100 Messrs. K. Honda. T. Terada, and D. Isitani on the 
(vii.) Nagasaki. 
Nagasaki is a well-known harbour on the western coast of 
Kiushiu ; the observations were made near the end of the 
bay. Since March of 1905 a tide-gauge of our system ha^ 
Fig. 7. 
fo/fAHO/?/ 
Nagasaki x 
been set up in the same place by the Office, and many 
significant records obtained. 
In the bay. the secondary undulation is so conspicuous that 
it is usually known as abiki. The observed periods are 
22 m -5-25 m -2! 32 m 0, 34 m '5-37 m '6. 40 m 'l, 44 m -5-45 m '2, 53 m '6. and 
69 m *0-72 m, : the amplitude of the conspicuous undulations 
often exceeds half a metre. On one occasion, about ten 
years ago, the amplitude of the abiki was over 2 metres, and 
a large number of boats and steamers are said to have been 
damaged. The largest amplitude since the beginning of the 
tide-gauge observation was 1*54 m. observed on May 2, 1905. 
PL III. contains the record of the famous abiki. 
The conspicuous abiki is generally associated with weathers 
in which the isobars in the neighbourhood trace a devious 
course, because of the co-existing low barometric centres. 
Since it is well known that a tornado is frequently associated 
with such a distribution of isobars, it seems then very pro- 
bable that in such a weather a sudden local disturbance of 
