north polar distances of the principal fixed stars . 65 
It will be remarked in the Catalogue, Table III., that the 
Pole star, as determined with the Dublin instrument at the 
two epochs, agrees exactly. 
Predicted, 1823, i° 38' 7", 3 
Observed, 1 38 7 ,3 
This is a mean between Mr. Pond's observed and pre- 
dicted places. 
A circumstance above alluded to is of some importance. 
In Table IV. will be found the annual variations as found by 
Mr. Pond, by myself, and by Mr. Bessel. Mine are be- 
tween those of the other two, but nearer to Mr. Pond’s than 
to Mr. Bessel’s. The effect of this would be, as to mine, to 
reduce the mean southern motion of Mr. Pond, about a 
quarter of a second ; but if Mr. Bessel’s annual variations be 
adopted, they would, in conjunction with the above suppo- 
sition relative to the Pole star, intirely take away the mean 
southern motion of Mr. Pond’s Catalogue. 
It will be found, I conceive, difficult, in forming a Cata- 
logue of stars by a mural circle, to avoid a small constant 
error, and if the Greenwich observations of the Pole star be 
consulted from the beginning, we shall find enough to in- 
duce us to suppose, that such errors may exist in one or both 
of the Greenwich Catalogues of 1813 and 1823. 
In respect to the annual variations, I shall not venture to 
give an opinion whether Mr. Pond’s or Mr. Bessel’s be 
more exact. I shall only state that mine, which are generally 
between the two, were formed, as will easily be seen on 
examination, by a careful comparison of my Catalogue of 
1823, with the Catalogue* deduced by Mr. Bessel from Dr. 
Bradley’s observations. 
MDCCCXXIV. 
* Astron. Fundament, p. 138, &c. 
K 
