44 THE AGE OF THE EARTH 



This Address is already unduly long, and yet not long 

 enough for the magnitude of the subject of which it 

 treats. As we glance backwards over the past we see 

 catastrophism yield to uniformitarianism, and this to 

 evolution, but each as it disappears leaves behind some 

 precious residue of truth. For the future of our science 

 our ambition is that which inspired the closing words 

 of your last President's Address, that it may become 

 more experimental and exact. Our present w r atchword 

 is Evolution. May our next be Measurement and 

 Experiment. 



