The Invincible Reefs.

Otago Witness, Issue 1795, 17 April 1886, Page 12

The Invincible Reefs.

The directors of the Invincible mine (Head of the Lake) have requested Mr A. H. Morrisby, a very competent mining manager, to inspect and to report on their mine, and have received the following report from him : —

Having received your instruction to report on the Invincible mine, I left Queensfown by steamer on April 5 and arrived at Glenorchy same day, and on the following morning proceeded to the mine, having picked up your Mr Hope on the way, dml he accompanied me ; saw the manager, who afforded me every information and assistance in connection with my mission. The invincible reef runs nearly north and. south, or one point west of north underlying very slight I v West, and is to all appearance a pcrma'ient. and strong lode. I entered the mine- by No 2 level, which intersects the lode at a distance of Jl'Ou . The reet is driven on north and south lor 2"'tttt, iphl stoped out more or less to tin* surface. 111 thr sout h end ot this drive a splice or split in t tie iP'jt occur-., going northwards, and trends moiv nc-tH |v tljau the true lode. This quartz ba-< bo»7i vnW-'l until recently, but lias proved too poor to pay at ptc<i>m . This part of the reef will average about Bit in wMI li. and is connected by a win/.e. with the okl surface workings. The true lode on Uii.s level pinches out, going north ; but. possibly the spur or splice above referred to will prove the extension of the main or true lode — in (act junction with it. again further north. I would therefore suggest that this portion of the lode be fmther prospected when time or the finances of the Company permit. Two hundred f»et from this No. 2 level south a win/.e is sunk 96ft deep to connect with machine level. The reef gave out in the winze at about OStd, aiul from there to machine level blank ground ex'sts at this particular place, although quart/, more or less is fr 'quent somewhat deeper.

The mine manager was compelled to opmi out on the lode in the winze north nt a depth ot 2ift, or three sfope?, in order to keep the mill going until the uprise from the machine level is broken through. The quaitz is at present raised by windlass and bucket, and is necessarily a very slow process ; but inasmuch as it is n necessity — an emergency case, in tact — ifc needs no further comment. I may mention that the mill has been kept going entirely from this level, the lode averaging 6ft in width . The machine level is now in a distance of Tftoffc to where the uprise starts. Tho latter is risen about 35ft, or within about 45ffc of the winze above al the time of my visit.. Water was struck 111 this ribe, clearly showing the proximity of the lode. This is fcho lowest working level in the mine, and is n-i exp"ns!v« piece of work; and I think lhar thib level should have been driven from near tho iiiacliinnhouse in one straight course to intersect, the win/.e from No. 2 level. However, as it now stands it will ans^ cv .13 a highway for the com evanre to tlif* mill.

I estimate the block, when opened up between N<i. 2 and the machine level, to contain I'pprnxinmtnli' about 41100 tons of payable quaitz; mid pi l'vioui to this becoming exhausted, I would point, our to you the-nrcessit.y of prospecting further north on the lode in No. 2 level, for although payable stone may exist further south than the machine level, yet there is no practical way at present to con\ 0 v it. t o tlipmill.

Some half mile south of the machine le\elinthe lowor lease a prospective tunnel has been driven west to cut the lode at 1 10 ft. showing a very extensive body of stone. Ten tons were raised from here and carted to the mili for n trial, with the result of soz !sd\vfc retorted gold, or lljdwt per ton.

There are at present 21 men employpd in and about the mine and mill— l 2 men raiding 'quartz, 4in the uprise, 4 in the machine-house, and 1 gettingtimber and working the horses. These men are, paid nt the rate of £3 per week. There are four horses used packing and hauling timber. The quartz at present is conveyed to the mill by shoots, but so soon as the machine site level is connected vt ith the « orkings above. Ihe whole will be brought by tram at a cost, ot about Gd per ton.

The machine is driven by water, the wheel being 21ft diameter and 4ft breast; n. ]n-hpnd battery by Messrs Thomson and Co.. of Castlemaine, Victoria. The gold is saved in berdans from Messrs Kiucaid. M'Qiieen, and Co , Dunedin. There are seven berdans kept, constantly going and one iron amalgamating barrel. The mill is well found in every particular, and works well. This is, in fact, the most complete plant up country.

The blankets are washed hourly, the proceeds keeping one pan employed ; the others are grinding the tailings as they leave the tables. By careful manipulation and skill the appliances "here are capable of saving a large percentage of gold— in fact there should be no great loss at all, although the stone being so impro^nticdwith mineral, and fcKe g«ld being very flno, necessitates very careful nnd skilful amalgamation. In conclusion. I consider theproßpects of the mine are very promising, but requires very skilful management to develop it thoroughly. The lode Js large and permanent, but in every instance where it has pinched out or where the quartz has gone poor the work has been discontinued. Prospecting on the lode should always continue, and would be the means of opening more ground and ensuring a future for the mine, besides would keep the mill going to advantage. The same applies to the mill, perhaps more conspicuously.