ON THE DISCUSSION OF LEITH TIDE OBSERVATIONS. 



35 



how small are the results in which this coincidence is found. The coefficient 

 of the term now spoken of, is at Loudon 3 inches ; at Plymouth it is 1 inch ; 

 at Bristol, when the rise and fall is very great, this coefficient is 6 inches ; 

 at Leith, by the present discussion, its amount is found to be little more than 

 1 inch. The smallness of this term also leads us to this inference, that 

 Mr. Ross's table of double entry may be used to obtain the corrections of 

 heights for parallax and declination, almost without a sensible error. The 

 table being obtained from Leith observations, will require a constant multi- 

 plier to adapt it to other places. 



TABLES. 



(1.) Mr. Ross's table of the correction of height for parallax and declina- 

 tion. 



(2.) Mr. Ross's table of the difference of the parallax correction from the 

 mean for each hour of transit. 



^3.) The mean value of this difference for each hour of transit. 



(4.) The mean value of this difference for each 3° of declination showing 

 that the declination correction is nearly as the square of the declination. 



(5.) The semimenstrual inequality of height for Leith. 



b2 



