NO TRACE OF A BEGINNING 183 



thought to have followed each other consecutively were 

 found to have been separated by prolonged intervals 

 of time. Thus the idea arose and gained universal 

 acceptance that, just as no boundary could be set to 

 the astronomer in his free range through space, so 

 the whole of bygone eternity lay open to the require- 

 ments of the geologist. Playfair, re-echoing and ex- 

 panding Hutton's language, had declared that neither 

 among the records of the earth nor in the planetary 

 motions can any trace be discovered of the beginning 

 or of the end of the present order of things ; that no 

 symptom of infancy or of old age has been allowed 

 to appear on the face of Nature, nor any sign by 

 which either the past or the future duration of the 

 universe can be estimated ; and that although the 

 Creator may put an end, as He no doubt gave a 

 beo-inning, to the present system, such a catastrophe 

 will not be brought about by any of the laws now 

 existing, and is not indicated by anything which we 

 perceive. This doctrine was naturally espoused with 

 warmth by the extreme uniform itarian school, which 

 required an unlimited duration of time for the accom- 

 plishment of such slow and quiet cycles of change as 

 they conceived to be alone recognisable in the records 

 of the earth's past history. 



It was Lord Kelvin who, in the writings to which 

 I have already referred, first called attention to the 

 fundamentally erroneous nature of these conceptions. 

 He pointed out that from the high internal temper- 

 ature of our globe, increasing inwards as it does, and 

 from the rate of loss of its heat, a limit may be fixed 

 to the planet's antiquity. He showed that so far from 



