Page:Rambles on the Golden Coast of New Zealand.djvu/208

164 incline is in favour of the load, being about 1 in 6, and therefore requires no engine-power to work. The total length of this line is 1078 yards, and has a double line of 20 lb. steel rails, with which all travelling roads in the mine are laid. The rails used for boards are 14 lb., being light and handy for frequent shifting. This endless rope passes over an elevated wheel placed on the tipping bank. It travels at right angles to the rope working from the dip. The total daily output is about 400 tons, and is all passed over a fixed screen of ¾-in. mesh. The small passing through this mesh is called slack, and, as already described, is again elevated and made into nuts. The fine dust is converted into coke or washed into the adjacent river Grey, as the market for coke is not equal to one-half of the available fine coal.

The interior of the mine you enter by means of a tunnel from the level of the tipping bank, and ascending this road over which the endless rope is working, you pass through the old workings, about 35 to 40 acres in extent, now comparatively worked out. Probably at some future time a large quantity of steam coal and coking coal will be drawn therefrom. One cannot help being struck with the brilliant appearance of glow worms, which are to be seen on the pillars of coal throughout the mine. The effect is grand, and almost affords sufficient light to enable you to pass along without the aid of your naked candle. There is also another striking feature in these old workings, to see what was once the pavement and 16 ft. apart from the sandstone roof, has now actually in many places come together, not by any failure or depression in the roof, but by the floor or pavement rising up. This is technically called “creep,” and is caused by the pillars being taken out or so reduced that the underneath strata being relieved of the great pressure of coal removed, expands and creeps, until it meets the roof. This was a source of frightful cost and interruption a few years past to the proprietors, having had to keep cutting away the bottom, on various occasions several feet at a time, in order to maintain a road open to the upper or new portion of the workings. It is said that in the old collieries at Home, a whole mile of such a road has been known to close up completely in one night by the floor lifting up. During these years the area of coal workings was contracted, owing to the presence of the fault already noted cutting off the coal to the westward, and baffled all attempts on the part of Mr R Elliott, the then mine manager, to find it.

In 1877, Dr Hector, at an interview Mr Kennedy had with him at his office in Wellington, described the nature of this fault, and expected it was a down-throw of 100 ft. At this time, Mr Elliott believing it was a whinstone dyke, put a level tunnel into the rock at right angles to the fault slip, a distance of 200 ft., costing £1000, without any result. This was abandoned and a double tunnel started on the line of the slip, as advised by Dr Hector. When this was driven about 800 ft., the gas was giving off very freely, and the air became too bad for working without mechanical appliances for ventilation. A 16 ft. gurbal fan was procured and erected in the interior of the mine to be driven by a turbine. The water being partly obtained from the drainage of the mine, was brought in from the surface. It was never worked for any length of time, only being