23

H.—ll

tube being perforated and enclosed in a calico bag. The cartridges are enclosed by tamping in the same way as powder, and they are slaked by means of a small force-pump. The time occupied in drilling a hole 3 feet deep and 2f inches diameter, including setting up the drill, averages twelve minutes ; charging a hole with cartridges and tamping up, four minutes ; and pumping in the water, one minute. In ten to thirty minutes, according to the hardness of the coal, on the "removal of the sprags, which are left in, the coal falls clean from the roof in large masses ready for loading, practically making no small. The following are among the principal advantages claimed for this system : There is no smoke or noxious smell of any kind. The roof is. not shaken by this process; no vacuum is created as is the case with a blown-out shot; and the coals in falling produce much less dust, thereby reducing the danger which is generally admitted to arise from the air of a mine being heavily charged with small particles of coal. Skilled labour is unnecessary, and the coal can be got with much less exertion to the collier than by wedging. The apparatus is simple and inexpensive, it is easily carried about and kept in order, and it can be used in narrow and cramped workings in thin seams. After pumping the water into the charged holes the men need not discontinue working, as is the case with gunpowder, for, by simply moving away from the face of the coal while the sprags are being taken out, all risk of injury from falls is avoided. Any number of holes can be loaded, and by applying the water to them in quick succession a continuous and gradual pressure is brought to bear along the face, which causes the coal to fall in large masses. It is thus brought to bank in a better condition for stacking or carrying than by other means, and the results, when compared with wedging or powder, show a considerable increase in the percentage of large coal got.

Comparative Result of Wedging and Lime Patent at Shipley Collieries.

Experiments have been made at lifty different collieries in England and Wales-with uniformly satisfactory results, and I hope to see the appliance introduced into New Zealand. Messrs. Sebastian Smith and Moore's price-list is as follows: Press complete, £65; drilling machine, with pair of bits, complete, £4; hand-pump, with stirrup, flexible hose, and patent coupling, £2 2s. 6d.; hydraulic tubes, perforated, slotted, and annealed, each, Is.; steam taps, with nozzle to receive coupling, Is. 6d.; grooved rammers, 35.; buckets, galvanized, and painted to indicate charges, 3s. 3d.; hand cartridge-boxes, 45.; each charge, consisting of seven discs, and calico'bag, 3Jd. And their address is 3, Queen Street, Cheapside, London, E.C. I have, &c, : : ?. S. Herbert Cox* The Under-Secretary for Mines, Wellington. Inspector of Mines.

Wedging: . No. 2 Stall, Woodsiclp. Lime Patent: No. 1 Stall, Woodside. Date. Hours of Tons Labour. got. Hours of Labour. Tons got. eek ending January 25, 1882... eek ending February 1, 1882... eek ending February 8, 1882... Total ... 96f 100 123 | 225 178 225 58 71 90 274 236 . 258 3i9f • I 628 219 768