ON LORD KELVIN'S ADDRESS ON THE AGE OF THE 

 EARTH AS AN ABODE FITTED FOR LIFE. 



By Prof. T. C. Chamberlain/ 



In the early half of the century, when the more sober modes of inter- 

 preting geological data were struggling to displace the cataclA'smic 

 extravagances of more primitive times, it is not strange that there 

 should have arisen, as a natural outgrowth of the contest, an ultra- 

 uniformitarianism which demanded for the evolution of the earth an 

 inmieasurable lapse of time. It is not remarkable that individual geol- 

 ogists here and there, reacting impatientlv against the restraints of 

 stinted time limits imposed on traditional grounds, should have incon- 

 siderately cast aside all time limitations. It was not unnatural that 

 the earlier uniformitarians. not yet fully emancipated from inherited 

 impressions regarding the endurance of rocks and the innnutability of 

 the "•everlasting hills," should have entertained extreme notions of the 

 slowness of geological processes and have sought compensation in 

 excessive postulates of time. Natural as these reactions from primi- 

 tive restrictions were, a reaction from them in turn was inevitable. 

 This reaction must have ensued, in the nature of the case, whensoever 

 geologists came seriously to consider those special phenomena which 

 point to limitations of time. But in the earlier part of the centuiy 

 geological attention was absorbed in the great phenomena that testify 

 to the vastness of the earth's history. The time for the study of limi- 

 tations had not come. 



Nevertheless, however inevitable must have been the ultimate recog- 

 nition of limitations, it remains to be frankly and gratefully acknowl- 

 edged that the contributions of Lord Kelvin, leased on physical data, 

 have been most powerful influences in hastening and guiding the reac- 

 tion against the extraxagant time postulates of some of the earlier 

 geologists. With little doubt, these contributions have been the most 

 potent agencj^ of the last three decades in restraining reckless drafts 



^Reprinted from Science, n. s., Vol. IX., No. 235, i)p. 889-901, June 30, 1899; and 

 Vol. X, No. 236, pp. 11-18, July 7, 1899. Lord Kelviu's addre^^s is reprinted in the 

 Smithsonian Report for 1897, also in Science, May 12 and 19, 1899. 



223 



