6 THE PRESIDENTIAL ADDRESS 



recent discoveries that * if it had not existed, the palaeontologist 

 would have had to invent it.' 



I can never forget the words spoken to me after the lecture by a 

 dear friend of my youth, the late Viriamu Jones, Principal of 

 University College, Cardiff : ' At every sentence I felt myself 

 bowing to Huxley and saying " you are the greatest man here ; no 

 one else could have said that as you have said it." ' 



As Huxley's lecture continued in a calm spirit an embittered 

 controversy, so his thoughts on the immensity of past geological 

 and biological time lead naturally to another controversy on the age 

 of the earth conducted intermittently at our meetings between 1892 

 and 1921. It is, I think, a good example of the invaluable help 

 which the British Association brings to discussion when there 

 appears to be a difficulty in reconciling the conclusions reached by 

 the followers of different sciences. Lord Kelvin's estimate of a 

 hundred million years as the period during which the earth had been 

 cool enough to permit the existence of life upon its surface — a period 

 reduced by Prof. Tait to ten million — was a great difficulty to 

 geologists and biologists who believed that an immensely longer 

 time was required for the history of the fossiliferous rocks and the 

 evolution of animals and plants. Thus, to quote only one instance, 

 Darwin writing to Wallace in 1871 and referring to ' missing links,' 

 said, ' I should rely much on pre-Silurian time ; but then comes 

 Sir William Thomson, like an odious spectre.' The geologists 

 resisted more firmly. Thus Sir Archibald Geikie, in his Presidential 

 Address at Edinburgh in 1892, concluded his discussion of the sub- 

 ject with these words : ' The geological record furnishes a mass of 

 evidence which no arguments drawn from other departments of 

 Nature can explain away, and which, it seems to me, cannot be 

 satisfactorily interpreted save with an allowance of time much 

 beyond the narrow limits which recent physical speculation would 

 concede.' At the Leeds meeting in 1890 I had many opportunities 

 of meeting Prof. John Perry, and when we were walking together on 

 the Sunday afternoon I asked him to tell me something of the Kelvin- 

 Tait conclusions and how far they must be accepted. He had been a 

 demonstrator under Kelvin and spoke of the intense interest with 

 which he had followed his lectures at Glasgow, and he gave me no 

 hope of escape. His change of opinion, throwing a most interesting 

 light upon the influence of the British Association, was the result of 

 the Presidential address at Oxford in 1894, when Lord Salisbury 

 chaffed the believers in natural selection, telling them that he did not 

 wonder that they required many hundred million years for so slow 

 a process, but that ' if the mathematicians are right, the biologists 

 cannot have what they demand. . . . The jelly-fish would have 



