Dr. Brinkley on the 
296 
I have thus stated the results of my observations, and the 
conclusions that seem to follow as to the parallax of the 
respective stars. The many causes that may lead, if not to 
actual error, at least to a high degree of uncertainty, induced 
me in the paper alluded to, to speak with hesitation as to my 
explanation. The observations of Mr. Pond, as far as they 
go, seem to invalidate that explanation, particularly as to 
a. Cygni and a Lyras. 
It is by observation alone that the decision can be made. 
No conjecture as to the relative distances of the stars can be 
of any material weight. The conjecture, in itself probable, 
that the brightest stars are nearest to us, seems opposed by 
another conjecture, also by itself probable, that those stars 
are nearest which have the greatest proper motion. 
Some of the brightest fixed stars have scarcely any sensi- 
ble proper motions, while those of some much smaller are 
very perceptible. The two stars, 61 Cygni, have each an 
annual proper motion of about 5", 3 in right ascension, and of 
3'' in declination. These stars are of about the 6th magni- 
tude, and one a little brighter than the other. 
This great proper motion seemed to render it probable, 
that these stars are sufficiently near to us, to have a visible 
parallax. I accordingly made observations on one of them, 
but found nothing satisfactory. 
Also 40 Eridani, which is of the 5th magnitude, has so 
great a proper motion, that we might conjecture it to be 
nearer to us than many of the brighter stars. 
The uncertainty, therefore, respecting the relative dis- 
tances, as deduced from their degrees of brightness, weakens 
conclusions against parallax drawn from differences of north 
