UNDERGROUND WORKINGS OF A WESTERN COLLIERY. XLIX, 



perpendicular to the cleat so that the working may progress end 

 on. The third method of "half on" or the laying of the wall face 

 at an angle of 45 degrees to the cleat is adopted in only moderately 

 strong seams as a compromise between the other two, so that 

 advantage may be taken of the influence of the cleavage planes in 

 order to secure the greatest quantity of coal in the best condition 

 with the least labour. The long-wall system possesses the important 

 advantage of giving the greatest quantity of coal because all the 

 seam is extracted, whereas in the pillar and stall system a portion 

 of the pillar is always lost, but as a rule it entails more initial 

 outlay for roads and yardage work; it also gives the greatest 

 amount of large coal, because in the narrower workings of the 

 other system the coal must necessarily be more broken up. 

 Another advantage of this system is that the ventilation is simple 

 and more easily effected and the miner works in better air and in 

 larger room and his labour is more efficient. 



On the other hand there are circumstances which may render it 

 absolutely necessary to adopt the pillar and stall system, for 

 instance the long-wall in some cases requires a great deal of rubbish 

 or stone for packing the "gob" behind the workmen to take the 

 weight of the descending roof so as to prevent damage to the 

 surface, and the packing may be difficult or costly to obtain. In 

 this coalfield, and I believe in all the coalfields of New South 

 Wales, the long-wall system has never had a fair trial in spite o£ 

 its manifest advantages, but whether this is due to prejudice or 

 to some other tangible objection such as the cost of filling the 

 "gob," with the existing high rate of wages I have never been 

 able to determine. Diagram G. illustrates an ideal form of pillar 

 and stall setting out, and Diagram H. illustrates the system of 

 long-wall working. 



Haulage. — Until lately the haulage was done by horses, the- 

 skips being drawn out of the working places to a flat in the head- 

 ing or main road where they were made up into trains and drawn 

 thence to the shaft, but this slow and expensive system has partly- 

 given way to steam haulage. Now there is a steam hauling engine 



4— Sept. 18, 1901. 



