146 



MR. LUBBOCK ON THE TIDES. 



This is the opinion of those most competent to form one, from their daily expe- 

 rience, and is no doubt correct. The subject is one of considerable importance, as 

 regards the accuracy of which tide predictions are susceptible, and merits further in- 

 quiry, in order to ascertain, if possible, the error which may be expected for a wind 

 of given force and direction. 



In order to obtain the correction for the calendar months, I begin by forming the 

 following Table, which gives the moon's declination roughly, but sufficiently near for 

 my purpose, in different months of the year, supposing her to move in the ecliptic. 



Table A. 



The difference between the interval from the mean time of the moon's transit and 

 the time of high water, and the mean interval, is according to the Table given in the 

 Philosophical Transactions for 1831, p. 412. 



Table B. 



i 



The number —3, January, moon's transit 1^, was inferred by subtracting 1** 39™ 

 from 1*^ 42"™, column A.* Column A. is the semimenstrual inequality -|- a constant. 

 If we suppose the proper argument of this inequality to be the apparent time of the 



* Philosophical Transactions, 1831, p. 401. 



