of Bessel's Astronomical Observations. 349 



Both determinations possessing nearly equal accuracy, the 

 mean of both is to be applied, and the difference of this mean 

 from the formula by which the table has been calculated, is to 

 be added ; hence the following correction : 



+ 0"-416 + 0"-120 sin 2z + 0"-050 cos 2z— 0'-215 sin 4c 

 + 0"-365 cos 4z, 

 where the upper signs are to be taken when the lower microscope 

 A gives zenith distances, the lower one when it gives altitudes. 



It is moreover necessary to allow for the correction of re- 

 fraction found in article 7, and lastly to convert the zenith di- 

 stances into declinations, for which purpose I have adopted 

 the latitude 54° 42' 50"*52. In this manner the following re- 

 sults have been obtained: 



I T<> ba continued.! 



