MR. LUBBOCK ON THE TIDES. 



163 



Tables XLIII. and XLIV. may probably be safely employed for all the ports in the 

 United Kingdom. It should be borne in mind that these Tables cannot in any case 

 be depended upon to within two or three minutes, from the great irregularities of the 

 phenomena to which they refer, and from the difficulty of ascertaining by observation 

 the precise time of high water. The observations upon which they are founded are 

 only recorded to the nearest five minutes, and they were not always made with so 

 much care as might have been desired. 



For the Height of High Water at the London Docks. 



Table XXIV., column B., containing the semimenstrual inequality + a constant. 



Table XL VII. containing the correction for the moon's parallax. 



Table XL VIII. containing the correction for the moon's declination. 



The last two Tables have been formed by arbitrary changes from Tables XLIII. 



and XLIL, which Tables present great irregularities ; for the height of high water 



is subject to much greater irregularity than the time. The effect of changes in 



the moon's parallax upon the height appears to be considerably greater than that of 



changes in her declination. 



Column A. Table III. 



Containing the semimenstrual inequality + a constant, and showing the Interval 



between the Moon's Transit and the Time of High Water, from the Philosophical 



Transactions, 1831, p. 401. 



Table XLIV. 



Showing the Correction for the Moon's Parallax, formed by arbitrary alterations 



from Table XLIL 



y2 



