92 K. HONDA, T. aEllADA, Y. YOSHLDA, AND D. IÖITANI. 



to work again after several hours. The oscillation of the bay 

 continued over two days with its proper periods of 23.6"" and 

 45.5"'-57.5'" (PI, III, Fig. 2). 



In the above four cases, the wave was more or less affected 

 by the proper oscillations of the hays. The tide-gauge at Chôshi 

 in Shimôsa has however been set up in a mouth of the river 

 Tone, so that its record in the case of the sea wave is the 

 most suitable for the investigation of the wave, inasmuch as 

 the sea is not much affected by any proper oscillation of 

 enclosed water. The record of the tide-gauge at Hanasaki, 

 which is situated on a small inlet in the Pacific coast of 

 Nemuro, possesses the same advantage as that of Chôshi. Thus, 

 in the records of Hanasaki and Chôshi (PI. LV, Fig. 1-2), w^e 

 observe, for the first one hour,'^' a similar series of waves of the 

 period of about 7". This period was found superposed on the 

 larger waves of some ten minutes. 



The sea wave also crossed the Pacific and reached the 

 western coast of America. It disturbed the tide-gauges of 

 Honolulu and San Francisco (PI. LV, Fig. 3-4). The period of 

 the w^ave in Honolulu w^as 23.4,"- 26.0'" which is nearly the 

 same as that of Krakatoa waves ; in the first part of the record, 

 we may however observe a wave of double period. The record 

 of San Francisco was marked by irregular zigzags ; we can 

 however trace waves of periods 24.3'" and G.2.™ 



In the following table, the result of the calculation for the 

 velocity of sea waves through the Pacific are given : — 



^) After the first hour, the tide-gauge at Hanasaki stopped. 



