188 
Iron . 
Experience has shewn that the three qualities of coal 
just mentioned, will smelt and give carbonation to the 
following proportions of the same species of torrefied iron* 
stone : — 
112 lb. of clod-coal cokes will smelt - « 130 lb. 
112 lb. of splint-coal cokes will smelt - =105 lb. 
1 12 lb. mixed soft and hard coal cokes will smelt 84 lb. 
Let the iron-stone be supposed in the blast-furnace to 
yield 40 per cent . then we find that the l-20th of a ton of 
the respective qualities of cokes will smelt and carbonate 
the following proportions of iron, viz. — 112 lb. clod-coal 
cokes, 130 lb. iron-stone, at 40 per cent . = 52 lb. iron ; 
112 lb. of splint-coal cokes, 1051b, of the stone = 42 lb. 
of iron ; and 1 121b. soft and hard coal cokes, 841b. of 
the iron-stone == 33, 6 lb. of iron. We then have for the 
quantity of metal produced by one ton of each quality 
of cokes ^ 
Clod-coal 52 X 20 = 1040 lb. 
Splint ditto 42 X 20 = 840 lb. 
Mixed ditto 33,% x 20 = 702 lb. 
This furnishes a datum, whereby we easily obtain the 
quantity of the various cokes necessary to produce 1 ton 
of carbonated crude iron by common proportion : for if 
1040 lb. of metal are produced by 1 ton, 2240 lb. of clod- 
coal cokes, the quantity of the same cokes requisite for the 
production of 1 ton, or 2240 lb, of metal, will be ; 
T. C. Q. lb « 
4824 • 6 lb. = 2 3 0 8 
Splint coal cokes 840 : 2240 j : 2240 : 5^73 • 3 lb, = 2 13 1 9 
Mixed ditto 702 : 2240 : ; 2240 s 7147 • 5 lb, = 3 3 3 7 
If to the quantity of cokes necessary to manufacture 1 
ton of crude iron, we add the quantity of volatile matter 
driven off in the process of charring, which may be thus 
estimated upon the average of each quality ~ 
