X GEOLOGICAL REFORM 837 



geologist — would for a moment admit tlie hypo- 

 thesis that the present state of underground heat 

 is due to a heating of the surface at so late a 

 period as 20,000 years ago. If that is not admitted 

 we are driven to a greater heat at some time more 

 than 20,000 years ago. A greater heating all 

 over the surface than 100° Fahrenheit would kill 

 nearly all existing plants and animals, I may 

 safely say. Are modern geologists prepared to 

 say that all life was killed off the earth 50,000, 

 100,000, or 200,000 years ago ? For the uniformity 

 theory, the further back the time of high surface- 

 temperature is put the better ; but the further 

 back the time of heating, the hotter it must have 

 been. The best for those who draw most largely 

 on time is that which puts it furthest back ; and 

 that is the theory that the heating was enough to 

 melt the whole. But even if it was enough to 

 melt the whole, we must still admit some limit, 

 such as fifty million years, one hundred million 

 years, or two or three hundred million years ago. 

 Beyond that we cannot go." ^ 



It will be observed that the " limit " is once 

 again of the vaguest, ranging from 50,000,000 

 years to 300,000,000. And the reply is, once 

 more, that, for anjrfching that can be proved to the 

 contrary, one or two hundred million years might 

 serve the purpose, even of a thoroughgoing Hut- 

 tonian uniformitarian, very well. 

 ^ Loc. cit. p. 24. 

 208 



