ob K. HONDA, T. TEE ADA, Y. YOÖHIDA, AND D. ISITANI. 



siele, while those at Hinoura and Yebisujima give the tide on 

 the Paeific side. The tide at Ogeura is aflected by these 

 two. 



The tidal curves of the strait are much complicated by the 

 influence of tlie two tides in opposite phases and by the super- 

 position of the secondary undulations. 



The records of Shioyasumi show a characteristic feature 

 (PI. XXVIII, Fig. 1-3); the tides at Hinoura (PI. XXX, Fig. 1) 

 and Yebisujima (PI. XXIX Fig. 2, 4) are not simple. 



At Ogeura, which communicates with Ilarimanada and 

 the Pacific, the tidal curve (PL XXX, Fig. 2, 3) has a very 

 peculiar form. As regards the high or low water at this station, 

 it agrees roughly with that on the Pacific side. 



In these four stations, conspicuous, but not regular, undula- 

 tions are observed, the periods of which are 



63^", 90'"-120'" at Shioyasumi. 



43"\ 54™-59'", 75'"-86"\ lir"-12r" at Hinoura. 

 5r"-63"\ 08--74"\ 84™, 94™-llG™ at Yebisujima. 



54'"-57'", 120,"180'"-200"' at Ogeura, 



The tide of Kameura, which is about 1 km. distant from 

 Shioyasumi and in the inside of the strait, is comparatively 

 simple. The secondary undulations are very inconspicuous, 

 though we can sometimes trace the undulations of the periods 

 16'"- 20'" and 51'"-{]4-". 



Comparing the phases of the tide just inside and outside 

 the strait, we observe that they are nearly opposite to each 

 other (PI. XXIX. Fig. 1,2; PI. XXVIH, Fig. 3 ; PL XXX, Fig. 1.) 

 a fact which at first sight appears very curious. X^ow, Hari- 

 manada is connected to the other seas by three necks, namely 

 Naruto Strait, Bisanseto and Akashiseto, of which the first. 



