FURNACE. 
iron, and the cavity filled up with powdered charcoal. The 
fire-place, from the e cover, 18 eae feet ; the 
at the 
The height of the chimney, the inventor ene at 
not sh bie than thirty feet, and the width nine oe 
throu 
Although this furnace has not _ generally adopted, the 
thought is very ingenious, and, 
certain en The fcale 
'; firft, from os cha ange in 
panfibility of the fteel rod ; and, fecondly, from the afe 
of the conducting power in the bricks. Thefe jen 
al much obviated by attending to thefe changes. At all 
eve the oe rometer = enable the se rator to find the 
re ir hea at, | 
wreae: ny ee fition. 
ot vena s fhewn in has Ti. 
rie eee 3 ' the ae 3 c the cover; ae is 
through which the flame rever ae. 
ae ene up the ane: 7; d is a door for introducing the 
oo to be ope erated sae 
bis furnace is ufed for oatting various oo 
as the ores of metals, for the purpofe of expeliing 
tile matter. It may be alfo employed for ie cu 
of metals, the door d being a little opened for the admiffion 
of atmofpheric air. 
igs 5. is a ap aaaeeepemie of Mr. Knight’s portable air- 
furnace ; a is the fire-pl is clofed 
ee, 
fue uch 
regifter $ 
for the reception els eisa 
recefs for the neck of a retort. fig. g. is a dome fitting 
the top of the furnace, to which the tube See 10. iS con- 
nected, which unites with another tube inferted inte a com- 
mon chimney. ig. 8. is a fand-bath, which is ufed in the 
abfence of the dome, and, like it, is connected with the tube 
is furnace is made of jones iron, and lined with an 
ear thy peas Fig. a per{pective view of Dr. 
portable ce ee Bern bats for its < confined afh- 
pit, has not as yet been improved eae a6 isthe fire- 
be the afh-pit; ea r the adiniffion of 
, &c.3 d, another door i> the ge porpole and alfo 
for the introduction nofa mule. Sig. 11. 18 a cover, and 
isa chimney, which 3 is lengthen: db 
by the fame with another 
ehimne "This = like the lait, is made of rolled iron, 
and lined with ch pe and, 
Another air-fura of gr2at power, and very convenient 
for Saale has been coi ai ae nd eae by Mr. 
Moubhet in his numerous — ee experiments ms iron 
and ue 
he i obigingly fi fi write us with the ering ona deferip 
aig or commuting oma. 
y- ‘furnace ie iron, with a flanch pro 
more, een fe erves ohead of bearers s for ie 2¢ bars. : ee fig. 2. 
ght 
f the hight | above is five inches ¢ 3 flue feven 
inches long, and keeps opening into the chimney, as may be 
fen i in fig. 3,atE. Ifthe wile is pee! 25 feet in height, 
a larger due is requifite ; and if beyond 35 feet, a — flue 
will throw the heat more re pila a the furnace. In 
general, however, more in 
from too large a flue. 
{pace for the admiffion of air; it projects 24 inches. out- 
wards, and forves ae operator to ftand upon. 
q, in fizs. tand 2, is sthe — in fiz. 3» which 1 isa ground 
,or cemern 
planof the chir oe furnaces, Cis 
Ing-furnace, in wich the. crucibles are a annealed, 0 i aceil 
the 
the matter to be operated aon: ‘into the al eee T 
alio ferves inttead of a -cementing-furnace, being eafily 
m ade to produce a heat of Wedgwood: i € 
le of any fize, fi from g to 141 inches fquare, a g-inch chimney 
Gane fuificiently wide to the extent of an 18-inch furnace. 
1 is carried up five 
alar 3 ay thea gradually incline 
ey which they enter about pals feet above the flues : 
are Bee ie > from t he grates of this aflay ue 
nace <6 thet of the chimney, the interval is 33 fee 
i ee ace has melted rains of malleable i iron io 
ten Diases ; and half a n lumps in 40 minutes, 
If the materials to be operated upon are prepar ed with 
jidgment any experiment, to the extent of half a pound of 
matter, ma ef ada in half an hour, and Iefs quantities 
in much ee time. approaching to its highelt heat, 
a Stourbridge clay eeitle (which drop in 168 of eS 
wood, ) will difappear i in 15 minutes, from the time that it i 
put in, The firit five bring it to 140° of Wedgw rood, a 
which caft iron eee ae boils in it at 162°, and mallea ble 
iron boils a 179 > of Wedgwood. It is prcebable, 
however, a the advantage of hee furnace do not refute 
or from 
the fize of its opens mor, it is kel depends upon the 
fine; the opening of the gr-te bars; the fize of the fuel; 
particule rly ihe feeding of th: fire 
F 
from the height of the 
fie 
“URNACH, Atacnd, or “fnan. This is elfo called a 
{xeep, and is ufed for fey varating inctals from cinders » flag, 
roken tedis, er Acibles, &c. See Swene. 
Pos ae, ay. "She furnaces above defe bed may all be 
ufed for alfaying or cupelling, fee Plotes I, I, 
Furnace, calicd ‘ or focur furnace. Tt us was a 
conitruction of air-furnace, calculated to preferve an 
equabie ¢ cugree of heat for a confideralle length of time 3 it 
y the alchemiits and chemifls of ihe 
cry in their tedicus and repeated 
c. but is not at prefent in ule. 
ON 
receaqins 
dutilations, cal Icinatio 
F es Balling. ee 
ACE, Bellows or Blajt. Having gi @1 amaccount o 
the pr oe. and defcribed the varieties oz air, or drat ight 
— we fha cies fome account of thofe furnaces which 
e fupplied w hia thei vanical means, and are 
calle d blaf-fur owever, will not comprife 
thofe on the ee “Teale for Riting iron, as ae i has 
been amply treated under the article Bras 
fhall, therefore, confine ourfelves to the fi aller ih ane 
employec a in chemical experiments requiring great and fud- 
de 
was much einployed 
t and pr 
It will appear, from what has been obferved refpecting 
the principles a ‘furnaces, that if the afh-pit of a common 
air-furnace were made perfectly clofe in every part, except- 
ing through the grate, and an opening into the e afh-pit into 
which = nozzle of a pair of double bellows may ah in. 
rte 
