90 



TIDES AND BENCH MARKS 



The harmonic constants given below were obtained from the hourly heights 

 of the sea at Nassau, for the year beginning July 1, 1903, by a process essen- 

 tially similar to that outlined by Professor George H. Darwin, in the report of 

 the British Association for the Advancement of Science, for the year 1883. 

 The amplitudes (//) or semiranges of the components, and their epochs (*) 

 or component-tidal intervals expressed in degrees, as given in the table, have 

 been corrected by a process for eliminating the small residual effect of one com- 

 ponent upon another. 



HARMONIC CONSTANTS. 



From one year of hourly heights beginning July 1, 1903. 



Symbol. 



M 

 M 2 

 Ms 

 M t 



2N 

 Ox 

 OO 

 J"i 



Oi 



20 

 Ko 



Si 



S 2 



s* 



Pi 

 Sa 

 Ssa 



Name of Component. 



Smaller lunar elliptic diurnal.... 



Luni-solar diurnal 



Luni-solar semidiurnal 



Smaller lunar elliptic semidiurnal 

 Smaller lunar elliptic diurnal . . . 

 Principal lunar series 



Larger lunar elliptic semidiurnal 



Lunar elliptic semidiurnal, second order 



Lunar diurnal 



Lunar diurnal, second order 



Solar diurnal 



Larger lunar elliptic diurnal 



Lunar elliptic diurnal, second order. . . 



Smaller solar elliptic 



Principal solar series 



Larger solar elliptic 



Smaller lunar evectional 



Variational 



Larger lunar evectional 



Larger lunar evectional diurnal. 



Solar annual 



Solar semidiurnal , 



Speed per 

 solar hour. 



15.5854433 

 15.0410686 

 30.0821372 

 29.5284788 

 14.4920521 

 28.9841042 

 43.4761563 

 57.9682084 

 86.9523126 

 28.4397296 

 27.8953548 

 13.9430356 

 16.1391016 

 14.9589314 

 13.3986609 

 12.8542862 

 30.0410686 

 15.0000000 

 90.0000000 

 60.0000000 

 30.0000000 

 29.9589314 

 29.4556254 

 27.9682084 

 28.5125830 

 13.4715144 

 0.0410686 

 0.0821372 



Amplitude. 



H 



Feet. 

 0.0169 

 0.2848 

 0.0654 

 0.0459 

 0.0144 

 1.2422 

 0.0067 

 0.0171 

 0.0059 

 0.3026 

 0.0402 

 0.2138 

 0.0092 

 0.0872 

 0.0377 

 0.0056 

 0.0017 

 0.0104 

 0.0034 

 0.0044 

 0.2101 

 0.0124 

 0.0087 

 0.0282 

 0.0675 

 0.0081 

 0.3115 

 0.1013 



Epoch, 



118.73 

 120.50 

 246.10 

 246.59 

 101.97 

 213.3? 

 153.73 



65.31 

 279.15 

 190.54 

 167.70 

 124.06 

 116.94 

 121.59 

 118.28 

 127.59 

 237.36 

 171.96 

 104.04 

 318.81 

 237.36 

 237.36 

 224.51 

 202.73 

 189.28 

 125.59 

 143.90 



32.88 



The mean lunitidal intervals may be obtained from the harmonic constants 

 by the equations 



HWI = 0.0345 (M\v) (1) 



L WI = 0.0345 ( Ml w) -f 6.21h. (2) 



where HWI = mean high water lunitidal interval 



" LWI = " low " 

 and v and w are such that 



