70 K. HONDA, T. TEKADA, Y. YOSHIDA, AND D. ISITANI. 



(c) Bay of Tsuruga. 



If the bay is considered as a rectangular bay, whose depth 

 is 28.5 m. and whose length is 15.1km,, the period of oscil- 

 lation is calculated to be GO.O" ; tlie corrections due to the 

 section and to the mouth are respectively -Iß.S''' and +15.8"\ 

 The corrected value is therefore 59.0™ in a fair accordance 

 with the observed period. 



The last two are good examples showing that the correction 

 due to the section and that due to the mouth, nearly cancel 

 wdtli each other. Similar remarks apply for many other bays. 



When the mouth of a bay is decidedly contracted, the 

 simplest formula completely fails to give the period of oscilla- 

 tion, in wiiich case formula (G) is to be used. We give here 

 two examples of calcidation by formula ((3) or (7) and show how 

 the results of calculation accord with the observed values. 



(a) Bay of Aomori. 



This bay may also be taken as an example of double-bays 

 discussed in p. GO. lîeferring to the annexed figure which 

 show^s the general outline of the bay, tlie shaded portions were 

 considered as necks connecting external sea and two basins S 

 and S'. Necessary data for the calculation of periods, estimated 

 from tlie chart are as follows : — 



6==13.5km. b' = U.7km. 



/ =11). km. r= 5.3 km. ;.= 120km. 



/^=54.8m. h' = il.5m. 



.S=4.75xlOMan.' .S' = 9.4xl0Mvm.'^ 

 whence for two values of (^ we obtained 5.25 and 0.49, and for 

 the two periods 100™ and 325™ in fair accordance with the ob- 

 served values. 



