100 



COALFIELDS AND COLLIERIES 01-' AUSTRALIA 



out, but either the heat distilled off explosive gases from the 

 coal, or gases were formed by the, action of water on the red- 

 hot coal. It is well known that when making producer gas,, 

 if the amount of air admitted is limited, the generation 

 of carbon dioxide (CO}) commences at 750deg. F., and is 

 formed exclusively at about 1300deg. F. At a, higher tem- 

 perature combustion takes place too quickly to be complete, 

 so the poisonous carbon monoxide (CO) is formed, while at 

 ISOOdeg. F. this gas is exclusively generated. When 

 steam is added at a high temperature, it is decom- 

 posed into oxygen and hydrogen. Anyhow, an explosion 

 took place, and probably both the above causes played 

 a part in it. That portion of the mine was sealed 

 off by an arched wall, with the convex portion turned 

 inwards. Since it has been re-opened no signs of a 

 fall has been discovered which could have caused a wind 

 blast: besides, this colliery, in common with the others in the 

 Lithgow Valley, is not a gassy mine, naked lights being used 

 in all of them ; so the explosion must have been the result of 

 the fire. 



The mine is worked from tunnels. There is one intake 

 and main haulage road (Fig. 37) over a mile long, and two 

 return air ways, one on either side- of the intake, all driven 



Fig. '17. Entrance to Lithgow Valley Colliery. 



