THE OTAGO GOLDFIELDS.

Otago Witness, Issue 2201, 7 May 1896, Page 19

THE OTAGO GOLDFIELDS.

JCHEIK 'PAST HISTORY, THEIR TRBSKNT POSITION, AND THEIR FUTURE PROSPECTS. (BxOtjr.Special XKxmmtssioneb.) no. iv. THE>VALLBY OF THEiOLUTHA. "Thb Island Block Gold Minlnq -Company. At 'he time .of my visit to the claim- the comp -ny was on Very rich wash, something like £120 -rorth of gold going into the boxe* daily, whR-h uaeauta clear pnJlt of £50 daily. How long-thiß/maylasb it is Absolutely impossible to No 'reliance whatever win -be •placed <on ian.i indications the ground may.give. In faot, »11 the familiar indications of the presence of k goldimay beiviaible, and itjnay be/found, as:ifc •has frequent}; rbecn,'that .the bottom does cot Bhow a colour. On one occasion, after working .fora-week on what, appeared .to .be good goldbearing ground, they washed up for 7oz of ,gold. .Not; .a greater distance than a chain .below.that .ground they opened a new.paddvok <snd tojik out 5320z of gold. Yet in both Jn&tancee .the indications -were ptecrsely similar. .The only feasible explanation to account for -this apparent contradiction of a principle msaally reliable in gold mining is that an eddy,or •whirlpool,-having fifsfc by a 'process of ohtiming distodged*and separated .the gold from the •bottom, it was taken up by the current .-and .deposited farther downthe river. I -was shown .gecuud-where as much aei9ffc of very promising wash was found, but nut .a <colour«f gold was visible .any where in it. iAU the jgold 4» wi this 2ft of .the bottom, and no iudio&tiuna Are visible until that depth ha» beenreaobed. This means that from,36ft to 40ft of ground,has to be sluiced.-away and lifted by the elevator before,any idea ctn bs formed of the kind of _grannd they<are workbg on, and a large umouot •\ of dead work.is frequently the result.- In 1893.84 the profits of. the company amounted to .£2OOO, but last year a loss of J1740 was eua-taiut-d on the 12 months' operations. It should be explained that in the latter case the'uiiantisfactory results obtained are attributed by the imanager to the interference of the county council, which compelled him to shut down oue elevator and abandon a piecs of ground in which it ia believed the river had left a very rich deposit of gold. Regardless of the correctness of this supposition—and suppositions, it must be said, scarcely furnish a reliable basis of belief in dealing with this ground —the company must have Buffered -a Berious loss in being deprived of .the services of one elevator during a large part of the 'year. As a further result they found - themselves compelled -to discharge niae of their bands.

One very agreeable effect of .the operations of the company has been to lead to the settlement of miners and their families on the coltiv*ble patches of land in the neighbourhood df the mine. In the days preceding the advent of the •company 'the country round about was a solitude. There, were not • mon than 'two houses between Rae's Jnnotion and Miller's Flat. Bince then a very healthy transformation has ;t»ken plaoe. Comfortable cottages, .trim if ardens, .and cultivated patohes of ground, .in .company with a l l the other familiar indications of contented And industrious settlement, meet the eye on almost every hand. There is also a post and telegraph .office, which .helps to keep the little community in sympathetic touch with Jfchat larger world l df which they -are one of the ' Industrial outposts. } Pat to. any, tfther use 'the five acres' of Jand taken ~up by the Island 'Bl<x.*k Company could not have produced snob, 'epl nriid -results ; ' and certainly no more blo- ' quest testimony could be desired to abowthe talue of oar aunferoaa UndfSS • factor ia promoting settlement.

The company has one of the best hydraulic plants ''that have ever been used in the colony, ao expense having bten spared in proem ing the beat, most modem, and 'substantial equipment. 'The company .have alao an *xoel lent . supply of jnat*r. .Their claim, -constructed .©ntfche Fruidburn, is in the form of ,a -weir, and when full .covers sax area of about,so acres. It is built of .cement .masonry on a solid rook foundation, and is 17ft high. The .top portion is formed of double timber, and braced fcr?4olb mils, and has two bays of timber with .a .centra pillar.

