TIDAL OBSERVATIONS. 133 



Loiig-iDeriocl Tides. 



Yr. 1 869-70. Ao = 7-290S ft. Average inclination of moon's orbit to earth's equator = 21 °- 1 8. 

 S 11 L N MS 



Years 1S68-G9 and 1S69-70 combined. 



E T 



E2 °'°353 0-1108 



e., i2°-04 38°-96 



The following arc the results of two of the ellii^tic dinmol ticlc-comi^oiients, 

 whose arguments (§ 2) are (y + a— n;) and (y—Scr + za), termed hereafter J 

 and Q. The period chosen for their evaluation was STO** 5''. These results 

 have been obtained since the Liverpool Meeting. 



Series J. Series Q, 



1868-69. 1869-70. 1808-69. 1869-70. 

 E, 0-0800 0-C434 0-1 1 10 o-iioo 



i78°-58 i65°-88 3o8°-23 32o°-34 



f. 



fter moon's 

 syzygies. 



Ectardation of phase of Spring-tides =i'>-095 = i<' 2'> 17™"! a 



Coincidence of phase of Declinational tides =o''-365 = o'' S"" 46"/ 



A comparison between the calculated and recorded heights for Kurrachee 

 is appended (§ 70). A graphic representation of the heights of high and low 

 water, as calculated bj- the system of harmonic analysis and the method pur- 

 sued by Mr. Parkes, together with the actual recorded heights for Nov, 1869 

 also accompanies this Eeport. 



68. The series of hourly tide-heights (1869, April 24 to May 6), calcu- 

 lated for St. George's Pier, Liverpool, referred to above, are here given, and 

 will give a moderately accurate idea of the amount of precision at present 

 arrived at. It must not, however, be forgotten that the recorded heights are 

 not corrected in any respect, and include all instrumental errors &c. The value 

 of the Helmholtz shallow-Avater quarter-diurnal tide (MS) is given in a 

 separate column, and its effect shown in improving generally the precedin"- 

 differences. 



