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dredging operations at the time of my visit, but no returns at that time had been got. The Golden Link Claim is situated at the junction of the Shotover and Kawarau Bivers. Frankton Beach Company. —This company have not been successful in carrying on dredging operations. They have recently purchased the claim belonging to the Golden Bar Company, and removed their dredge to it, but their capital being exhausted they had not, at the time of my visit, commenced active operations. Sand-hills Company. —This company have been successful in their dredging operations last year, notwithstanding the difficulties they had to contend with in time of floods and stranding of their dredge. This is the only dredge in the colony which is worked by electricity, which is generated about one and a-half miles from the place where dredging operations are carried on. These returns .show that they are working payable ground, being from 12oz. to 30oz. of gold per week. Southland District. Waipapa Company. —This company suspended operations for a considerable time pending the arrival of a large Welman pump from England, similar to that used on the Six-mile and Lake Brunton Companies' dredges. It is stated that when this company first commenced dredging operations in February, 1889, they only got about 60oz. of gold for six months' work, but for the year ending September, 1890, they got about l,ooooz. of gold. This pump has now arrived, and dredging operations have been resumed. Lake Brunton Company. —This company is dredging near the ocean-beach, south of the Waipapa Company, and opposite Lake Brunton ; the depth of the ground where the auriferous wash is deposited is only about Bft. Underlying this wash is a layer of peat. The best portion of drifts lies close to the bottom, and in some places it is very stony. It is said that stones 60ib. in weight are thrown on the washing-tables. One would hardly credit, with the experience that has been gained in working dredges for lifting auriferous drifts, that such a thing should take place as heavy stones and material passing over gold-saving tables. Wherever this takes place there is a large portion of the gold lost. It is also said that this company are getting fair returns from the ground. Other two dredges have been erected during last year—one by the Otara Company and one by the Bushy Boint Company. These dredges have Gwynne's centrifugal pumps instead of Welman's. The runner is 3ft. in diameter and only about 2in. wide, which will cause these dredges to be a failure, inasmuch as they are not capable of lifting large stones. Six-mile Dredging Company. —This company has been carrying on dredging operations very successfully last year. A description of their dredge, which is one of the Welman pattern, fitted with a pump-runner 3ft. Gin. in diameter, with a 13in. delivery, was given in my last report. This company was formed in October, 1889, with a capital of £12,000, of which £2,250 was given in scrip to the promoters, and £7,421 has been paid in calls. The ground that this company are working is about five miles further north on the ocean beach from Waipapa Point, and from the returns they have been getting last year it should be a valuable mining property.

LOCKS AT THE OUTLETS OF THE OTAGO LAKES. A good deal of correspondence has taken place with reference to the construction of locks near the outlets from Lakes Hawea, Wanaka, and Wakatipu, for the purpose of damming up the water in these lakes for certain periods during the winter months, so as to allow the miners to work the beds of the -Clutha and Kawarau Rivers for gold. In regard to the construction of the locks referred to it was first necessary to ascertain whether it was practicable to dam up the water in these lakes without damaging property along their shores, and also to see whether good foundations and abutments could be got for the construction of works of this character. On my visit to the district in January last I examined the outlets from each of these lakes, and measured the width and depth of the rivers, and ascertained the velocity of the water in each. The depths of water in many instances were difficult to get accurately, on account of the high velocity of the stream; but measurements were taken at different places in the river so as to check the others; at the same time they cannot be taken as being thoroughly accurate, but merely a close approximation in ascertaining the volume of discharge; it has, however, to be borne in mind that the quantity of water coming out of each of these lakes was considerably greater at the time of my visit than during the winter months. Possibly the volume of water in the rivers would not be more during the months of June, July, and August than one-half of the quantity flowing at the season of the year when it was measured. There are sometimes floods in the winter as well as during the summer months; but in general they are not so high, as the flooded state of the rivers during the spring and summer months is due to the melting of the snow on the mountains. In considering the question of constructing locks near the outlets to any of these lakes, the widths of the openings into each of the rivers would have to be considerably increased in order to provide for the outlet of the flood-water. Not only will the area of the present water-way have to be increased, but a certain width of the locks will be taken up in divisions and piers. To take a case for example: say a river is 300 ft. in width, having an average depth of sft., and a velocity of 7ft. per second, the volume of discharge would in this case be 10,500 cubic feet per second. If each of the gates are taken as oft. wide, this would require sixty gates to have an equal area of water-way ; but the friction of the water in passing through these small openings would be increased by about 25 per cent. There would have to be seventy-five gates of sft. wide to have an equal carrying capacity to the original outlet; therefore it may be said that locks, including piers and divisions between the gates, would have to be about twice the width of the present outlets, irrespective of the distance that they would have to be carried into the banks on each side to get sufficient abutments. The gates in the locks would have to be of such a description as to be easily worked, either