EARTHQUAKE OF CENTRAL JAPAN, 1891. ^99 



ed studies of individuîd earthqnuke«, and ;i comparison of the results 

 (obtained tlierefnjiu with the facts of the u'eolo^ical structure of the 

 region concerned. The chief merit in this Hne of study is (Uie laro-ely, 

 at least, to the Austrian geologists, Suess, Floernes, and lUttner. The 

 last-mentioned author gave a finishing l)low to the fantastic liyjMjthesis 

 of Falb, in liis \V(jrk on the earthquake of l>elluno, in 187o,* 



Although we are as yet not in a position to be perfectly clear on 

 the dynamics (rftlie formation of mountain-ranges, still we are already 

 in possession of a certain knowledge on this subject through the study 

 of the Al})s. Long ago, Eiie de Beaumont saw in the origin of nioun- • 

 tains a radial, e]e\'ating ])ower, but to this C. Prevent made strong 

 objections. The latter taught us that tlie elevation is only the effect of a 

 depression of neighbouring regions; and the same view is advanced in 

 the works of Le Conte and of Dana, in a more t)r less modified shape. 



Suess was led by his investigation of the tectonics of the Alps, 

 to express himself to the effect that unequal contraction and the hori- 

 zontal shifting of the earth's crust resulting therefrom are the cause of 

 foldings of strata. 



Again, in his '^ EntstcliiuKj lier Alfx'ti,'' Suess says that all moun- 

 tain-ranges are (rf one-sided, unsymmetrical structure, the jjrobable 

 explanation being thaï tliey originate at the mai-gin of a great depres- 

 sion which exerts a horizont:d, lateral pressure. The concave side of 

 mountain-chains on which they face depressed regions we may 

 naturally expect to be much disturl)ed and ruptured; and seismic 

 activity and volcanic eruptions are usually manifested jxu-ticularly at 

 this weak point. Professor H. Crednerf holds the same view about the 



* lieitrruje zur Kentitnixs des Krdhelk'ns ran lU'llunn. Sitzlx^r. d. k. Akademie d. Wissea- 

 schaften. 69 Bd., 1874. 



t (a) Bas vorjtlandisrlii' Knlhcheii vom 23 Nov., 1875. Zeitschr. für die ges. Naturwissen- 

 schaften. 48 Bd. 1876. (h) Das dippoldiswahh'y Erdbeben von .5 Oct., 1877. Zeitschr. für die 

 tCHs. Natui'wissHnsfhaften. 50 Bd. 



