are required to obtain a ton of
cast-iron. The proportions of
the materials dumped into the
furnace are Hi tons of coke, ItJ
of roasted ore, 0} tons of lime-
stone, every 24 hours, producing
7 tons of pig-iroQ every 12 hours
Advantage is t;iken of a sidc-hiU
to make a convenient access for
charging and delivering.
In the illustration, a repre-
sents the regulating-cylinder, 8
feet in diameter and bigitt ; '),
the Hoating piston, loaded with
weights, proportionate to the
power of the machine ; c, a valve 2U inches long,!! inches wide
bv which the air is passed from the pumping-cyhnder into the
rc-ulator ; •/, the a|!erture at which the bUyit rs forced into the
pipe leadiAg o the luyere. The pipe is 13 inches in diameter;
the wider this can be made, the less is the fnetion and the more
powerful the bl.ust ; e is the blowing or pumping cylinder, J tcet
hi"h and 6 feet in diameter, the piston within u having a stroke
if from 5 to 7 feet; /", the blowing piston, with is va ve or
valves of wl-.ich there are somelunes several distributed o^e^
the surface of the piston, the area of each being proportioned
to the number; s is a pier of stone or masonry suppor.ing t,,e
regulating-cylinder, to which is attJiched the flange and blo»-
""-cvlinder ; A is the safety-valve or coc-k, by the simple tnrn-
in° of which the blast may be admitted to or shut olt Iron; the
furnace, passing to a collateral tube on the oppo.ite side: ., the
tuyere, by which the blast enters the furnace ; the end of the
taper pipe which approaches the tuyere receives small pipes of
various diameters, from 2 to 3 inches called nos^-P'P" ■'»'';;«
are applied at pleasure, as the strength and velocity ol the blast
Fig 5224.
Smelting- Furnace a/ die
Pacific States.
Sfiuare ; this and the bosh-stones are always made from a coarse
gritted freestone, whose Iracture |iresents large loundcd grains
of Muart?,. connected liy a cement le-ss pure , , „ „,
The de.-criiition by an iroii-masti-r. as given by J R. Cliapm,
gives a sensible idea of the pioccss —
" You must know that there are about 140 tons of material
in the furniicc, in the proportion ofliU to 75 tons of ore. CO tons
of coal and 15 to 20 tons of limestone, li d ilUo the furnnce at
the opening above The furnace is 40 lect Fquare at bottom,
and 41) feet high, with a hollow space or " llask - in tUc- renter,
lined with fire-brick, and about 14 feet in diameter The ma.
teiial dumped into the fnrnaie litcon;cs n^cllcd. and the iron,
bein.' the heaviest, sinks to the bottom, while the flux, like oil
upon water, tloats upon the surf ice, and, having an aftiiilty for
tlie dross of the coal and iron, it grasps and holds it separately
from the metal, until it is drawn off in what is called ^lag. I his
is done once every hour. The gases evolved pass out at the
chiumey. The trouble is, the iron also has an affinity tor the
dross, and does, and will, retain some of it, uot«ithstanding all
"''" The floor of the building is of fine sand, divided into two
parts by a track, on either fide of which gutters, or riai)i«s,nr«
formed leading from the mouth of the furnace. At cquiil dis-
tances are 8 br.inch goiters, or sow^. as they are techni.aly
called, which condiu t the molten ore to feed the j„?^\n the
berl All these are nicely forn.cd by i uch Fet of hands after the
previous cast has been cooled and removed." See I3l.AST-ruB-
^"" You see, there are 26 7"2' i" «■''"'• «'"' * '"'?■' '" "\* '""' ■'
that is, thev break the sow into 4 pietes, each the size ct a ;.i?.
There are lii bcds.and confcquentlj there are 480 pigs, or iil out
11 tons ill each cast. At each of the branch gutters, or s,m-s a
man is stationed with a spade, with wlii.h he prevents the
metal Bowing into his bed until the bed below him is filled,
when he suddenly transplares it. and, cutlirg olt the flow down-
ward, turns it into his own led. The next man does the same
in successi<m, and when all the beds on one side of the tr.ack
arc filled the How is turned in the sair.e n anner into the other
r,/n.i.r, and the process is rep. aled until all are filled, when the
opening in the Ha^k is closed by d.-.y prepared for that purp. se.
