1000000031

703 / 868

S 1\1 o 608 S l\! O
T.trcr.·élion of lhe "ir in confcquencc or ¡'C~lt, il is cvido,,'Ol,
th.n Ibe llHlIt: Ihe :¡ir is hc:ucJ, wi;h ,he g rC'alt r tOI ~C ((Oe
I ( I"IJ p;,,,'¡,,o) \~ III ita(cend, b~caurc: Ihe dllrarc:nce oClwcl.n
the w"'lJ.!ht 01 lhe lXlero ..1:.tnu intcrn,tl ai r ""di I.>c &rc:.\t:!'r ~
anJ ~s Ihe: :Ji. wdl be lhe more h...atetl (he neArer tt is mlde::
\0 pals hy the lire in ils ~ntry into the chimne)'. ir is evi·
dentorha! Ihe fm~Jler Ihe opcning al AE ¡s, or, Inother \VOlds,
t he Jowt. r the 1Mnde of Ihe chllnnry ¡s. the ¡tlr will be (or–
cL'd lO ¡ufs (he nedrer the hrc, and therdur!! be more rrlrcfi"d,
¡¡nd :lf~t:nJ " ilh Ihe gre;\tcr \'clocity ¡ fo that lowering [he
m:1 nde of the: ¡;hlmncy will often cure {mokc:.
HIII il is frcqueRtly inconveoient 10 llave the mande of
the chi:nney tOO low. Ilo\Vcvcr, Ihe r~ nl:: e:ffcél m ,IY often
he produc.:J by ;¡nolhcr cont rivaoce. For as the ti rc.plac( lS
I1fu.. J1y nl.lJe \I.·ider thao the lengül of lhe gr:¡¡c, a great
dc,¡J of cool air podres at (he two fide:1 of (he gr,ue ,,,,¡thout
bcincmuch healcd. Thisgreitd y dimini!hes lhe luétlon oft~e
chimne:y: hu t il may cafily be: preventeJ by building up the
'·...c..ncics at eaeh kJe of lhe grate, fa ;'5 tOallow no air 10
ent:: r from below, ex.:e pt what coll1cs immcdiately through,
or before ,he rire. For this purpore, gr.Hes cunri !ing of a
fleat hcwed none al eacfi eod , wilh ;,r. brean aad bOllonl of
¡ron firted 10 tht::m, as replcfcnted ?l hg 2 . are cxtrcn::ly
con\'enient. Du: lhe ap~rturc of the ciHmney is afien nOl
fuddenly contrcléterl ~bove lhe D1ande, but goes up tapering
Oowly. as in lh: fame fig. 2. This flrlléture allows a quan·
tity of cool air tOenler al lhe t\/Jo corners of the mande,
~nd !leal up lhe tUbe without comine ñear the fire . The
mon eary anJ effü'lual mcthod of r~nH::dyiog lhis dtfeét, is
to pldce a {hee-l cf miiled iron withtn the mande on each
fide, as low down as roflible, nllkiog them OJnt a Jittlc up
;\;.r;¡rds towOITds the middle ot the ehimney; as at A, ñg. 2.
the m,nde being reprereotcd by the dotled line. By lh"
contri vanee, Iht: air, which enlers at the fide,of lhe molntle.
b::ore it C1n afcend ilHO the chimney, is forced ~o pars very
n~H the fire, an-J of co~ rre is much rarifled. The good ero
fd ls o( this 1V0uld be flilJ roore fl rongly (clt , i( one o( lhefe
l11atcs werc pbced a littlelower thl o [he other, aod made fa
long. lh>! the OlOul¡l erofs " eh other, as at AD, fig. , .
by which m~an5 every particle of air that \Yent up lhe cbim·
ney behovc.:d 10 pdfs immediateJy abo\'e lhe Gre. 11 is al ·
moll unnecdl'lTy tOobferve, that thefe piares ought [O be fo
eontri\'(d as h) be takcn OUt at plcarure tO ;Jlow lhe chimncy
to be cI~aned.
