86 POPULAR LECTURES AND ADD/JESSES. 



"'greater than his estimate, or thirty thousand 

 "millions of years'' 



10. It is to be presumed that Professor Huxley 

 repudiates these figures when he says, " If \vc 

 " accept the limitation of time placed before us 

 " by Sir William Thomson, it is not obvious on 

 <: the face of the matter that we shall have to alter 

 " or reform our ways in any appreciable degree : " 

 but I am at a loss to understand how he can ask, 

 c< Has it ever been denied that this period may be 

 enough for the purpose of geology ? " 



11. In marked contrast to them, is Professor 

 Phillips's careful analysis of " the geological scale 

 of time." x By reckoning the actual thicknesses 

 of different strata, and allowing T ] r of an inch per 

 annum as a not improbable mean rate at which 

 they have been deposited, he finds ninety-six 

 million years as a possible estimate for the anti- 

 quity of the base of the stratified rocks ; but he 

 gives reasons for supposing that this may be an 

 over estimate, and finds that from stratigraphical 



1 Phillips's Life on (lie Karth. Cambridge. iXC,o (Krde Lecture), 

 p. 119. 