Newsimnliesof coal, ore, and limestone are dumped in aboie,
and the operation of smelting goes on for the next 12 hours.
The iiig-iion is used cither for casting, or for conversion mto
wrought-iron by puddling, etc. S^â– e^'ASTl^G; I'UDrui'O.
Iloweirsfurna.efor making malleable iron direc from the
ore with stone coal, patented in the United Stites about 1.^31,
was thus desclibedbv the inventor: "This furmirc .ombines
within itself the advantagis of a close furnace and an open hre.
In the upper or clo-e poi tion, being all that above the he. rth,
with anthracite .oal, excited by a proper bast, a fl'-P" c of heat
is generated much greater than ran po.s.sibly be <'''.'™<^^,'^'J|,'«.
ordinary fire with chaico:il ;
while the lower portion, o|'cning
SIlTOpshire Smdting-Fumace.
may require, k. the bottom of the hearth ,2 feet square ;(, the
top of the hearth, 2 feet 6 inches square : k t. the hrght of the
Wth, 6 feet 6 inches; Ms also at the bottom of the boshes,
and where thev terminate is of the same size as the top of tlie
hearth only the former is round and the latter square. >n, the
ton of the boshes, 12 feet diiimeter and 8 feet perpendicular
hi.'ht. Ji, the top of the furn.ace, at which the materials are
charged, commonly 3 feet diameter: m n, the i"'"""' "'.",'>:
of the fnrnace from the top of the boshes upward, 31) »■""""'
n k total bight of the internal parts of the fnrn.ace, 44* l«t.
o o, the lining ; this is done in the nicest "f""?"'. "â– '";. Vâ„¢'
bricks made on purpose, 13 inches long and 3 ini^hes "i, ^,
p p. a vaeancv round the outside of the first lining. 3 'nches
broad, .and filled with coal-dust ; this space is .allowed lor the
expansion which might take place in consequence of '« /;"f''-
ing of the materials by heat when descending to the bottom of
the furnace. 7 7, the second lining, similar to the lirst. r
ca.st-iron lintel on 'ivhich the bottom of the ''!-^''.",f,''P;:'';;*^
r < the rise of the arch ; the arch on the outside is 14 feet 'iigh
-vnd 18 feet wide, v v are the extremes of the hearth, 10 feet
into the hearth and permitting the f.ee action of the blast upon
the burthen, performs all the offices ol the o\wu or forge file.
The ore, descending to the region of the tuveres hccoines per-
fectlv fu-ed and passing below the influence ot the 1 last, a part
!s driven out at the open front The burthen in the lurnace
being temporaril.v supported by bars, the masses arc' gatlieied
into a to,.,,, which is removed by tongs and taken to the forge-
hammer."
Smetz-glass. Tliis is fornipd by fusins leiiptlis
of colored glasb into eacli otlifi-.iii liiyeis citlu-r Icvi-l
Of contoitcd, so tlie section shall resemble canieh.in,
afrate, onv.v, etc. „, ,. ,
Smid'dum-tails. (Miniiu;.) The slimy mud
deposited in oie-washing.
Smift. (Mhiinti.) A match of paper satuiated
with niter or other combustible substance, for igiiit-
in" a charoe of powder. A fuse.
I Paiier iiibbed over with oun).ow.ler and grease is
al.siO used bv miners. See SLUW-MAfciI. _
Smit'ing-liue. {Naulical.) A rope by vliieli a
' yarn-stoi.pered sail is loosened without .sending the
men aloft. .,.,,. , . ,
Smock-mill. A form of windmiU in which a
cap rotates on a vertical axis to present the sails to-
ward the wiiul. The term is u.sed in eontradistinc-
I tion to posl-.n-Ul, in which the whole mill rotates lor
a similar pnipnse. .„, , ,
Smoke-arch. (Slcam-mgmc.) The smoke-bo.x
of a loruiijotive.
i Smoke-ball. (Ordnnncc.) A paper shell (lUcd
witli a c<iiii)>osition which, when isiiiied. emits vol-
umes of smoke. It is thrown into niilitniy mines to
i sutibeate working )iartie.s, or into forts to cover an
i advance. It has also been u.sed its a signal.
