SECONDARY UNDULATIONS OF OCEANIC TIDES. 55 



The photograph No. 6 and Fig. G show a fundamental 

 oscillation of the principal part of the bay as a whole, in which 

 case the small inlet of Kure almost stands still. The photo- 

 graph No. 7 and Fig. 7 indicate an oscillation of the inlet of 

 Kure, where the water energetically oscillates between Kure and 

 a neighbouring inlet. 



(e) Bay of Hososhima. PI. XC. 



The scales of the model were as follows : — Length 1 : 

 10,140, and depth 1:366, so that the factor r was 531. The 

 fundamental and the binodal oscillations were found to have the 

 periods 2.2r and 0.90' ; multiplying In^ r, we get 19.6™ and 8.0'". 

 The phase of the fundamental oscillation is the same for all 

 parts of the bay, while that of the binodal is opposite for the 

 mouth and near the end of the bay ; the photographs No. 8 and 



9 show also these two modes of oscillation. In the actual bay, 

 the periods corresponding to these two modes of oscillation were 

 also observed. 



(/) Bay of Nagasaki. PI. XCI. 



The scales of the model were as follows : — Length 1 : 12,130, 

 and depth 1 : 548, so that the factor r was 518. 



The bay had two modes of oscillation, that is, the funda- 

 mental and the seiches -like oscillation. The former had its node 

 at tlie wide mouth opened to the north-western direction, while 

 the latter had its loops of opposite phases on the Nagasaki 

 and Fukahori sides. The photographs No. 10 and 11 and Fig. 



10 and 11, show the two modes of oscillation. It is interesting 

 to observe that in the seiches oscillation (Fig. 11), when the 

 water flows from tlie wide mouth toward Fukahori, there is 



