302 M\Herschel’s and Mr. South’s observations of the apparent 
59 a Serpentis continued. 
Position. 
° o . 
90—41.22") 
4.3-5° 
40.40 
41.30 { 
44-3° 
42.55 
44. o 
41. oj 
S 
June 12, 1823. 
Five-feet Equatorial. 
7th and 9th magnitndes. 
Small blue. S. 
Position = 47 0 32' 
Distance = 3".534. 
Mean — 42.28 
Mean result. 
Position 48 0 5' np ; Distance 4". 151 
Distance 
Parts. 
10. o" 
13. o 
11. o 
11. 5 
II. o 
IO. 2 
IO. O 
Mean = 10.96 
Z — + 0.23 
1 1. 19 
1822.95. 
1781.79 Position 44 0 33' np ; Interval 1 D, or i-f- D ; H. Cat. of 1782 (with 227), 
z\ D, with 460. 
1802.34 4 2 2 5 n P’ I nterva ^ 4 or 5 D ; H. Account, &c. 
1819.61 40 3 np; Distance 3".76 ; Struve, Additamenta, 193. 
There is a great disagreement between our angle and 
M. Struve’s, but the latter is only the result of a single 
measure ; and in the case of very close stars of very unequal 
magnitudes, and of opposite colours, a single measure can 
never have any dependance placed on it. We have in- 
stances of this kind in e Bootis, Rigel, Struve’s N° 430, &c. 
The distance however has undoubtedly undergone a re- 
markable change ; in 1781 the interval with 460 was 2^ D, 
corresponding to about 4" of distance between the centres. 
In 1802 it was four or five diameters, which could hardly 
represent less than 7" central distance, while it now seems 
again on the decrease. This agrees with the idea of a rapid 
rotation of one star about the other in a plane nearly passing 
through the eye, the small star being at its greatest elon- 
