143 



This is the first cost of materials and wages for producing 



cwts. qrs. lbs. 



Ore-lead, 10 22 



Slag-lead, 2 24 



11 1 4 



Cost of smelting one ton of soft ore cut from a soft rock : 



5. d. 



Coals (11 cwt.), 1 lOi 



Coke, 2 



Lime (1 cwt.), 10 



Turf (123 sods), 6 



Wages of smelter, at 12*. per ton of lead, .75 

 Wages of slag-smelter, at 70*. per ton of lead, 2 



14 9^ 

 This is the first cost of materials and wages for producing 



Cwts. qrs. lbs. 



Ore-lead, 12 1 3 



Slag-lead, 2 5 



12 3 8 

 " The whole of the produce may be commercially consi- 

 dered as ore-lead ; for the smelter is allowed to send to market 

 one-tenth of slag-lead, yet it will all rate as ore-lead. 



" For the sake of distinguishing the results, I caused the 

 two heaps of ore to be smelted separately. Had they been 

 smelted together in a state of mixture it is well known that 

 the produce would have been greater, and at a less cost, as 

 one ore acts a flux to another ; and in the great smelting es- 

 tablishments the practice is to mix the different qualities. 

 The arithmetical mean of my two results is 12 cwt. 12 lbs. 

 of lead from one ton of mixed ore : but we may take it at least 

 12icwt., or 62^ percent., had they been smelted together, 

 at a cost of 155. per ton of mixed ore. Hence, to produce one 

 ton of pig-lead, 32 cwt. of ore should have been smelted. 



