THE WAIHI MINE.

Dominion, Volume 4, Issue 1129, 17 May 1911, Page 8

THE WAIHI MINE.

CAPTAIN RICHARDS'S REPORT. (By Telegraph.—PrcS3 Association.) Auckland, May 16. Mr. C. Rhodes, local director of. the Waihi Gold-mining Company, has received a' cablegram from London instructing him to open and publish the sealed copy of Captain Richards's report on the mine, which had been sent to him for that purpose. This report is of considerable length, and is accompanied by three blue prints, which are referred to by Captain Richards. These plans may bo seen at the company's office. Among the main features of the report are the following:— Ore Reserves. The amounts of the ore reserves on each level arc showu on figure 3. It will bo seen that the tonnages in tho upper levels &vc small, and that the greater proportion is contained in the lower third of the mine. The proportion of reserves to what has been extracted in different levels as shown in the diagram indicates that development work has been kept, well ahead of extraction of the ore. The methods employed in making estimates of ore reserves correspond closely to those adopted Generally by mining engineers of repute, only ore that is actually blocked out with exploratory working being included. By comparing previous estimates and yields and examining other particulars, I am satisfied tho work has been carefully carried out. Tho reserves of ore in the mine

cannot bo considered largo in view of the present position in the lower levels, and 071 this account I am of opinion that an active exploratory campaign is necessary. Ecduction of Output. The output of the mills has in recent years been increased in accordance with the increase in the amount of ore developed by each successive level down to the seventh and eighth. The reduced amount developed between the eighth and ninth levels ha?, therefore, upset the relatione between mill supply and demand, and to make good the difference it will be necessary to draw on the ore contained in the arches left between the different upper levels. This work will entail a good deal of preparation, such as drives in the wall rock and the filling of depleted stopes to the back in each place before ore can bo extracted. These operations will need to be done carefully, as any attempt to rush (be work would entail risk to the mine and lo the lives of the miners. Taking account of this, and the number of miners that can be economically employed in each face, it is evident that a reduction from the present output will soon be necesrary. I would also point, out that owing to the character of the ore. and the way it occurs in the reefs, a, fast rate, of exploitation would entail a considerable risk of much unprofitable material being mined and treated at a loss. Development. Developmental work up till now has been practically confined to the Martha reef, and the others in the immediate vicinity, and in an area, that represents about onefifth of the property held by the company. From the evidence concerning the causes and extent of the Assuring of the bedrock, and the genesis of the contents of the veins, it would appear that other important reefs can be expected to occur in the area. The vein bearing dacites are covered with recent ore of andesite and rhyolite, except around tho Martha and Silverton Hills, and as a number of the veins do not outcrop even when the dacite is exposed, developmental workings must be conducted at a d;pth. In the vicinity of Silverton Hill several extensive reefs were opened in the early days of the field. They wore worked for gold, but the development of them ceased previous to the introduction of tho treatment processes that rendered tho Martha, group of veins profitable. One of these, the Silverton. which is farthest away from tho latter, is stated to havo contained very rich ore in places. These reefs to all appearances belong to tho same system as the Martha and those contiguous to it, -and the mineralisation can bo expected to be of the same general character, varying only in degree and in position in the reefs. The workings being inaccessible at tho time of my visit, no examination could be made except on the surface, but judging from what could bo seen, and by all accounts, they wcro not of anv considerable extent. Below the lower levels of the Martha group of reefs developmental work must bo slow and somewhat expensive on account of the volume of water to be contended with, as compared with that ahove them. For this reason it is advisable that tho proposed exploration of tho area from levels already drained to intersect other reefs should be pushed on first. Prospecting by means of diamond drills, which has hitherto been opposed by the friable nature of tho ore. may possibly bo carried out with satisfactory results in the deep levels, owing to changes in the vein material that may produce a core sample suitable for assay.

A- CABLE TO LONDON. (By Telegraph—Press Association.)

Auckland, May 16. Tho local director of the W'ailii Goldmining Company has cabled lo London as follows:— . , '

"No. 9 level: Royal'lode, west of No. 5 shaft, crosscut 20 feet driven (550 ft. to 570 ft.), assay value 4s. per ton. Edward reefs, from perch crosscut, 20ft. driven (?55ft. to 275 ft.). assay value ss. per ton. No. 4 shaft: North-west crosscut, reef at 631 ft., next 15ft. assay value £1 10s. 9d. The reef is now wider than tho drive. The course of the vein is 190 degrees. B pump has been completed. Electric work plant is working well."