31 



Nos. 1 and 2 were exposed to the sun, the bulb of No. 2 be- 

 ing coated in the manner before stated. Nos. 3 and 4 were plac- 

 ed in the shade — No. 4 having its bulb coated. 



The sky was cloudless. The indentation produced by the moon 

 appeared perfectly free from prominences of any kind, although 

 their occurrence in the case of a solar eclipse is by no means un- 



In computing the longitude three seconds were subtracted from 

 the observed time of the beginning, the sum of the sun and moon's 

 semi-diameters was diminished 5" for irradiation and inflection, 

 and the error of the lunar tables, in latitude, deduced and applied. 

 The following were the results : 



Longitude W. of Greenwich in Time. 



From the beginning, 4h. 45m. 288.587 

 From the end, 4h. 54m. 36s.525 



Correction of the moon's latitude (the solar tables being sup- 

 posed correct) 4-2"6. 



Ihe individual results of the occultation, before referred to, 

 were as follows : 



Immersion of 1 y n^j 1831, June 17th, 4h. 54m. 468. 



Immersion of y « ' *' Aug. 29th, 4h. 55m. 78. 



Emersion of ditto, " Aug. 30th, 4h. 55m. Ss. 



Immersion of 1 fx, Ceti, " Oct. 21st, 4h. 54m. 50s. 



Immersion of Aldebaran, Dec. I7th, 4h. 54m. 36s. 



Emersion of do. " do. 4h. 54m. 12s. 



The moon's semi-diameter was in each case diminished 2" for 

 inflection, and in computing the results of the eclipse, as well as 

 those of the occultations, the ellipticity of the earth was assumed 

 to be 1-309. 



The mean of all the observations places the Academy in longi- 

 tude 4h. 54m. 43s.03 W. of Greenwich. The observation of the 

 emersion of Aldebaran was, however, considered at the time to 

 be of somewhat doubtful accuracy. Its result, it will be obscrv- 



