Dr. Brinkley on the 
276 
I there detailed my reasons for supposing that I could not 
have been misled by any source of error in the instrument, or 
in the mode of observing ; and I trust, whatever may be the 
final result as to this subject, that I shall not be considered 
as having too hastily adopted the explanation by parallax. 
I remarked, in the essay to which I have referred, my 
reasons for not being surprised that the Greenwich circle did 
not immediately confirm my results. However, after several 
years observations, Mr. Pond was led, although he had 
found discordances of a similar kind, but much less than 
mine, to doubt the explanation by parallax, and certainly 
with good reason, as two instruments that might be supposed 
equally adapted for the examination, seemed to give different 
results ; in consequence of which he took measures for sub- 
mitting the matter to another kind of trial. He most laudably 
applied to the Royal Society, as visitors of the Royal Observa- 
tory ; and by their assistance, and by the advantage of 
vicinity to the first artists, he has been enabled to put up his 
fixed telescopes. 
Thus, unless unforeseen difficulties shall be found to exist, 
this question is likely to be soon decided ; and certainly on 
many accounts, it is a most interesting question. 
It is now about sixteen months since Mr. Pond informed 
me of his doubts respecting the conclusion I had drawn from 
my results, and from that time I have anxiously looked to 
every observation that tended to confirm my conclusion, if 
just, or invalidate it, if wrong. 
The last two years have been very unfavourable for astro- 
nomical observations ; so that my opportunities always, in 
consequence of the cloudy atmosphere, very few, have been 
