Mr. Pond on the parallax of the fixed stars. 159 
year 1812, was supposed to be well adapted to this species of 
investigation, and, I confess, I expected to find the effects of 
parallax in Dr. Brinkley's stars, and perhaps in some 
others, almost as decidedly as the effects of aberration and 
nutation. I soon however found ( what indeed if I had suf- 
ficiently reflected on the subject, I ought to have foreseen )» 
that this instrument (at least in the manner in which I em- 
ploy it) is not so exactly adapted to the purpose as might at 
first be supposed. My principal object was to obtain the 
mean places of a certain number of stars, with the greatest 
precision that the nature of the instrument admitted. I there- 
fore availed myself of the principles of its construction, to 
give every possible variety to my observations, by bringing 
a new system of divisions to bear upon those stars. The 
effect of parallax was necessarily involved in these changes ; 
and, though I certainly did expect that under all these disad- 
vantages a parallax so considerable as that assumed by Dr. 
Brinkley, would have become very apparent, yet, upon not 
finding it, I did not think it by any means fair to infer its 
non-existence, more particularly as the discordances I really 
did meet with, were very universally in favour of parallax. 
Finding, therefore, that I could not elucidate this question 
in a perfectly satisfactory manner without dedicating the cir- 
cle entirely to this investigation, I rather directed my atten- 
tion to contrive some other instruments which might be 
employed exclusively to this object. 
At the last visitation, I proposed that two or more tele- 
scopes should be fixed to stone piers, and directed to the par- 
ticular stars whose parallax was suspected ; that each telescope 
should be furnished with a micrometer, by which the star 
