[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.

[12] Abstract of a paper (“The Mechanical Feeding of Silver-Lead Blast Furnaces”) presented at the Mexican meeting of the American Institute of Mining Engineers and published in the Transactions, Vol. XXXII. For the first portion of this paper see the preceding article.

[13] Abstract of a paper in Western Chemist and Metallurgist, I, VII, Aug., 1905.

[14] Much better work is being done at present, smelting the Western zinc ores, and the residue contains about one-third of the above figure, or 7.5 per cent. of zinc oxide. The high per cent. of ZnO left in residue was mainly due to poor roasting.

[15] There was also considerable coke used of an inferior grade, made from Kansas coal.

[16] Part of the ZnO in roasted matte came from being roasted in the same furnace the zinc ore had been roasted in.

[17] There was less residue on the charges during this month, which accounts for the larger tonnage with a lower blast.

[18] Translation of a paper read before the Naturwissenschaftlicher Verein at Aachen, and published in Metallurgie, 1905, II, i, 1-6.

[19] 35 to 40 cm. = 13.78 to 15.75 in. = 8 to 9.12 oz. per sq. in.

[20] Engineering and Mining Journal, 1904, LXXVIII, p. 630; article by Donald Clark; reprinted in this work, p. 144.

[21] Owner of the patents.—Editor.

[22] Abstract of a paper in Metallurgie, II, 18, Sept. 22, 1905, p. 433.

[23] This method is described further on in this book.

[24] Translated from Metallurgie, Vol. II, No. 19.

[25] British patent, No. 17,580, Jan. 30, 1902, “Improved process for desulphurizing sulphide ores.”

[26] W. C. Roberts-Austen, “An Introduction to the Study of Metallurgy,” London, 1902.

[27] A. Lodin, Comptes rendus, 1895, CXX, 1164-1167; Berg. u. HÜttenm. Ztg., 1903, p. 63.

[28] Comptes rendus, loc. cit.

[29] Translated from the Zeitschrift fÜr das Berg.-HÜtten-und Salinenwesen im. preuss. Staate, 1905, LIII, ii, pp. 219-230.

[30] Translated from the Zeitschrift fÜr das Berg.-HÜtten-und Salinenwesen im. preuss. Staate, 1905, LIII, ii, pp. 219-230.

[31] The manufacture of sulphuric acid from these gases has now been undertaken in Silesia on a working scale.—Editor.

[32] A paper presented before the American Institute of Mining Engineers, July, 1906.

[33] Engineering and Mining Journal, Sept. 2, 1905.

[34] This term is inexact, because the hearths employed in the United States are not strictly “Scotch hearths,” but they are commonly known as such, wherefore my use of the term.

[35] Percentages of lead in Missouri practice are based on the wet assay; among the silver-lead smelters of the West the fire assay is still generally employed.

[36] This improvement did not originate at either Alton or Collinsville. It had previously been in use at the works of the Missouri Smelting Company at Cheltenham, St. Louis, but the idea originated from the practice of the Picher Lead Company, of Joplin, Mo.

[37] This refers especially to the Savelsberg process.

[38] A. D. Carmichael, U.S. patent No. 705,904, July 29, 1902.

[39] Metallurgie, 1905, II, i, 1-6; Engineering and Mining Journal, Sept. 2, 1905.

[40] Metallurgie, 1905, II, 19; Engineering and Mining Journal, Jan. 27, 1906.

[41] Metallurgie, 1905, Sept. 22, 1905; Engineering and Mining Journal, March 10, 1906.

[42] Engineering and Mining Journal, Oct. 21, 1905.

[43] Translated by W. R. Ingalls.

[44] As originally published the title of this article was “Lead-Smelting without Fuel.” In this connection reference may well be made to Hannay’s experiments and theories, Transactions Institution of Mining and Metallurgy, II, 188, and Huntington’s discussion, ibid., p. 217.

[45] Excerpt from a paper, “Concrete in Mining and Metallurgical Engineering,” Transactions American Institute of Mining Engineers, XXXV (1905), p. 60.

[46] A Discussion of the Paper by Henry W. Edwards, on “Concrete in Mining and Metallurgical Engineering,” Transactions of the American Institute of Mining Engineers, XXXV.

[47] Engineering News, Nov 30, 1899, and U.S. Patent No. 665,250, Jan. 1 1901.

[48] A discussion of the paper of Henry W. Edwards, on “Concrete in Mining and Metallurgical Engineering,” Transactions of the American Institute of Mining Engineers, XXXV.

[49] Abstract from the Journal of the Chemical, Metallurgical and Mining Society of South Africa, May, 1903.

[50] Abstract of a paper in Transactions American Institute of Mining Engineers, XXXIV (1904), p. 175.

[51] Silver not given. This was the case, also, with the gold in the bullion. The slimes contained 0.131 per cent. of gold, or 39.1 oz. per ton.

[52] A constituent company of the American Smelting and Refining Company.

[53] Translated from Zeit. f. Berg.-HÜtten.-und Salinenwesen im preuss. Staate, 1905, LIII, p. 433.

[54] Abstract from a paper in Zeit. f. Berg.-HÜtten-und Salinenwesen im preuss. Staate, 1905, LIII, p. 439.

[55] Translated from Zeit. f. Berg.-HÜtten.-und Salinenwesen im preuss. Staate, 1905, LIII, 490.

[56] Abstract from a paper in Zeit. f. Berg.-HÜtten-und Salinenwesen im preuss. Staate, 1905, p. 400.

[57] Abstract from a paper in Zeit. f. Berg.-HÜtten.-und Salinenwesen im preuss. Staate, 1905, p. 400.

[58] Abstract from an article in Zeit. f. Berg.-HÜtten.-und Salinenwesen im preuss. Staate, 1905, LIII, p. 444.

[59] Translated from Oest. Zeit. f. Berg.-und HÜttenwesen, 1905, p. 455.