71 



I find by above 500 observations of circumpolar stars the 

 latitude of the observatory of Trinity College, Dublin, 

 53" 23' 13",5 using the French tables of refractions published 

 in 1806. Or 5.T 5J3' 14",2 using Bradley's refractions. 



In the preceding catalogue the third column shews the 

 mean north polar distance, Jan. 1, 1813, the refractions ha- 

 ving been computed by the French tables, to which tables 

 I give the preference for reasons assigned in the paper which 

 follows this. 



The fourth column shews the seconds of the north polar 

 distances, as computed by Bradley's tables. 



It appeared to rae on several accounts of much impor- 

 tance, to compare observations made nearly at the same time 

 by different instrun^ents. The mural circle at the royal 

 observatory, Greenwich, and the circle at the observatory of 

 Trinity College, Dublin, may be ranked amongst the best 

 instruments that have been constructed. As soon therefore 

 as I was informed that the Greenwich circle was in use, I 

 determined to repeat my observations of the principal fixed 

 stars, and the present catalogue is the result of observations 

 in the latter part of the year 1812 and in the year 1813. 



To institute a comparison between the north polar dis- 

 tances deduced by Mr. Pond and myself, it is necessary 

 that the same tables of refraction should be used by each. 

 Therefore as Mr. Pond has used the tables of Bradley, I 

 also computed my observations by the tables of Bradley, 

 and the result of the comparison of the observations is found 



