QUARTZ TUNING.

New Zealand Times, Volume LXXI, Issue 4513, 14 November 1901, Page 7

QUARTZ TUNING.

CHANGE OF METHODS ADVOCATED. In concluding his annual 1 report on quartz-mining in New Zealand, Mr John ilayes. inspecting engineer, says: - “Taking the future character of quartz mining operations into consideration, it appears more than probable that the bulk of tho output of gold from this source will he obtained from ores of lowgrade. This being tho case, it is quite evident that the question of working costs must receive very careful thought, tod every effort made to produce the Ore at tho lowest possible price per ton. consistent, of course, with the safe and efficient working of mines. To work low-grado ores economically it is necessary that the output should bo large, and winding and pumping operations, as well as the handling of tho ore, concentrated ag much as possible. To do this the old-fashioned ideas of numerous shafts, geared winding-engines of small power, light loads and slow speeds, with the necessary staff of enginemen, brace and chamber men, truckers, etc., comparatively idle during a good portion of their time, will have to be superseded by works laid out on a thoroughly comprehensive system. So far as my observation has yet <rone, there are very few quartz mining properties in New Zealand where the whole output could not be raised in one shift, and from one shaft, if the mine were laid out with a view to the highest possible degree of efficiency and economy. With a good roomy shaft, sunk in a suitable position, teefs intersected at convenient levels by : l system of crosscuts, ore from inter■nediato levels tipped into passes or connecting with the winding,level below (so as to obviate too many j‘hanging on’ places in the shaft), large cages, direct winding engines, a plentiful supply of trucks, and winding from different levels carried on during stajted hours, a very large output could easily be maintained, with a minimum cost for labour in raising and handling the ore. In illustration of this I would point to the many collieries in England whore from one shaft an output of over 100 tons per hour is 'maintained from depths exceeding 1000 ft. Systematic and reliable ventilation could also he (provided for by 'means of an indepen. dent air-shaft and ventilating-fan, the [shaft being sunk on the underlay if only lone reef is worked, or, if vertical, connected with the reefs by means of crosscuts, and the air conveyed through the workings much in tho same manner ag is done in coal-seams lying at fairly high angles, and worked on the longwall system.