98 Messrs. K. Honda, T. Terada, and D. Isitani on the 
those at Heshima 24 m '6-27 m -6, 39 m *7, and 55 m 'l. At Kure 
secondary undulations of the periods 15 m 0-16 m 3 and 6V3 
Fig. 5. 
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were noticeable. Here it is to be observed that at the last 
three stations the records are not so rich in results as those 
at Yamasakibana. 
Comparing the records of Kure and Yamasakibana taken 
on the same days, it will be seen that the waves with the 
periods 35 m -40 m appeared only at the latter station, and those 
of 16 m only at the former. Again, comparing the records of 
Yamasakibana and Otani of the same days, the waves of 
35 m -40 m are found common in both stations, while waves of 
18 m are peculiar only to the latter. At Heshima, which is 
situated at the mouth of the minor inlet of Otani, waves of 
16 m are noticeable by their absence, while waves of 35 m - 
40 are apparently traced, though not of so great amplitude 
as at Yamasakibana. 
Thus, we may infer that the undulation of 35 m -40 m is the 
fundamental oscillation of the bay, having its node near 
Kure, and that the undulation of L6 m at Kure is the oscilla- 
tion of the minor inlet. The undulation of 18 m at Otani is 
