MINING AT WAKATIPU.

Otago Witness, Issue 2456, 10 April 1901, Page 19

MINING AT WAKATIPU.

(From Otjr Wakatipu Correspondent.)

ACHILLES GOLD MINE, BULLENDALE.

This mine, which may be regarded as the oldest quartz mine in Otago, has a history dating back to 1862, when Messrs Olson and Senthberg found their way so far back into the wilds of the Wakatipu mountains as the head of Skippers Creek, which has ever since marked one of tho outposts of mining activity — Mount Aurum, like a sentinel, overlooking and marking the northern boundary of the auriferous country of the Wakatipu. Skippers has gained a name as one of the richest creeks, if not the richest, in Otago, and it is also here where is to be found the lodes of the Achilles Gold Mine Cempany, which have turned ov\ gold in more or less quantities for a greater length of time than any other quartz mine in Otago; £>nd though there were breaks in the working time of the mine, the value attaching to the property was such that it cannot be said that it was ever abandoned or eutirey neglected.

Tho mine is situated at a distance of 35 miles from Queenstown, at one of the head gullies of Skippers Creek", named Murdoch's Gully. The lodes, which run east and vvect, cross the gully at right angles, dipping north. It had been supposed that there were three lodes in tho claim, running parallel, in intermittent blocks of stone. The present manager (Mr J. F. Donne), however, differs from this view, and ho confines himself to tho north and south lode, looking upon the intervening country as a stockweric formation, intersected by numerous leaders and veins branching from either lode and joining it again loop fashion, but never going down apy depth, sometimes carrying very fair gold. Having visited the mine upon several previous occasions, leads me to think this conception of its character to be the most feasible one of any previously formulated. The bulk of the gold produced has come from the north lode, which has also been the most permanent and reliable.

For some time past work in the mine has. not been profitable. No. 6 and No. 7 levels have disclosed large bodies of stone, but it has not proved profitable. Nests of sugary and melted quartz occur occasionally, carrying visible gold, and sometimes are even rich, but they are of no extent. These nepts have ever since the mine was started given rise to reports of new rich finds, which had really no foundation in fact, and recently there was a repetition of the mischief. There is no mine in which there is not occasional leakage of information. In some instances tli3 directors are to blame. It not infrequently happens that the miners' wages are allowed to get into arrears, and what wonder when there is a sudden improvement in tho stone the hope of an early squaring of accounts makes the creditors blab.

During my conversation with Mr Donne, he happened to make the remark that New Zealand quartz mining had been too much confined to shallow depths, no mine of great deDth being heard of, and very sagaciously

gave expression to the opinion that at greater depths the quartz might be more continuously payable than was found £o be the case nearer the surface. It is a historical fact that Sir Roderick Murchison, the eminent geologist of the fifties and sixties, pronounced it as his opinion that the quartz mines of Australia did not live down to any greater depth than 300 ft. The result was that an injurious check was put upon quartz mining, from which it did not lecover for many yeart), and though the notion has been exploded long ago. it has been revived only recently by a New Zc-aland authority repeating the =amc remark, stating that New Zealand lodes did not live down more than SOCft. The Achillep gold mine, as well as other quartz mines in the Wakatipu, furnish a flat contradiction to this statement, and quite put aside the dictum.

In the face of this as?ertion, it is, reassuring that a gentleman of Mr Donne's experience and intelligence has the courage to put forth an opinion that runs contrary to scientists' scientific assertion As the question is one upon which a good deal devolves, it may be pointed out, as has be-en repeatedly done in this column, that in every mine at Wakatipu in which exploitation has been carried to a considerable depth the scientific opinion has been refuted. The Shotover quartz mine, which is on the same lino of reef as the .Achilles gold mine, has now been proved to exist at a depth at least of 2000 ft vertical measurement, and is going down to an at present unknown depth strong and healthy.

The physical surroundings of the Achilles gold mine are, like its history, a good deal up and down. The gullies surrounding it on all sides are steep to a degree, and precipitous where steer) does not apply, as a description The miners' hut", at some little distance off, appear liiv.e bird cashes hung up, one above another, upon a wall. In the winter it is dangerous to life and limb to go and see your next-door neighbour, unless you are rspeciallv sharp shod This description of thp country applies to the whole of Skipoors Creek, about 10 mi'es long, and to tho greater part of the Shotover Valley, through whic'.i the road from Queenstown to the Achilles mine lies, about equally divided as to uphill and downhill

Jt is positively astounding to view and see at work bulky, not to say ponderous, machinpry, brought to the 1 place over country w Inch tires the wayfarer, either on foot or on horpeback, to the utmost, shaking every bone in the body as if beaten with stick" Tho new Skippers bridge has certainly 111 ad p things a little better, but upon the whole the reduction in the cost of freight to the Achilles gold mine will be scarcely perceptible. The quantity of machinery on the ground is no less astonishing than its bulk and heavy character, and cannot be estimated at a money value- of lc«s than £40,000 or £4-5.000, representing, not including uped-up stampers, moriar boxes, ptc, about 8000 or 10,000 tons. Another item that courts for a good deal against the affairs of the mine is the time consumed in the transport, and aLo the injury to the machinery during the transit. Several times Las it happened that costly parts came to grief when near their journey's end.

