SECONDAEY UNDULATIONS OF OCEANIC TIDES 43 



stations, the shorter waves of 35'"-42™ period appear only in the 

 latter station, and those of 10'" only in the former. Again, 

 comparing the records of Yamasakibana and Otani on the same 

 days (PL XXXVII, Fig. 1,2), 35"M2™ waves are found common 

 to both stations, while 18™ waves are peculiar to the latter 

 station. At Heshima, which is situated at the mouth of the 

 minor inlet of X^omi, the IG™ wave is absent, and 35™-42" 

 waves are apparently traced, though not of such great ampli- 

 tude as at Yamasakibana. 



Thus we may infer that the undulation of 3 5 '"-4 2™ has a 

 node near Kure, and that the period of about 16'" at Kure seems 

 to be due to the oscillation of the minor inlet. The undulation 

 of about 18" is probably due to the seiches between Awa and 



A 



Otani. 



Calculated values of the periods corresponding to these sup- 

 posed modes of undulation show a fair agreement with the 

 actual periods. 



As will be seen soon after, investigations with models also 

 lead to the same conclusion. 



(4) Yotsu (Aug. 28-30, 1903). PI. XXXVIII, Fig. 3. 



This station is situated on the western part of the Pacific 

 coast of Tosa ; the secondary undulations were very incon- 

 spicuous. Periods of 14.0"-15.4'" and 75.8'" could however be 

 traced. 



V. COASTS OF KIUSHIU. 



(1) Hososhima (Dec. 21-26, 1904). Top. 56. PI. XXXIX- 

 XL. 



Hososhima is an elongated bay on the eastern coast of 

 Hiiiga ; here Kelvin's tide-gauge is constantly working. It has 



