The removal of the zinc is effected in a second reverberatory furnace. Formerly the steam-method was used, but the rapid wear of the kettles, and the excessive formation of oxides called for a change in the process. The zinc-silver alloy is distilled in a crucible of 200 kg. capacity, and is cupeled in an English cupel furnace. The details of the reverberatory furnace are shown in Fig. 48. The composition of the final products is shown by the following analyses; Lead: Zn, 0.0021 per cent.; Fe, 0.0047 per cent.; Cu, 0.0005 per cent.; Sb, 0.0030 per cent.; Bi, 0.0007 per cent.; Ag, 0.0010 per cent.; Pb, 99.998 per cent.; Silver, Ag, 99.720 per cent.; Cu, 0.121 per cent.; Fe, 0.005 per cent.; Pb, 0.018 per cent.; Au, 0.003 per cent. INDEX Alloy, retorting the, in lead refining, 267 Alumina, experience with, 259 American Smelting and Refining Co., 4, 6, 26, 93, 113, 252, 295 at Murray, Utah, 287 Atmosphere, effect of on concrete, 242 Bag-house, cost of attending, 246 standard, 246 Bag-houses for saving fume, 244 Bartlett, Eyre O., 244 Bayston, W. B., 199 Bennett, James C., 66 Betts, Anson G., 270, 274 Between products, working up of, 39 Biernbaum, A., 41, 148, 160 Blast furnace of circular form, 253 Spanish lead, 307 Blast, volume and pressure of in lead smelting, 76 Blower, rotary, deficiency of, 251 Blowers for lead and copper smelting, 256 now more powerful for lead smelting use, 252 Blowers, rotary, method of testing volumetric efficiency of, 254 _vs._ blowing engines, 254 _vs._ blowing engines for lead smelting, 251 Blowing engines, when to use, 259 Bonne Terre lead deposits, 18 orebody, Missouri, 13, 14 Borchers, W., 114, 116, 127 Bormettes method, combination processes in, 222 Bradford, Mr., 55 Bretherton, S. E., 251, 258 Broken Hill Proprietary Block, 14, 59 Broken Hill practice, 51 Proprietary Co., 52, 113, 124, 145, 175, 178, 206 Bricking plant for flue dust and fine ores, 66-70 Briquetting costs, 62 methods of avoiding, 63, 64 process, operations, in 59 Bullion, analyses of in lead refining, 281 refined lead and slimes, analyses of, 282 Canadian Smelting Works, 275 Carlton Iron Co., 63 Carmichael, A. D. 56, 199 Carmichael-Bradford process, 175-185 brief estimate of, 209 claims of in patent, 199 recommendations of, 124 process, points concerning, 131 Cement walls, how to build, 241 Channing, J. Parke, 254 Charge-car in smelting, true function of, 94 feeding of in lead smelting, 77 mechanical character of in lead smelting, 78 Charges, effect of large in lead smelting, 77 Cherokee Lanyon Smelter Co., 104 Chimney bases, 237 Chisholm, Boyd & White Co., 64 Clark, Donald, 114, 144, 175 Cœur d’Alene mines, 5, 6, 7 Concrete flues and stacks, advantages and disadvantages of, 242 in metallurgical construction, 234