C—B

26

These sample assays, with the exception of one which was made from stone selected by the prospectors, do not appear to show that the lodes are payable for working, but they prove that auriferous and argentiferous lodes exist, and, moreover, hold out inducement for further prospecting. On my recent visit to this field in January last the prospects of the place had considerably improved. A number of new lodes had been discovered, some of these showing ruby silver, which was not found on my former visit. The whole of the assays, however, show that there is vevy little gold in the lodes, and that silver will be the main product to be looked for. The following assays were made at the Colonial Laboratory from samples of ore selected by me promiscuously out of different reefs—namely : — No. 1 sample, Kaimanaku Creek—Stibnite found, but no silver. No. 2 sample, Mary's Reef—Traces of bullion. No. 3 sample, Blue Eeef—Bullion, soz. Odwt. 20gr. No. 4 sample, Wilson's Eeef—Bullion, 107oz. 18dwt. No. 5 sample, .Silver Eeef—Bullion, 102oz. 19dwt. 7gr. Samples of the same stone' were handed by me to Mr. Park, of the School of Mines, Thames, who assayed them and got somewhat similar results. According to some of the assays made from stone forwarded by the prospectors and others from the field, very high results have been obtained; but it is well known that it is very seldom that a stone is selected from new discoveries for assay unless it has the appearance of containing metallic substance, and the piece operated on is so small that unless great care is taken in selecting average samples for assay it gives very little criterion as to the value of the lode. Where assays have to be made to ascertain the value of the ore, a hundred or more samples are taken and all mixed up together. They are then divided and redivided until the quantity left is only sufficient for assay purposes. But, even when an average assay has been made, although it will give the assay-value per ton, the question of getting a fair percentage of the value of such assay when the ore is treated in bulk is a matter which remains yet to be decided. These auriferous and argentiferous lodes have been discovered within the boundary of a State forest where it is estimated that there is 129,000,000 ft. of valuable kauri timber standing, and where regulations have been made for gum-digging being carried on within its boundaries which prohibit any person being in the forest during the six summer months, so as to guard against the forest being set on fire. These regulations caused heartburnings amongst those who were prospecting for gold and silver, as it prohibited them from working during the best season of the year. After repeated applications for mining leases, and urgent protestations of the people of the district against the closing of the forest during the summer months, the Government proclaimed the district a goldfield on the 6th March last. It is yet premature to say whether the field will become a payable one for working or not. There are a large number of quartz lodes in the Puhipuhi Forest, and between it and Cape Brett, but there is not sufficient work done to prove whether any of these lodes will be payable for working. The distance of the field from any place where reduction-plants are erected retards its rapid development, and will lead to reduction-works being erected near the vicinity of the mining operations. When once this is done the question of the permanency of the field will soon be decided. One of the most important questions in connection with this field is the erection of a suitable plant for the proper treatment of the ore. If the ore were in the form of chloride it would be easily dealt with, but when the silver occurs in sulphides a chloridizing process will have to be adopted. A somewhat similar character of ore is found in the Owhyhee District, Idaho, on the Pacific Slope. The process adopted there for the treatment of the ore is what is known as the Washoe process ; but if the ore contains a very large percentage of sulphides it would have to be crushed dry and roasted with a little salt, to chloridize the metal, before putting it in the pans, as it is almost impossible to get the sulphide of silver to settle in tanks such as are used in the Washoe process, the sulphur being so light a metal and having so great an affinity for other metals that it is carried away by the water. It may, however, be of some benefit to the proprietors of mines in the Puhipuhi district to briefly describe the Washoe process. Washoe Pkocess. This process is somewhat similar to that w Thich was used by Mr. Eailey at Karangahake. The ore as it cornea from the mine is first put through rock-breakers with the jaws set very close, so as to break up the ore as fine as possible. From the rock-breaker the ore is fed into a stampbattery having screens from thirty- to forty-mesh, according to the character of the ore. No more water is used in the stamp-mortar than is actually necessary to keep the'screens clear. As the pulverised ore comes from the mortar it falls into a launder, which conveys it to a series of settling-tanks, with the water flowing through them, and on the first one becoming full of crushed pulp it is shut off and emptied. These tanks or vats are placed in front of the stamp-battery, and are so arranged that the waste water has to pass through the whole series before getting away. Each tank, as it is filled, becomes the final one of the series, and as soon as emptied receives all the muddy and partly-clarified water after passing through the other vats. From these vats the pulp is removed, and taken to the grinding and amalgamating pans. These pans are of different designs, according to the ideas of the millmen who use them, but the principal pans used are the Wheeler, the Wheeler and Randall's, the Varney, Hepburn and Peterson's, McCon's, Jlorn's, and Fountain's combination pan. The quantity of ore with which the pans are charged depends on their size, and varies from 6001b. to 5,0001b., but the ordinary charge in the pans most generally in use is from 1,5001b. to 2,5001b. In charging the pans the muller is raised a little from the bottom, so as to revolve freely at first. Water is supplied by a hose-pipe, and at the same