336 GEOLOGICAL REFORM X 



I do not wish to " Hansardise " Sir William 

 Thomson by laying much stress on the fact that, 

 only fifteen years ago he entertained a totally differ- 

 ent view of the origin of the sun's heat, and 

 believed that the energy radiated from year to 

 year was supphed from year to year — a doctrine 

 which would have suited Hutton perfectly. But 

 the fact that so eminent a physical philosopher 

 has, thus recently, held views opposite to those 

 which he now entertains, and that he confesses his 

 own estimates to be " very vague," justly entitles 

 us to disregard those estimates, if any distinct 

 facts on our side go against them. However, I am 

 not aware that such facts exist. As I have already 

 said, for anything I know, one, two, or three hun- 

 dred millions of years may serve the needs of 

 geologists perfectly well. 



III. The third line of argument is based upon 

 the temperature of the interior of the earth. Sir 

 W. Thomson refers to certain investigations which 

 prove that the present thermal condition of the 

 interior of the earth implies either a heating of 

 the earth within the last 20,000 years of as much 

 as 100' F., or a greater heating all over the surface 

 at some time further back than 20,000 years, and 

 then proceeds thus : — 



" Now, are geologists prepared to admit that, at 

 some time within the last 20,000 years, there has 

 been all over the earth so high a temperature as 

 that ? I presume not ; no geologist — no w.odern 



