re
IS
kind!t:d . tO thc
10p
of lhe
building. fhrough which thc:·1mokc ..fccnds , and
I~
d,fper.
fed ioto the aunofphere. T hde lubes are c.. lled chlm –
neys; which. when con{tru(tcd
10
a propcr m"nacr, carry
off the:
fm okc enli relYi hUI, when improperly conllru{ted,
they catry off the fnv)ke imperlc(ih,
10
the cre'lt anooy'
ance of lhe inh.d)it,¡nts.
As
uur
m..
fons al prcltnt fccm to
have a very
imperfl.tlknowledge o( Ihe manner io \Vhich
chimneys ought
10
be bmlt , Wl! eco harJl y perform
a m'o
re
acceplable (el vice
10
Ihe publlc Ihan to point OUt the mano
ner 10 which they ought
la
be cooflruéted
Co
as
10
carry
off
:he
Cmoke
eOllrtly; as well as to explain lhe cauCes
from IVhieh , he dereét, (o
o(.en
complained or generdlly
proceed, aod Ihe method of removing tht m.
Although we would oaturally imagine. that lhe cauCes
which occ.fion fmoke io rooms are exceedingly various ;
yet , upon examinalion, it will be found thal they- m"y
all be
rl"'ducecf~to
one of thefe thrc:egeneral heads, eaeh
uf
whieh
will
adm;t of (everal varieties.
I.
T o
a
f.uhi. ,he form of tbe tube, or chimney
;t(elr.
n.
T o (ome r.ult in .he o.her parts of .he building,
.nd • wrong poGtion of the ehimney wi,h re(pea
'0
.he(e.
Or,
111 .
To , n improper fi.u>tioa of the hou(e with re(pell
to
external objeéh . And it is oC the utmo!l con(equeoce,
in
attemptioR, a cure. accurately to diílinguiOl (rom which
or thefe defeéls .he fmoke proeeeds, i. will be necell'ary
to point out wilh care the feveral
phenomc.nawhich are
peculiar to each.
1.
Of
(moke occ>fi oned by
a
fauh in .he form of ,he
chimney ¡tCelf. 8UI, be(ore we proceed. il will be necer
fary to premife
fomethin~
with regard
10
the gefteral caufe
of
the afcent af fmoke in chimneys.
The earth i5 every where fur rounded with a great body
of air . called Ihe atmoCphere. T his ..ir is an eJ;.!lic fluid
fubjeéled to many particula; lau's, as hi:llh beco full y ex–
plolioC'o under
the~
..n itle
P N[UMA TI CS'
where it hilth
been fuffi ciently
d~monftrated ,
thal ,
lik~
other 8uids, it
hath a conHant
teD~ency
to preferve an l'quilibl ium
iD
al l its
p~n.s ;.
fo thal, if
at
any time the \Vt'ight o( it :.tt 00(' place
is
dlmlnt{hed, lhe heavier air rurbes from al! fiJes !owards that
poiot , till the equilibriu mbe again renared. We there like·
w.ife
ra~/,
thal heat was one of the moOpowerfuJ mean5·of
? Iflu.t blng this general equilibrium of the ai r, by exp;¡,nd.
In :! H
to a gre.H dcgree. and makinc the faOle quantity
VOL . lI1. N°, 94'
2
occupy
:l
mnch grcatcr fpace th:\n llcforc, and
confC'Cl'l:ntl y
he
·1.I0Ie:
Jlghtcr.
Hco~e
il
nccefl'.irily follo'.' s.
thar
whcre·cvcr
a
lite
IS
kincl lcd.
lhe
'lir
itll:11Cdif.tcly('on1l<'1I0I1S
l O
it
w: f1
be
hcaled, and of confcqucnce riHírictl ::lnd
1O'~Jl
IIgh!
i
wjud\
muH
",fc:..'od
InlO
tllC h'ghc:r renions of the
ali11"
l p~l . r.:.
ull
it bcrorm::s
01
the:
bUlle
Cr:wi1y wuh the <lir
COlltlt,U\J.I: lO
i:;
wlllle
Ihe dcnfcr culd
;tlr
bdow ru!hes lo\Vanl
the
point
from which il departed, is there hcaled :mu lardicd in
il S
turn ,
amI
afccnds in lhe fcinte manncr, cArrying the fl1lol:e
Or vapour aliliog froOl
Ihe
bu rn:og
b(ldy
along
with
It.
