lOS 
M. Struve^s Observations on Double Stars. 
m. Pole Star. R. Asc. 01^ 56'. Decl. 88° 21' N. 
2d and 11th Mag. 
M. Struve has found for the effect of parallax — 0".325 but in 
the opposite direction;to which it ought to be. The constant of 
aberration was 20". 11 2, whereas he found it 20".800 by other 
stars. Baron Zach found it, from Bradley’s observations, to be 
20",232 ; Bradley made it 20."25, Delambre 20."255, and later 
astronomers 20".36. The following are M. Struve’s observa^ 
tions : 
DiJflf. of R. Asc. in Time^ 
Angle of Position. 
Distance. 
Diff. of Decl. , 
1815, — 21".04 
60® 16 
18".50 
— 16". 10 
1819, 20 .53 
60 25 
18.05 
— 15 .70 
21. y Aries. R. Asc. 
44'. Deck 18^ 
’ 55' N. 
4th and 4th Mag. 
Angle of Position in 1779,8 was 84° 0' HerscheL 
1780.8, 86 5 Ditto. 
1802.2, 89 10 Ditto. 
1819.8, 84 3 Struve, 
M. Struve considers that the differences are attributable to er- 
rors of observation, and not to any motion in the stars. 
22. « Pisces. R. Asc. 1^ 53'. Decl. 1° 53' N. 
3d-4th and 5th-6th Mag. 
Angle of Position in 1781.8, was 67° 23' Ilerschd. 
1802.1, 63 0 Ditto. 
1819.9, . 70 48 Struve. 
M. Struve thinks that none of the stars move. 
23. y Andromeda. R. Asc. 1^ 53'. Decl. 41° 28' N. 
3d and 5th Mag. 
The largest of these two fine stars is yellow ^ and the smallest 
blue, 
Angle of Position in 1781.8, was 19° Herschel. 
1802.1, 26 U Ditto. 
1803.1, 26 5 Ditto. 
1804.1, 27 Ditto. 
1819.9, 25 ^6 Struve. 
Diff. of R. Asc. in 1819.9, + 0".837 Ditto. 
Distance calculated, . 10 .48 Ditto. 
DifF. of Declin. ditto, - + 4 .52 Ditto, 
