151 NOTES ON THE NORTHWEST. 



sometimes accumulates in such quantities towards the bottom 

 as to render it dangerous to work. This happens chiefly in 

 the hot months of summer ; and at such seasons the miners 

 are frequently compelled to discontinue their labors. 



" The means of ventilation yet employed are very simple. 

 A cloth funnel, its upper portion so placed as to receive the 

 breeze and to deflect it into the shaft, is the only contriv 

 ance. 



" The lead ore, which, wdth a few local exceptions, is 

 alone found or worked in this district, is the galena, or sul- 

 phuret of lead ; the same species of ore from which nearly 

 all the lead of commerce is derived. 



'' One of these local exceptions, however, is to be found 

 at Mr. Brigham's mines, near the Blue Mounds, where car- 

 bonate of lead is raised in considerable quantities along witli 

 the galena. This carbonate is also found in other portions 

 of the district. It is very easily reduced — more so than the 

 sulphuret, inasmuch as the carbonic acid is more readily 

 expelled than the sulphur." 



The value of the lead sent down the Missisippi annually 

 for several years has been something over one million dollars. 

 A considerable quantity also goes by the lakes to New York : 

 and probably, taking into the computation what goes out in 

 both directions, and what is used in the country, the whole 

 produce of the mines is one and a half million dollars. 



It is evident, upon an examination of this statement, that 

 the business of mining is not a very profitable one to tliose 

 eneajred. Takinsc the whole value to be one and a half 

 million dollars, of which one-third goes to the smelter, we 

 "have one million dollars to be divided among, say 3,000 la- 

 borers, or three hundred and thirty-three dollars to each, as 

 the result of the year's labor. But this is very unequally 