Smoke-bell. A glass bell suspeuded over a
SMOKE-BLACK.
2224
SMOKE-CONSUMING FURNACE.
gas-light, to intA*r(!ept tlio smoke and pivviint its
bliiL-kfiiinj; tliL' ri-iliiig iininediutfly owv tiic jt-t.
Smoke-black. LamiilihiL-lc olitaiiu'd by lU^posit
of siii-ikf iiviiii iMiiiiiiig iv.siiious material.
Smoks-board. A lioanl iilaucl against a fire-
j>l;ii.- lo k .i-p -Mii't.it* tVoiii i.sbuiiig into a room.
Smoke-box. {Sccc-m.) a. A fliamlH-r in which
tlu» smoke ami IhmIl-iI gases of tlie lines are collected,
and iVoiii wliicli tliey [>ass to liie cliimiiey, i'linnel,
or stack. Some forms uf leverting-tlue boilcia liave
jaioke-boxcs at each end.
b. In locomotives, the end of the boiler on which
the cldmiiey is placed, it receives the draft from
tlie tubes. Locomotives witli iaside cijUudcrs have
tiiem phuM'd in this lio\, which keeps them and the
eti-am-pipes at a hi.;li temperature.
Smoke-con-dens'er. An apparatus for pre-
ci;iiuitiiig the soot and smoke emanating from fur-
iiaees undcrgioiiiid or in otiier conhned situations.
The chinnu-y of tlie furnace is led into the upfier
part of the precipitator a, where it encounters a
<:->. Fig. 6225.
Smoke- Condenser.
strenni of water delivered by a pump into the head
of tlie apparatus and falling through a perforated
diaphragm A, termed the sf mm or ."itrum. The shower
of water falls successively through a series of cups c
and saucers d, ami after having eliminated the fine
solid partieh's from th(? smoke, is discharged through
a pi|ie at tlie bottom. Where the water supply is
laiirc the cup'^ and sunrers mav h>' dispensed with.
Smoke-con-sum'ing Fur'nace. Smoke has
hren tlelini-d as the visible elUuvium or sensible ox-
lialation nf anything burning. So far as our snbjeet
is Cfmeerned, it may be eonsiilered as partieles of
finely divided earl>ou or pellicles of rarbon contnin-
ing iullannnabh' gas. The object of tin' deviees to
be eited is to so apply the fuel that the escaping
combustible matters shall hz exposed to incandescent
fuel and a due supply of vital air, which conjunction
of agents wid eonsume the eombustiblc gases and the
partieles of carbon suspended therein.
In 1S19, the Hritish House of romnions appointed a commis-
sion to '• I'lKiuiru how lar it niij^iit be pi\u tic.iljlo to conqiel
pi:r.>otis using ste.tui-i.*u;j:ine.-> ami furnaces to ci'cct tlieui in a
manner less prejudici.il to public licilth anj comfort, and re-
port tlieir observations thereupon to this House â– '
A Iar{;e number of practical aud Ptieiitific men were exnm-
ined, and, the connnis - -ion bceoming satistiid that " the reduc-
tion ofsnuike from furnaces mitrht be practically r.ccompU.-lieil,"
a bill wa.s brouj^ht forward and past^ed wliiih made tin* avoid-
able prudui'tion of smoke from furuace-chinuieis an indictable
and finable ollense.
(Complaints apiinst tlic snioUe nuisance are of ver}- old date.
(jieat prejudice \V!is felt in former timc' in Kitgland aj^ainst
the burning; of coal, known then !is sea-coal, beiau.-^e it was
brouf^ht from the Tytw to the Thames by sea It was supposed
to be injurious to trade, health, tlie complexion, and a whole
CJitalogue of evils wsus feared from its use. In 130(J, the king
of Kiigiand issued a proclamation against its uFe,aud a connnis-
sion was issued lor tlie purpose of astertaininf; who burned sea-
coal v\ithin the city aud its neighborhood, and to punish tliem
by fine for the first offense and by the demolition of their fur-
naces if they per.-isted; buteven these severe proceedings tailed
to put down tlie nuisance. A law was therefore p;ussed, making
the burning of sea-coal within the city a capital olfcnse, and
permitting its use only in the forges in the mighborhood. In
the reign of the first Edward a man was tried, convicted, and
executed for burning sea coal in London.
