170 Hot Blast in the Smelting of Lead. 
Should the writer be able to repay thereby a moiety of debt which 
is constantly accruing against him by the scientific labors of 
others, as published in your Journal, he will be much gratified. 
To reduce the sulphuret. of lead, merely requires that the 
sulphur should be disposed of by combustion; hence a process 
so simple is partially effected by the most simple means. Yet 
it can only continue successful, when the heat is not so high as 
to fuse the galena, and when all parts of the ore «undergoing the 
process, are well supplied with atmospheric air to effect this com- 
bustion. If the blast be heated and made to diffuse itself equally 
through the whole ‘charge,’ carrying with it the flame of light 
fuel, pine or other light wood leaving but little coal, the reduction 
of the ore is effected with an economy and dispatch, hitherto un- 
known in the processes of reducing this metal. The following 
is a description of the hot blast furnace, used at Rossie in the state 
of New York. The form of the furnace is not new. 
Fig. 1. > 
4? i 
Scale of fan 
A ( fig. ‘Ss is a cast iron reservoir twenty four inches square and 
twelve inches deep, the iron of the sides and bottom is two inches 
thick ; to this is attached the hearth B, with flanges projecting at 
the sides, the whole twenty two inches in length, and including 
the flanges thirty two inches wide. ‘The hearth descends about 
one inch i in twelve, and has a groove for the melted lead to dis- 
charge into She rdsccvoir C, in which it is kept fused by a small 
fire under it, D, is a cast iron air-chest, making an iron wall sour 
teen inches: high, above the sides of the reservoir. It is six i 
es thick outside; the iron being about three fourths of an inch 
