58 On the ElemeTits Jor reducing Polar Distances. 

 For which time the sun's' 



longitude is 



Number for aberration 



17° 40' 

 23 3 



I 5 23 COS 9'9n32 

 Log. maximum r2S739 



Abenation = 15",80 1M987T 

 Hence the aberration of jS Draconis on August 10, 1809, 

 was Is'^jSO, which is additive to the mean place to get the 

 apparent, as the cos 1° 5' 23" and M are both negative. 



The effect of deviation may be computed from the ge- 

 neral Tables of Deviation I gave in the Philosophical 

 Magazine of last month, which, together vvith the Annual 

 Precession, will give the whole reduction, except a small 

 quantity arising from the semi-annual solar nutation, which 

 is too small, except in very nice observatio»s, to be con- 

 sidered. 



