SECOND AEY UNDULATIONS OF OCEANIC TIDES. 71 



It is interesting to observe that the formula, which is 

 derived from a quite different consideration as compared with 

 tlie usual view, will give fairly concordant values. 



(b) Bay of Osaka. 



The Bay of Osaka which is almost surrounded by land, 

 communicating with external sea by two narrow necks, Akashi- 

 seto and Yuraseto, may be taken as an example of those bays 

 discussed in p. 64. For the resultant conductivity of necks, tlie 

 sum of separate conductivities was duly taken. Data for the 

 calculation of the period estimated from the chart are as 

 follows : 



Akashiseto : b^= o.d km. 



l,= 6.2 km. 

 /?i = 41. m. 

 Yuraseto : b.,= 5.0 km. 



l,== 1.2 km. 

 7^,-27. m. 

 >S'=1.47 X 10'' km'., / =^150 km., 

 whence from (6) 2'=270"\ which fairly accords with the largest 

 period observed. 



In the following tables, the mean depth, the length and the 

 period calculated by formula (1) are given in the 4th, the 5th 

 and the 6th columns respectively ; in some bays, the periods 

 corrected for the variation of the section and for the mouth are 

 given with the figures underlined. The observed periods, which 

 would possibly correspond to the calculated values, are given 

 in the last column. The letter S placed after some calculated 

 periods indicates that the periods followed by S are those for 

 the lateral or seiches oscillation in the bavs. 



