HISTORY OF DISCUSSION 199 



continued with varying animation. Evidence of the 

 most multifarious kind has been brought forward, and 

 arguments of widely different degrees of validity have 

 been pressed into service both by geologists and 

 palaeontologists on one side, and by physicists on the 

 other. For the last year or two there has been a 

 pause in the controversy, though no general agreement 

 has been arrived at in regard to the matters in dispute. 

 The present interval of comparative quietude seems 

 favourable for a dispassionate review of the debate. I 

 propose, therefore, to take, as perhaps a not inappro- 

 priate subject on which to address geologists upon a 

 somewhat international occasion like this present meet- 

 ing of the British Association at Dover, the question of 

 Geological Time. In offering a brief history of the 

 discussion, I gladly avail myself of the opportunity of 

 enforcing one of the lessons which the controversy 

 has impressed upon my own mind, and to point a 

 moral which, as it seems to me, we geologists may 

 take home to ourselves from a consideration of the 

 whole question. There is, I think, a practical outcome 

 which may be made to issue from the dispute in a 

 combination of sympathy and co-operation among 

 geologists all over the world. A lasting service will 

 be rendered to our science if by well-concerted effort 

 we can place geological dynamics and geological 

 chronology on a broader and firmer basis of actual 

 experiment and measurement than has yet been laid. 

 To understand aright the origin and progress of the 

 dispute regarding the value of time in geological specu- 

 lation, we must take note of the attitude maintained 

 towards this subject by some of the early fathers of 



