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ALLUVIAL MINING. The greatest portion of gold produced in the colony up to the present date has been obtained from the alluvial drifts; and it may be interesting to know that according to the statement showing the quantity of gold entered for exportation up to the year ending the 31st March last, the gold, obtained from the alluvial workings was equal to 60 per cent, of the total gold-production of the colony. The total value of the gold entered for exportation last year was £889,545, of which gold to the value of £373,676 was obtained from quartz-mining, thus showing that more attention is now being given to this branch of the mining industry, which may be said to be our only permanent gold-mines. The principal portion of the gold yet obtained has come from Otago and the West Coast, where the largest portion of the workings are in alluvial drifts. Notwithstanding the fact that during the last thirty-four years many shafts have been sunk, and large areas of ground sluiced away, it has made but little impression as yet upon the features of the country. It is said by some that alluvial gold-workings partially destroys the land; but the accuracy of this statement is questionable, as in many places where alluvial workings are now carried on, the land would in any case have been of little or no value to the agriculturalist, and, so far as pastoral pursuits are concerned, the shallow ground where the alluvial drifts were worked in the early days is now covered with a sward of grass almost equal to that which existed before the surface was broken. Alluvial workings were first discovered in the Collingwood district, about thirty-eight years ago, but comparatively very little work has been done on this goldfield. The reason of this is, perhaps, that the outbreak of the Otago Goldfields attracted people from all other parts of the colony, and the richness of the discoveries, especially in Gabriel's Gully, Wetherstone's, Waitahuna, and in the Shotover and Skipper's, led men away with the idea that those parts of the colony contained such fabulous and easily-procured riches, that would enable them to accumulate vast fortunes in a short period. The diggings were at first confined to shallow workings, from sft. to 10ft. in depth, the ground being stripped and turned over in large paddocks, the bottom layer of the auriferous wash-drift being merely run through narrow sluice-boxes, or a cradle, and then what would not pay a very high rate of wages was thrown away as valueless. Since that time, however, improvements have from year to year been made in the appliances for working the ground on a far more extensive scale, and also for saving the gold which the drift contains. There are at the present time very few places where men are earning a livelihood by driving and paddocking as in the early days. The most of the alluvial workings are now carried on by hydraulic sluicing and dredging operations. The latter has of late years become an extensive branch of the mining industry, and a very large amount of capital is invested in it. Dredges are now placed on every river and stream which contains auriferous wash, and they are also working shallow flats where in former years the water to contend with was too heavy, which prevented the miners working the ground economically either by driving or paddocking. Hydraulic elevating is also an innovation in the system of mining. It is only some seven or eight years ago since this method was first introduced on anything like an extensive scale, when Mr. J. R. Perry, a very enterprising gentleman, introduced this system for the purpose of working the tailings in the bed of Gabriel's Gully; but a great many alterations had, from time to time, to be made in the plant in order to get it to work successfully. The size of the supply-pipes, the position of the jet, the size of the throat, and the height of the material to be lifted were all items to be taken into consideration, and as each difficulty arose it had to be combated with and overcome. Mr. Perry succeeded, after considerable expense, in constructing a very efficient plant. Since then, however, elevator plants have been greatly improved. There are immense areas of auriferous drift in Otago which would pay for working either by hydraulic sluicing, or hydraulic elevating, and, in shallow flats where there is much water to contend against, dredging operations are being carried on successfully in many places. The recent explorations of Mr. McKay, Mining Geologist, show that there are very large areas of quartz drift extending from the Maerewhenua Goldfield across Central Otago to Switzer's. In many places where these drifts are being worked some of the claims are yielding a large amount of gold, as, for instance, Mr. John Ewing's claim at Kildare Hill, St. Bathan's, may be cited. The line of these drifts extends over Mount Buster, across the Maniototo Plains, to the Manuherikia Valley, following down the side of the Dunstan Eange to Clyde. The same formation again appears in different places in Otago—at Switzer's, Mount Criffel, on the side of Lake Wakatipu, and in many places in the Tuapeka County. These quartz-drifts are some of the oldest alluvial deposits that are to be found in the colony. On the West Coast the gravel drifts are of considerable extent, but differ materially in character from those found in Otago. The oldest drifts here are what is termed " Old man," or " Maori bottom," where, notwithstanding the opinions held by many miners that this " Maori bottom" does not contain gold, the denudation of the material has been the means of supplying a large portion of the gold found in the valleys and river-beds of the West Coast. On the top of Mount Greenland, at Ross, and also Napoleon Hill, these drifts are at the present time being worked, and in some places giving good returns; this being especially the case with regard to some layers on Napoleon Hill, which have paid remarkably well to drive out and wash in the ordinary manner, whilst the Mont dOr Company, at Ross, has been working in these drifts for many years, and have also obtained good returns. There is a large extent of ground on the top of Mount Greenland which would pay for working if a good supply of water was available. Mr. Antonio Zala opened a claim here about twelve years ago in similar ground to that worked by the Mont dOr Company, at Ross, but the claim was worked under great disadvantages, as it was at a high elevation, and there were no possible means of obtaining a proper supply of water. In fact,