Diurnal Tides on the Coasts of Ireland. 117 



Adding together the first two of each of the preceding results, we find 



Range of Lunar Tide at High "Water = 0-80 ft. 

 Range of Lunar Tide at Low Water = 0-50 ft. 



Hence, by equation (3), 



cot(m-2„.)=QT5Q = cot(32^), 



or, converting the arc into time, 



m-i^ = 2'' 12°'; 



but since m, the Moon's Hour-angle at High Water, expressed in Courtown 



time, is 7'' 40"", we obtain 



?„ = 5'' 28". 

 By equation (4), we have 



Max. value of 231 sin 2;" = \/(0-80)' + (0-50)' = 0-943ft. 



From which we find 



ilf=0-719ft. 



Also, since the mean value of the Solar Tide is 0'30 ft., we have 



Max. value of 2S sin 2(t = 0-600 ft., 

 and, therefore, 



;?= 0-410 ft. 



Combining the foregoing results, we obtain for the Tide Constants at Cour- 

 town: — 



1. Lunitidal Interval = 5* 28". 



2. Solitidal Interval = 5'' 1". 



3. Age of Lunar Tide at High Water = 6" 22\ 

 Age of Lunar Tide at Low Water = 3" 12*? 



4. Lunar Coefficient =0-719 ft. 



5. Solar Coefficient = 0-410 ft. 



6. Ratio of Solar to Lunar Coefficient, — 



or 4 = 0-570. 



The Theoretical Tides at High AVater were constructed with the forego- 

 ing Constants, and compared with the Observed Tides. The results of this 

 comparison are contained in the following Tables: 



