Iron • 18$ 
Clod coal \ or 37| fier c. produce in cokes ■§ a 62-} Jier 
Splint coal £ — 50 - — 4 or 50 
Mixed coal \ — 62,5 — , . - , — -} — ■ 374 
Then, for the quantity of the respective coals used in 
the raw state, we have the following results in proportion 
T. C. Q. lb. 
Clod coal 5 : 4824 • 6 : : 8 : 77 19^ — 3 8 2 19 
Splint coal 4 : 5973 • 3 : : 8 : 1 1946 — 5 6 2 18 
Mixed coal 3 : 7147 • 1 : : 8 : 19158-} = 811016 
These great disproportions of quantity, used to fabric- 
cate 1 ton, or 2240 avoirdupois pounds of the same quali- 
ty of crude iron, will convey a striking and impressive 
idea of the multifarious qualities of coal which may be ap- 
plied and made to produce the same effects. It should 
also convince the manufacturer that the study and analy- 
sis of his own materials is the first and radical approach to 
true knowledge, and certainty of operation. Divest him 
of this knowledge, and view him guided by the customs 
and rules prevalent at another manufactory, where the 
coals and ores may be as different as has been already men- 
tioned, and we will no longer wonder at the uncertainty of 
his results, and the numberless errors of his direction. 
Before I enter into the practical discussion of the ap- 
plication of coal, I beg leave to indulge myself in the fol- 
lowing calculations : — We have already seen that the pro- 
duction of 2240 lb. of carbonated crude iron requires 
48241b. of clod-coal cokes ; these may be averaged to con- 
tain 4*5 per cent . of ashes, which, deducted from 4824, 
gives 4607 lb. of carbon used for 1 ton of metal : this sum, 
divided by 2240, farther gives, for 1 lb. of cast iron thus 
manufactured, 2-056 lb. of carbon. 
We next find that 2240 lb. of the same metal requires 
of splint-coal cokes 5973*3 lb.; we farther find, from a ta- 
ble of the analysis of coal, furnished in a former pa- 
per, that 100 parts of the raw coal contained 4-2 parts of 
ashes® As it is there stated to lose 50 per cento in char- 
