iv TEEFACE. 



that stationary waves may be produced between the Kuroshiwo 

 and the shore, but when the water here is once disturbed, we 

 may expect most promiscuous groups of waves to be propagated 

 from the disturbance ; tliese waves will be swallowed by the 

 bays and estuaries lying in their way, especially when the 

 periods of oscillation are in close agreement. 



Sir G. H. Darwin,'^' in his w^ellknown lectures on " Tides " 

 delivered in 1897 speaks of the tides in Venice : — 



" Every visitor to Venice must, however, have seen, or may 

 we say smelt, the tides, which at springs have a range of some 

 four feet. The considerable range of tide at Venice appears to 

 indicate that the Adriatic acts as a resonator for the tidal 

 oscillation, in the same way that a hollow vessel tuned to a 

 particular note, picks out and resonates loudly when that note 

 is sounded." 



Later investigation in 1904, 1905 and 1906, which were 

 mostly undertaken by Drs. Honda and Terada, assisted by 

 several graduates of the university, in nearly all the bays 

 bordering on the Pacific Ocean and the Japan sea, revealed the 

 truth of the acoustical analogy first propounded by the great 

 authority on the tides. 



Led by this consideration, Dr. Terada treated the problem 

 of the secondary oscillations by bringing in the theory of re- 

 sonators in close contact with the vibration of bays and 

 estuaries. As an outcome of the discussion, a mouth correction 

 must be added to the period calculated according to Merian's 

 formula, as is wellknown in the theory of organ pipes. Still 

 more interesting is the mutual influence of the dumb-bell shaped 

 bays, bearing close resemblance to the acoustical resonators 



* Tides, p. 168-1G9, First Edition. 



