HISTORY OF THE CONSERVATION OF ENERGY 107 



To the geologist, yonder snow-capped peaks symbolized eternity; to 

 the physicist, the mountains were as transient as the clouds. 



A calm statement of the geologists' attitude was made before the 

 British Association in 1892 by Sir Archibald Geikie. 38 In one place 

 he expresses himself as follows : 



Lord Kelvin is willing, I believe, to grant us some twenty millions of 

 years, but Professor Tait would have us content with less than ten millions. 

 ... I frankly confess that the demands of the early geologists for an unlim- 

 ited series of ages were extravagant . . . and that the physicist did good 

 service in reducing them. . . . That there must be some flaw in the physical 

 argument I can, for my own part, hardly doubt, though I do not pretend to be 

 able to say where it is to be foimd. Some assumption, it seems to me, has been 

 made, or some consideration has been left out of sight, which will eventually 

 be seen to vitiate the conclusions, and which when duly taken into account 

 will allow time enough for any reasonable interpretation of the geological 

 record. 



Five years later an American geologist, Professor T. C. Chamber- 

 lin, invaded the domain of physics and made a vigorous attack on 

 Lord Kelvin's argument, challenging the correctness of some of his 

 assumptions. 39 This criticism did not secure the attention it deserved, 

 for scientific events soon took a different turn. 



Lord Kelvin's address of 1897 is permeated, as Professor Chamber- 

 lin puts it, " with an air of retrospective triumph and a tone of 

 prophetic assurance." " It is only by sheer force of reason," says 

 Kelvin, "that geologists have been compelled to think otherwise, and 

 to see that there was a definite beginning and to look forward to a 

 definite end of this world as an abode fitted for life." Nor was this 

 feeling of retrospective triumph confined to Lord Kelvin or to the 

 students of the problem of the age of the sun and earth. At the close 

 of the century physicists and chemists gloried in the triumphs of their 

 predecessors, in such achievements as are indicated by the words " con- 

 servation of energy," " conservation of mass," and " atomic theory." 

 In physical research the nineteenth century was a golden age. It pro- 

 duced Faraday, Helmholtz, Mayer, Joule, Kelvin, Eayleigh, Eowland 

 and many other great men. With the close of the century timid souls 

 doubtless feared that the golden age had come to a close, and they per- 

 haps experienced strange emotions like those attributed to Adam in 

 the Garden of Eden, on seeing the sun go down, not knowing that it 

 would ever rise again. 



Others were perhaps haunted by another fear — a feeling that the 

 great and fundamental truths of science were all revealed to the full 

 sight of man, and it now remained only to work out the less important 



38 Smithsonian Report, 1892, p. 125. 



39 Science, N. S., Vol. IX., pp. 889-901; Vol. X., pp. 11-18, 1899. Reprinted 

 in Smithsonian Report, 1899, pp. 223-246. 



