356 LORD WROTTESLEY ON THE PERIODICAL OBSERVATION OF STARS. 
believe, that a single individual measure, either in position or distance, however 
discordant, has been ever rejected on that or any other ground; but all sets contain- 
ing less than four measures have been invariably rejected. 
It would seem, then, that though, in one point of view, comparisons at opposite 
seasons must be treated as possessing value, yet we are after all driven to rely in a 
great measure on the final means ; for notwithstanding the well-founded objections 
that may be urged to combining observations made in different years, the discord- 
ances above alluded to show, that a greater number of measures are required to 
eliminate error, than can possibly be obtained in any one, or even two years. 
Now if we examine the final means of the two periods in Table IV., we shall find 
five stars only, viz. 32 Eridani, 41 Aurigee, I Gerninorum, Anon. Cancri, and I of H 95, 
of which we can affirm that they have any pretensions whatever to be considered as 
fulfilling the condition above stated ; — with respect to ^ Gerninorum and Anon. 
Cancri, the small weights of the results of the late period render any conclusions 
drawn from them extremely liable to doubt ; this is the more to be regretted, in the 
case of the last-mentioned star, inasmuch as the smallness of the distance of its com- 
ponents renders it a very eligible object for observation. 
When however we examine the results obtained with reference to the direction of 
the changes observed, they seem to be entitled to rather more consideration. 
In the w/and nip quadrants an apparent motion to the westward of the larger star, 
assumed to be the nearest to the earth, must increase the angle of position, and in 
the ^and sp quadrants the contrary effect must take place: — therefore at that epoch 
of observation when the sun is to the west, and therefore the earth to the east, of the 
star observed, the maximum angle may be expected to occur in the two first named 
quadrants, and the minimum in the others ; in the case of double stars, whose com- 
ponents are equal, it is plain that two different conclusions may be drawn from the 
periods at which the maxima occur, according as the one or the other be taken as 
the nearest star. 
Omitting therefore the five stars, whose components are of equal magnitude, 
omitting also the four binary stars, and 2 Comae Berenices and s Draconis (which 
exhibit differences less than their probable errors), this interesting result appears, 
that of the eight that remain, there is only one, that is, 41 Aurigae, the changes in 
whose angles, however small and little entitled to confidence they may be, do not 
conform in direction to those, which would take place, were a sensible parallax 
admitted in the brighter of the stars themselves. 
This is most probably only an accidental coincidence, and I am very far from wishing 
to estimate it at more than its real worth ; but in the case of 32 Eridani and I of H 95, 
where large, and to a certain extent trustworthy, differences concur with normal 
directions of motion, it may not perhaps be too much to assert, that this constitutes 
them objects of interest to the astronomer, possessed of adequate means to prosecute 
an inquiry, which, I fear, I must be said rather to have attempted than to have suc- 
ceeded in. 
Wrottesley, October 22, 1850. 
