THE ISLAND BLOCK GOLD MINING COMPANY ROXBURGH.

Otago Witness, Issue 1975, 26 September 1889, Page 11

THE ISLAND BLOCK GOLD MINING COMPANY ROXBURGH.

Experts in mining matters have, within the last few years, laid it down as an almost established fact that hydraulic mining, in its several phases, offers one of the safest, most regular, and most lucrative outlets for capital ; and evidence of this is being offered by various companies which have recently commenced sluicing operations on an enlarged scale. At St. Bathans, especially, for years past, the auriferous gravels there, under circumstances not the most advantageous, have been profitably treated on the hydraulic elevating principle for a yield of lgr of gold (valued at less than 2d) per cubic yard, and it was thought indeed that very little reduction in the cost of treatment could be made. But it is possible, it would appear, to treat auriferous gravels at a cost of about Jd per yard, provided that the supply of water for sluicing is permanent and sufficient, that good fall in the tail-races is obtainable, and that (last, but not least) the affairs of the mine are regulated by a manager who understands his work thoroughly. Such a man, apparently, is Professor C. E. Rawlins, M.E., F.G.S., London, the general manager of the Island Block Gold Mining Company (Limited), Roxburgh. The expedition with which Mr Rawlins has had the machinery erected on this company's mine, and the thorough efficiency of the machinery itself, have already become matters of history; and it ia now that particulars of the cost of extracting the precious ore from the gravels being operated upon will be read with feelings of considerable interest by all interested in gold mining. Recently the machinery was set going, and at the present Mr Rawlins is sluicing away a secondary wash formation on the east side of the Molyneux. The following are the particulars of one particular run, reliable data of which were carefully collated by Mr Rawlins : — The period of the run was 12 days, during which 22,000 cubic yards of material, sand, mud, and gravel came under the operation of the hydraulic jets. The total yield was 50oz of gold, being a Bhade over lgr to the yard. The cost of treatment, not including the cost of erecting the plant, was £62 Ba, made up as under : 12 men at 7s per clay, £50 8s ; managerial expenses, £12 ; total, £62 Bs. "Valuing the gold at £3 15s per ounce would bring the value of the product up to £187 10s The cost of treatment was thus equivalent to almost exactly 33 per cent, gross output, leaving a profit on the run of 12 days of slightly more than £120.

Under experienced management, such as the Island Block Company seem to bave secured, wo may expect splendid returns in the imme« diate future from our long-neglecteri auriferous gravels ; to which, however, the attention of capitalists is now, we are glad to notice, being turned, with so far results of the most pro» raising character.