34 M. Bessel 07i the DecUnation of the principal 



exact comparison of those results with my own so interesting, 

 that I have long formed the desire of applying to Mr. Pond's 

 original observations the same method of calculation which I 

 applied to my own. Taking therefore advantage of the nu- 

 merous observations (direct as well as reflected) contained in 

 the volume of 1822, obligingly sent to me by Mr. Pond through 

 the kind intervention of Dr. Tiarks, I requested M. Olufsen, 

 who is now here, to assist me in their reduction. I now com- 

 municate the results of these labours to the lovers of astro- 

 nomy, since the explanation which they give, respecting the 

 difference between Mr. Pond's standard catalogue and mine, 

 is calculated to establish the true state of the case. 



M. Olufsen has reduced all the observations of the pole- 

 star and fundamental stars made with the six mici'oscopes, to 

 the beginning of 1822, by means of the Kiinigsberg table of 

 refraction, and Professor Schumacher's Ephemerides. 



The pole-star has been observed by direct vision, at 123 

 upper and 144 lower culminations; and by reflection, with 27 

 upper and 45 lower ones. Those direct observations, at both 

 culminations, which could be advantageously combined for 

 finding the declination of the pole-star, have given the cor- 

 rection of my tables, deduced from Mr. Pond's determinations 

 in 1813, with the weight of 192 observations, = — 0",35; 

 agreeing to within one hundredth of a second with my deter- 

 mination, in part vii. of my Observations, page xxiv. After 

 having corrected the declinations contained in Schumacher's 

 tables, by — 0",35, we calculated, from the direct observations 

 of this star, the places of the pole upon the instrument ; and 

 then the mean, taken out of every ten successive observations, 

 contained in the following table, with the corresponding days : 



The 



