628 



GEOLOGY AND MIXING INDUSTRY OF LEADVILLE. 



Unless tbe ore contains luoie than a certain percentage (5 per cent, to 30 per 

 cent.), the lead is not paid for at all. 



These rates are subject to constant flnctuation, according to — 



1. The price of fluxes. 



2. The amount of fluxes required in smelting. 



3. The jirice of charcoal and coke. 



■4. The character of the ore : whether large lumps or sand ; whether highly sul- 

 phureted or highly silicious ; whether rich or poor in lead ; whether rich in oxide of 

 iron or without it. 



The cost of treatment has varied during the year ending June 1, 1880, from $15 

 to $30 per ton of ore. The ])rice paid for silver and lead in the ore varies naturally 

 with the New York market. During the year ending June 1, 1880, the variation for 

 silver has been from full New York quotations and no discount to a discount of 10 

 per cent., the average discount having been about 5 per cent, oft' silver quotations. 



Lead is bought by the unit, i. e., 1 per cent., or 20 pounds in the ton ; and its 

 price has varied from 15 cents to 45 cents per unit during the year 1879-80. The 

 price per unit of lead depends on individual agreement, and also on the contents of 

 the ore in lead. At some smelting works the cost of treatment will be $16 to 825, 

 with a deduction of 5 per cent, oft' silver, and the price of lead 20 cents to 25 cents 

 per unit when the ore contains above 30 per cent. At others, the cost of treatment will 

 -equal $20, the deduction oft' silver 5 per cent., aud the i)riee for lead 15 cents jier unit 

 when the ore contains above 5 per cent. 



Gold is i)aid for at the rate of $18 per ounce, but only when its amount exceeds 

 •one tenth of an ounce per ton of ore. 



Cost of transportation — When the Ore is bought direct from the mine, its trans- 

 portation is paid for by the mine owners, and the cost of handling varies from $1 

 to .§1.85 per ton of ore, according to distance; but when the ore is purchased at the 

 sampling works, the smelters have to pay for its transportation to their bins at the 

 above rates. 



SAMPLING. 



Method — The general method of sampling carried on in the camp is the follow- 

 ing: In shoveling the ore from the ore-wagon to the ore-bin, every tenth shovelful is 

 thrown asiile into a wheelbarrow. Thence the sample thus obtained is wheeled to the 

 sampling floor and passed through the crusher. It is tlieu well mixed with the shovel, 



