316 COALFIELDS AND COLLIERIES OF AUSTRALIA. 



before required by the men, and the flames will warm the 

 glass. The illuminant used is a mixture of colsa and kerosene 

 oils. The lamps are locked with the iisual leaden rivet, a dozen 

 of these being cast at a time in one mould. Formerly they 

 tried Stoke's alcohol lamp when testing for gas in the mine, 

 but now they use hydrogen with a Hebblewhite Grey lamp. 



The coal is tipped on to two shaking screens with a billy- 

 fair-play below to weigh the slack. The round coal falls on 

 to a steel picking table, where the "chidder" slate and 

 brasses is picked out and the balance weighed on a Pooley 

 machine. As each skip is tipped on to the screen, its token is 

 taken off and slid down a wire to a lad who places it on the 

 picking belt near the heap of coal to which it belongs. As the 

 coals falls into a hopper waggon, the token is taken off and its 

 number noted by the weighman. 



The Jeffrey conveyor used at this colliery is shown in 

 Pig. 202. It is used for slack only. The slack from the 

 screens is raised by a bucket elevator to a travelling belt of 

 steel that carries it to a shoot which directs it into a waggon, 

 but when there are no waggons, or if it is desired to store the 

 slack, the mouth of the shoot is closed, the slack fills it up, 

 and then the buckets of the conveyor that circulate round the 

 framework (to be seen crossing the picture in the near dis- 

 tance) are able to reach the coal and convey it to the top of 

 a tower from which it is fed on to another conveyor at right 

 angles to it. This conveyor travels towards a second tower, 

 partly shown in the foreground. There are several slide 

 valves in the bottom of the trough along which the buckets 

 travel; by pulling out the proper one, slack is made to fall in 

 any part of the open storage hopper desired. This hopper is 

 excavated in the ground, and is V-shaped, and lined with 

 bricks. At its bottom a tunnel runs for its full length, 

 large enough for men to walk along in it. There are 

 doors in this tunnel which can be opened from the inside, so 

 when it is wanted to load the slack stored in the hopper, a door 

 of the tunnel is opened and the buckets scrape the slack along 

 till it reaches the far tower, when it is lifted up to be even- 

 tually emptied on to a short conveyor with a shoot at the end, 

 which is lowered over the waggon to be filled. The capacity 

 of this plant is 1.00 tons of slack per hour, loaded into wag- 

 gons from the storage. The buckets are triangular in cross- 

 section, for they have to act as scrapers when in a horizontal 

 position, and as vessels when in a vertical position. The 

 buckets are fastened to two strands of a roller chain. The 

 hopper is given an inclination lengthways to assist any rain- 

 water to flow towards the end, where a pump raises it to the 

 surface. 