" Much has been written on this branch of the subject [con-
suming smoke]. The principles concerned are extremely sim-
ple ami easily applied.
" The volume of air supplied must be neither greatly in excess
nor greatly deficient of that necessary for perfect coml>u^tion.
If it be seriously deficient, the fuel, if bituminous, is partly only
distilled or sublimed into black smoke and tarry soot, the ad-
lierence of which to the boiler surfaces becomes a cause of far-
thf'r loss of I'llect,
" If tlic fuel be carbonaceous only, as coke, anthracite, etc ,
its gases are only oxidized to the state of carbonic oxide in
part: and if the fuel be wood or peat, the hist result occurs with
the distillation of various tarry and acid products (pyroligueous
acid), highly destructive to iron boilers.
" If the volume of air be greatly in excess, the heat of the
furruice is reduced, and may be so to an extent tn canine even
imperfect combustion, and a great volume (or weight) of air is
uselessly lieatcd and discliarged by the chimney.
" Non-bituminous fuel is more easily burned perfectly than
bituminous ; with either, hut especially with the latter if com-
bustion is to be practically perfect, there nmst he n suflidcnt
draft to carry the air-current steadily through the fuel. The
layer of this upon the dead-plate and grate should never exceed
10 to If) inches, and is best not to reach fior 7 ; but thin firing re-
quires very careful stoking, or bare patches of prate are exposed,
occasioning much loss. ^Vith coke or anthracite, aud especially
with a lilast, a much greater depth of fuel may be pmcticable.
" The air is best admitted partly beneath and through the
fuel, and partly in atljustHble volumes, at or just behind the
bridge, where it should be so arranged that the air and com-
bustible gases shall mingle as completely as possible. Thi- is
the plan so much and so justly insi^^ted on by Mr- C. W. Wil-
liams, Mr. Prideaux, and several others. '1 he air adn iticd
shonbl be heated ; and this is best of all done by the use of Mr.
C Siemens" regenerator, applied to the fines of the boiler be-
tween the latter and the chimney-stack. It the nir be cold the
combustible g;u;es are chilled more or leFs.and below a red heat
these cannot burn perfect 1\ or without the production of smoke.
The area of air aperture a't tlie biiilge is fixed by Mr. Uilliams
at 1 square foot for every 3(J square feet of grate, when the lat-
ter burns £5 pounds of coal per foot per hour, ami in like pro-
portion for lai'ger consumption. The maximum of economy
will, in perhaps a'l boilers, be elTected by the regenerative prin-
ciple ; and in this case the air passed into the Hues above the
fuel or at the bridge may be admitted at even 800° or 900° Fah.
" When the proportioning and arrangements of the furnnce-
grate and draft are such as to insure the conditions for coui-
pleto combustion, the next great point to be jittended to is, that
the rate of passage through the Hues, or past the heat receptive
; surfaces of the boiler, must be such thnt the combustion of
gases shall have been perfected before they have been robbed
of so much heat hv the boiler as to fall in temperature below
; that few complete nxidafion : if not, smoke, soot, or tiirry prod-
j net-* may be still fnrnu-d in the remoter ends of the fines.
" Where the re-xenentive system cannot be applied to the nir-
I supply, -Mr. Fairhairn's double furnace cylinclrirnl boiler, for
alternate firing, is the next bi-st arrangement. It is one that
practically works well with the ordinary amount of stokt-r's at-
tention, which alone can be reckoned on.'' — Ar^'Strong.
One principal difficulty has arisen from the usual practice of
placing the coals on top of the incandescent fuel, so that as the
smoke? is evolved it h.is free )iassagp to escape by nieiins of the
chimney. This is the simplest way of leeiling a fire, but is
evidently wasteful. unless secondary means be employed to con-
sume the matters thus escaping.
