Johannesburg Chamber of Mines, likewise framing his calculation on certain yearly increases in the milling power, calculated that in the five years following the full resumption of mining operations, 17,000 stamps would be at work, or an increase of 11,000 on the number before the war. Allowing for a fall in the grade of ore milled, in consequence of cheaper methods permitting of a lower grade of ore to be dealt with, the 17,000 stamps, he considered, would produce at least £50,000,000 sterling a year. Writing before the war, and basing his estimate on observations made by Mr. Eckstein that in five years the number of stamps in working would be 12,000, Dr. Hatch, likewise following the milling power basis, calculated for a yearly gold production of £36,000,000. Mr. Bleloch's opinion, taking the production in the nine working months of 1899 of £20,000,000 as a basis, is that the rate of production would probably double itself after the war. "If this be so," he adds, "in fifty years' time the product of the Rand will have reached over £2,000,000,000, and if such an accelerated progress is made, the whole of the vast amount now estimated may be dug out of the Rand within sixty or seventy years." The latest estimate published, that of Messrs. Leggett and Hatch, going on the basis of the average increase of production of £4,000,000 per year in the three years before the war, and that the production in 1899--a broken year owing to the war--was £19,000,000, concludes that, allowing eighteen months from January 1, 1902, for the industry to be restored to the conditions existing in August 1899, a similar increase of production will bring the output to at least £30,000,000 per annum by June 30, 1906, and if this rate of production were to be maintained from then on, the total production of £1,233,560,700 would give a life from January 1, 1902, of forty-two years and a half. But as the production will decline gradually, instead of coming to a sudden stop, the life of the industry is likely to be prolonged for some considerable number of years beyond the period indicated. If, on the other hand, the annual output should exceed £30,000,000 for any considerable period, as is, perhaps, within the bounds of possibility, this would partially offset the extension of life due to the gradual decline of production. It is to be added, in explanation of Messrs. Leggett and Hatch's estimate, that it contemplates working along a strike of forty-seven miles only, and to the restricted depth of from 4000 to 6000 feet. The following tabulated comparison of these several estimates will assist their comprehension, it being explained that Mr. Bleloch's estimate is reduced to the extent of 25 per cent. as a set-off for probably barren sections, &c.:--