Hot Blast in the /Smelting- of Lead. 



173 



Fig. 3 is a crusher of cast iran. Into this the ore and gangue 

 is thrown, and reduced so that none of it is larger than half inch 

 cubes, and as httle of it crushed very fine, as possible. 



Fiff. 3. 



Single crusher used at Rossis. — a, driving pinion, b, wheel attached to lower 

 crusher c. d, upper crusher, filled with lead and weighed down by lever d. 

 Whole pressure of the crusher, say 4000 lbs. 



Fig. 4. 



^J^ 



Fig. 4 is a bucket sieve ; A, a square box with iron bottom, per- 

 forated with small holes, suspended in the vat of water, B, in 



