─────────┬─────────┬────────┬──────────┬────────┬─────────────┬─────── TYPE OF │CHARACTER│ CHARGE │NUMBER OF │ CHARGE │DAILY OUTPUT │OUTPUT SHAFT │OF CHARGE│PER DAY,│FURNACEMEN│PER MAN,│OF WORK-LEAD,│PER MAN, FURNACE │ │ TONS │ │ TONS │ TONS │ TONS ─────────┼─────────┼────────┼──────────┼────────┼─────────────┼─────── 3 tuyere│ A │ 36 │ 6 │ 6.0 │ 6 │ 1.0 8 tuyere│ B │ 38 │ 6 │ 6.3 │ 8 │ 1.3 3 tuyere│ C │ 36 │ 6 │ 6.0 │ 12 │ 2.0 8 tuyere│ D │ 72 │ 12 │ 6.0 │ 26 │ 2.1 15 tuyere│ E │ 270 │ 34 │ 7.9 │ 90 │ 2.6 ─────────┴─────────┴────────┴──────────┴────────┴─────────────┴─────── ┌──────────┬──────────────────────────────────────┐ │ CHARACTER│ CHARACTER OF CHARGE │ │ OF CHARGE│ │ │ CODE │ │ ├──────────┼──────────────────────────────────────┤ │ A │ Sintered concentrate and gray slag │ │ B │ from reverberatory furnace. │ │ B │ Gray slag from reverberatory furnace.│ │ C │ Huntington-Heberlein product. │ │ D │ Huntington-Heberlein product. │ │ E │ Huntington-Heberlein product. │ └──────────┴──────────────────────────────────────┘ A slight difference only is produced by the new process in the consumption of coke; the economy is a little over 1 per cent., the coke consumed being reduced from 9.39 per cent. to 8.17 per cent. of the total charge. But with the high price of coke, even this small difference represents a considerable lowering of the cost of production. With the great increase in the blast pressure, it would be supposed that the losses in fume would be much greater than with the former method of working. But this is not the case; on the contrary, all experience so far shows that there is much less fume developed. In 1904, for instance, the shaft-furnace fume recovered in the condensing system amounted to only 1.06 per cent. of the roasted material, or 0.64 per cent. of the total charge, as against 2.03 and 1.0 per cent., respectively, in former years. The observations made on the quantity of flue dust carried away with the gases escaping into the air through the stack showed that it is almost nil. Now, from the loss in fume being slight, from the tenor of lead in the slag being low, and, on the one hand, from the quantity of lead-matte produced being much less than before, while on the other the losses in roasting the ore are greatly reduced—from all these considerations, it is clear that the total yield must have been much improved. As a matter of fact, the yield of lead and silver has been increased by at least 6 to 8 per cent.