distances and -positions of 3 80 double and triple stars , &c. 229 
(sf Eootis) continued. 
place, the distance remaining nearly the same. A more exact 
coincidence could hardly have happened. If this double star 
be a binary system, of which there can be little doubt, its 
period is about 6 22 years, and the most probable mean annual 
motion is o°.e;j82, in the direction npsf , or retrograde. 
Whether this combined system have a motion in space, or 
not, may be perhaps best ascertained by comparing its place 
now, and hereafter, with (x, and the data for this comparison 
will be found under the head of that star, as follows. 
No. CCIV. R. A. 15 11 i8 m ; Decl. 38° 1' N. 
lu, Bootis ; Struve, 486 ; VI. 17 ; 
Double ; pretty unequal ; both white. 
Parts. 
90—8. 33 
7- 39 
8. 50 
8.41) 
7-30 > S 
7-4°) 
Mean — 8. 9 
May 9, 1821. 
Five-feet Equatorial. 
sf 
Position = 8i° 51' sf 
Distance == 1' 48 /, .978 
Distance. 
Parts. 
344- 2 
346. o 
344- 5 
345 
345 
345 
H 
0 I 
6 IS 
A 
Mean = 345.17 
Z — — 0.11 
Mean 
Z = 
Position. 
137*7" 
39-3 
4 a 3 
39- 8 
4 2 -3 
42.5 
40.2 
41.2 
.0.0 
>S 
340.08 
1.40 
345.06 
Difference of Declination of the two stars. 
July 9, 1823. 
Five-feet Equatorial. 
Difference of Declination = 1' /$" .q6<2.. 
Whence, with the foregoing angle of posi- 
tion, we find. 
Distance = i' 48". 050. 
338.68 
