304 T. Terada and T. Matttzawa 



In-onglit l)aclc from Europe a Sarasin limnometer. Tlie subject lias 

 lieen attacked both experimentally and tlieoretically. Model experiments 

 have been freely resorted to for studying different possible modes of 

 oscillations and determining the periods and the positions of nodes. 

 The mathematical physicists were furnished with suitable themes for 

 wielding their weapons. Opportunities offered by the summer excur- 

 sions of students have been utilized for observations. Want of space, 

 however, compels us to j)ass on without commenting upon even the 

 most interesting of the results obtained by these investigators. It is to 

 be regretted that no limnometer record could be obtained on the 

 occasion of the recent great earthquake which, had there been one, 

 might have yielded data of incalculable value. 



Lastly, we may mention in this place some of the physical 

 researches which may be of more or less geophysical significance. 



Shida's baro-variometer has already been alluded to. Instruments 

 for similar purposes have also been devised by Tokuiti Yosida,^^^ and 

 later also by H. Nagaoka."^-^ 



The magnetization of rocks and the variation of magnetization by 

 longitudinal stress has been studied by R. Otani/"^ He found that 

 the magnetic susceptibility of different volcanic rocks varies between 

 0.002-0.006 and increases sensibly with the magnetic field. Compres- 

 sion in the direction of the magnetization decreases the intensity of 

 magnetization which rapidly approaches the asymptotic value. dT/I 

 varies between 0.1-0.01 for the ultimate value of dl and decreases 

 with the field. The investigation of the susceptibilities of soils, sands 

 and some rocks has also been later accomplished by H. Takagi.^"*^ 



Seiji Nakamura and Seiji Kikuchi'^*'^ determined the magnetic 

 moments and the directions of magnetization of six spindle-shaped 

 volcanic bombs from Mt. Mihara, Oosima, and Mt. Aso, and communi- 

 cated a valuable hint on the modes of formation of these remarkable 

 forms of bombs. 



K. Fuji and T. Mizoguchi*^"^ devised a method of determining the 

 ranges of melting and solidifying points of lava by measuring its 



(1) J.M.S. 31 (1912), 247. 



(2) N.S.B.K., [iii] 4 (1922), 92; Sci. Pap. Inst. Phys. Chem. Res., 1 (1923) 135. 



(3) T.S.B.K., 5 (1910), 190. 



(4) Sci. Eep. Toll., [i] 2 (1913), 15; 3 (1914j, 127. 



(5) T.S.B.K., 6 (1912\ 268. 

 (G) T.S.B.K., 7 (1914), 243. 



