SMELTESTG CHARGES AT INDIVIDUAL SMELTERS. 



No. 3. 



657 



Charge, 640 pounds. Smelting charge, 760 pounds. 

 No. 4. 



Charge, 635 pounds. Smelting charge, 755 pounds. 



Iii the preceding smelting charges the proportions are 



Data relative to the consumption of ore, fluxes, and fuel not being obtainable at 

 this smelter, one of the most important in the camp, the construction of an average 

 smelting charge is impossible ; but the general rule observed a.t the works in the com- 

 position of the smelting charges is the following: The ore-beds are made to contain 

 equal parts of gangue and metallic iron, 20 to 25 per cent, of each, and from 1C to 25 

 per cent, of lead, about six pounds of lead for one ounce of silver. When the propor- 

 tion of gangue and iron is equal iu the ore-bed, the ore is mixed with 1Q per cent, of 

 dolomite; but when gangue is iu excess hematite is added iu sufficient quantity to 

 make the balance. At this smelter the slags obtained are called acid slags. The fuel- 

 shovels used at this and other smelters are drawn to scale in Figs. 1, 2, and 3, and the 

 ore and slag shovels are shown in Figs. 4 and 5, Plate XLR 7 ". 



SMELTER I. 



Smelting charges made in August, 1^80. 

 [At this smelter the ore-bed was made with Morning Star, Duukin, Iron mine, and Apassiz ore 1 



Charge (oie and flux), 799 pounds. Smelting charge (ore, flux, and fuel), 946.5 or 930 pounds. 

 MON. XII 42 



