TIDAL OBSERVATIONS. 3~3 



28. These equations, solved ty successive approximations, give the follow- 

 ing values of the coefficients for Ilamsgatc, 1864 : — 



ft. 



2 Z j-o-cjq6 [ *^® coefficients for the lunar monthly tide (elliptic). 



E= 0-0316 «=69°-78. 



D = 4-0-0277 I *'^^ coefficients for the lunar fortnightly tide (declinational). 



R = 0-0331 e=:56°*83. 



D'= —0-0508 } *^^ coefficients for the lunieolar fortnightly shallow-water tide (syncdic). 



E = 0-0960 6 = 2ii"-93. 



■p =_o-i2i6 f ^^^ coefficients for the solar annual tide (elliptic and meteorological). 

 R = 0*1270 e=253°-2o. 



G = +0-0225 1 the coefficients for the solar semiannual tide (declinational and meteoro- 



H= +0-0713 J logical?). 



R= 0-0748 e = 72°-48. 



29. The epochs of these long-period tides have also to he corrected on 

 account of their phases having heen each assumed equal to zero at the com- 

 mencement of the observations, or, more strictly, at the time corresponding to 

 the mean of the first twenty-four hourly observations. The amplitudes require 

 no augmentation. The amplitudes and corrected epochs are as follow : — 



The reduction of the Eamsgate observations, so far as at present discussed, 

 consists in the analysis of the year 1864 only. 



30. A series of tide-records, taken near the entrance of the George's 

 Docks, Liverpool, has been supplied, on application, by the kindness of the 

 Board of the Mersey Dock Estate. The heights through about twelve hours 

 each,_ during a few interruptions in the tide-curve (caused by the accidental 

 stopping of the clock &.c.), have been inferred from the tide-diagrams of the 

 self-registering tide-gauge at Helbre Island, at the mouth of the Dee. 



The following years have been selected and analyzed in a manner quite 

 similar to that previously described for Eamsgate. It should have been 

 stated that the epochs of the tide-components for Eamsgate, Liverpool, and 

 also for Portland Breakwater, hereafter described, have been referred to the 

 meridian of Greenwich, Greenwich mean time having been used in the 

 records of the observations. 



31. Liverpool (Lat. 63° 40' N., Long. O^ 20" W. of Greenwich). 



Year ... 1857-58. 1858-59. 1859-60. 1866-67. 1867-68. 1868-69. 1869-70. 



ft. ft. ft. ft. ft. ft. ft. 



Ao= 16*7192 16-8208 16*8289 168998 17-0862 17*4877 17-1350 

 1*= 28°*5 27°-9 27°o i80*4 iS°-4 i9<'-3 2o°-6 



* I is the average in(-lina(ion of the Moon's orbit to the Earth's equator, or the irean 

 maxiimim declination, for the period. 