The Races and the Wvteti -Supply

The water used for motive power is conducted to the different sites where it is required in five races, at different levels L and from different sources, in all comprising about 47 Government beads. In addition the company have recently acquired the water right of Old Man Cieek, running on an average two Government heads. Taking the races in rotation, there is No. 1 race, the highest race, from Mount Aurum, 7400 ft long, conveying about six heads of water, which is used for the generation of electricity to drive the hauling and pumping machinery at the mouth of the main shaft. However, this supply is available only during the open season, and when the water freezes up, as it does during the winter months, the old electric plant at the left-hand branch, at a distance of a mile and a-half from the mine, supplies the electricity.

Races Nos. 2 and 3, at a lower elevation, pay their water into a tank 140 ft above the mill, driving the cam shaft, concentrators, and other appliances connected with the treatment of the concentrates, and also tho air-compressing machinery, which, however, is not much used. The batteries are driven by a, Pelton wheel.

Race No 4- is taken from and terminates at the left-hand branch at a distance of a mile and a-half from the mine. This race is used for generating electric power by the aid of a Pelton wheel, under a pressure of 170 ft. The electricity is conducted over a spur of Mount Aurum by cable, a mile and a-half distant.

Race No. 5 picks up the tail water from tho races paying their water into Murdoch's Gully, where the mine and batteries arc f-ituated, driving a small saw-mill and other machinery requiring - motive power.

The Bvttery,

The mill consists of six batteries of five stamps each, each stamp weighing 8001b. No. 20" mesh wire cloth is u?ed at the mortar boxes; the discharge passes over blanket strakes 6ft wide, the width of the boxes, and 15ft long, after which no further double is taken with tho tailings. The concentrates, washed off the blankets, are amalgamated in an amalgam barrel, sft by 4-f t, holding one ton of concentrates, which are treated with one bottle of quicksilver.

The battery and other gold-saving appliances are contained in an iron house that has served for their protection for a number of years, and gives ample proof of the rigour of the climate of Skippers Creek. Indeed, the query is whether a better house would not pay the company, by the improved protection it would afford their property.

The Mi:;e \nd Mine Works,

The mine is worked by an incline shaft of a total depth of 728 ft, following the underlie of the reef. At about 380 ft from the surface there is a kink in the shaft, which doe^ improve the hauling of the ore out of the mine The size of the shaft is 12ft by 4ft, and it is fitted with two skits, one for the ascending and the other for the descending trucks. The slip ft is securely timbered with Bin bquare red birch beam? The vertical depth of the mine from the surface to No 7 level is 528 ft A compartment by itself accommodates the pump, and the mine making very little water, though since No. 7 level having been opened there was a slight increase, its work is light.

The mine has been worked from seven levels, about 100 ft apart, and though the whole of the mine works have to be closely timbered, the ground presents no difficulty in the working. But the inferior nature of the timber upon the ground requiics close and constant supervision, as both pr,ops and caps have been known to break, requiring to be replaced after being six: months in the ground. This chciuastajac©

adds considerably to tho working co?t of the mine.

The Surface Tr\i:w\y

The shaft and engine-house, with hauling and pumping plant, being situated upon a steep sidling ( at a considerable elevation above the mill level, afforded the opportunity of approaching the shaft at a level of 137 ft from the surface by an adit, saving so much hauling and pumping. In this manner the shaft is connected with the mill by a tramway at a convenient level to deliver the otfe^at the batteries automatically, so that it does not require to be handled after it comes up the shaft. The ore is filled into trucks at the face, run to the bottom of the shaft, thence taken up to surface tramway 136*0 ft long, is landed there, and run out to the tip head above the mill. Here it is passed over grizzlies, the fine stuff passing into the bins, the coarse lumps being passed through tho rock-breaker, and then falls into the bins, whence it is fed to the mortar boxe-o by automatic feeders, with the aid of which one man suffices to attead to the six batteries, and there always must be one man to watch the progress of the work.

The Plant.

It would require a good column or two to describe the multifarious machinery on and about the mine, and then it could be only superficially done. Suffice it to say that there are two complete electric plants, one. at the shaft mouth, capable of generating 90 h.p.. another at tho left hand branch of Skippers Creek of about tho same capacity. Tv, o Pelton wheels are run in connection with the dynamos. There are blacksmith and engineers' shop completely fitted with tools, etc. ; two sawmills — one on' a large scale, dealing with logs up to any size tho local bush contain^, the other being on a smaller scale ; and a, whole hoat of appliances, all of the best construction and make. The rails in the mine, shaft, and surface tramway are of steel, and sub stantially laid down.

To a practical eye it is clear that the mine is under the direction of a man -who underslard° hi 3 ou&iness. The directors haVe of late been unfortunate with their mine mar tigers, there having been no less than three or four during a less number of yeara, and every change of manager means a change of syblem, none living long enough to take effect

POSTSCRIPT

Since writing the above I have had an opportunity of visiting the Shotover Gold Mining Company's mine, which furnishes incontestable proof of the fallacy of the dictum that Otdgo reefs do not live down. Parties interested in the question are referred to the next follow incc article of this series, which will give a full description of th? exploitation in that mine and the revealments made by them. This reference to the subject is made in support of the soundness of Mr Donne' 0 view that the reefs of Otago have not yet been followed to a sufficient extent to speak definitely as to their living down or not.