116 Catalogue of zodiacal Stars. 
known to have been very negligently drawn up in this respect 3 
yet the numbers have acquired by long usage such a degree of 
authority, as to render any alteration of boundary an invidious 
task. It has been, however, attempted by Bode, with consider- 
able success. In the present compilation, where a star has been 
placed by Bode in a constellation different from that assigned by 
Flamsteed, both constellations are put down, and the number of 
each catalogue placed in a line with its proper constellation, as 
may be seen in the instances of 54 Ceti, 16 Trianguli, and others. 
As to the numerous disagreements between Bode and Piazzi, the 
same minuteness has not been thought necessary, and in these 
cases the authority of the former is implicitly adopted. An ole- 
lisk inserted in this column, indicates that a note is attached to 
the star. 
6. The magnilude of each star is given almost invariably from 
the same authority as its mean position. 
7. The approximate Right Ascension in Time. Here the m- 
nutes only of right ascension are inserted in the column, and the 
‘hours stand at the head of it. If greater accuracy be wished for, 
it may be derived from the quantity in the next following column, 
by the well known rule for converting space into time. 
‘§. The mean Right Ascension in degrees, minutes, seconds, 
and tenths, is in general taken from the accurate catalogue of 
Piazzi. A few stars are inserted, which do not occur in that 
work, and with regard to these, the authorities for position will 
be found in the notes, 
9. The Annual Variation in right ascension, comprises the 
joint effect of precession and proper motion, which the limits of 
the page would not permit to be given separately. Should the 
precession alone be wished for, it may be readily had from the 
formule : 
An. Pro. in R.A.. = 46”:0i1 + 20.046 sin R.A. tan Decl. 
Decl. = 20”:046 cos R.A. 
The above coefficients are Bessel’s, those used by Piazzi are 
46-0395 and 20”-064. In every case where the star is found in 
Bessel’s Catalogue, the precession as well as proper motion is 
taken from it; in other cases Piazzi’s numbers for the right 
ascension are diminished by 0"-04 between 64°16 and 5840; 
by 0-03 thence to 42-65, and by 0"-02 thence to 31”"90. The 
error occasioned by this approximate method cannot in any in- 
stance amount to 0”-01, and that only with regard to the smaller 
stars, whose proper motions have not hitherto been ascertained. 
The numbers in this column marked with an asterisk, are those 
which exhibit the effect of precession only. 
10, De- 
a 
