688 GEOLOGY AND MINING INDUSTRY OF LEADVILLE. 



a source of trouble and tbe plan should be condemned altogether. The furnace is 

 worked with nine tuyeres, 3 inches in diameter at the nozzle, inserted, as usual, in the 

 water-jackets; one of the tuyeres is placed in the back jacket and four on each side. 



Each jacket is not only provided with inlet and outlet pipes for the circulation of 

 water, but a general circulation has been established between all the jackets by means 

 of pipes screwed into them at the base and communicating with one another. 



Dust-chambers. The system of condensation of lead fumes adopted at this smelter 

 is poor, and "leading" is consequently of frequent occurrence. The four furnaces 

 are connected by means of the sheet iron flues F [ F il F M F iv with the sheet-iron 

 chamber M, connected by means of the brick flue N with the stack F (in Fig. 1, Plate 

 XXXV11I). The sheet-iron chamber has already been seen in transverse elevation 

 (Fig. U, Plate XXXVII). Neither chamber M nor N is divided into sections, so that 

 the condensation of fumes is very imperfect. Both chambers are provided, as usual, 

 with sliding doors d for the extraction of the dust. 



At smelter II, flue-dust is mixed with liiberuia ore (an argillaceous ore contain- 

 ing no lead) and introduced afterwards into the composition of ore-beds. 



SMELTEH I. 



Smelter 1 is erected on the northern bank of California gulch, in a situation so 

 similar to that of smelter C that the general description of the latter applies word for 

 word to these works. The only peculiarity at Smelter I is that the furnace and feed- 

 ing-floor levels are connected by a vertical elevator used for hoisting slags to be 

 resmelted. This elevator is placed in the main building. Tbe boilers are worked at 

 a pressure of 70 pounds to the square inch. The machinery consists of a GO horse- 

 power engine, two Baker blowers, one Blake crusher, and the pump. 



The slag-pots are independent of the cars and are identical with those which 

 have been described at smelter A. The smelting plant consists of two Piltz furnaces, 

 identical in capacity, shape, and dimensions, and constructed by Messrs. Fraser & 

 Chalmers. These furnaces are similar to furnaces of the same pattern used at smelt- 

 ers B and H, but have only one slag spout. The water-jackets B also are made in 

 but two sections, and the frame of the crucible of four cast iron plates, segments of a 

 circle. One of these furnaces is shown in elevation in Fig. 2, Plate XLV. It may be 

 seen that each Baker blower, W, is in direct communication with the induction -pipe I, 

 the general system of connecting all the blowers with a main blast-pipe not being in 

 use here. 



The system of condensation of lead fumes consists of a sheet-iron box, D 7 , 8 

 by 8 feet, and 10 feet high, provided with a sheet-iron stack, F. Each furnace is con- 

 nected by means of a sheet-iron flue, F', with a similar chamber, from which the dust 

 is extracted through hinged doors d'. The amount of flue dust caught in both cham- 

 bers is about 5 tons per week. The dust is mixed with milk of lime, the mixture is 

 dried and then resmelted gradually with the smelting charge. 



The smelting capacity of the works is about 40 tons per twenty-four hours. 



SMELTER J. 



Smelter J is a well-constructed smelter standing on the southwestern bank of 

 Big Evans gulch, and is disposed exactly iike smelter H, with this difference, that the 

 offices and laboratory stand on one side of the main smelting building instead of beirg 



