Harmonic Analysis of Tidal Observations. 47 



YOKOHAMA. 



Long. 139° 88' E., Lat. 35° 27' N. 



This is a temporary tide observatory established for the sake 

 of the construction of tlie harbour. The first observation record 

 was made on the 28th of June in the year 1899. The observa- 

 tions are made every half-hour in the daytime and every hour in 

 the night-time. As lias been already stated, this observatory is 

 not furnished with a tide-gauge in its elaborate from, but a tide- 

 staff was fixed at a place where the state of the water seemed 

 comparatively calm, and the direct readings are recorded. We 

 copied their observations made eveiy hour, and the series obtained 

 in the years 1900, 1901, 1902, 1903, 1904 and 1905 have been 

 reduced. 



The highest high-water recorded in the years which we have 

 reduced was 2.64, referred to the zero-jooint of the instrument, 

 and occurred on September 23, 1903. The lowest low-water 

 recorded was -0.09, referred to the same origin, and occurred on 

 May 1, 1900. Thus the extreme range is 2.73 metres. 



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

 of the instrument, is obtained for each year-series as follows: — 



1900 l!306 



1901 1.363 



1902 1.347 



1903 1.362 



1904 1.373 



1905 1.367 



