THE STORV OP THE EARTH 35 



favour, but as the main grounds for wishing to substitute 

 it for the accepted version are dynamical it cannot be 

 closely examined here. There does not seem to be 

 sufficient reason for departing from the general teaching 

 of geologists which I have summarised. 



From this point onward the story of the earth, apart 

 from its living inhabitants, is mainly one of the wearing 

 down of the rocky crust by ice, water, and other dis- 

 integrating agencies, the deposit of the rubbish in vast 

 layers at the bottom of the sea and lakes, the re- 

 conversion of the stuff into rock by the pressure of 

 hundreds of thousands of tons of water, and the 

 upheaval of the new-formed rocks to the surface by the 

 slow rise of parts of the crust by pressure from below. 

 The elements of geology are so widely known that we 

 have here to do little more than briefly sketch the larger 

 changes through which the face of the earth passed in 

 order to attain its present aspect. 



At the beginning of settled geological history, during 

 what is called the Cambrian period, large masses of land 

 had emerged from the ocean in the northern hemisphere. 

 The region about the present great lakes of North 

 America, the region about the Baltic, and part of Siberia 

 seem to be amongst the oldest parts of the earth as we 

 know it. On these broken and low-lying lands the 

 torrential rains fell with destructive action, and the bed 

 of the ocean round them filled with the debris that went 

 to form the earliest stratified rocks. But as the water 

 wore away the land, fresh tracts emerged from the ocean. 

 At an early date a continent seems to have stretched (so 

 Suess assures us) across the site of the present North 

 Atlantic Ocean. Parts of Eastern North America, 

 Greenland, the Hebrides, and most of Scandinavia, 

 seem to be parts of that real lost " Atlantic " of earlier 

 ages. Some authorities think that the earth had assumed 



