Seiches in Some Lakes of Japan 



37 



minutes period is easier to detect than a long-period motion 

 executing a complete oscillation in fifty or sixty minutes. Thus, 

 the extraordinary long period of 230 minutes recorded at Otsu, of 

 whose real existence we have no doubt, is not at all significant on 

 the curve of frequency just spoken of, for the number of observed 

 times is very small ; and therefore we have purposely omitted to 

 include it in the last table in order to do justice to the other 

 motions. In the next table, we give in the first column the periods 

 just determined and in the other columns the periods observed at 

 several stations which are nearly equal to those in the first column 

 the values which had been previously pointed out as certainly 

 existing in a given place being printed in heavy faced type. 



TABLE 23. 





o 



1 

 B 



Q 



Ol 



B 



9^ 



B 





8- 



t 



P 

 O 



B 



p 



o 



c 



? 



o 



m 



CD 



f 



CO 



h-" 



m 





9.4 

 30.5 



8.5 

 25.2 



22.7 

 12.0 

 10.6 

 16.7 

 72.6 



30.7 

 11.0 



9.7 

 31.8 



9.6 

 30.3 



8.5 

 25.3 

 22.2 

 12.5 

 10.3 

 16.5 



9.4 

 30.1 



8.5 



22.0 



30.0 



12.0 

 11.3 



32.1 



11.9 

 10.5 



74.4 



9.2 



11.6 



16.5 



9.5 

 31.5 



24.9 

 22.8 

 12.0 

 10.5 

 17.1 



9.2 

 10.2 



9.8 

 30.1 



8.6 

 25.4 

 22.9 

 12.4 



72.9 



31.9 



71.1 



30.4 



8.9 



The extraordinary period of 231.2 minutes observed only at 

 Otsu must be a motion peculiar to the shallow southern basin. 



