1 825.)! Astronomkal Sockty, "Jft 



sion of the distinct topics of aberration, annual precession, and 

 nutation; exhibiting the analytical formulae which have beea 

 proposed for the computation of their respective values at any 

 time, past, present, or future; assigning the reasons for the 

 adoption of those values of the constants which he has preferred ; 

 and so transforming the several formulae, as to facilitate and 

 effect their reduction into one class of comparative simplicity, 

 which forms the basis of the tables themselves. Thus the total 

 corrections for right ascension and declination respectively, 

 assume the forms 



AS = Aa'+ B6^+ Cc'+ B d' 



where the quantities denoted by a, b, c, d, and the accentuated 

 fl', b% c', d'y are constant for each star, while the quantities A, 

 B, C, D, are common to every star. The quantities A, B, are 

 rendered equally constant for all the stars by the assumption of 

 a fictitious year, commencing at that moment when the Sun's 

 mean longitude at Greenwich at mean noon on Jan. 1, is 281° ; 

 which is, therefore, assumed as the tabular date, and the mode 

 of adopting it to the current date is explained. 



The author then explains the arrangement and use of the 

 tables. The general catalogue of the stars is arranged in the 

 order of the right ascensions, and reduced to Jan. 1, 1830. The 

 left hand page is confined to the right ascensions, the right hand 

 page to the declinations. Col. 1, on the left hand, exhibits the 

 numbers of the stars. Col. 2, the names; to which are prefixed 

 Flamstead's numbers, and the letters of the alphabet, by which 

 they are usually distinguished. Col. 3, denotes the magnitudes 

 of the stars. Col. 4, AR in time, for Jan. 1, 1830. Col. 5, the 

 annual precession in time. The remaining columns contain the 

 logs, of «, b, c,d, each previously divided by 15 to reduce them 

 to time. 



On the right hand page. Col. 1 is the same as Col. 1 on the 

 left-hand. Col. 2, exhibits the declinations of the stars, Jan. 1, 

 1830. Col. 3, annual precession. Cols. 4, 5, 6, 7, the values of 

 a'y b\ c\ d'. Then there are two columns headed B and P, de- 

 noting the corresponding numbers in the catalogues of Bessel 

 and Piazzi respectively; while the last column is reserved for 

 those which are to be found in Hevelius, Lacaille, Mayer, 

 Zach, &c. 



There are several subsidiary tables which Mr. Baity also 

 succinctly explains ; and he further developes the pnnciple^^f 

 correction iox proper motion, &c. when necessary. ^ ,,. j,- 



The general rule for the use of the tables is thi^v^^^^yi^. ^^e 

 out from the general catalogue, and opposite the given :Star, th^ 

 logarithms of a, b, c, d, and a\ b% c% a, with their proper signs j 



