344 THE INVISIBLE WOELD 



requires a seven times longer period for its Evolu- 

 tion. Man on Earth has the advantage of this 

 longer period, and, in the fullness of his Evolution, 

 should be seven times the bigger fellow. 



When, therefore, Earth becomes so far advanced 

 in Evolution as to require for irrigation a system 

 of canals projected from the equator both ways to 

 the polar ice fields, the engineering job will be 

 seven times greater than that job on Mars. But 

 Earthites, with their seven times more skillful en- 

 gineers, will be equal to the situation. 



The immense cold storages of water at the poles 

 are thus used in the day of need to supply the wants 

 of man and prolong his days on Earth. 