SMOKE-CONSUMING FUKNACE.
2225
SMOKE-CONSUMING FURNACE.
To obviate this, and cause the smoke to pass over a mass of
burning fuel, various contrivances Jiave been invented for in-
troduciog the fresh fuel beneath tbat which is already burning :
among these may be mentioned Cutler's; and Dr. Arnott's,
which is an improvement upon it. Tbese and otliers are adapted
for opeo grates. See Grate, Smoke- consuming ; Base-burning
Stove.
Watt, in his specification of 1785, claims " constructing fur-
naces so that the smoke or flame of the fresh fuel is cau.«ed to
pass, together with a current of fresh air, through, over, or
among fuel which has already ceased to smoke, or which has
already been converted into charcoal, coke, or cinders, and
which is intensely hot '' Severn! ways of effecting this are de-
scribed by him. The introduction of fresh air, to consume the
carbonaceous particles which have escaped the action of the air
originally admitted to the furnace, is a very important element
in producing a successful result, and appears to have been
original with Watt. It has been introduced into most, if not
all, subsequent devices of value.
Among the plans suggested and practiced for securing the
perfect combustion of the fuel and its resulting valuable gases,
may be cited : —
1. Introducing the fuel into the fire in such man-
ner tliat tht? smoke and gases evolved pass through
a bed of red-hot niattt* r.
To this class belong : —
a. The Achunor or constant furnace of the alchemists, used
for keeping up a
Fig. 5226. constant heat for
many consecutive
days, in their patient
and laborious at-
tempts to transmute
ba-'^e nietils into
gi»ld, or produce the
elixir of life- Along-
side tlie fireplace
wjis a hollow con-
tjiining charcoal,
and closed above by
a tight lid. As the
fire consumed the
fuel, the charcoal
descended and re-
Detasme's S/7io/ce- Consuming Furnace, plenished it.
h. Delasme's base-
burning furnace, exhibited by him at St. Germain's, in ItjSo.
It was in the form of an inverted siphon : the shorter leg c con-
tained a grate o, and served as the tire-chamber, the longer leg
i constituting the chimney ; the smoke was thus caused to pa.^a
through the incandescent fuel, and more or less perfectly burned.
The fire was kindled at the top, and the chinmey i was heated
by a lamp to originate the draft.
c. Watt's base-burning furnace, in which a body of coal is
supplied in a hopper,
Fig. 5227
till
WaWs Base-buniii
coal gradually lall-
into the fire as the
substiiuce of the lower
lajer is consumed. The
coal-chamber may be
covered in by a tight
'XT I'^^l' ^o ^â– ^ to prevent the
draft of hot air through
it; or the inlet draft of
air may be conducted
through it. The former
is perhaps the preferable
mode, and the coal
Furnace. should be discharged
through a throat of
such capacity as, on the one hand, not to choke, and on the
other, not to encourage, the access of fire to the contents of the
supply-chamber.
In its character as a smoke-consuming furnace, it will be
noticed that the fresh coal is constantly in contiiet with the in-
candescent fuel, and that all the gjises evolved by the combus-
tion are obliged to pass through a body of hot coals, whereby
the hydrogen and carbon which constitute the valuable portion
of the smoke are consumed.
This feature is to be found in some stoves in which a body of
coal is brought into contact with the fuel in such a manner that
the volatile products of the fresh coal are compelled to pass
through the incandescent mass of fuel.
d. Stoves of the base-burner class, in which the fuel is intro-
duced beneath the fire. See Stove, Base-burnkr ; Magazine.
e. A furnace in which the escaping smoke from one fire is
burnt at a second fire ; also found in Watt's patent, 1785.
