OE NEW ZEALAND.

29

G.—No. 4,

workings are for tho most part alluvial, but quartz reefs exist in various parts, some of which have been tried but hitherto with little success. The alluvial workings are mostly constructed on the system known as ground sluciing by which large areas of ground can be rapidly and cheaply washed away and the gold saved in the tail races. This style of working is favored by the fact of the gold being chiefly found in a sort of gravel containing but little clay and which is readily moved, and disintegrated by the action of water. Skirting the basis of the mountains are numerous spurs stretching away for miles into the plain country and formed almost entirely of ground of various ages. It is from certain layers of this ground that the miners extract the gold by the agency of water; as a rule these beds of wash dirt are by no means rich in gold; it is necessary to wash great quantities to obtain renumerative results. Thus it happens that only those places are worked which afford special facilities, in the shape of proximity to a supply of water and good fall for the disposal of the tailings. This latter point is of as much consequence as the supply of water, and it frequently happens that ground known to be richer than the average has to be left unwrought because it lies at too low a level to enable the miner to get rid of the waste ground after washing. The method of ground sluicing has been so often described that I need not here enter into any particulars respecting it, beyond remarking that the ingenuity and perseverance of the miners are frequently taxed to the utmost in the construction of the tail races that are requisite for the carrying out of the process. In some places these have to be made of great length, in others the needful gradient can only be given by deep and broad cuttings, while in others a sufficient fall can only be obtained by tunnellings through spurs that intervene between the ground to be washed away and the low lying gully or flat into which it is desired to discharge the tailings. As a rule the sinking of shafts is never practised except for the purpose of prospecting ground to find if it will pay to sluice. There are no underground workings of alluvial ground in the district. At Macrae's Flat, the ground being richer than in most other parts, and the supply of water insufficient for the ground sluicing system, the miners work by paddocking, thai is by working open excavations of slight depth, and thus exposing the wash dirt, which they put through cradles and sluice boxes. At Cambridge diggings, in the Rock and Pillar Bange, somewhat similar processes are adopted. These may be taken as the only exceptions to the general rule of ground sluicing in alluvial workings in this district. From what has been said above, it will be apparent that in most parts of the district the number of miners must depend mainly upon the supply of water and the other facilities for sluicing, referred to. But the supply of water has the most decided effect in determining the number of miners that a district can maintain ; for fall can in most instances be found if the ground is good enough to warrant the expanse of the necessary works for tailings. To supply the water for working, a number of races have been constructed, bringing into the various mining localities all the water that can be got within moderate distances. Some of these races are works of no small magnitude, and for their construction have demanded considerable engineering skill. The races that are brought in to Naseby are mostly the property of registered Companies, which derive most of their profits from the sale of water to the miners. The price was, until recently, £2 to £2 10s. per " Hogburn head," according to the altitude at which the water is wanted, the water at a higher level commanding a higher price ; the price is now uniformly £2. The " Hogburn head" is a stream of water passing through an orifice sixteen inches by one inch, and running for the working day of eight hours. The Government head, or head of water according to the mining regulations in force in Otago, is twenty inches by two inches, measured through a box which is so contrived as to give a pressure of six inches. It is roughly estimated that the Government head of twenty by two inches, or forty square inches transverse measurement, is equal to two and a half times the Hogburn head of sixteen by one, or sixteen inches square, and as the Government head flows for twenty-four hours while the Hogburn head is only allowed to run for eight hours, it follows that the Government head is equal to seven and a half Hogburn heads. Water being so valuable as an agent in mining, every effort is made to economise it; all the water race companies have dams in which they store the water which their races bring in at night and on the Sunday, and besides this, the water is wherever possible used a second time. Still, with all the economy possible, water can only be made to serve a certain number of miners. In some places this number will be more than in others, according to the character of the strata ; some soil requiring a heavier stream to move it than others ; but in every place there is a limit to the number of miners that can be profitably employed, and that limit is exactly regulated by the quantity of water that can be had. The past year has on the whole been an unfavorable one for the sluicing interest. It has been throughout a dry season, and for the last few months there has been a positive drought; so great has been the want of water, that for a short time, recently, the races brought into Naseby have not carried much more water than was sufficient for domestic purposes, and sluicing has therefore been for the time interrupted. From this it has resulted that many miners have had to go away to seek a livelihood elsewhere ; but this will not cause any permanent falling off of population, as the miners are sure to return to their work so soon as a return of wet weather assures them of a supply of water for sluicing ; in fact, none have gone away except those whose necessities have obliged them to do so. The great majority have preferred to wait in expectation of a change in the weather, and in the mean time to occupy themselves with such work as they could find to do at home. This drawback of the drought has seriously affected the production of gold, but it is only reasonable to expect that after so long a season of dryness a change favorable to the miners must soon take place, and then it is to be hoped the district will resume its usual prosperous condition. Quartz mining has not as yet been successful in this district. Beefs shewing every indication of richness were found at Boughridge, in the Ida valley, five years ago or more, and mines were opened and expensive machinery put up for reducing the quartz. The prospects seemed good, but the returns were insufficient to meet the expenses, and the works were stopped and the machinery sold. The buyers of the machinery made the discovery that gold must have been lost in working it, and so strongly were they convinced of this, that they sent men to wash up the gully down which the tail water from the machine had been discharged. What they got has not been made public, but as they 8