F U R N A C E. 
with the workmen in filling the furnace, The dimen- 
fions, as to height, are as follosv; 
From B to C lieight iz feet 
C to A. ditto 6 
A to IJ ditto 6 
D to E ditto ....... 13 
Height of the hearth, andfirft row of boihings, 
not Ihewu in the figure .......15 
Height of the bottom itones, and falfe bottoms, 4 
Total height of this furnace from the foundation, 56 feet. 
G G, the lining, made of fire bricks. II, thecomnion 
building, which might be either of fimd-ftone, or of bricks, 
Tlie reafoning wliich led to the conftrudlion of tltis fur¬ 
nace, proceeded from a belief that the bofites and throat 
or fquare of a blaft-furnace were of the greateft'import¬ 
ance on twoaccounts. Firll, becaufe they fupportedthe 
weight of the materials ■, and I'econdly, becaufe they con¬ 
centrated the heat. Tltefe adling conjointly, permitted 
the lead poffible quantity of materials to pafs, till they 
dropt away in a date of femi-fufion, or complete fepara- 
tion. In furnaces, however, the cones of wltich were 30 
feet high and upwards, this was conceived impollible to 
take place for any length.of time, to any conliderable eK- 
tent. Tlie height and gravitating prell'iire of the materi¬ 
als were more than fufficient to counteradl the mod,favour¬ 
able condrudtion of bodies : and as this could not admit 
of diminution, the fufpenlion of the materials and the 
concentration of the heat mud be effedted by fome other 
means. This, at ore time, was believed to have been 
completely eftecled by the fcheme of an additional fquare, 
and an extra fet of bodies; and th«e is little doubt but 
tliat, by converting perpendicuLir to lateral prclfiire, the 
ftifpenfion of the materials was reduced at lead to one 
lialf of its former intenfity. It was not doubted but that 
the procefs of fraeltiiig and reparation would commence, 
in part, at A ; that what efcaped fufion and reparation in 
that quarter, would be eafily refolved below ; and that 
the procefs of combiidion intenfely at work in two did'e- 
rent places at once, would greatly facilitate the general 
reduifion, and add confiderably to tlie produce in iron of 
the furnace. Thefe fanguine expeftations were however 
unfortunately not realized ; the lolitary indance of one 
furnace only being condrutted in fupport of tliis theory, 
and its mere temporary endurance, was a high proof of the 
inutility of the plaji. From tliis we therefore proceed ta 
the new-invented furnace of Mr. Watt of Birmingham. 
STEAM-ENGINE FURNACE. The condru6tion 
of this furnace is deferibed in tlie fpecification of the pa¬ 
tent obtained for the invention by Mr. Watt as follows 
His “ improved methods of condrucling furnaces or fire, 
places, confid in can dug the fmoke or dame of the fredi 
fuel, in its way to the flues-or chimney, to pafs, together 
with a current of frelh air, tliro'Ugh, over, or among, 
fuel which has already ceafed to I'moke,. or which is con¬ 
verted into coaks, charcoal, or cinders, and which is in¬ 
tenfely hot; by wliich means the I'moke and grolfer parts 
of the flame, by coming'into clofecontaT with, or by be¬ 
ing brought near unto, the faid intenfely-hot fuel, and 
by being mixed witli the current of f^'^efii or unburnt air, 
are conlumed, or converted into l.eat, or into pure flame 
free from fmoke.” Tliis is done, “ fird, by dopping 
up ev-ery avenue or palfage to the chimney or flues, ex¬ 
cept fucli as are left in the interdices of tlie fuel, by plac¬ 
ing the fredi fuel above, or nearer to, the external air 
than that which is already converted into coaks or char¬ 
coal ; and by condruftitig the fire-places in Inch manner 
that ^lie flame, and the air wliich animates the fire, mud 
pafs downwards, or laterally, or horizontally, througli 
the burning fuel, and pafs-from the lower part, or inter¬ 
nal end or fide, of the fire-place, to the flues or chimney. 
