THE 



"DOCTRINE OF UNIFORMITY" 



IN GEOLOGY BRIEFLY 



REFUTED. 



[/\i/>cr read before tJie Royal Society of Edinburgh, 

 December 18, 1865.] 



Tur "Doctrine of Uniformity " in Geology, as 

 held by man)' of the most eminent of British 

 Geologists, assumes that the earth's surface and 

 upper crust have been nearly as they arc at present 

 in temperature, and other physical qualities, dur- 

 ing millions of millions of years. But the heat 

 which \vc know, by observation, to be now con- 

 ducted out of the earth yearly is so great, that if 

 this action had been going on with any approach 

 to uniformity for 20,000 million years, the amount 

 of heat lost out of the earth would have been about 

 would heat, by 100 Cent., a quantity 

 of ordinary surface rock of 100 times the earth's 

 bull. calculation appended.) This would be 



