172 COALFIELDS AND COLLIERIES OF AUSTRALIA. 



machine, and places some in the cut to support the coal. 

 When the machine reaches the end of the face, it is placed 

 on a truck and flitted back to commence a fresh cut. 



Where the coal is thicker, and the pillar and bord method 

 is used, the coal is found to be harder, and does not make so 

 much slack; in fact, it has to be shot down. Carbonite is 

 used for shooting down coal, and saxonite for shooting- in 

 rock. On either side of an intake heading is a return 

 heading, known respectively as right and left. These are 

 connected with the main heading by diagonally arranged 

 ut-throughs, placed about 2i chains apart, and made 4 yards 

 wide; those cut-throughs on opposite sides do not branch oft' 

 from the same point, but alternately as shown inFig.^106. The 



Fig. 106. Welsh Bord System. 



Welsh bord system is used, and these bords are turned oft' from 

 both right and left headings, with necks 4 yards wide and 4 

 yards long. They are then widened out gradually on either 

 side till 18 yards wide, and are then driven straight on. A 

 track is laid along both sides of the bord, and any dirt is 

 thrown in the middle. The bords are made indefinitely 

 long. The coal pillars between the bords are 77 yards 

 wide. Crosscuts are driven through the pillars at suitable 

 intervals, which serve the purpose of roadways. Waiting till 

 the bords are in to make these roadways, which shorten the 



