108 K. HONDA, T. ÏEILIDA, Y. YOSHIDA AND D. I«ITANI. 



however, the mean depth can not differ mueli from 30 m. The 

 period calculated from these data is 8.8''. In order to see, if 

 any long wave corresponding to this result of calculation exists 

 actually in record, the mareogram of Karang Kleta was analysed 

 by means of the tide-rectifier. Eliminating tlie great parts of 

 diurnal and semidiurnal components, the remaining curve reveals 

 to us an evident trace of waves with the mean period of 8.0'' 

 (PI. LXIV, Fig. 1). 



The exciting cause of this wave is probably the compound 

 tide usually denoted by MK, the period of winch is about 8.2'', 

 nearly coinciding with the proper period of the Madura Strait. 

 (d) Port Adelaide, Australia. A mareogram (PI. LII, Fig. 

 3) of this Port given in the Krakatoa Peport shows remarkable 

 change of diurnal inequality on successive days. On eliminating 

 the principal parts of diurnal tides, the resulting curve shows 

 apparent beats of semidiurnal tides (PI. LXIA'', Fig 2). The 

 period of the characteristic component which forms beats with 

 the usual semidiurnal tides, is about 10.9'', as estimated from 

 the rectified curve. It is probably to be attributed to the 

 standing oscillation of the St. Vincent Gulf. Taking the mouth 

 line from Trowbridge Point to Cape Jevis, and the end of the 

 Gulf at Wakefield, w^e have /=140km. The estimated mean 

 depth is 21.5 m. Hence 7 = 10.8'', which coincides very well 

 with the observed period. 



(e) Port Phillip, Austraha. Mareogram (PI. LII, Fig. 4) 

 of Williamstown given in the above quoted Eeport, shows some 

 irregularities of tide which suggests the existence of very long- 

 undulation peculiar to the bay. The curve was rectified (PI. 

 LXIV, Fig. 3) and a period of 8.3'', was detected. Xow the 

 period of seiches in this nearly enclosed basin can by no means 