-Eaoh .opening in the masonry is double(Planked -m* .totaca .timber, and bolted .to the iron. - It has three gate opeDiuge, .with .an iron door, on« of which can be ased to «mp% ,the -dam, the other two.opemngs are in fhe flume, 'the lower t>ne briog,on a level with -the main level of the reservoir, so that nearly the whole of- 1 the > water stored is available for the race. Thethird opening is'sitnate immediately above ►'.the'Sfflond, and -is .only use 3in the of ■more water being required 'than -the second ■opening is capable .of -supplying. Qco,a«ioa« | ifiian it 'is found -necessary bo -bring in an additional supply from the TaU«burn ,tho .upper, opsniug will then be used. In .times of flood the overflow ' Water runs over tbe top of the dam, which is 66ft in length, with a touse of 14ft, .and Bft wide on top. The main flume, which commences .at the. dam, is laid for six •chains'on'the edge of a/gorge on a dry masonry Trail. There are two by-wa»hes in the floma iorletting the water out when necessary. At the ■end.of:ths flume, cuming from tbe dam there is ■a solid.rock cutting', end. ntbe r trussing a small brink where there , is 36ft -of boa^s. it crooaea theTiuidburuby.a flume lUit long, with a fall of 2fin ,to ,the chain, tha flume being ,60fb above the bottom of tbe creek. The race is then constructed for 90 ohains in earth aud rook cutting, with tbe exception of three short flumes, two of which are over gullies 'having >a ;lenglh of 50f t each, and ooe •long a rocky ledge .h 140 ft loug. The conduit is in .earth and rock cutting*, with a fall of lin to the chain. The company hold the right tq 28 sluice heads from the Fruidburn and 12 *luice heads from the Tallaburn. The water is taken -across the Clutha in I a pipe laid on masonry piers built at each side of the river, the masonry -.being built on a solid ■foundation and laid in cement. There are four •wire rope cables laid over the lop of the piers, the span batween the latter being 462 ft. Tha pipe in suspended by suspension rods 'from 'the ,o»bles:on the same principle ns the roadway of ia suspension .bridge. The fcdfcal .leugth of pipes from the penstock to the claim on the' west side .of the river is 180 chains, and tbe total head of water in the bottom of the .paddock .is about 760 ft. '.The 'elevating >pipe is 15in in diameter, with a 'heavy hematite oast irou liver, at the bottom 3in in thickness, this latter reducing the inside diameter at, tho bottom of 'the elevating pipeto9in The water is led to the elevator nozzle, which is '2£in in diameter, by a 9in pipe. The pipes are all made ' of steel, hating lap-welded joints, in 18ft lerjgths, with .a .collar welded oa each end. At the -back of thepe collars are flanges made of angle-iron, which aie slipped on to each pipe before Ahe last collar on the end is Tvelded on. These flanges. came^against the .collar, and are .boltedjto.the flange? on the .adjoining .pipe. .The end of .one pipe is butted against the -adjoining x>ne, having a thin insertion ring between the ends, and they are held fast together with bolts 'through the 'flanges. This is what is called the '-Kimberley joint, which 'would be considered 'highly satisfactory wore it not that at tho bends, where there is a high pressure, the pipes are liable to 'leakage; and indeed these leaks are Of frequent occurrence, and are tho cause of much .trouble, and loss of time. Ttore are two mflta* of .pipes two.milea long, of 15in each, having a. fall of .800 ft. No each" pipes, for superiority of material and perfection of finish, have ever been nsc-d for hydraulic purposes in the colony The whole of .the pipes were manufactured in Birmingham, and cost 8s per lineal foot for -those 15in in -diameter and thick, 6j'lod per foot for thosa of similar diameter and 3-16tn thick, and 4s -9d per foot lor thoie l'lin in diameter and .3 16in thick. The sluice bozei are3ft'wide and lfttdecip, of kauri timber l£in ■in thickuess, tbe sides being lined, on (he inside with light, iron. The ripples are made o£ 2in | angle iron placed crosswise in tb^e ;box .l£in .apart, the ends being ri vetted to icon sides. [ After the material has passed over about 160 ft ' in length of these .ripples the bottom of the sluice is covered with coco&nut matting, having perforated plates placed on the top of strips of I wood laid ab each Bide of the box above the matting. This allows the fine sand and gold to pass through the perforations in the plates and ■on the oocoanut matting, while thecoarie gravel and atones are carried down on the top of the plate? to wbere the tailings are deposited. The whole of the workings are lighted at night with the electrio light, and a telephone connects the manager** residence with the .house of the man who has charge of the dam. This enables the water to be shut off .at any time at the head works, or more let on, as occasion demands, without any waste of time. It is worthy of note that the company were the first to lead the way in elevating gravel on the river. Cement only had been previously lifted by elevators in tha colony. Mr O. C. Bawlins, who has a seventh interest in the property, has from the outset piloted the company through the heavy undertaking on which, uuder his advice, they first embarked. While the work of .equipping >tbe mine and preparing for its subsequent development was in progress, Mr Rawlins acted as engineer and superintendent, and gave many proofs of resource and capacity -for the gigantic wo r k he had undertaken. Hi« management, though accompanied with much up-bill work of a disheartening character, has been a decided sur cjjs?, and he has in many waysjdeserved well of .the company. ~"

