PLANT OF SMELTER E. 681 



Furnaces. The smelting capacity of these works is 40 to 50 tons of ore per 24 

 hours. Smelting is carried on in two blast furnaces of unequal capacity, constructed 

 by Messrs. Fraser & Chalmers, of Chicago. The small furnace is ciicular and jacketed 

 all over. Its smelting capacity is 15 tons of ore per 24 hours The crucible is lined 

 with steep, made of two parts fire-clay and one part coke dust. The distance between 

 tuyere and feed-hole is 10 feet 9 inches. The depth of the crucible is 28 inches. The 

 diameter of the riveted wrought-irou-plate water-jacket is 36 inches. This jacket is 

 siugle. The furnace is worked with five tuyeres, each 2 inches in diameter at the 

 nozzle. The average pressure of blast used at smelter E is one inch of mercury. The 

 large furnace presents the same general appearance as the small one, and is jacketed 

 all over; but it is elliptical in section, the axes at the feed hole being 69 inches and 54 

 inches, respectively, and the axes of the riveted wrought- iron-plate water-jackets 52 

 inches and 34 inches. The water-jacket is made in four sections. The furnace is 

 worked with seven tuyeres 2 inches' diameter at the nozzle. The depth of the crucible 

 is the same as that of the small furnace, namely, 28 inches and it is lined with the same 

 kind of steep. The furnaces have projecting fore hearths and lead siphon-taps, and 

 are constructed on identically the same principles as the circular furnaces at smelter 

 B, made by the same firm. The furnaces are barred out every four days, and the 

 length of run is about three months. 



Dnst-chamber. Both furnaces are connected by means of sheet-iron flues with a 

 brick chamber, flue-shaped arid placed under the feeding-floor. This chamber is 75 

 feet long, 4 feet wide, and 6 feet high. It is provided, as usual, with a sheet-iron stack 

 about 30 feet high, placed at the extreme end. The chamber is not divided into sec- 

 tions by internal walls, so that the condensation of fumes is rather imperfect; doors 

 placed at short intervals allow the clearing away of the dust. 



At smelter E flue-dust is mixed with lime in the proportion of one ton of dust for 

 300 pounds of lime (dolomitic), or about 15 per cent. The mixture, after moistening, 

 is molded into bricks, which are then dried in the air and laid over ore-beds to be 

 resraelted. 



SMELTER F. 



Disposition of works Smelter F is the model smelter of Big Evans gulch. The 

 smelting building is capacious and well distributed, and everything in the construction 

 of details of plant indicates extensive previous experience in smelting and no small 

 amount of forethought. Like all the smelters in Big Evans gulch, smelter F is divided 

 into two levels. The boiler, engine, and blast rooms are placed on the left of the fur- 

 nace room (facing the furnaces) and on a level with them. There are two fine boilers, 

 worked at a pressure of 65 pounds to the square inch, and the engine is of 50 horse- 

 power. The machinery driven by this engine consists of two Baker blowers 2 two 

 Blake crushers, a small griiiding-mill, and the pumps feeding the water-tank. The 

 system of blast- pipes is identical with the one used at smelter C. It is provided with 

 safety-valves and dampers, and the excess of blast is ejected by means of a damper 

 placed at the extreme end of the main pipe. Several rows of ore-bins and fuel-bins 

 are placed on the feeding floor of the main building, and reserves of fuel stand at the 

 back and outside the works. A broad wagon-road runs through the entire length 

 of the works. The offices occupy a detached building placed near the entrance of the 



