1909.] OUTLOOK OF SEISMIC GEOLOGY. 261 



opening a new world to students of biology, the way to progress in 

 seismology was effectually closed through the commanding authority 

 of a pseudo-scientific work of great compass, written by the English 

 physicist. Mallet. Darwin's great theory was an induction reached 

 on the basis of extended observations and of meditations with an 

 open mind ; Mallet, on the other hand, approached his work firmly 

 intrenched in a preconceived notion which the facts were assiduously, 

 though perhaps unconsciously, twisted to confirm. 



Assuming that Mallet's method had been a sound one, his 

 elaborate observations conclusively proved the fallacy of his theory; 

 for instead of pointing to a definite centrum, his results ranged with 

 noteworthy uniformity between depths of 10,000 and 45,000 feet. 

 The history of science furnishes no more striking example of a great 

 monograph wrought out with laborious scientific method and yet 

 absolutely lacking in scientific spirit or judgment, for with a naive 

 simplicity Mallet drew from his results the conclusion that, " the 

 probable vertical depth of the focal cavity itself does not exceed 

 three geographical miles, or 18,225 feet, at the outside." Nowhere 

 in the two bulky volumes of his report is the possibility of a non- 

 existence of the centrum even raised. 



As was true of the famous fallacy of Werner concerning the 

 origin of basalt, it was here the commanding position of the author 

 which gave his theory its authority ; and, although the impractica- 

 bility of his method soon came to be generally recognized, the funda- 

 mental idea was destined to survive at least half a century as the 

 standard doctrine of seismology. It was the brilliant system of 

 Huyghens for treating the propagation of wave motion carried over 

 bodily to seismology, which caused it to be so warmly welcomed by 

 physicists and elasticians, to whose care this branch of science was 

 thereafter entrusted. As late as 1899, the depth of the imaginary 

 origin of a particular earthquake was sought by no less than four 

 different methods with results which ranged from 21 kilometers on 

 the one hand to 161 upon the other, these results apparently not 

 shaking the worker's faith in the reality of the earthquake focus. 



It becomes ever more clear that men of science discover in the 

 main those facts only which their working hypotheses indicate to be 

 important. For this reason a theory which is largely correct, grows 



