XIII. A Historical Sketch of the Development of 

 Seismology in Japan. 



Bi 



Torahiko Teraua, D. Sc, 



Professor of Physics, Tokyo Imperial University, 



and 



Takeo Matuzawa, 



Assistant Professor, Tokyo Imperial University. 



I. Introduction. 



The islands of Japan, extending over 29 degrees of latitude 

 from the torrid wilderness of Formosa to the cold solitudes of the 

 Kuriles, have often suggested a comparison with a narrow strip of the 

 continental mass torn off from the worn out margin of the vast 

 Eurasian main body. To say nothing of the theories of Richthofen, 

 Hobbs, Wegener, and others the shape and position of the land cannot 

 but suggest something very unusual in the physical and chemical 

 conditions of this part of the earth's crust, either as the remnant 

 effect of the past processes which must have occurred in course of the 

 genesis and the subsequent evolution of the land, or as the physical 

 consequence of the prevailing states of things. Things may happen 

 which could never be experienced in other parts of the world where 

 the simple and uniform structure of a large crustal mass is enjoying 

 the golden era of peaceful stability, i'rom time immemorial, the 

 islands have, indeed, been the site of incessant displays of volcanic 

 and seismic activities. The present features of the land covered with 

 an intricate net-work of cracks and creases bear infallible witness to 

 these past cataclysms. To cite a single example, the vast plain of 

 Kwanto is covered with volcanic ashes to a depth of several metres 

 beneath which relics of former populations are from time to time 

 turned up. In the myths and folklore of the nation, we may not 

 infrequently trace the repercussion of emotions which natural calamities 



