On the Motion uftke Sun and Solat' Sijstem. 243 



be made to coincide with the lines s a, of both the stars, 

 whereby their real motions will be reduced to nothino". It 

 has also been proved, by adding Capella to the fbrme°two, 

 that when three stars are concerned, some real motion must 

 be admitted in one of them. Now, suicc all parallactic 

 motions are directed to the same centre, a single line may 

 represent the direction of the effect of the parallax, not 

 only of these three stars bat of every star in the heavens. 

 According to this theory, let the line 5 P or 5 S, in Fig, 2, 

 stand for the direction of the parallactic motion of the stars; 

 and as in the foregoing Table we have the angles of the ap- 

 parent motion of six stars with the parallel of each star, we 

 must now also compute the direction of the line i^ P or ^ S 

 with the parallels- of the same stars. This may be done as 

 soon as an apex for the solar motion is fixed upon. The 

 difference-between these angles and the former will give the 

 several parallactic angles P s a or S s a, required" for an 

 investigation of the least quantity 7n a, belono;incr to every 

 star. ' too/ 



For instance, let the point towards which we may sup- 

 pose the sun to move, be A Ilerculis ; and calculating the 

 required angles of the direction in which the effect of paral- 

 lax will be exerted, with the six stars we have selected for 

 the purpose of our investigation, we find them as in the 

 following Table. 



Table III. 



Jngles of the parallactic Motion n'ltk the Parallel. 



Sirius - - - 32° 54' 8,5" south-preceding. 



Arcturus - 17 2.3 45,7 south-precedinU 



Capella - 85 10 3^9 soutli-followinff. 



Lyra - - 35 59 49,5 north.-foHowing. 



Aldebaran - 71 21 35,4 south-following. 



Procyon - 47 43 44,6 south preceding. 



The difference between these parallactic and the former 

 apparent angles, with the parallel of each star, will iiive 

 the required angles for our second figure. They will be as 

 follows : 



Table IV. 

 Mgles oft/ie apparent with the parallactic Motion. 



Sirius - - 35° 55' 32,2'' south-following. 



Arcturus - 38 5 56,3 south -following. 



Capella - 13 3.4 41,5 south-following. 



Lyra - - 20 21 7,8 north-preccdinti. 



Aidcbaran - 5 8 J, 9 south-preceding. 



Procyon - 2 18 39,9 suuth-follouini:. 



Q2 " By 