Mr Ka'wliDS hftS for some years been nursing a scheme having for "its purpose the working of a }ck>» waste ot swamp. on the Island Block, lying between Stable's - creek and Stewart's | aofommodafsion .house. The land consists of .a morass of black mud, which it is thought i could be operated on by a dredge driven by electric power, at present going to waste in one' of tho company's water raws. The advantages of the application of electricity to dredging are obviously mani-

fold. There would be, for instance, tho saving of fuel— a c»nnidor»ble source of expense in .the working of a dredge, to say nothing of the constancy and easy application of the electrio current. It is olaimsd for the ground in question that there would be no rise jmd fall in the water, no travelling silt, and no dangerous current* to face. At places there are beds of joffc slime into' which a pole may be driven witboat any great effort to a depth of 15ft .or 20ft. Jn auoh plocas a dredge would certainly fare badly ; but Mr JRttwlins, before .whose hopeful nature difficulties vanish even imoco rapidly than does -the morning mist 'before the bud, pr opoies to deal with these mud deposits fey means of a powerful suction pump, which would lift and force tbe material .many ohains astern. It was recently stated that * oompsny -was in course of formation for thetpurpate of working tbe ground with a couple of dredges, but -the statement; is probably premature. Island Block Extended sCuhm. The Island Block Extended has done nothing •to redeem the evil reputation that has clung to it for so maDy years.' Ana yet there are fcho/ie, eb there hava been in , its darkest days, whose .faith ia the /property is asirobust andijunahaken .as in the early times. The manager had little ; to say as to tbe prospects of the mine, and. his monosyllabic utterances wera deeply tinged with gloom. Like the honest knife^griuder, he had "no story to tell," and ,the .outlook was not of the kind to .impart much warmth ,to the -imagination.' They -were working on private •property, vainly followingtho lost lead of gold, havingcontracred to pay the owner 10>per cent, of the gold obtained Their vf»sh-up'for aev.en days' sluicing <g«Ya them 21oz Tdwt. A continuauce of such yields would pay the company, but .in this claim there .se^ms to be no continuity in .any direction but the one that leads to disappointment. They have taken lOOoz of gold out of the claim since Christ-mas, which after paying the wages of 11 men employed in the mine and other expenses would furnish .but an exc&ediugly narrow margin of profit. It is significant that gold has never been got in the river fronting this claim, though it ihas been worked right up to the bank. The company hive a very fine plant and. a, good water supply, having a head of .about; 800 ft, and it is probable that they .will ultimately take .the* water over the river to work. into ithe ground bounding 'their dredging claim. (To be continued;)