THE BAHAMA ISLANDS 



89 



RECAPITULATION. — Continued. 



1903-1904. 



No. of Obs. 

 H. W. L. W. 



Lunitidal Interval. 

 High Water. Low Water. 



Mean. 

 H. W. L. W. 



1903. 



707 



Mean 



Correction 



707 



-10.8 



-10.8 



Corrected Intervals . . 

 4.37 — 1.66 



7 22.8 1 11.8 



2.71 — uncorrected mean range. 



The mean range of tide, as given by the direct summation of high and low 

 waters, usually requires to be corrected for the longitude of the moon's ascend- 

 ing node, there being whole series of years during which the mean annual 

 range is greater than an average for the lunar cycle, followed by another 

 series of years having a smaller mean annual range than the average. For 

 the series at Nassau the longitude of the moon's node is iV = 181°. 8 for the 

 middle of the series, which gives I = 18°. 3 for the inclination of the lunar 

 orbit to the terrestrial equator. The corrected mean range is equal to the 

 product of the observed mean range by the factor F{Mn) obtained from 

 Table 14, of Appendix 7, Coast and Geodetic Survey Report for 1894. This 

 gives, putting Mn for the corrected mean range, 



Mn = 3.71 X 0.972 = 2.634 ft. 



Another determination of the corrected mean range is given after the table 

 of harmonic constants, where various other ranges, such as spring and neap 

 range, etc., will be found. 



