78

C—B

" grey" sand and quantities of black sand. A semi-vertical seam of inferior lignite forms the south-western boundary of the paddock, which, on being exposed, is seen to be really a line of fault against which a semi-vertical seam of sandy-clay rich wash is found. The elevator had fortunately been sunk on what has proved the deepest part of the paddock, which is thus more conveniently worked. Elevating, 64 ft. vertical height. Improvements have been made in elevator and nozzle-tips, giving greater efficiency, the main breaking-down nozzle under the water-gauge pressure oi 195 lb. per square inch being capable of directing a stream of water like a solid bore on the 70 ft. face at a safe distance of 60 ft. and over. It was found that notwithstanding the very fine character of the gold saved, the proportion obtained under the ripples of the upper run of boxes had been as three to one of the gold recovered from mattings on the tables. The hydraulically worked log-haulers facilitate handling of heavy stones and buried forest-timber to such an extent that dividends are now frequently paid to shareholders. From thirty to forty fossil footprints of a bird, apparently of the rail species, were found on the banks of an ancient creek, on the " bottom," when cleaning up. Orepuki Goldfields. The usual number of ground-sluicing and driving claims continue to be worked as regularly as the limited supply of water to the field will allow. Accidents, Hydraulic and Alluvial Mines. Fatal. 5/4/05. Frederick Morrow, miner, Orepuki, was working in a drive in his private claim and had not set sufficient timber to maintain the roof, which settled dowii and crushed him to death. 5/9/05— David McKissock, nozzleman, Round Hill Gold-mining Company's claim, Waikaia, was struck by a fall of gravel from a face and killed. Deceased -had been standing too close in to the face for safety. Non-fatal. 2/2/05.— James Smith, winchman, Smith Gold-mining Company, Round Hill, had his left arm broken by log-hauling winch-handle reversing suddenly. Smith had been holding the handle care--28/7/05.— James Christie,|miner, Kitto and party's claim, Blue Spur, received slight injuries to his head and hands through returning prematurely to what was judged a miss-shot. GOLD-DREDGING. At the end of December, 1904, the total number of dredges in Otago and Southland was 184. At the end of December, 1905, this number had dropped to 172. During the year there was a decrease of 11 working dredges in Otago and an increase of 4. working dredges in Southland. The total number of dredges in'Otago was lessened by 10. Of this number 7 were dismantled and not re-erected, and 3 were removed to Victorian dredging-fields. Regarding the 11 dredges standing in Otago, 6 of these had either worked out or proved their claims unpayable, 3 are of the older type of machine and incapable of working the remaining portions of their claims, while 2 are sunk. In Southland the increase of working dredges was 4. The 5 dredges standing have worked out the payable portions of their claims. There are 48 dredges in operation in the Southern Mining District, which are owned by private parties. A noticeable feature of the development of the industry is the acquirement of dredgmg-properties by parties of working shareholders, who are able to work to advantage claims abandoned as unprofitable under large-company ownership and management. The industry has decreased in the gorges of Clutha and Kawarau Rivers, not on account of lack of gold, but principally owing to the type of machine ordinarily placed in the gorges having proved inadequate and incapable of profitably working the claims. The Alpine Consols dredge working in the gorge of the Clutha River, below Cromwell, having proved capable of breaking through the hard cemented " false bottom " previously worked to, the dredgemaster (Mr. Goodger) was gratified to find an underlying seam of rich dirt which will considerably enhance the life and value of the claim. A number of improvements have been effected to working dredges, among which may be mentioned an invention by Mr. William Adams, owner of the Paul's Beach dredge, for saving by amalgamation in a rotary cylinder the fine gold which usually escapes ordinary dredge gold-saving appliances. Improvements to gold-saving tables and appliances are receiving close attention, with the result that a larger proportion of gold is being recovered from the dirt. Increased attention has latterly been paid to recovery and assay of black and grey sands associated with the gold-bearing gravels. ) A shaking sluice-box has been successfully installed on the Rising Sun Company s dredge at Ci ro tyiwg] 1 Water-power application to dredges has been improved upon by Mr. R. T. Stewart, manager of the Argyle Sluicing-claim, as applied to the Argyle and Golden Beach dredges, the result being a considerable reduction of working-charges as compared with steam-power. Water-tight bulkheads in the pontoons for minimising risk of sinking are coming into more general use, and the freeboard of several dredges has been increased by addition of subsidiary pontoons as required. . Twenty-one dredges are now furnished with the electric light and ten with acetylene gas. Ihe type of dynamo found most suitable is one capab'e of producing 100 volts, equal to 12J amperes, at 750 revolutions per minute. ......