THE STRENGTH OF THE EARTH'S CRUST 555 



by the best hypothesis will be a more accurate measure of the 

 capacity of the rigid crust to carry without viscous yielding loads 

 which have been borne through geologic time, hidden loads whose 

 magnitudes in many regions appear to mask by contrast the present 

 relief between mountains and valleys. 



The measure and the meaning of the variable distribution of 

 mass within the lithosphere constitutes an inviting field of geology, 

 discernible in the present, but whose real exploration is a work of 

 the future. 



[To be continued] 



