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The detailed lists of dredges working and building are attached to the reports of Inspectors of Mines. Gold-saving on Dredges. I am indebted to Mr. George J. A. Richardson, of Invercargill, for the following paper and accompanying drawings : — '■ As year by year the lifting-power of gold-dredges has gradually increased so that at the present time over 100 tons per hour can be lifted, the question naturally arises, How is it that the gold returns do not increase in like ratio with the amount lifted? The only conclusion that can be arrived at is that the gold-saving appliances are not progressing with equal strides in comparison with the lifting-capacity of the dredges. Reverting to the oid-fashioned cradle, it will be admitted that the same quantity of matter cannot be washed with a 12 in. that can be dealt with by an 18 in. cradle, and the same rule applies in dredging. Boxes with an area and water-supply sufficient for 25 tons per hour are totally unfitted to cope with 100 tons per hour. Not only will the loss exist in not saving the gold from the 75 tons over the 25 tons for which the boxes are adapted, but the increased quantity will result in a return of less gold from the 100 tons than would have been obtained if only 25 tons (the capacity of the tables and water-supply) had been dealt with, inasmuch as the cloths become clogged almost immediately after the dredge starts, and thus the gold is prevented from coming in contact with the saving surfaces. Instances no doubt exist when the lifting-capacity of 100 tons per hour, with saving-tables and water-supply equal to 25 tons per hour, will not overtax the saving appliances. For example, if the matter dredged is composed of 75 per cent, of stones and boulders the tables will only be called upon to deal with the remaining 25 per cent., whereas if the whole 100 tons were box-matter the tables would be quite inadequate. It is therefore of the greatest importance to the proprietors of every mining claim to ascertain the percentage of box-matter, and that this information should be handed to the engineer, to enable him to provide sufficient room on the dredge to allow of adequate table-accommodation. Last year I visited a dredge with a lifting-capacity of 60 tons per hour; a large proportion of the 60 tons was box-matter. The saving appliances consisted of a 3 ft. launder, about 25 ft. long, over which the whole of the matter passed; an under-run supplied the tables, which consisted of three boxes, each 3 ft. wide and 12 ft. long. It is needless to say that the loss of gold was very great but the dredgemaster was quite satisfied, and pointed with the greatest satisfaction to the distance covered during the previous month, and the fine heap of tailings. On trying a prospect at the end of the launder there was no doubt that the tailings contained payable gold. The dredge operations had not paid the shareholders up to the time of my visit. The dredge was styled a " compact little dredge " —that is, sufficient space to crowd the machinery on without regard to gold-saving appliances. The use of screens on dredges is a very questionable benefit; the initial expense is heavy, wear-and-tear considerable, besides the cost of power and fuel required to work them. The screen is of no benefit other than to carry off the stones and boulders, which can be accomplished, and a more effectual washing secured, by causing them to travel over iron riffles. The riffles will also effect the saving of any heavy gold, should the same be present in the spoil lifted, whereas the screen will deposit the heavy gold with the stones. It is needless to quote further to prove that the present system of gold-saving is far from perfect; it is admitted by all interested in the industry that there is room for improvement, and the craze for increased lifting-power will terminate as soon as the question of gold-saving is fully appreciated. From personal experience I am satisfied that on beach claims, composed of heavy black and grey sands, it is impossible to deal with more than from 25 to 30 tons per hour, and save anything like a fair percentage of gold. One dredge under my charge on a beach claim was capable of lifting from 80 to 100 tons per hour, the superficial area of the saving-tables being 432 ft., water-supply eight Government heads; not more than 20 to 25 tons per hour could be put through with advantage, and from this quantity from 60 oz. to 80 oz. of gold per week was obtained ; every attempt to increase the quantity lifted only resulted in blocking the tables and consequent loss of gold. If satisfactory results are to be obtained, the following questions should have the attention of all concerned in gold-dredging, more especially when fine gold is present : (a) Area and position of tables; (b) quantity of water and even supply ; (c) even distribution of spoil and water over tables ; (a) size of runs or boxes ; (c) lifting separate runs without stopping dredge ; (/) constant attention to tables. (a.) After repeated experiments I found, in dealing with fine gold and black sand, that a wide spread of boxes is absolutely necessary, so that the spoil may be distributed over a wide space of

District. Working. Standing. Under Removal. Building. Total. )tago iouthland 99 26 10 4 84 17 197 43 Total for Southern district Vest Coast district 125 20 10 1 4 101 21 240 42 Grand total ... 145 11 122 282