PROGRESS OF CONTROVERSY 215 



twenty than forty.' 1 But in none of his papers is 

 there an admission that geology and palaeontology, 

 though they have again and again raised their voices 

 in protest, have anything to say in the matter that 

 is worthy of consideration. 



It is difficult satisfactorily to carry on a discussion 

 in which your opponent entirely ignores your argu- 

 ments, while you have given the fullest attention to 

 his. In the present instance, geologists have most 

 carefully listened to all that has been brought forward 

 from the physical side. Impressed by the force of 

 the physical reasoning, they no longer believe that 

 they can make any demands they may please on past 

 time. They have been willing to accept Lord Kelvin's 

 original estimate of 100 millions of years as the period 

 within which the history of life upon the planet must 

 be comprised ; while some of them have even sought 

 in various ways to reduce that sum nearer to his lower 

 limit. Yet there is undoubtedly a prevalent misgiving, 

 whether in thus seeking to reconcile their requirements 

 with the demands of the physicist they are not tying 

 themselves down within limits of time which on any 

 theory of evolution would have been insufficient for 

 the development of the animal and vegetable kingdoms. 



It is unnecessary to recapitulate before this Section 

 of the British Association, even in briefest outline, 

 the reasoning of geologists and palaeontologists which 

 leads them to conclude that the history recorded in 

 the crust of the earth must have required for its 

 transaction a much vaster period of time than that 



1 The Age of the Earth, Presidential Address to the Victoria 

 Institute for 1897, p. 10; also in Phil. Mag. January 1899. 



