294 T. Terada and T. Matuzawa 



remarkable echelon formations of mountains and islands of this 

 country have already been pointed out by T. Tokuda/^^ Fujiwhara's 

 investigations seem to throw some light on the probable mode of 

 formation of these forms. Further, Fujiwhara^^^ discussed recently the 

 mechanism of the occurrence of the Kwanto Earthquake from his 

 point of view, making full reference to the other's opinions on this 

 matter. 



Among the other opinions, we may cite those by T. Ogawa, N. 

 Yamasaki, T. Kato and H. Yabe from the geological points of view, 

 and of K. Suda, S. Ono, M. Matsuyama, T. Terada and many others 

 from the seismological or geophysical sides. Most of these theories 

 have already been quoted here and there so that repetition would be 

 superfluous. We may perhaps here specially mention Matsuyama's*^^^ 

 view which was developed in consideration of the remarkable slow 

 oscillation with a period of ilOs observed in the seismogram of the 

 great earthquake. According to his view, the remarkable deformation 

 of the crust subsequently established must have taken place by plastic 

 yielding, not by any abrupt process. 



In this latter connexion, we may cite the interesting result of 

 Imamura's'^''^ latest investigation into the seismograms of the recent 

 earthquakes. He compared the records of the peculiar slow motion at 

 the initial phase obtained with an instrument having different degrees 

 of magnifications, and found that they were quite irreconcilable with 

 each other if the slow motion be assumed to be due to a horizontal 

 displacement, while they can be fairly explained as caused by a 

 suitable tilting of the crust. 



Geophysical Investigaton. 



The importance of geophysical investigations in general for the 

 advancement of the science of earthquakes, has early been recognized 

 by Milne and other pioneers whose attempts in that line may be 

 found in the volumes of the Transactions. Among the earlier mem- 



(1) Journ. Geol. Soc, 25 (1918), 534. Also Geogr. Kev., 2 (1925) 946. 



(2) Kensinziho, 1 (1925), 161. 



[o) Comptes Rendus des Seances de la 2-me Conference a Madrid de I'Union 

 Geodesique et Geophysique Internationale, Section de Seismologie, 1924; Kokurain-Eisei. 

 1, No. 3 (1923). 



(4) To be published shortly. 



