8 COALFIELDS AND COLLIERIES OF AUSTRALIA. 



stages, though we may not be able to see the change actually 

 taking place. To borrow an illustration from the late Charles 

 Kingsley bread does not look like wheat, yet it is chiefly 

 formed from it. 



There are three ways by which we may ascertain how cer- 

 tain changes came about by observation, by experiment, by 



Fig. 12. Sphenopteris australis. 



deduction. When possible, all three methods are employed in 

 the search after truth, so that one can check the other. ' It is, 

 of course, impossible for us to see coal made from vegetation 



