54 K. HONDA, T. TEBADA, Y. YOSHIDA.. AND D. ISITANI. 



values. The photographs No. 3 and 4, together with Fig. 3 and 

 4, show the motion of the water particles corresponding to these 

 modes of oscillation. The stream hnes (Fig. 3 and 4) in the 

 case of the lateral oscillation deserve a special notice. The 

 greater part of these lines extends from Aomori to Ominato side, 

 while the remaining lines run from Aomori toward the entrance 

 of the bay ; the case is just analogous to tlie corresponding 

 oscillation in the bay of Hakodate. 



(c) Bay of Moroiso. PI. LXXX\^I1L 



The scales of the model were as follows : — Length 1 : 6,066 

 and depth 1 : 226 ; the factor r was 404. The fundamental 

 oscillation was 2.28'; multiplying by /■, we get 14.8™ in a good 

 accordance with the observed period. The photograph No. 5 

 and Fig. 5 show this fundamental mode of oscillation. 



{(l) Bay of Susaki. PI. LXXXIX. 



The scales of the model were as follows : — Length 1 : 24,300, 

 and depth 1 :915, so that the factor r was 803. 



The bay has a very complicated form and many small inlets 

 inside it. By exciting short waves, some inlets energetically 

 oscillated, while the others stood almost still, showing beauti- 

 fully the phenomenon of resonance. 



Waves of different periods were excited and corresponding 

 modes of oscillation of the bay were studied. A period 2.80' 

 was that of the oscillation of the bay as a whole, period 1.36'' 

 that of the lateral oscillation between Awa and Otani, and 

 period 1.25' that of the oscillation of the small inlet of Kure. 

 Multiplying them by r, we get 37.5™, 18.2™ and 16.7™ respectively, 

 which agree very well witli the observed as well as the 

 calculated values. 



