-t 
fer Smeliing Iron from the Ore: 4t 
feet high: .—B, the floating pifton, loaded with weights pro- 
portionate to the power of the machinc.—C, the valye, by 
which the air is pafled from the pumping cylinder inte the 
regulator: its length 26 inches, and breadth 11 inches,— 
-D, the aperture by which the blatt is forced into the fur- 
nace. Diameter of this range of pipes 18 inches. The wider 
thefe pipes can with conveniency be ufed, the lefs is the 
friction, and the more powerful are the effets of the blaft. 
—E, the blowing or pumping cylinder, fix feet diameter, 
nine feet high : tparnal of the pifton in this cy linder from five 
to feven feet per ftroke.—F, the blowing pifton, and a view 
of one of the valves, of which there are fometimes two, and 
fometimes four, diftributed over the furface of the pifton. 
The area of each is. proportioned to the number of valves : 
commonly they are 12 416 inches:—G, a pile of folid {tone 
building, on w hich the regulating cylinder réfts, and to 
which the flanch and tilts of the blowing evlindel are at- 
tached.—H, the fafety -valve, or cock; by the fimple. turning 
of which the blatt may be admitted to, or fhut off from thie 
furnace, and pafled off to a collateral ube on the oeppofite 
fide.—I, the tuyere, by which the blaft enters the furnace. 
The end.of the tapered pipe, which approaches the tuyere, 
receives fmall pipes of various diameters, from two to three 
inches, called no/e-pipes. . Thefe are applied at pleafute, and 
as the ftrength and velocity of the blaft May tequire. —K, the 
bottom of the hearth, two feet f{yuare—L, the top of the 
hearth, two fect fix itiches fquare: KL, the height of the 
hearth fix feet fix itches. —L is alfo the bottom of the bothes, 
which here terminate of the fame fize as the tep of the 
hearth ; only the former ate round, and? the latter fquare.— 
M, the top of the bofhes, 12 feet nid lig and ¢ight feet of 
perpendicular height —N, the top of the furnace, at which 
the materials are, “cha ed; commonly three fect diameter. 
—MN, the internal cavity of the furnace from the : top of the 
bofthes upw ards, 30 feet high.—NK, total height of the inter- 
nal parts of the furnaces 44; feet. —OO, the lining. This.is 
done in the niceft.manner with fire-bricks made on purpole, 
13 inches long and three inehes thick.—PP, a vacancy which 
18 left all round the outfide of the firft lining, threé inches 
broad, arid which is beat full of coke-duft. This {pace is 
Vou, V. i alluw ed 
