82 The Rev. Samuel Haughton on the Solar and Lunar 



Adding the first two of each of the preceding, we obtain 



Range of Lunar Tide at High Water = 0-59 ft. 

 Range of Lunar Tide at Low Water = 0-34 ft. 



Hence, by equation (3), 



cot(m-L)=J:|^=cot(29'57'), 



or, converting the arc into time, 



m-i,„ = 2M"'; 



but since ni is the Moon's Hoiu:-angle, in Portrusli time, at High Water, and 

 is equal to 5'' 47"", we have, finally 



/„. = 3'^ 43'". 



By equation (4), we have 



Max. value of 21/ sin 2ju = a/(0-59)= + (0-34y = 0-681 ft. 



From which we obtain 



ilf= 0-519 ft. 



Also, since the maximum value of the Solar Tide is 0-25 ft., we have 



Mas. value of 25' sin 2(t = 0-500 ft, 

 and, 



5=0-342 ft. 



Combining these results, we have for Tide Constants at Portrush: — 



1. Lunitidal Interval = 3" 43"'. 



2. Solitidal Interval = 11'^ SO"". 



3. Age of Lunar Tide at High W^ater = 5" 9*. 

 Age of Lunar Tide at Low Water = 4'' 19*. 



4. Lunar Coefiicient = 0-519 ft. 



5. Solar Coefiicient = 0-342 ft. 



6. Ratio of Solar to Lunar Coefiicient, — 



4 = 0659. 

 M 



