Silver-lead blast furnaces, mechanical feeding of, 81 blast furnace, proper conditions, 73 smelting, details of practice, 73 smelting, modern, 73 Slag-smelting costs, 34 Slime analysis at Broken Hill, 51 Slimes, analyses of in lead refining, 281 desulphurization of by heap roasting, 51 treatment of at Broken Hill, 53-55 Smelter, new, at El Paso, Texas, 285 Smelters’ pay, 32 Smelting, average cost of per ton, 98 Smelting Co. of Australia, 263 costs, 48 detailed costs of, 101, 102 of galena ore, 38 preparation of fine material for, 59 Solution, washing from slime, 277 Sticht, Mr., 256 St. Joseph Lead Co., 16 St. Louis Smelting and Refining Co., 81 Sulphide Corporation, 145 Sulphur dioxide, effect of on cement, 240 Sulphuric acid, making of at Broken Hill, 174 Tasmanian Smelting Co., 145 Tennessee Copper Co., 255 Terhune, R. H., furnace gratings, 84 Thacher, Arthur, 14 Ulke, Titus, 270 United Smelting and Refining Co., 88 States Zinc Co., 295 Vezin, H. A., 252 Walls, retaining, 237 Walter, E. W., 260 Waring, W. Geo., 24 Welch, Max J., 229 Wetherill, Samuel, 244 Wheeler, H. A., 10 Zinc, amount required in lead refining, 265, 266 crusts, treatment of in lead refining, 267 oxide in slags, 108 retort residues, analysis of materials smelted and bullion produced, 106 retort residues, smelting, 104 FOOTNOTES: [1] During 1905, antimonial lead commanded a premium of about 1c. per lb. above desilverized, owing to the high price for antimony. [2] The figures for 1903 and 1904 have been added in the revision of this article for this book. The production of lead in the United States in 1903 was 276,694 tons; in 1904, it was 302,204 tons. [3] Ounces of silver to the ton of lead. [4] These figures are doubtful; they are probably too high. (See table on p. 5). [5] The production of zinc ore in this district has now been commenced. [6] The manuscript of this article was dated Oct. 5, 1905. [7] Translated from _Zeit. f. Berg.-Hütten-und Salinenwesen_, LIII (1905, p. 450). [8] This paper is published in pp. 148-166 of this book. [9] Abstract from _Transactions_ of the Australasian Institute of Mining Engineers, Vol. IX, Part 1. [10] In the course of subsequent discussion Mr. Horwood stated that the losses in roasting were 12½ per cent. in lead and probably about 5 per cent. in silver. As compared to roasting in Ropp furnaces the loss in lead was 5 to 6 per cent. greater, but the difference of loss in silver was, he thought, not appreciable. Mr. Hibbard said that the Central mine had obtained satisfactory results with masonry kilns.—EDITOR. [11] Abstract of portion of a paper presented at the Mexican meeting of the American Institute of Mining Engineers, under the title “The Mechanical Feeding of Silver-Lead Blast Furnaces.” _Transactions_, Vol. XXXII, pp. 353-395.