440 Introduction to tin- Sixth Section 



a. Urste Minor is. 



8 Ursa: Minoris. 



By these tables n + kc = p was calculated from each obser- 

 vation, and the mean of all values obtained during a certain 

 Eeriod was considered as the value of p for that period. I 

 ave endeavoured to determine the change of p by the obser- 

 vations ; but it has always been so small and irregular that I 

 have been obliged to give up the attempt, from which, how- 

 ever, no considerable error can arise, almost the same stars 

 having constantly been observed during the whole period. 

 Thus, for the whole period from the 12th to the 27th of June 

 1820, the following values obtained by the mean of 14 ob- 

 servations were adopted, p = — 0".2451, kss — 0.996. 



In order to find n from p = n + k c, c must be determined 

 by reversing the instrument, and either by the meridian mark 

 or observations of the two pole stars. In order to apply the 

 first method with success, I have given the meridian mark 



on 



