36 K. HONDA, T. TEEADA, Y. YOSHIDA, AND D. ISITANI. 



met with widely varying periods and often with considerable 

 amplitudes. 



For Kishiwada and Imazu, the short waves are generally 

 very complicated, periods of 1.4'"- 1.5'", and 2.0'"- 2.5'" being very 

 frequent. 



The records of Iwaya, when compared with those of the 

 other stations are characterized by tlie simplicity of the short 

 waves, the most prominent waves being of two groups, i.e. 1.0'"- 

 1.3'" and 2.r"-2.5'". 



(24) Bay of Hiroshima (Jan. 17-23, 1904). Top. 44. PI. 

 XXVI, Fig. 1-2 ; PI. XXVIl, Fig. 1. 



The observation was simultaneously made in a small bay 

 of Yedajima and in the harbour of Ujina. 



In Yedajima, the tidal curve was often accompanied by a 

 regular and inconspicuous undulation of 00.0'". The period is 

 far greater than the value calculated from the dimensions of 

 the small bay of Yedajima. In Ujina, the undulation of the 

 same period and phase as in Yedajima was also observed ; 

 hence the undulation wdiich was observed at Yedajima and 

 Ujina, is probably due to the oscillation of the bay of Hiroshima 

 as a whole. The calculation according to this consideration 

 gives a fairly coincident value Ol.G'". 



Beside this undulation, an oscillation of a shorter period 

 9.5'" was occasionally found both at Y^edajima and Ujina. 



Tlie tidal wave in the bay undergoes a considerable change 

 both in its form and phase, as compared with the tide on the 

 Pacific coast. Here the tidal range is considerably large, and 

 its form in the neighbourhood of its maximum or minimum 

 is comparatively steep, as it is usually the case in a deep 

 inlet. The retardation of the tidal phase is about 3 hours as 



