93 



173. The accepted values of i^(Mn) corresponding to successive 

 values of I, and of (Ki+0i)/M2 ranging from to 1, are shown in 

 table VI. This table is abstracted from table 14 of the Manual of 

 Tides by Harris, published in the Report of the United States Coast 

 and Geodetic Survey for 1894, part II. 



Table VI. • — Factor f(Mn) for correction of Mn for longitude of the moon's node 



174. The values of I at the middle of each calendar year from 1890 

 to 1969 are shown in table VII. 



Table VII. — Inclination, I, of moon's orbit at middle of year 



175. Application of corrections. — The correction to the observed 

 tidal range in any month or year is readily determined from tables 

 VI and VII if the harmonic constants M2, Ki, and Oi have been 

 determined for the station. If these constants are not available, the 

 ratio of (Ki+0i)/M2 at the nearest station for which they are deter- 

 mined may be used, if the tide is of a similar type. Otherwise the 

 ratio is taken as equal to 2 (DHQ-}-DLQ)/Mn, as explained in 

 appendix II. 



176. Example. — At Fort Hamilton, New York Harbor, Ki = 0.322 

 feet, Oi=0.172 feet, and M2=2.210 feet. The value of (Ki + 0i)/M2 is 

 then 0.22. For comparison the great diurnal range is 5.29 feet and 

 the mean range is 4.73 feet. The value of 2 (DHQ +DLQ)/Mn is then 

 0.24. The mean tidal range for 1902 was 4.79 feet. The value of / 

 for 1902 is, from table VII, 19°. 2. The corresponding value of F{Mn) 

 for (Ki+Oi)/M2=0.2 is, from table VI, 0.974. The mean range cor- 

 rected for the longitude of the moon's node is then 4.79X0.973 = 4.67; 

 which is 0.12 feet less than the observed range. Observed mean low 

 water for the year was 2.44 feet below mean sea level, and mean high 

 water 2.35 above mean sea level. Applying half the correction to 

 each, these elevations, corrected for the longitude of the moon's node, 

 become respectively 2.38 feet and 2.29 feet. 



