Wisconsin and Missouri Lead Region. 



Fig. 3. 



Furnace about four feet high, four feet deep, and five feet front. 



Tvveer introduced from behind, opposite the hole for the exit of the lead and slag. 



Fuel — charcoal. 



L, vessel to catch the lead. 



S, hole to catch the slag ; in this runs a current of water. 



into the first vessel, the slag floats over it into the next, through 

 ■which runs a stream of water. Here it is cooled, and then ladled 

 out and thrown away.* The amount of lead produced by one 

 of these furnaces, varies of course with the quality of the slag. 

 At O'Neill's slag furnace on the Peccatolica, near Mineral Point, 

 where the charge consists of the rich reverberatory furnace slag, 

 and that from the old ash furnaces, twenty seven pigs of lead are 

 frequently obtained at one shift or day's work ; twenty five, how- 

 ever, are considered a good day's work. The hands employed, 

 are a smelter, back-hand, and assistant. 



Having given this particular account of the furnaces, I will 

 now enter into an examination of the lead business taken as a 

 whole ; and most of the data for the estimate I shall take from 

 the report of Dr. Owen. 



The whole number of furnaces in Iowa, Illinois, and the terri- 

 tory of Wisconsin, he judges to be fifty. This was in the year 

 1839, since which there has been. no great variation in the busi- 



* It is supposed this glassy slag is nearly free of metal ; but having analyzed it 

 by digesting in nitric acid, separating the silica, throwing down the lead as a sul- 

 phuret by hydrosulphuric acid, and converting this into sulphate of lead, I found 

 it to contain 24.72 per cent, of oxide of lead. 



Vol. xr.ni, No. 1.— April-June, 1842. 7 



