332 Dr. Brinkley’s observations for investigating 
might it not have been expected that stars, in which the effect 
of parallax in declination is only a small part of the whole, 
would have shown a great parallax of declination as well as 
others, if the appearance of parallax is to be attributed to 
some other cause ? Aldebaran, [3 Tauri, a Orionis, Castor, 
Procyon, Pollux, &c. are so situate, that only a small part 
of the whole parallax could affect the declination, and there- 
fore if these stars had exhibited a change of place of a second 
or two, it could not arise from parallax. The results of 
observations made with reference to this are given in Table 2. 
by which it will be seen that no sensible change of zenith 
distance takes place in these stars. This appears a very 
important circumstance. Also, these stars in summer passing 
the meridian in the day time, and in winter in the night, the 
absolute temperatures of the air differ much more than in 
the summer and winter passages of a Lyras and of « Aquilas ; 
therefore naturally greater irregularities might be expected 
as to the former stars, than as to the latter. This also ap- 
pears deserving of notice. 
To examine this question in another way, I instituted a set 
of observations on stars in the same part of the heavens as 
those in which I had found the discordances that appeared 
to arise from parallax. <y Draconis I had already observed ; 
and the circumstance of its not exhibiting the same changes 
of place, as I had found in 2 Lyras, appeared to afford a con- 
firmation of my explanation. But this and a. Aquarii are the 
only stars out of seventeen that appear not to be affected by 
similar changes. Hence a new difficulty. It certainly is 
not likely that those stars, some of them only of the fourth 
magnitude, should be nearer to us than some of the stars of 
