The Rev. Dr. Robinson bw the Longitude of the Armagh Observatory, 117 



The consistency of these results is very remarkable, the probable error of 

 their mean being less than OM, but its agreement with the longitude given by 

 other means is not less striking. 



From solar eclipses* of 1826 and 1836, and 19 occultations, 24 in all, I 



found 



+ 26.35.58. 



Three others were doubtful, as the star-paths were nearly tangents to the moon ; 

 but as the sum of the coefficients produced by the uncertainties of parallax and 

 declination is nearly = 0, I add their mean with the weight of two = 34M5, 

 and the occupation longitude is 



4- 26"°. 35'. 47. 



The longitudes deduced from lunar transits give 



Greenwich, 7 of first L. . . 26 36.26 

 3 of second L. . . 32.04 



Dublin, 30 of first L. 

 „ 9 of second L. 



Cambridge, 1 1 of first L. 

 „ 3 of second L. 



26.34.15 



35.16 

 42.49 



26.38.82 



38.79 



28.38 



26.33.58 



* The beginning in 1826 ; the beginning and end in 1836 ; and the beginning and end of the 

 Annulus. 



