eiclios in Some Lakes of Japan. 



45 



TABLE 26. 



Hakoné. 



Hotokegasa'ii. 



Diff. 



h. m. 



h. va. 





14 1 



14 5 



4 minutes. 



8 



12 



4 



15 



18 



3 



22 



25 



3 



A pair of dotted curves in Figs. 10 and 11 shows that this 

 motion was in same phase at Umijiri and Hakoné, 



Of other oscillations with shorter periods To and T^, we can 

 not say anything definitely from the limnograms. The experi- 

 ments conducted with a model of the lake first enabled us to learn 

 some details about them. 



The model was made of wood and measured about 33 cm. in 

 length. Three different modes of free vibration were found with 

 periods of 



t, = 1.672 sec, 

 to=0.693, 

 U=0A39, 

 which are in the ratios 



tj:t2:t3 = 1.000 -.0.4] 5 -.0.263. 



The photographs of these three different oscillations are given 

 in PI. IX., which shows very clearly that the first belongs to the 

 uninodal, and the second to the binodal oscillation. Comparing 

 the ratios tj : ts : U with the ratios of the periods in the actual lake 

 given in p.43, we see at once that T] and T2 correpond respectively 

 to tj and t?, being the uninodal and the binodal seiches; but of the 



