106 K. HONDA, T. TER ADA, Y. YOSHIDA AND D. ISITANI. 



components, that component will become more or less prominent, 

 according to the degree of proximity of tlie proper and the 

 exciting period. Again, it is possible that astronomical com- 

 ponents of superior orders, compound tides resulting from 

 the combination of several astronomical components or many 

 indefinite components arising from meteorological causes, may 

 sometimes become prominent by the resonance of bay water, 

 though almost insensibly small in open sea. Moreover, the case 

 may occur, in which a solitary wave of wide extent caused by 

 some disturbances either meteorological or geotectonic, excites 

 the oscillation of a long period proper to a bay. These oscillations 

 in a bay will more or less deform the tidal curve and cause an 

 anomaly of tides peculiar to that bay. According to this view, 

 the proper periods as given by our formula were calculated for 

 different bays or gulfs, which are notorious for abnormal range 

 of tide, and also those for which some remarkable irregularities 

 of tide was observed in the mareograms given in the Report of 

 the Krakatoa eruption often cited. 



The results of calculations, together with their bearings 

 upon the tidal irregularities for a number of bays, will be given 

 below. 



(a) Bay of Fundy, Canada. Near the end of this bay, 

 spring tides range 15m., while near its entrance the rise is only 

 2.5 m. to 3.5 m. For the calculation, the mouth line was taken 

 from Cape Cod to Cape Sable ; and the end of the Bay was taken 

 at Port Greville. Then /=460km., h=Ul m.; hence 7^=13.0". 

 If the mouth line be taken l^etween Yarmouth and Machias, the 

 calculated period is 11. ß''. In any case, the proper period of this 

 bay would be very near 12 hours. The abnormal high tide may 

 then partly be explained by the coincidence of the proper period 



