249 
Motion of the Sun, and solar System . 
quantities. The six principal stars, whose intersecting arches 
have been given, when their proper motions in right ascension 
and polar distance are brought into one direction, will have the 
apparent motions contained in the following Table. 
Table II. 
Names of the 
Stars. 
Direction of the apparent 
Motions. 
Quantities of the apparent 
Motions. 
Sirius 
68° 49' 40", 7 south-preceding 
i",i 1528 per year 
Arcturus - 
55 29 42,0 south-preceding 
2,08718 
Capella - 
71 35 22,4 south-following 

Lyra - - 
56 20 57,3 north-following 
o,3 2 435 
Aldebaran 
7 6 29 37,3 south-following 
0,12341 
Procyon - 
50 2 24,5 south-preceding 
1,23941 
Sum of the apparent motions 
5 ", 35337 
We must now recur to what has been said, when the con- 
struction of the triangle expressing the three motions of a star, 
that is not at rest, was explained ; and, as we are to find out a 
solar motion which will require the least real motion in our 
six stars, an attention to this triangle will be of considerable 
use; for when the line pa. Fig. 1, which represents the real 
motion, is brought into the situation ma, where it is perpendi- 
cular to sp, the real motion which is required will then be a 
minimum. It also follows, from the construction of the same 
triangle, that if by the choice of an apex for the solar motion 
we can lessen the angle made at s by the lines sp and sa, we 
shall lessen the quantity of real motion required to bring the 
star from the parallactic line spin to the observed position a. 
It has already been shown, in the case of Sirius and Arcturus, 
mdcccv. K k 
