5& 



absolute quantity of the right ascensions at the two periods, cannot 

 be so much depended on as the iuni-solar precession determined as 

 above, and on this account the quantity of direct motion of the 

 echptic on the equator will not appear entitled to equal confidence. 

 This quantity is 18'',68 in 66 years, and must be left for future in- 

 quiry. 



It will not, I conceive, be considered that the former conclusion 

 respecting the Pole Star was founded on slight circumstances.-^ 

 The relative permanency of the position of it and the small Star, 

 and the constant interval between the Pole Star and ^ Ursae Majoris 

 appeared to fully justify the deduction that was made, especially 

 when it is considered that the relative position of ^ Ursae Maj. and 

 its Comes has ren>ained the same. It required therefore very strong 

 evidence to shew the contrary. This evidence has been, I think it 

 will be allowed, obtained in deducing from the several Stars near 

 the equinoctial colure, nearly the same quantity of proper motion in 

 declination for the Pole Star, and the same as that deduced by the 

 Pole Star itself by help of a Cygni, Rigel and a Orionis. It may 

 indeed be objected, that the three Stars a Cygni, Rigel and a Orionis 

 are not fixed, but have all the same quantity of proper motion in 

 parallel directions. However, if all the circumstances connected 

 with the fixedness of these Stars be considered, such a supposition is 

 in itself highly improbable, and the contrary appears to be put be- 

 yond all doubt by the comparison of « Cygni with the small Stars 

 near it. 



Since the former paper was read, *'a Catalogue of right ascensions 

 of the principal Stars has been completed from observations made at 



• This catalogue in R. Ascension, and that in N. P. D. determined by the circle both reduced 

 to 1825 are hereafter given, as they have been used in all the computations. 



