49

C—2

Clarke's (Wyndham) Pit. —Work at this pit was resumed in March by a new owner, who is now working the upper portion (about sft.) of the seam of lignite. The lower portion is flooded, but the water is kept below the upper portion by occasional pumping. About 12 yards to the west of the pit the gravel overburden is being carted away for road-metal, thus stripping an area which will later be worked for tho lignite. Diamond Lignite-pit. —Work has boen continued in the lower lift throughout the year. Black Diamond Mine. —A small area of coal was opened up inbye the bottom east level, but it proved very disappointing. The coal became very stony, and, although driving was continued for a while in the upper portion of the scam, it eventually became too stony to work, so the section was stopped. A prospect-level, going south-west, was driven a short distance into the faulted ground at the bottom of the dip. All the miners are now employed in the north-cast section, and when this small area of solid work is completed only pillar-extraction will remain to be done. Smilhvale Mine- About three-quarters of a mile east of the Black Diamond Mine three men have been prospecting on freehold land between the Ohai Railway and the Nightcaps-Ohai traffic-road. A surface tramway has been laid from the road down to a level in a 4 ft. seam of coal which is rather dirty. This level is in 100 ft., and a couple of inclines have been driven to the outcrop. The small output is hauled up to the road by a stoam-winch, and conveyed from there by motor-lorries. Mossbank Mine. —During the past year development has preceded in a south-easterly direction, and most of the output has been won from the land sublet from the Wairaki Coal Co. To the east the workings are being cut off by a large washout which is now running about south-east. Some of the places in No. 4 section are within a couple of chains of being under tho Wairaki Settlement traffic-road. The coal continues to be very variable in quality, in some places being clean and hard, while it is stony and dirty in others. In Nos. 4 and 5 sections it has improved considerably, but it still contains many stono backs. In No. 5 section a dip has been driven almost due south, and the face is about 14 chains north of being under the Ohai Railway. Another coal lease has been applied for over land south of the railway, and if the title be granted it is intended to drive a pair of dip headings under the railway to work this southern area. Many brick stoppings have been built between main intake and return airways, consequently the mine-ventilation is much improved. No inflamable gas has yet been found in this mine. Wairaki No. 1 Mine. —ln the No. 1 oast section the solid work is nearly completed, and throe pairs of miners are working pillars in that section. Only four single solid places aro being worked in No. 2 east section. These places are in fairly clean coal, 25 ft. thick, with a good parting about 9 ft. from the floor. Tn the main and back levels inflammable gas has been reported on many occasions since July, and consequently instructions were issued in September that until further notice the ventilating-fan must be run continuously from 4 p.m. on Sundays until the men ceaso work on Saturdays. The charts in tho fan-house show that this instruction has been duly complied with. The face of the main level is now almost under tho Ohai Railway. In the No. 3 west section fourteen single solid places are being worked. No work is now being dono in No. 2 west section, whore the coal is rather dirty. Tn the No. 1 west soction the quality improved considerably, but the places entered the faulted area, so the solid work is almost finished and pillaring will soon start there. Finely crushed limestone is now used for stone-dusting the mino roadways. On both sides of tho main haulage-road many concrete and brick stoppings have been built, and a steel and concrete overcast is nearing completion on tho haulage-road. A fine concrete housing was built for tho doublo inlet Sirocco fan. This fan-house is equipped with steel doors for air-reversal if required. The haulage-engine being too close to the mine-entrance, a new foundation is being built. The engine should be at its new site early in the coming year. Wairaki No. 2 Mine. —A few miners were employed early in tho year at pillar-extraction, but owing to slackness of trade thoso men were found employment in tho No. 1 mine and the No. 2 mine was temporarily stopped. Linton No. 1 Mine.' —Down the dip the solid work below the main lovel is nearly finished, and a pair of miners is now working at pillar - extraction. The No. 1 level area was sealed off, as the heated water percolating through from the rise-section fire caused heating there also. Three pairs of miners continued pillar-extraction in the rise area. The fire in tho goaf has given much anxiety, and many additional concrete stoppings were built around it. Most of these stoppings are now cool, but two of them recently showed a temperature of 100° Fahr. on the outside of the stoppings. Linton No. 2 Mine. —In the No. 1 south section pillaring in -both upper and lower workings is being done simultaneously, and tho first workings in the upper portion of the scam were kept immediately over thoso of the lower portion. The tops, 5 ft. to 12 ft. thick, above the upper workings are first won ; then tho coal between the two sets of workings, 10 ft. to 12 ft. thick, is fetched back together with portions of the pillars. This method has proved to be a safer one and gives a bettor percentage of extraction than the old method of working over 30 ft. of tops from the lower workings. Below No. 3 south level in tho small dip area six pairs aro on solid work, and in the No. 3 inner section, under the No. 2 south upper workings, five solid places are being worked. Since March all the coal in the Linton mines has been filled with shovels instead of forks. Within a month a great improvement was noticeable in the reduction of dross and coal-dust on the haulage and trucking roads. Stone-dusting in compliance with the regulations is now regularly done with crushed limestone of sufficient fineness to comply with the regulations. This stone-dust is purchased at Winton and railed to Ohai. To work the extensive area of coal proved to tho north of the 100 ft. downthrow fault a dip is being driven at a grade of 1 in 4, and it will cross the fault when in 700 ft. After crossing the overlying measures the drive is now in the main scam, and a connection for ventilation and pumping purposes has been made to the dip section of No. 1 mine. Formerly the miners were paid on the basis of two tubs to the ton, but now all the coal is weighed near the screens and the miners paid according to the weight shown. The bathhouse near the mine, built during 1920, was burned to the ground on tho 29th April last. Another bathhouse has been built on the old site and of the same design as tho former one. Tho lamp-cabin for the Oldham electric lamps proving too small, an addition has been added to it, and a hotter method of checking the miners' lamps is now in vogue. The electric cap-lamp is much favoured by tho miners. Birchwood Mine. —On the west side most of tho pillars were successfully extracted, but on the east side a severe creep, due to tho small pillars, came on early in the year, and eventually resulted in a fire breaking out on the 28th November. Consequently the main portion of the Birchwood mine workings had to be sealed at the main intake and return air-ways, and no further work can be done there. Many attempts were made to extract the lower oast pillars, but the timber sets in tho levels were crushed within a week or so of their renewal, the fine-grained sandstone then closing the places. A small strip of country between the No. 12 east level and tho fault not having previously been worked, a place was driven off the No. 12 east level, but, as the pillars being formed wore much too narrow, instructions were given for this lower level to be stopped. In August a short dip drive was put down into a small area of coal proved by boring on the flat land south of the Morlcy Stream. Tho coal proved vory stony to the south and west, and on the north a largo washout was struck. After taking off somo side coal and working back tops the materials were brought out in December and tho section was then stopped. About 10 chains east of the main mine-entrance a dip going south has been started, from which a small area of the bottom scam will be worked. The bottom seam is 0 ft. thick in that locality. A few pillars in the main seam between the old horse level and the fault are also being worked. The bore put down from the surface 17 chains south-west of the face of the main drive was stopped at 030 ft., no coal-seam being mot. Ohai Coal Co.'s Mine. —A few pillars, both in the north and south sections, still remain to be won, and there is still some top coal to win down tho dip, so the mine at the present output will last until May next. A few chains north of the large downthrow fault a borehole was drilled from the surface. Owing to insufficient easing, the borehole fell in when it was down to 450 ft., no coal having been met.

7—C. 2.