PLANT AND SMELTING OPERATIONS. 



659 



General discussion By comparing, in a tabulated form, the average data obtained 

 in tbe preceding discussions relative to eacb smelter witb tbe relation between the 

 actual and tbe nominal capacity, it will be possible to some extent to realize the rela- 

 tion between the composition of smelting charge and tbe time. 



NOTE. The relations of actual and nominal capacity, as here given by Mr. Guyard, cannot be relied upon, as 

 he has ansamed that each smelter was running 365 days during the year, whereas in point of fact the running 

 time must have been much less and must have varied widely in the cases of different smelters, none of which were 

 probably running at their full capacity for any great length of time. (S. F. E.) 



SECTION III. 

 PLANT AND SMELTING OPERATIONS 



SMELTING PLANT IN GENERAL. 



Furnaces All tbe furnaces of Leadville are built on tbe same general principles 

 and contain the same essential parts, but they belong to two distinct styles: the rect- 

 angular or square and the circular or round. The following description is made from 

 furnaces of both styles used at Smelter B, but a glance at all the other furnaces 

 sketched for tLis report, in which the same parts are designated by the same letters, 

 will show that the differences are only in details. 



Square furnaces (see Plate XXVI). The general appearance of these furnaces 

 is that represented in elevation. Fig. 1. The furnace is formed of two independent 

 parts: (1) The masonry 0, supported on a main cast-iron plate support, 0, resting on 

 cast-iron pillars, P. (2) The crucible A upon which rest the water-jackets B. The 

 space between the water-jackets and the masonry is filled up with fire-brick, b. This 

 arrangement, as it is easy to perceive, is most convenient for repairs of parts exposed 

 to injury or destruction, and cannot be too highly commended. It is universally 

 adopted in the camp. The masonry is firmly bound by braces Q, the system adopted 

 for bracing varying with almost every furnace. Immediately above the feeding-floor, 

 P', are to be seen the feed-holes, H, provided with sliding doors, S'. The smelting charges 

 are thrown into the furnace through these holes. 



The different parts of the masonry are the following (see vertical section, Fig. 

 3): C is the shaft of the furnace. The portion of the shaft immediately below the 

 feed-holes is called the throat. It is seen also in horizontal section in Fig. 4. D is the 

 chimney. J7is the stack. The stack can be closed or opened by means of the damper Q. 

 The stack is also connected with the dust-condensing chambers by means of the sheet- 



