104 K. HONDA, T. TERADA, Y. YOSHIDA, AND D. ISITANI. 



27. Fob. 9, 1834. Sea wave on the coast of Tsliikari ; three -vyaves 

 coTintecI. 



28. 1835. Sea wave at Hanasaki. 



29. April 25, 1843. Sea waves on the coasts of Oshima, Knshiro 

 and Nemnro ; two large waves conuted in ß'^ a.m. -10'' a.m. 



30. Dec. 23 and 24, 1854 (Ansei). Notoiions sea waves on the 

 Pacific coast. 



31. Aug. 23, 1856. Sea waves occurred on the coast of Oshima 

 and Ibnri in Hokkaido. 



32. June 4, 1893. Sea waves in Kurile Islands (Chishima) ; at 

 Shibetori periods of 5 waves estimated were 20™-30"\ 



33. March 22, 1894. Sea waves on the coast of Nemuro ; periods 

 of more than ten waves were estimated to have been 20"'-30"\ 



34. June 15, 189(). Great sea waves on the entire coast of Sanriku. 



35. Aug. 5, 1897. Sea waves on the coasts of Sanriku. 



§ 9. OSCILLATION OF LARGE BAYS AND 

 ANOMALY OF TIDES. 



Thus far, wc have generally treated of secondary undula- 

 tions, the periods of which are much shorter than those of the 

 principal tidal components, viz. the diurnal and semidiurnal. We 

 will now proceed to consider those undulations of much longer 

 periods, which commonly exist in the tides near the end of 

 long inlets or estuaries. 



Exaggeration of oceanic tides which takes places in shallow 

 seas and in estuaries, has often been explained merely by the 

 law of amplitude given by Green.* Airyf attenipted to explain 

 anomalies of tide observed in some rivers by the consideration 

 that for a wave of fmite amplitude different parts of the wave 



*) Green, Camb. Trans. 6, 1837; Math. Papers, p. 225. 

 t) Airy, Tide and waves, Art. 198 



