290 COALFIELDS AND COLLIERIES OF AUSTRALIA. 



in the process of extraction. In pillar work only the coal 

 above the morgan is won. On account of the height of the 

 seam, the support for the drill used when boring shot holes has 

 .an extension rod, but when this support cannot be used, a hole 

 is jumped in the face of the coal, and a square bar driven in, 

 which serves as a bracket to which the nut, the feed screw 

 of the drill works in, is attached. 



The work at present being carried on is mostly pillar 

 drawing. AVhen a district has been prepared by doing the 

 first working in the middle coal, the miners proceed to take 

 down the upper coal in the bords and roadways, except oppo- 

 site the stooks left temporarily for support. The pillar be- 

 tween two roadways is then divided in half cross-ways by' an 

 imaginery line, but the pillar is attacked from both roadways, 



Bon* 



Bord 



c ~ 



--*-- 



1*1.*** 



fiortf 



Bore/ 



Fig. 188. Pillar Drawing. 



the working from one being in advance of the other, so that 

 ^he different parties of men shall not meet half-way, and leave 

 a large unsupported space open, which might cause a disaster. 

 Each half of a pillar is again divided by an imaginary line, but 

 this time it is halved lengthways, instead of across. The pillar 

 coal is then worked in two lifts, as shown in Fig. 188. The 

 lift (a) is taken out to the limit of the imaginary cross-line ; 

 the men then turn round and work out (b), in strips of 3 to 

 4 yards wide, after which they extract (c) as far as the stook. 

 When the whole of the pillar has been extracted from both 

 ends, except the stooks, the coal is dropped from the roof of 

 the roadway (d), between the stooks, and finally the stooks 

 \e) themselves are taken out. The top coal in the adjoining 



