Harmonie Analysis ot Tidal Observations. 31 



TONOURA. 



Long. 132° 4' E., Lat. 34° 55' N. 



As one of the permanent observatories, this belongs to the 

 Land Survey Department of the Army, and is located on the 

 coast of the mainland, facing the Japan Sea. The site is on the 

 eastern side of a branch of Hamada-Wan. The first registration 

 Avas made on July 5, 1891, and since then recording has gone on 

 pretty smoothly. 



The series of marigrams obtained in the years 1895, 1896, 

 and 1901-4 were harmonically reduced and their results are given 

 in the accompanying table. 



The highest high-water recorded here was 3.00, referred to 

 the zero-point of the instrument, and occurred on August 21, 1904. 

 The lowest low-water was 4.30, referred to the same origin, and 

 occurred on January 30, 1903. Thus the extreme range of height 

 becomes 1.30 metres. 



The height of the mean sea-level, referred to the zero-point 

 of the instrument, Avas derived as follows : — 



1895 3.Ö99 



1896 3.720 



1901 3.703 



1902 3.735 



1903 3.732 



1904 3.689 



