M MacDougal roasters, 73–79. M‘Murty-Rogers sintering process, 58, 80. Magnesia in slags, 150. Magnesite linings (see _Basic linings_). Malachite, 46. Malleability, 1, 22, 31, 33. Management of converters, 212. Manganese and copper, 21, 23. Manhès, 193, 200. Mansfeld furnace, 122. Mantle plates, 140, 153, 154. Marchésé, 238. Mass influence, 194. Mathewson, E. P., 89, 125, 127, 145, 207, 211, 215. Matte, 36, 37, 50, 61, 118 (see also _Grade of matte_). " anodes, 238. " for converters, 134, 135, 192, 200, 202–204, 211–213. " in pyritic smelting, 178, 181, 183, 186, 188. " -pool in reverberatory smelting, 87, 91, 94–97. " Properties of, 38, 39, 91. Mechanical charging of blast furnaces, 140, 153, 167, 188. " operation of roasters, 69–75. " properties of copper, 18, 30, 33, 34, 43, 45, 238, 241, 242. " rabbling, 69–75. " treatment, Effects of, 20, 30, 32, 34. Mechanism of casting ladles, 225–226. " furnace refining process, 223. " pyritic process, 171, 172, 183. Melaconite, 46. Melting agent, Blast furnace as, 113, 114. " function of blast furnace, 114, 117. " point of copper, 24, 117. " " copper-mattes, 37, 38. " " slags, 148. Merchant copper, 238, 239. Metallic copper in blast-furnace slags, 116. Metallography, 26. Mexico copper ores, 46. " " output, 15. Michigan copper output, 17. Milton, J. T., 34. Mineral industry, 17, 191, 243. " statistics, 17. Mining in Britain, 2, 5, 6. " Germany, 5. " Spain, 5, 7, 8. Mitchell blast heater, 144. Mixed silicate slags, 149, 150. Mixing of samples, 49. Modern smelting practice, 37, 51, 61, 62, 65, 66. " " " Development of, 9. " reverberatory smelting, 87. Modifications of converter practice, 214, 216. " electro-refining, 238. Moisture in briquettes, 58. Monel metal, 21. Monopolies in copper industry, 11. Mono-silicates, 149, 150. Montana copper ores, 8, 46, 52, 63. " " output, 17. Moore, R. R., 80, 215. Moss copper, 38. Moulds of casting furnaces, 224–226. Mount Lyell, Tasmania, 171, 172, 174, 195. Mud (see _Slimes_). Muffles, 69. Multiple system, 227–229. Muntz metal, 21.