M, Struve and Prof. Arnicas Observations m DmbU Stars, 335 
1. ^ Cassiopeia. R. Asc. 0 h 38'. Decl. 56° 51' N. 
Greatest star, 4th Mag. Least , 8. 9th Mag. 
In 1814, M. Struve found the difference of Right Ascension 
of the two stars to be 1".14, the Angle of Position 16°. 7, and 
consequently the Distance 9". 7. Sir W. Herschel had found their 
distance in 1779 to be 11 ".275, and the angle of position 28° in, 
that year, but only 19°.3 in 1803. In 1818 and 1819 M. 
Struve found the difference of right ascension to be 1".3, and 
the angle of position 9°. 8 N. following. Hence their distance in 
1819 is 10".82, and the difference of declination 1".84. The 
diminution of the angle of position is therefore positively ascer- 
tained, having varied as follows : 
In 1782.5 
1803.1 
1814. 
1819 
= 27° 66' Sir W. Herschel. 
= 19° 14 Ditto . 
= 16 7 Struve. 
= 9° 48 Ditto. 
2. 66. Whale. R. Asc. 2h 3'. Bed. 3° 17 S. 
6th and 9th Magnitudes. 
In 1819 DifF. of R. Ascension, 
Diff. of Declination, 
Distance, 
Angle of Position, 
Struve; 
0".842 1781 
0.8 
16.15 
38°.40 
Herschel, 
16 // 875 
3. a Auriga. R. Asc. 5 h 6'. Decl. 39° 58' N., 
6th and 10th Magnitudes. 
1819 Diff. of R„ Ascension, 
Diff. of Declination, 
5".105 
1.55 
4. Castor. R. Asc. 7 h 23'. Decl. 32° 17' N. 
3d and 4th Magnitudes. 
The large star is yellowish-white, and the small star bluish- 
white. 
1813, Angle of Position, - - gf° 52 
Difference of Declination, . 0."21 
Distance, - - - 5°. 6 
3819, Difference of R. Ascen., - 0."424 
Angle of Position, - - 0° 4' 
Distance, - - 6".i 8 
