GQ K. HONDA, T. TEE ADA, Y. YOSHIDA, AND D. ISITANI. 



Special interest is attaclied to the case, when one of the 

 basins becomes infinitely large ; the problem is then reduced to 

 the case of a bay communicating witli open sea by a narrow 

 neck. Taking ;.=A'=:4L, where L is the length of the bay 

 measured along tlie probable direction of propagation of waves, 

 we obtain from the above equation, 



Another simple case frequently met with is that of a 



dumb-bell sliaped bay communicating with an external wide 



sea by a narrow mouth or neck at the end of one basin. 

 Using tlie same notations as before, we get 



and 2P.E-fj{S-ri'-vS'-f-\ 



where ).^^, X and /' may be put equal to mean lengths of tlie two 

 basins for the first approximation. Since Sy^ = bhç — h'h'ç' and 

 S'r/ = yii'^', we get 



c c 



and 2P.E.=gi^ Ä^"^";^}' 



where hhç = X, .h'h'ç' = X\ 



^ + 4(0.923 + logqi') = i, 



t nil \ no J c 



V 2 / V'-^N 1 



_,+._(0.9^3 + log^) = -; 



