character to a pyritic, involving greater difficulty and cost to treat. This mine was the first to introduce frue vanners, the cyanide process and the treatment of slimes, expending as much as £80,000 in the last innovation. By means of these it raised its gold extraction from 65 to 90 per cent., and gave encouragement and impetus to all mining on these fields. The latest costs published for the month of September this year of thirty-six mines in working give an average of 26s. 3d. per ton, which shows that operating charges are now at about the same ratio as they were before the war. Although so reduced, however, they are still relatively higher than they may be expected to be when the mines settle back into their normal grooves. The reason for this is that only a few mines are now working up to their full battery power, and, while costs are on the full scale, results are less, surface dumps are being drawn upon for mill service instead of the mine itself, owing to lack of full supply of labour, &c. When, however, the effects of the important fiscal reductions just made have had time to exercise their effect in reducing the cost of imported mining stores, foodstuffs, and the smaller machinery and metal goods charged by the mines to the working account, further reductions in the working costs will be possible. Of the actual money value of this per ton of ore milled, various opinions have been ventured. It has been estimated by experts that it is possible under favouring circumstances to reduce the expense of working by some 10s. per ton, at which rate ore yielding over 5.6 dwt. per ton bullion could be made to yield a profit. The importance of this not only in improving the present position of all mining undertakings, but in stimulating the low-grade mines to come into the working stage, can hardly be overestimated. With the various difficulties besetting the mining industry removed, the future working cost level should be lower than at any preceding period, taking into account the benefit of the recent fiscal reductions and other governmental assistance in prospect. [Illustration: GENERAL VIEW OF THE SURFACE WORKS OF A RAND GOLD MINE (KNIGHT'S) Showing the head-gear at top of the shaft, the stacks locating the engine-rooms. A sloping tramway will be seen leading down from the shaft-head, and iron waggons bringing the crushed ore, and taking it away to the "battery" or "mill." The waggons are driven by an endless wire rope, and discharge automatically. Beyond, in the middle distance, may be seen the huge white heap of "tailings," the waste débris after the gold has been extracted. Each mine has its own electric-light plant. Photo by Barnett & Co., Johannesburg]