The Rev. Dr. Robinson ow the Longitude of the Armagh Observatory. 1 19 



If each of these be subtracted from the corresponding longitude of Armagh, 

 we obtain that of Dublin, such as would be given on the system of computation 

 employed. But I have found by a direct comparison the longitude of Dublin : 



It is, I think, evident, that the original longitude of the Bishop of Cloyne, 

 25.21.00 is the true one. That illustrious astronomer had latterly increased this 

 a second, probably induced by the result of lunar transits ; but though I am sure 

 he would not have done this without weighty reasons, yet I think the evidence 

 of these chronometers would have been considered by him irresistible. 



