Diurnal Tides of the Coasts of Ireland. 



123 



2. 

 3. 



4. 

 5. 



Combiniug these results, we have for the tide constants at 

 Donaghadee, — 



1 . Lunitidal interval = 7^ SS"". 

 Solitidal interval =11^ 12"!. 

 Age of lunar tide 



at high water =6'! 5^. 



at low water =5'i 2^ 



Lunar coefficient =0"868 ft. 



Solar coefficient =0-383 ft. 



6. Ratio of solar to lunar coefficient, 



or If =0-441. 

 M 



The theoretical tides at Donaghadee were constructed with 



the foregoing tide constants, and compared with the observed 



tides, with the following results. 



Donaghadee Tide, Table A. 

 Positive heights at high water for sixteen and a half lunations, 

 commencing 1850, September 29'^ 5^ 51°*, and ending 1851, 

 December 22<i 221' 24m. 



Donaghadee Tide, Table B. 



Negative heights at high water for sixteen lunations, commencing 



1850,September29d5i»51'^,andendingl852,January5<i21i»12°i. 



K2 