This is thus described in the words of the inventor: "I
place the fresh fuel on a grate as usual, as at n, and beyond
that grate, at or near the place where the flame passes into the
flues or chimneys, I place another small grate b, on which I
maintain a fire of charcoal, coke, or coals, which have been pre-
viously burned, until they have ceased to snmke, which, by
giving intense heat and admitting some fresh air, consumes the
smoke of the former fire.'^
140
A modification of the Watt furnace, Fig. 522S.
by a Mr. Thompson, patent ITUlJ, had
an extension of the grate bars and TKi**^''^
arched bridge, about 5 the distiince from 'p' T
the front end. Beneath this bridge the
volatile products of the first part of the /
furnace were carried, and detlected upon ( /
am;issof incandescent fuel, which occu- h^ ^- ^.-^^-^ .â– ' ~
pied the rear portion of the furnace, ^ Wjrp â– , -
where they were met by a current of ; i^' -i_^__ r—
air admitted back of the bridge. This : \ _
backward portion was kept supplied j , \
with red-hot coals from the former fire, i- ]
or by coke or charcoal s«paiutely intro- ' ' —
duced. U\('/'> /I r' â– . -I'l â–
Gregson's patent, 1S15 (also English), Fmnucc,
depended upon the exposure of the vola-
tile and inflammable results of combustion, to intense heat at
an aperture at the back of the fire and passing through the fire-
bridge.
Losh's double-fireplace furnace, 1815, is another example of
this class.
This furnace has two fires, which are alternately replenished
with fuel. The fireplaces are connected, and either is thrown
in connection with the chmiuey by means of suitable flues and
dampers. The fireplace which has just received coal pours its
smoke and ga.'Jes into the mass of red-hot coals of the other fire,
from whence the volatile matters, deprived of their inflammable
gases and carbon, pass to the chinmey. When the time conies
to replenish the fire, the one which has acted as the secondary
furnace receives the coal and delivers the smoke under the
arch of the division wall to the other fire, which is connected
to the chimney, by change of dampers.
The City Flour Mills, Upper Thames Street, London, are fitted
with boilers consuming their own smoke, gencniting steam for
an engine of 220 nominal horse-power. The boilers are 7 in
number, and the engine is on the marine principle. The engine
was formerly one of the stitionary engines on the Blackwall
llailw^iy, when the carriages were drawn by a rope.
The furnaces are arranged in a row, with communicating
flues guarded by dampers. When one fire has received fi-esh
coals, its immediate connection with the chimney is closed, and
the smoke is discharged into the adjoining furnace, whose fixe
is burning red.
2. The phin of admitting a second body of air to
inthinie the unconsumed combustible matters which
pass away from the fire.
John and James Robertson, of Glasgow, patented a furnace
in 18Ul, in which, by means of a pipe, air was admitted directly
into the body of the fuel while burning, — the first practically
successful contrivance of the kind.
in other cases, the air is admitted at or near the fire-bridge
or in a chamber behind the fire-bridge.
Kvctt's reverberatory furnace (English patent, 1812) has a
co7i(lucior which introduces a body of air through the bridge-
wall, and ejects it upon the eddying volumes of smoke and gas
which occupy the dome of the metal-chamber The size of the
aperture in the air-tube was regulated by a valve. This is, per-
haps, an advance upon \\'att's patent of 1785, in which the
accessory body of air passes through the grate bars-of a supple-
ment^try fire, which assist^* in the combustion of the smoke.
Chapman's furnace (1S24) had hollow grate-bars, forming a
series of parallel tubes opening into two boxes, one in front and
the other behind the grate. The rear one connected with a
hollow fire-bridge, which discharged heated air in jets into the
volume of smoke passing over the bridge, thereby causing the
heated gases to ignite.
C. Wye Williams' furnace depends for its action on the thor-
ough intermingliDg of the gas evolved by fuel with atmospheric
air before the temperature of the carbon contained in the gas,
then in the state of flame, be reduced below that necessary for
sit ignition, — about SOU®, according to Sir Humphry Davy.
This is effected by admitting the proper proportion of air
through several* hundred half-inch orifices in and above the
door-box. According to Mr. Willi.ims, it is hnmaterial in what
part of the furnace the air is inti-oduced, provided that the above
condition be attended to. In the experimental furnace at the
Newciistle trial, the area of the openings for the admission of
air was equal to four inches square for each square foot of grate-
bars.
This received the prize of £.500 offered by the Colliers' Asso-
ciation of Newcastle for the best furnace of the kind.