336 



COALFIELDS AND COLLIERIES OF AUSTRALIA. 



stack, the draught caused by the heated air ascending, be- 

 ing sufficient to draw the foul air out of the mine, so that 

 fresh air can replace it. Underground the overcasts are cut in 

 coal instead of in stone, as it is cheaper, besides giving some 

 remuneration in the form of coal. 



That portion of the mine which has been sealed off on 

 account of the fire has solid brick stoppings from 9in. to 23in. 



Fig. 211. Furnace and Stack at Air Tunnel. 



thick. Pipes are built into the stoppings at the highest points, 

 so that the temperature and pressure can be taken when de- 

 sired by means of thermometers and water gauges. 



Stanford Merthyr Colliery. 



This colliery belongs to the East Greta Coal Mining Com- 

 pany, and is managed by Mr. H. M. Williams. A portion of 

 it was formerly known as the Stanford Greta mine. 



