y€ Mr. Herschel's and Mr. South's observations of Lhe apparent 
(3 Orionis, Rigel ; continued. 
Distance. 
1781.81 Mean of 6 measures taken in 18 months. 
“ Account of Changes, &c.” - 9". 53 
1821.30; Struve, Dorpat Obs. iii. ut supra - 9 .250 
This series of measures affords a striking example of the 
difficulty of estimating exactly the position of the line joining 
the centres of two close and very unequal stars, and placing 
the moveable wire of the micrometer parallel to this imagi- 
nary line. The wa}' in which the same mean results from 
series of observations so discordant, is an instance no less 
remarkable of the efficacy of multiplying even inaccurate 
observations, when made under such variety of time and cir- 
cumstance as to avoid any possible bias. 
The slight diminution (• — d'.G^) in the distance may very 
possibly be owing to a real change. 
No. LIV. R. A. £ h 1 3 m ; Deck 3 0 21' N. 
23 Orionis ; Struve 172 ; IV. 84 ; 
Double ; considerably unequal ; large white ; small blue. 
Position. 
/> 
60.57 
62.55 
6 1. 9 
62.50 
63. sJ 
64. o 
63.10 
62.30 VS 
63. o f 
63- 5 J 
Jan. 17, 1822. 
Five-feet Equatorial. 
nj 
Position = 62° 40* nf 
Distance = 33".c>43. 
Distance. 
Parts. 
105. 1} 
106. 6 ( 
106. 7 r 
104. 8J 
H 
10 S • 5 ) 
io 3 . o r s 
i° 3 . 9 1 
104. 2 ) 
Mean =: 1 04.97 
z ~ — 0.34 
Mean = 62.40 
104.63 
