Secondary Undulations of Oceanic Tides, 97 
(iv.) Moroiso. 
About 4 km. north of Misaki, in the province of Sagami, 
there lies a small forked bay, the one branch of which is 
called Moroiso, the other Aburatsubo. In Aburatsubo a 
Kelvin's tide-gauge is constantly working, the records of 
x Observed station. 
which Professor F. Omori has frequently referred to as 
Misaki mareogram. The undulation is very regular and 
marked, having the period 13 m, 8-15 m, 6; the calculation of the 
period for the fundamental oscillation gives a fairly coincident 
value 13 m *4. 
The record shows an appearance of the beat of two waves 
of nearly the same wave-length. So it was suspected that 
the phenomenon might be due to the interference of the two 
distinct modes of oscillations of the two branches of the bay, 
which constitutes a vibrating system with two degrees of 
freedom. But this was found not to be the case, since the 
simultaneous observations at different parts of the bay showed 
the identity of the undulations with respect to their forms 
and phases. By comparing the records of the simultaneous 
observations at the inside and outside of the bay, we could 
distinctly trace corresponding undulations in the two records. 
The amplitude of the wave outside the bay is, however, very 
small as compared with that of the undulation inside the 
bay. 
(v.) Susaki. 
Susaki is a deep bay on the middle coast of Tosa in 
Shikoku. In it the observations were made at four stations — 
Yamasakibana, Otani, Heshima, and Kure. The diagrams of 
Yamasakibana are very conspicuous, and characterized by 
the simplicity of the undulations; the periods observed are 
30 m 9, 35 m, 4-38 m, 5 J 40 m -0-46 m, 8, and 50 m 0-54 m The 
periods observed at Otani are 17 m, 6-18 m '3, 35 m *4 and 53 m '3 ; 
Phil. Mag. S. 6. Vol. 15. No. 85. Jan. 1908. H 
