" the refining furnace, 221, 223, 239. " the reverberatory, 81, 82–88. " the roasting furnace, 88. Furnaces for refining, 219, 239. " roasting, 69. Furnace-refined (tough pitch) copper, 41. Fusibility of slags, 148–150, 176. G Gangue, 43. Garfield Smelter, Utah, blast furnaces, 156. " " converters, 194. " " reverberatories, 91. " " roasters, 75, 78. Gases dissolved in copper, 25, 26, 31, 40, 42. " for acid manufacture, 140, 146, 167, 181, 186, 188–191. " in blast-furnace work, 140, 146, 156, 159. " in copper, 43. " in furnace refining, 223. " in pyritic process, 172, 181, 186. " in reverberatory smelting, 89–91. " in roasting, 63, 64, 68, 78, 177. Gaseous fuel for reverberatories, 108. " products of the blast furnace, 159, 166–168, 181, 182, 188–191. German copper mining, 5. " " production, 15. " " smelting, 3. " silver, 21. Gibb, A., 37, 50. Giroux blast-heater, 144. Gobbing of furnaces, 174, 178, 188. Gold and copper, 21, 23, 34, 40. " in copper, 44, 217, 218, 226. " " ores, 46, 217. " " -smelting, 217. " in electro-refining, 229, 230–233, 238. Goodner, 50. Gossan deposits, 45. Gowland, W., 3, 17, 34, 90, 126, 145. Grade of matte, 61–65, 82, 87, 131, 175–194, 200, 203, 204, 211. " Control of, 82, 175–186, 200, 203, 204. Granby smelter, 154, 191. Granulation of slags, 165. Grate-area in reverberatories, 83–85, 88, 89. Grating in reverberatory smelting, 83, 85, 86, 92, 101. Great Falls Smelter, 108, 191, 195. Greenawalt, W. E., 243. Green-ore matte, 179, 181, 187, 188. " smelting, 179, 181, 187, 188. Guess, G. A., 171.