260 HOBBS— THE EVOLUTION AND THE [April 24. 



upon its fruitful genetic period when the modern view-point was 

 given it by Darwin. Looking back upon this evolution, we note 

 that the order is in every way a natural one. The facts of observa- 

 tion should first of all be assembled; they must next be compared 

 with a view to establishing correspondences, and, finally, the explana- 

 tion of the correspondences must be sought in genetic relationships. 



Of geology it may be said, that the natural order of-its evolution 

 was exactly reversed; for the genesis of the earth and the full order 

 of events in its history had supposedly been given to man through 

 divine revelation. The growth of the science began, therefore, 

 only after a measure of emancipation from the tyrrany of religious 

 dogma had been achieved. 



The Natural Development of Seismology Prevented by False 

 Theory. — It may well be doubted if there is another branch of 

 science which has been so long held in fetters by false theory as the 

 branch of geology which treats of earthquakes. Had fate been 

 more kind, it might have been the earliest to develop; for the seats 

 of ancient culture were in earthquake countries, and it will hardly 

 be claimed that the phenomena of earthquakings are not such as to 

 attract the attention. Theories of cause do, indeed, date back before 

 the beginning of the Christian era, the dominating one being that of 

 Aristotle which connected the quakings with explosive sources of 

 energy, conceiving that gases confined in subterranean cavities 

 brought on quakings in their struggles to escape. For the times, this 

 theory seemed to be well supported by facts, since earthquakes were 

 generally manifested at the time of great volcanic eruptions, and 

 volcanoes and earthquakes were common to the same countries. 

 The Aristotelian theory of earthquakes acquired prestige from the 

 adhesion to it of Strabo and Pliny among the ancient philosophers, 

 and at the opening of the nineteenth century, through its adoption by 

 von Humboldt and von Buch, who then dominated the field of geo- 

 logical thought. 



'The middle of the nineteenth century is a turning point in the 

 history of nearly all sciences toward a greater exactness of ob- 

 servation. Academic discussions in large measure gave place to 

 careful and painstaking observation or to laboratory experimenta- 

 tion. Yet almost at the moment when Darwin and Huxley were 



