THROUGH THE GEOLOGIST S EYES 



the process was so slow that the river sawed down 

 through the rock as fast as it came up. Nearly all 

 the great cosmic and terrestrial changes and revolu 

 tions are veiled from us by this immeasurable lapse 

 of time. 



Any prediction about the permanence of the land 

 as we know it, or as the race has known it, or of our 

 immunity from earthquakes or volcanic eruptions, 

 or of a change of climate, or of any cosmic catas 

 trophe, based on human experience, is vain and 

 worthless. What is or has been in man s time is 

 no criterion as to what will be in God s time. The 

 periods of great upheaval and deformation in the 

 earth s crust appear to be separated by millions of 

 years. Away back in pre-Cambrian times, there 

 appear to have been immense periods during which 

 the peace and repose of the globe were as profound 

 as in our own time. Then at the end of Palaeozoic 

 time how many millions of years is only con 

 jectural the truce of aeons was broken, and the 

 dogs of war let loose; it was a period of revolution 

 which resulted in the making of one of our greatest 

 mountain-systems, the Appalachian, and in an un 

 precedented extinction of species. Later eras have 

 witnessed similar revolutions. Why may they not 

 come again? The shrinking of the cooling globe 

 must still go on, and this shrinking must give rise to 

 surface disturbances and dislocations, maybe in the 

 uplift of new mountain-ranges from the sea-bot- 

 115 



