118 The Rev. S. Haughton on the Solar and Lunar 



Portrush Tide, Table E. 



Difference of observed and calculated times of vanishing of 

 diurnal tide at high water, expressed in lunar days. 



Ase of lunar tide =5<i 9^ 



Portrush Tide, Table P. 



Difference of observed and calculated times of vanishing of 



diurnal tide at low water, expressed in lunar days. 



Age of lunar tide = 4^ IQ*^. 



The agreement of the observed and calculated tides shown in 

 Tables A, B, C, D, E is very good, but the differences in Table F 

 are intolerable ; they do not, however, vitiate the accuracy of our 

 tidal constants for Portrush, and probably owe their origin to 

 the fact, that the diurnal tide at low water at this station was so 

 small in amount, that a very slight error of observation would 

 produce a considerable error in the time of vanishing. The 

 agreement between theory and observation, as respects the height 

 of the diui-nal tide at low water, is excellent. 



Section VIII. Diurnal Tide at Cushendall. 



The solar and lunar diurnal tides at Cushendall were deduced 

 from the calculated tides, and found to be as follows : — 