A chimo('y nuy OOt ooly be defeélivc by having the mano
tle lOO high, or by being toO wide (rom fide to fide, but alfo
by bcing tCO dcep between the fore Gde and the back, as i,
of[ó!o Ihe cafe in \'ery old houfes. lo this cafe. tbe d¡nance
bc[\,/ccn lhe fire and lhe mande is fo great, that mudl alr
p.. r.~s up witho~t bli!lC fuflic;cnlly riHifi~d, as i5 rcprefented
al ti:;. 3. This IlHy bl.: fOO1C[imes Cll fl:tI by br:nging lbe
Mate a li[tlc forwuJ, wh ich, by makir.g the IIre atl more
powc,f(.lIy upon lhe mande, rarcfie5 the 2ir more io iu
p.O"ge. BUl this c>n f<lJ on. produe: the defircu <
",nu it often uoes Ilarm : for when Ihe grale is brought [or·
ward. there is a breal vacaney lefl bet\/Jeea it and the bdck
"r th! cilil1lney, fa tha! the air p,tfl(s um!cr lhe l!r~t-:, and
arccnds b'!lund it \'cry I¡Hlc rarifi .!u; fo tllolt, iE the fcet of
are n lj( \'cry low, there will be as much Ion in ,h is
way as will be g IIl1ed io the other; anu as thrre is oot cnoug,h
9t' hcated air in the chimneys of tbis kind lhe va·
pour af:-ecd with rapidity, theyare afien choak,cd Wilh
t!!ick ruli~inous \'c\pours haoeinc in them} almoH in cqlljl.-
hrio ,:",ilh the ren of Ihe atmorphcre, fa Ih", dIe leñ{l plltr
(11 wmd bC,H5 lhem dowo Ihe clumncy, and pufhcs the
[molle ioto tll\.: room i whcrras, when il 15 f~r h~ck, It is J ri–
\'~n dow~ uplln lhe hc,uth, ;¡nd rifc:s upwél.rns agdin ""hen
the guH IS over, ar.d a grelt ,1eal oE it is C¡tClh.:d wHhin the
nunl.\: as il ri fes, which in lhe;: other c<tle \'Iould ha\'c been
dtfperfcd lhrough lhe room. Whcn thls is lhe c.,fe::. (he
muft "fflélu;¡,! mélhod of cure is, 10 bring th!! gralt: forward
ttlllht:: forepart of i.t is immcdi"lelyundcr the inner edge of
Ihe mant!rj then Ludd up rhe vacancyat lhe back of It, the
\Vhole wichh of Ihe:: ti r~. place from Cicle to fide, ralÍing it per–
pendicul.lIly tdl it is oiS hlCh as the back of lhe grcnc, and
thcn bcnt!ing it forewcirJ 10WHds thl! mClntle::. as is repre–
fentl.:d at fig. 4. ,"Vhc. n ít is as high as lhe workm¡;n ean
. Ie::t It b.: fuddenly lurned back ward again, flopiog a
Jiu le upward. as \O the figure; then fit ~ {hect of milJed
¡rOA lO the ¡nfiJe <?f the mande, m;,r.king it !1anl a littl: up·
ward IOW:HJ lhe blck pan, at a fmall diOaoce aboye the
ncw.eretled nufoor y, OIod exrend:ng wjrhin a fcw inchrs of
lh~ back wall¡ as al A, fil:. 4. By this conflrué1ion all the
~ir that cnlers into lhe ~ IlImnéy is nt.tde tO pars immeciately
abo\'e the tire, bClwccn it and lhe heHed iron, upon whic.h
the IIttme afts wilh lhe gt('.i!.ler force, OIS lhe bal k of the
tir:.place is bent a I: ttll! forward Ó1.bove the gratc, and
lhe heat is likewife r"flctlc:d inlO lhe .room with the
grealcr fo r..:e : at the Carne tIme, ir the fmoke is at lIny tirqe
beat down lhe chin.ney by a ruJden gun of wiod, it \\'111 be
etltclud by lhe Ol(':!!t of iron, anJ preY~nted f-rom comiog ioto
Ihe room If the file.place be very wide ¡bt:lweel'l the
lhe one fide and the other. Ihe Dew m¡fonry may be c..rried
quite up lo lhe {hect ot iron on eaeh ot the lides.
3d. As every fire rcquires a connOlot fllccdlion of frefh
air, lhe lube for convcying lhis rare6ed air tO the higber
regioos of lhe atmofphere mull be of a fuffi cient fize lO
connin Ihe whole of it, and aJlow it a ready P.l.rr39C¡ o:her–
wife a pan of it will be forced to feek fome cther patT..ge;
by which means, tbe "pÁrtOlenl mwhich the fire is placed
",ill be eonfi ,ndy filled with fmoke . Every ehimney there–
fore ought tO have a degrec of widencfs futlicieol tO carry
off th whol~ of lhe fmoke arifing from lhe fire ur.ally
bu rnt in it l otherwife the apanm: nt will be almon continua:Jy
611t.d with fmoke.- Thi5 is a hult more C.lnlmOD at rre–
feot tillO any of thofe alrcady mcntioned, efpecially in large
town1, whe-re lhe number of ehimneys in one \\Iall is orten fo
great lhal it is difficlllt tOget a fuffiCI~O[ fpace for each. The
mol! obvio\ls cure, whcre the ritualion admits orit , js 10 ",iJeo
Ihe cbiolne y. by opening a hale a little above tbe grille thro·
lhe b.lck·wall oE the: chunDey, !1anting a liule upwarJ, and
building on lhe outfide o( lhe w.1J a fmall chinlDey open rrom
,ha< hole tO lhe 10p o( lhe building, as in 6g. 5. whele AB
rcpreCen tS the oew tube going Ihrough the watrat Ihe openir.g
at A, whicb wilJ receive the fuperfl uous fmoke. flnd carry it
off T his addllion.1ehinlney mu~ .Iw,y' be earried as high
as lhe: other. BUI as th~re are mflny filu:Hions in \\ hlcn
lhis method of cure would be impral'ticable. \Ve mu'! lrye·
vcry method for accclcralin~ the ..fcenl of (he fmC'ke; (for
lhe more quickl y it afc(,l1ds. lhe more nOlr ro\Y may the rube
be;) and ",ilh lh.u view, the chirnney Olay be heii!htened 0It
tOP, Olnd conlra¿}l!d al bottom, in any or all the n .rious
WciyS we llave mtntioned. BUI if OOtH: of thefe ruethods
pr"ve C'fft'tlual, lel the ehimney be buíl, qllite clofe t\t the
\.inda pan , ICJ\'ing only as tnll¡;h room as i5 fumci~nt 10
eon:aiu ,he grale, h.,·ing a eover of metal fined lOtll3t.o·
penln: