85

a—3

face. No. 6 shaft : This shaft was started on the 4th August, and is now down 166 ft. from surface. At 151 ft. down the decomposed older andesite rock is met; from surface to a depth of 59 ft. is soil and sedimentary material; from 59 ft. to 134 ft. is hard rhyolite rock ; from 134 ft. to 146 ft. is pumiceous tuff; from 146 ft. to 151 ft. is an old surface containing boulders of rock and loose quartz. This shaft is used for sending down filling material in cages. Surface Works. —Two Elephant boilers have been built in at No. 5 shaft, and an air-compressor capable of working six rock-drills. A large coal-bin was made in front of boilers at No. 5 shaft, and also at No. 2 shaft, with a short tram and a steam-winch attached. A large blacksmith's shop has been erected at No. 2 shaft. Mine-development and Dead-work Footage.—Crosscuts through country, 3,115 ft. ; driven on course of lode, 7,852^-ft. ; crosscuts in lode, 1,277-J- ft.; winzes, 5,173 ft.; shafts, 736f ft. : total, 3-438 miles, or 18,154f ft. It was found advisable to considerably extend the storage-capacity of the hoppers at the several mine-shafts. This has now been done, and a new style of hopper-doors put in, which have been found to be a great improvement. Product.—A total of 179,485 tons (dry weight) lias been treated during the year, being 20,160 tons in excess of the total of 159,325 tons which was treated during the year 1901. Of this total, 65,498 tons has been dealt with by the dry-crushing and 113,987 tons by the wet-crushing processes. The product was 605,997-7 oz. of bullion, exclusive of concentrates and slag tailings shipped to Australia. In addition to a small quantity of concentrates which was dealt with at the Victoria mill, regular shipments of concentrates to Australia have been made monthly. A total of 84,722 tons has been shipped, the value of which, according to assay, was £48,632 12s. 2d. The value of the total product, computed on the usual basis of gold valued at £4 4s. and silver at 2s. per ounce respectively, was as follows: 605,9977 oz. of bullion (excluding concentrates and slag tailings), £470,286 7s. 7d. ; 847-22 tons of concentrates (assay-value), £48,632 12s. 2d.; net outturn of slag tailings, £1,219 15s. 3d. : total, £520,138 15s. The weight (avoirdupois) of bullion produced was as follows : Bullion (excluding concentrates), 18 tons 11 cwt. Oqr. 2 lb. The value of bullion per ounce —namely, 15s. 6d.—is lower. This is owing to the higher value of silver in the ore per ton, and the better extraction of silver obtained owing to extension of the wet-crushing process. During 1901 the average value per ounce was 17s. lOd. Reduction-works.—The respective tonnages crushed at the mills were as follows : Waihi mill (dry crushing), 45,175 tons ; Victoria mill (dry crushing), 20,323 tons ; Victoria mill (wet crushing), 107,833 tons; Union mill (wet crushing), 6,154 tons : total, 179,485 tons. The total average number of stamps running during the year, exclusive of Sundays and the Christmas holidays, during which the mills were stopped, was 3071. Waihi Mill (90 stamps).—An incline (self-acting) train was constructed and brought into use towards the end of the year to facilitate the despatch of fuel to the boilers, and of stores, machinery, &c, required at the mill. The old smithy, which was in a dilapidated condition, and also in a position which interfered with the alteration of the mill from dry to wet crushing, was pulled down, and a new one of larger capacity erected early in the year. The two steel solutionsumps used in the dry-crushing process were also in the way of the extensions, and were removed and re-erected ; a third steel sump of larger capacity was also erected. One of the dust-houses, which was also in the way of the rearrangement of the stone-breakers, was dismantled after the dust was removed and treated. A circular saw and travelling sawbench were also erected to facilitate the conversion-work. During the last six months of the year the alterations and additions to the plant necessary for conversion to the wet-crushing process were kept steadily going wherever this was possible without interfering with the running of the mill. The final alterations could not be made while the mill was running. It was consequently stopped at midnight on the 24th December, and with the exception of Christinas Day work was kept steadily going. On the 12th January a trial run of shafting, &c, was made, and on the 13th thirty stamps were dropped and ran intermittently. Ou the 14th January an additional thirty stamps were started, and have since run continuously with but slight stoppages. On the 21st January the last thirty stamps were started. The adoption of the wet-crushing process has necessitated very considerable alterations and additions to the plant. The shed over the kilns has been removed, and the old roofing, framing, &c, utilised where possible. The kilns are now used simply as storage-hoppers for a reserve of ore. The arrangement and position of the stone-breakers have been changed. A new No. 3 Gates crusher was procured, and has been erected on a large concrete foundation, the ore being tipped direct into it from the tramway-trucks. A revolving trommel and a second Gates crusher (No. 3. size) have also been erected, the ore passing through each in succession. Water-pipes have been connected to each of the mortar-boxes, and the pulp flows to the first two elevating-wheels, from which it flows over the Muntz-metal plates, and thence to the vanners. After being discharged from the last elevator-wheel the pulp passes into the separating-boxes, whence the sands pass to the thirtytwo wooden vats (which were used in the dry-crushing process), being fed into them by means of automatic distributers, and the treatment is completed in these vats. The slimes flow to a nest of V boxes, where the clear water is drawn off for refuse in the mortar-boxes, and the slimes pass to two steel collecting-vats 32 ft. in diameter and 14 ft. deep, the treatment being completed by agitation and double filter-pressing, six filter-presses haviug been erected. A large steel vat has been erected for making up the necessary cyanide-solutions, and a cyanide store erected immediately by this vat. Union Mill (40 stamps).—This mill ran for eighty-nine days during the year. A total of 6,154 tons was crushed. The mill was started (wet crushing) on the 15th September. Auxiliary steam-power to enable the whole mill to be kept continuously at work had to be provided. The mill had also to be connected by railway with the Martha Mine. Victoria Mill, Waikino (200 stamps). —At the commencement of the year 100 stamps at this mill were dry crushing and 100 stamps wet crushing. On the sth April fifty of the dry-crushing