333 COALFIELDS AND COLLIERIES OP AUSTRALIA. 



tu abandoning the mine; their width varies from 8, 10, 12, and 

 10 yards, depending on the depth of cover. The far end of a 

 bord does not break through to the next jig, but a pillar of 

 coal is left. The pillars of the top feection are not worked for 

 fear of the ground caving, which might let surface waters 

 into the workings. The mine is Avorked in panels, and when 

 one panel is worked out, it is sealed oft'. As carbon dioxide 

 is given oft' from the sealed panels, there is little chance of 

 lire being able to burn in such an atmosphere. 



The upper division of the lower seam is shot down in the 

 solid; but the lower division, not being so hard, will be un- 

 dercut. The props in the bords must have the smaller end at 

 least 4in. in diameter. There are four such props in a row, 

 placed 4ft. apart, centre to centre. The pillars on either side 

 of a bord are known as the upper and lower rib respectively. A 

 6ft. rib is left to support the fallen roof. After dropping the 

 top coal the roof is held up with long props, to the top of which 

 lids are nailed. The props are tightened up from the bottom. 

 These props serve as indicators, since they begin to speak when 

 the pressure of the roof becomes too great to be safe. 



Horses draw the skips along the levels. The empties turn 

 oft' into the levels from the tunnel oil the right hand side, 

 looking down hill, while the full are clipped on to the left hand 

 side of the endless rope. When required for any particular 

 level, a boy unscrews a clip and sprags the wheels of the 

 empties. On the full side of a level, the rails at the flat are 

 level, or dip slightly towards the tunnel. Monkey chocks are 

 placed between the rails, which hold the skips by their axles, 

 so that they cannot run away down hill. Should a stoppage 

 occur on the endless rope, the boy at each flat sounds a rail 

 hanging up if he is not the cause of the stoppage, and each 

 boy notes the delay, so that it can be accounted for and 

 checked. 



When necessary to continue sinking a tunnel, the angle 

 is so slight that there is no occasion to build n pentice: the 

 entrance is simply narrowed. There are six electric hoists in 

 this mine used for sinking slants and jigs. They were made 

 by the General Electric Company, and are 6 li.p.., 22.0 amp., 

 and 230 volts. The drum gear and bedplates were made by 

 Morison and Bearby. 



A fire and explosion took place in this colliery on Sunday, 

 29th October, 1905, by which six persons were killed and nine 

 injured. The electric bells started ringing at about 1.45 a.m.. 

 but the man in charge did not suspect a fire till he saw volumes 

 of smoke coming out of No. 1 tunnel at twenty minutes to four 

 in the morning. The fire burst out of the main tunnel and 

 reversed the air current, though the fan which was working 



