Part III.— TIDAL HARMONIC CONSTANTS. 



TIDAL HARMONIC CONSTANTS. 



The tidal harmonic constants given on the following pages have 

 been compiled from various sources, which are indicated by the- 

 references at the bottom of each column. All amplitudes have been 

 reduced to feet, and the epochs have been referred to the local 

 meridians. Values inclosed in parentheses have been inierred.. 



The combined length of the series, together with the first and last 

 year of the observations from which the constants were derived, is 

 indicated for each station. In combining the results from several 

 series of observations at any place the usual practice has been to take 

 separately the direct means of the amplitudes and epochs. 



A more precise method was used for combining the results for the 

 components Mf , MSf , and Mm as derived from the different series of 

 observations at the stations in India, where observations covering 

 periods of many years have been analyzed. This method consists of 

 the use of the following formulas : 



Mean amplitude of component A = ^l- XHg, cos Ka ) + ( ~ ^Sa sin Ka ) 

 and 

 Mean epoch of component A = tan~^ :^rfT 



^ ^ Si/a cos Ka 



n being the number of individual results combined and Hg, and «& the 

 amplitude and epoch, respectively, of any componoit A as derived 

 from each series of observations. 



The sources from which the constants have been compiled, together 

 with the corresponding reference nmnber used in the compilation, 

 are given below. The cooperation of all those who have so cour- 

 teously furnished the harmonic constants for various ports is very- 

 much appreciated by the U. S. Coast and Geodetic Survey. It is, 

 hoped that this cooperation will be continued, and all' persons who> 

 may secure additional constants for any station are invited to send a 

 copy of the same to the Director, U. S. Coast and Geodetic Survey^ 

 Washington, D. C. 



References. 



(1) Analysis by U. S. Coast and Geodetic Survey. 



(2) Proceedings of the Royal Society of London, vol. 45, 1888-89. 



(3) Proceedings of the Royal Society of London, vol. 39, 1885. 



(4) Annual tide tables of Russian Hydrographic Office for year 1910. 



(5) Resultater af Vanstands-Observationer paa den Norske Kyst,, Hefte VI,. 



1904. 



(6) Bihang till Kongl. Svenska Vetenskaps-Akademiens Hadlinger, vol. 15, 



part I, No. 11, 1889-90. (There is probably an error of 180° in the; 

 kappas of the diurnal components which has not been corrected.) 



316 



