in the relative Situation of double Stars, &c. 365 
Times of the observations. 
Observed 
angles. 
Calculated 
angles. 
Differences. 
Nov. 5, 1759 - 
56° 
3 2 ' 
56° 
3 2> 
o° o' 
Nov. 5, 1779 - - 
32 
47 
35 
2 9 
1 
*0 
to 
Feb. 23, 1791 - - - 
22 
57 
23 
36“ 
- O 39 
Feb. 2 6, 1792 
27 
16 
22 
32 
-f- 4 44 
Dec. 15, 1795 - 
13 
5 2 
18 
32 
— 4 4° 
March 26', 1800 
18 
8 
H 
3 
+ 4 5 
April 23, 1800 - - - 
IO 
30 
1 3 
58 
— 3 28 
Dec. 31, 1801 
7 
58 
12 
12 
— 4 14 
Jan. 10, 1802 - 
10 
33 
12 
10 
- 1 17 
Jan. 23, 1802 
10 
28 
12 
7 
— 1 39 
Feb. 28, 1802 - 
13 
0 
12 
1 
1 + 0 59 
Feb. 11, 1803 
7 
33 
11 
1 
00 
GO 
1 
March 23, 1803 - - - 
13 
23 
10 
54 
| +2 29 
March 27, 1803 
10 
33 
10 
53 
O O 
When the result of this Table is compared with that of the 
former, it will be seen that my observations agree not only very 
well with Dr. Bradley’s position, but even give more equally 
divided differences than before, so that the excess and differences 
counteract each other better than in the first Table. 
The time of a periodical revolution may now be calculated 
from the arch of 45 0 39', which has been described in 43 years 
and 142 days. The regularity of the motion gives us great 
reason to conclude, that the orbit in which the small star moves 
about Castor, or rather, the orbits in which they both move 
round their common centre of gravity, are nearly circular, and 
at right angles to the line in which we see them. If this should 
be nearly true, it follows, that the time of a whole apparent 
MDCCCIII. 3 B 