In
this
m
Inne r that conHant fuébon of 31r tow,¡rJ :i c'Ier'j
fire
is
produccd, and froOl this c.tufl.!
proc~ecls
lhe connal:t
ten·
dency of fRloke tO alcend upwards (rom
t!\1!
fU I
relee
of
the
eanh .
Bllt
as the body of (lUr atnlofphl'1(' is Orten
.agit:ucd
with
wind
Oc.
and.lsit is an el.tlllc thJid, it endeavours to
fpr"ad
urd f
cvery w;¡,y; from wlllch ca"fc.s
rhe
warm
ai r
would qUlck ly
be
d:ffllred ..mong 1h, cold al r before it could
aTICe
[O
aoy confi dC:l<lbJe he'ght ; fa that lhe
rm'/l e
would
al w.lys remolín low,
:wd
be tolrcd ai'out near
tih!
lurface
of
the earth: ..Hof whlch in::oO\'cniencies are :t'/olnt!d
I.>y
coofi–
oiog Ih!s heated alr In a tube, which prevenls
It
from 111' :<:ng:
with
{he externaJ"ir. tiJl it arnve: dt the hc'ght
10 \.
hu:h
we
der. re i. Ihould .re, nd .
T o rendcr
chIS
nl ll more clcar, fl'eP late
eLv r
where
~. B
(fig.
l .)
r~prefents
the
tub~
of <t chinln(.'y. having.1tire :H the
bOllom at
A. h
is ob\'ious. thal.
10 tllIS
(iIU;¡llon.
l~e
ai r
which \Vas heated by Ihe fi real
i\.
\V,II
aff..eod
c!tr<:tlly~!p·.\'.trd"
witho111 mixing wuh
Ihe
external .lir, lall
H
f\f1 1\t:S al
B.
beyond which it
will be
at hbcn y
10
ddperfe in lhe atmo·
fphere ; aod the more weighlY air
wh" h
prelTcs
10
ta (upj,ly
its place can have no accefs
10
il
bUI
al Ihe openlog betWeeA
A
and
E.
where il alCo is hc,¡ted
by
lhl! lire, .loJ
10
ils turn
aCcl'nds
tO
the top of lhe chlnlOtoY, Ihereby occafionlOg a
conflant ílreamof air
10
afcend up the chimney. which car–
ries the fmoke along with il. This is the mallner
in
which
fuliginous vapours are mOlde to afcend io chimneys
i
and by
attending
10
jt, we míly draw the folJowing corollaries Wilh
re~ard
tO the cocflrulhOD
lo0f
Ihis uíeful pan of our habi–
tatlons.
In,
Thc
higher lhe chimney,
that
is, the greater the
di–
llance between the fire-place and the top of the chimoey,
the greater
wíll
be [he dlfference between Ihe weieht of lhe
columo of heated air in Ihe tube, and another column of the
atmofphere of the fame di.meter without the thlmney, and
coofequt:otly Ihe air will eoter with the greater force al Ihe
opeoioc
AE,
and carry up the fmoke more readí ly along with
it:
for as lhe Wdrm air within Ihe tube conlinues rare6ed
lO
a
high dcgree tlll it ilTucs [rom the top of Ihe chimneYI
alld is, in every part of its lengt h, lichter
th~n
the f<tme bulk of
external air malked by
the
dOlled Jine
en.
it follows,
Ihat
the JOl'lger thefe
IWO
columns of unequal gravity are, the
gre.tter muU be Ihe dlfFerence of Iheir weight. H ence it
¡s,
that
high chlmncys
(C4/UÍJ parihul)
havc
a
crea!cr fcél'íon
of airo and are Icfs liable
lO
venl ill,
th~n
low ones. Afmo–
ky chlOloey may therefore CometiOles be cured
hy
raifing it
higher. 11 is hkewile obvious. that
if
any opening is made
inta the chimney, as al
F,
Ihe air
will
enter with lefs force
al
E ,
aod carry up Ihe {mnke with lers velocity. and
by
that rncans be In danger af
proJucin~
{moke in lhe room ;
for Ihis opcning.
2S
It
admits lhe: frelb air
i~lIo
Ihe luhe. has
n,.r1y .he
(ame
efl'ell
as
Ihortening .be tube (o ",ueh ",ould
have.
2d, As .he fmoke is foreed up the chilllney
mer~ly
by Ih.
7 O
t
raroracl'OD