In fome cafes, after the flame has paded througli the 
burning fuel, it is made to pafs through a very hot fun¬ 
nel, flue, or oven, before it comes to the botto-ra of the 
boiler, or to the part of tlie furnace where it is propofed 
to melt metal, or perform other office, by which means- 
the fmoke is dill more ed'eftually confumed. In other 
-cafes, the flame is carried immediately from the fire-place 
into the fpace under a boiler, or into the bed of a melt, 
ing or other furnace.” In Plate II. of Furnaces, fig. i 
Ihews a fedtion of a fire-engine boiler, and its furnace or 
fire-place, which has been chofen for an example of tlie 
application of this new method to the heating and evapo¬ 
rating of water. A A, the boiler, which may be made 
of any form fuitable to its life. B B, a flue, furrounding 
the boiler as ufual. C, the uptake, or paf.dige from the 
fpace under tlie boiler to the flues. I>D, a funnel or flue 
for the flame to come from the fire-place to the boiler. 
E E, a place to contain the afhes; and F, is a door to 
take them out at, which mud be kept continually Iliut 
during the time of working. G H, the fire-place : tlic 
fredi fuel is put in at G, and gradually comes down as the 
fuel below confunies. The part at H, is very hot, being 
filled with the cokes or coals which have ceafed to fmoke, 
I, an opening or openings, to admit frefh air and regulate 
the fire. K, a door into the fpace under the boiler ; 
which, being opened, admits air, and dops the draughf 
of the chimney when the operation is wanted to ceafe. 
Fig. 2. reprefents a leftioii of the fame fire-place in the 
other direflion ; in which MM, is tlie back of the fire¬ 
place ; L, the brick arch on whic’i the fuel lies ; and E,. 
thealh-hole. Fig. 3, gives an outfide view of the fame 
fire-place, dievving the air-holes II, and the adi-hole door 
F ; and fig. 4 is a plan of the fame, with part of the boil¬ 
er featiiig, taking in the Hue ZZ of fig. i. Tlie dotted 
lines reprefent the dues, and the arrows point out the di¬ 
rection of the flame. The fire is fird kindled upon the 
brick arch L, fig. i ; and, when well lighted, more fuel 
is gradually added until it is filled up to G ; and care is 
taken to leave proper interdices for the air to pafs, eitlier 
among the fuel, or between the fuel and the front wall N ; 
and as much air is admitted at 11, as can be done without 
caufing the fmoke to afeend perpendicularly from G,. 
which it will do if too much air is admitted at 11 . The 
dimenfions of this fire-place are adjuded for burning aVout 
eighty-four pounds weight of coals in an hour; where 
greater or lefs quantities are required to be burnt, tlie 
fui naces mud be enlarged or diminillied accordingly ; or, 
if mucli greater, more furnaces than one mud be employ¬ 
ed. Fig. 5, reprefents this new fire-place as applied to a 
furnace for fmeUing iron and other metals, and is con- 
dructed without the'funnel or perpendicular flue D, in 
fig. I. In this defeription, tlie fame letters refer to the 
fame parts in all the preceding figures. 
Mr. Watt alfo condruCts his new fire-places fo that the 
parfGH lies doping, or horizontal, and otherwife varies 
the figure or form, and proportions ; but in all cafe.s the 
principle is the fame ; the fredi or raw fuel being placed 
next the external air, and fo that the fmoke or flame 
palfes over or through tlie coaked or charred part of the 
fuel. He alfo occafion.illy covers the opening G, and 
caufes the air to enter only, or principally, at I I. In 
particular cafes, he places the fredi iuel on a grate as 
ufual, as at A A, fig. 6. and beyond that grate, at or near 
the place where the flame palfes into tlie flues or chim¬ 
neys, he places another fmaller grate B, on which he 
maintains a fire of charcoal, cokes, or coals which have 
been previoufly burnt until they have ceafed to fmoke ; 
which, by giving intenfe heat and admitting frelh air, 
confunies the fmoke of the fird fire. Ladly, he dates 
his new invention to confid only in the method of confuni- 
ing the fmoke, and increadng the heat, by caufing the 
fmoke and flame of the frelh fuel to pafs through very- 
hot funnels or pipes, or among, through, or near, fuel 
which is intenfely liot, and which has ceafed to fmoke; 
and by mixing it with fredi air when in thefe circuindan- 
ces ; and in the form and nature of the fire-places above-* 
mentioned; the boilers and other parts of the furnaces 
being 
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