370 On the relative Proportions of Coals and 
hence, as 1 cubic foot of this gas, at 29°84 of barometrical 
preflure, and 54°5, of temperature, weighs nearly 761 grains, 
we find, that in the formation of every pound of caft iron 
51400 
961 
~ formed ; ait in the produétion of 1 ton of metal, the afto- 
nifhing quantity of 151289,60 cubie feet. This quantity, 
however incredible it may feem, is only what would be 
formed under the above preflure, and at the above tempera- 
ture: when we take into the account the high temperature 
at which the decompofition and scope mation are effected, 
with the confequent increafe of elaftic force and of volume, 
our ideas are almoft unable to commenfurate the fum of the 
gas hourly formed, and thrown off, ignited to the higheft de- 
gree of heat. 
If the fame mode of calculation is adopted with the other 
qualities of coal, we will have the following refults :— 
17094 
28 
= 64,54 cubical feet of carbonic acid gas will be 
For the fplint-coal 2,442 Ib. or = 610,5 X 100 
: Ay se : . 1. (OLORS 
= 61050 grains of carbonic acid, which gives 2 
I 
\ 
i 
82,85 cub. feet for 1!b., and 82,85 x 2240 = 185,584 cub. 
; 20881 
feet for r ton. For the mixed coal 2,983 or = —- = 710 x 
; ete .. 41000 
100 = 71000 grains carbonic acid; that 1s, 7 ane = 9333 
cubical feet for 11b.; and 93,3 X 2240 = 208,992 cubical 
feet for 1 ton. By the fame calculation we may attain a 
pretty accurate notion of the quantity of atmofpheric air ne- 
ceflary to produce 1 |b. or 1 ton of caft iron; an average of 
the three varieties of coal will be fufficiently accurate for this 
: 14392 + 1700< 20881 
this purpofe ; thus EAs Mee RENAL Soe A ae 174555 OF 
2,4935 lb. of carbon are confumed upon the average of each 
pound of pig- iron : this is found to produce of carbonie acid 
ee igs 
gas = 62°341 X 100 = 62°30041 grains; which 
again divided by 761, the grains in one cubic foot gives 81°86 
cubic feet for the gas difcharged in manufacturing one pound 
7 of 
