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importance, entitled. There is no gainsaying the fact that the present practice of passing soil, clay, and gravels down the sluice-boxes at one and the same time is capable of being very materially improved upon with considerable advantage. It is well known that in the localities alluded to the gold is fairly fine, and in many instances may he classed as " very fine " when considered by the standard usually applied to alluvial gold. When buckets come up laden with a mixture of clay, puddle, and auriferous the whole lot are washed down the sluice-box together, some of the gold adheres to the plastic semi-plastic material, the result being that, instead of being separated and recovered, this gold is carried off and deposited among the tailings, and therefore lost. The extent of this loss is not recognised so fully as it might be, but if dredge-owners will go to a little trouble in the matter they can easily ascertain what the loss is. I submit the following suggestion : Make a square box 3 ft. long, 3 ft. broad, and 3 ft. deep ; inside measurements. When levelfull, the contents will be exactly a cubic yard. Half fill it with water, and then, say, once in every hour, throw in a dish of tailings, repeating this until the box is quite full and the surplus water has run off. The tailings, settling in the water, will be very compact by the time the box is full, but consolidation may be aided by ramming to some extent. Now cradle these tailings carefully, and weigh the gold saved by the cradle. This will be a fair index of the loss which is constantly going on, and I may remark that, acting on a suggestion of this kind some time ago, one dredgemaster in charge of a dredge working gravels overlaid by a bed of clayey matter made the experiment, and found the average loss to be 2 gr. per cubic yard. A little calculation will show how a loss of this kind works out: Suppose a dredge is lifting 50 cubic yards per hour for an average of twenty hours per day, and allowing for holidays, stoppages for repairs, &c, we take four and a half working-days per week all the year round. This gives 4,500 cubic yards of ground moved per week, and, assuming the loss to be 2 gr. per cubic yard, the weekly loss is 18 oz. 15 dwt. of gold, which, at the moderate rate of £3 15s. per ounce, represents the sum of £70 6s. 3d. Assuming, however, that the loss is only half the quantity. stated, at 1 gr. per cubic yard it means a weekly loss of £35 to an average-sized dredge, and I have very little doubt in my own mind that there are dredges now at work at which something like fifty pounds' worth of gold per week will be found to be going over the tail shoots, if careful tests of the tailings are made somewhat on the lines suggested. What I wish to convey is this : That (a) in the light of gold-saving alone, it will, in my 7 opinion, pay to strip the overburden—where such is of a clayey nature —off the top of the auriferous wash, and (b) the land can be restored to a much better state than is now being done. There has been an outcry in some quarters about valuable land being destroyed for agricultural purposes by gold-dredging operations. This has undoubtedly been the case in a few instances, but in others, where swampy marsh land has been dredged, the effect has been to drain and sweeten it, and it is now growing sweet grass and clover where rank sour grass and rushes grew before. At the same time, it cannot be claimed that this land has been left in anything like so good a condition as it might have been had advance stripping been practised, and the soil and subsoil, &c, deposited on the gravel tailings instead of their all being mixed up as at present. At Waikaka, Southland, trees have been planted on the tailings left by one dredge working on private land. At my last visit to the locality I carefully inspected this plantation, and found the young trees healthy and growing well. The idea of planting some of the tailings-areas which t i ,were formerly swamp lands with native flax suggested itself Jto my mind, and I submit this as|offering a means of profitablyjjutilising the ground from which the, alluvial gold has been won. Impeovements in Dredges. Roberts's Silt-elevator for Dredges. This elevator was designed to obviate the great wear-and-tear which takes place with the ordinary bucket or " baby " elevator which was originally first introduced by Mr. Edward Eoberts, C.E., of Dunedin, on the dredge " Moa," at Alexandra, and which has been 'argely adopted by other engineers. It is well known that any piece of machinery having a number of separate parts working in sand, or water heavily charged with sand, very quickly wears out, and this has been the case in a marked degree with silt-elevators on dredges. Mr. Eoberts early foresaw this, and in 1899 patented the wheel-elevator, claiming in the patent to receive the sand in any manner at the bottom of the wheel, and discharging it at the top, so that the wheel would be adapted for dipping the material from a trough or receiving it direct from the sands-shoots as in the plan illustrated. The latter plan is for many reasons the best, but principally because there is no friction in moving the wheel through a body of sand and water, and the wheel may be stopped at any time without any danger of silting up and the breakages consequent on the restarting of the wheel. In the design illustrated (which is similar to the wheels used on the Golden United, Sullivan's Lead, and Golden Eun dredges), the wheel A is fixed in a framework alongside the main elevator, and is capable of being raised and lowered with the elevator-frame. It is driven by gearing and belting from the main elevator countershaft and runs at a slow speed. The wheel-rim is formed " trough shape " with internal buckets. The sand and water from the tables being delivered by the sand-shoot C into the lower part of the wheel, and, the wheel revolving at a sufficient speed, the water and sand is taken away as fast as it is delivered from the sand-shoot, and there is consequently no boiling. It is then carried up slowly, the sand settling in the buckets and the surplus water being caught off the lips of the buckets by a collector B having suitable vanes and delivering the water at the bottom into the paddock. By the time the buckets reach the top of the collector the last of the water is discharged and the sand begins to deliver on the apron or shoot D, sliding down this shoot into the main elevatorbuckets in a continuous stream. There are no moving parts except the wheel and shaft, and no wear. The wheel also, being suspended freely, and having no parts in frictional contact with the material, can be of very light construction,