158 Mr. H. L. Pattinson on Smelting Lead Ore, §c. 



sinking down a little behind, the nozzle of the bellows is not more than 

 3 or 4- inches above the surface of the Lead. The blast is always direct- 

 ed downward into the hearth, so as to cut the upper edge of the work- 

 stone, as shewn by the dotted line leading from the bellows-pipe in Fig. 

 3, by which means it is more thoroughly distributed through the con- 

 tents of the hearth. In Figure 3, there is a space shewn between the 

 workstone and hearth-bottom. This is generally filled up with fire clay, 

 or a mixture of slime ore and bone ashes, properly moistened with water ; 

 but a plan sometimes adopted, is to have the hearth-bottom and work- 

 stone cast together, which renders stopping unnecessary. Another mo- 

 dification of the hearth, adopted by some intelligent smelters, is making 

 the bottom, instead of 44 inches, 10 or 12 inches deep, by this means 

 increasing the quantity of lead retained in the hearth, and proportionally 

 lessening its tendency to get too hot, during the process of smelting. 



In proceeding to smelt by means of an ore hearth, two workmen are 

 required to be in attendance from the beginning to the end of each 

 smelting shift, the duration of which is from 12 to 15 hours. The first 

 step in commencing a smelting shift, is to fill up the hearth-bottom and 

 space bellow the workstone with peats, placing one already kindled be- 

 fore the nozzle of the bellows. The powerful blast very soon sets the 

 whole in a blaze, and by the addition of small quantities of coal at inter- 

 vals, a body of fire is obtained filling the hearth. Roasted ore is now 

 put upon the surface of the fire, between the forestone and pipestone 

 at /, Fig. 3, which immediately becomes heated red hot and reduced ; 

 the lead from it sinking down and collecting in the hearth-bottom. 

 Other portions of ore of 10 or 12lbs. each, are introduced from time to 

 time, and the contents of the hearth are stirred and kept open, being 

 occasionally drawn out and examined upon the workstone, until the 

 hearth-bottom becomes full of lead to the dotted line n, Fig. 3. The 

 hearth may now be considered in its regular working state, having a mass 

 of heated fuel, mixed with partly fused and semi-reduced ore, called 

 Brouse, floating upon a stratum of melted lead. The smelting shift is 

 then regularly proceeded with by the two workmen, as follows : — The 

 fire being made up into the shape represented by the dotted line at /, 



