At the commencement, through inexperience, many serious mistakes were made. When the first diggers reached the bottom of the red sand, they thought no diamonds would be found in the next stratum. When, however, diamonds were found in the second stratum, the diggers had again to remove the debris, and so also when the "blue" was reached. Some of the claims in the Du Toit's Pan and Bultfontein mines were irregular in shape. The other mines, however, had been properly and regularly laid out. One or two shafts had been connected with the mines by underground galleries. These galleries were convenient in the case of falls of reef. Labor, at first, was cheap; but from 20s. per month, wages rose to 30s. per week, and food. The yellow soil offered no difficulty in working, being loose and broken, but the blue soil required blasting. Several methods were adopted for extracting the soil and carrying it from the mine before steam was introduced. The cost of wood for heating purposes was a serious item, but good coal had now been found at 160 miles from Kimberley, costing 13l. per ton; another serious item of expense was the transport over natural roads only, costing from 18_l_. to 30_l_. per ton. The machinery designed by the author for this industry was described. A sixteen horse-power direct-acting winding engine was introduced for hauling up loads at the rate of about one thousand feet per minute, and a twenty-five horse-power geared engine, for hauling up heavier loads at the rate of from six hundred feet to seven hundred feet per minute.