354 LORD WROTTESLEY ON THE PERIODICAL OBSERVATION OF STARS 
Results of the observations. 
Distanees. — In discussing the results of the observations, little need be said of the 
measures of distance : it was impracticable, consistently with the due prosecution of 
the more important task of measuring the angles, to take these measures of distance 
at shorter intervals, and at the epochs proper for eliminating the changes, if any, 
due to parallax: the small differences between the measures taken at opposite sea- 
sons must be ascribed to errors of observation. 
The following Table exhibits these differences ; it contains the means of the mea- 
sures of distance obtained at the early and late periods, with the sums of the assigned 
weights used in the reduction, and which means correspond, in respect to epoch, with 
the final means of the angles contained in the fourth Table ; the mean epochs them- 
selves therefore have been already given in that Table. 
The four binary stars are excluded from the following Table. 
Table V. 
Name. 
Mean 
Assigned 
A. 
Name. 
Mean 
Assigned 
A. 
distance. 
weight. 
distance. 
weight. 
y Arietis 
8-943 
8-838 
32 
-105 
2 Comae Berenices ... 
3-917 
3-914 
69-7 
8-4 
•003 
36 
32 Eridani 
6-881 
21 
•136 
178 (Bode) Librae ... 
12-016 
26-6 
•216 
6-745 
27-9 
12-232 
3-0 
w Aurigffi 
6-474 
6-309 
49-2 
39-1 
•165 
100 Herculis 
14-064 
42-1 
•081 
13-983 
115-5 
118 Tauri 
4-915 
34-7 
42-9 
•072 
579 2 
5-126 
63-8 
•062 
4-987 
5-188 
6-0 
41 Aurigse 
7-967 
7-873 
74-5 
20-5 
•094 
287 b and s 
8-148 
22-6 
•338 
8-486 
3-4 
5 Geminorum 
7-461 
7-309 
32-7 
11-4 
•152 
e Draconis 
3-101 
12-4 
•150 
2-951 
19-3 
Anon. Cancri 
3-669 
53-1 
•078 
I of H 95 :.... 
3-145 
49-7 
53-3 
•023 
3-591 
11-8 
3-168 
Cancri 
4-851 
59-6 
11-3 
•177 
4-674 
Angles of 'position. — In the discussion of the measures of position, it must be re- 
membered that four of the stars observed, viz. 39 Bootis, § Serpentis, g Draconis, 
and P XXII 306, exhibit differences in their mean positions, as compared with those 
given by other observers, of an amount sufficient to induce the belief that they are 
binary systems : the observations of these stars may therefore be at once dismissed 
with the remark, that they are useless for the purposes of this inquiry. Again, in the 
case of five other stars, viz. y Arietis, (p‘^ Cancri, 178 (Bode) Librse, 100 Herculis and 
579 Struve, the components are of equal magnitude, and parallax is in this case not 
only a priori highly improbable, but there is nothing in the actual observations them- 
selves of these stars, which can lead us to any definite conclusion as to its existence 
in fact. It is proper, however, to direct attention to the large differences in the case 
of ^2 Cancri, accordant in respect of sign. 
In order to arrive at any decision on the question, whether the changes in the 
angles of position of the remaining stars, exhibited in the sixth column of the fourth 
