Dr . Herschel on the Direction of the 
252 
Table V. 
Quantities and Sum of the least real Motions . 
it 
Sirius - 
°,S 5437 
Arcturus - 
1,28784, 
Capclla - 
0,10887 
Lyra - 
o,i 1281 
Aldebaran - 
0,01104 
Procyon - 
0,04998 
Sum 
2", 22491. 
The result of this investigation is, that by admitting a motion 
of the sun towards A Herculis, the annual proper motions of 
our six stars, of which the sum is 5^,3537, may be reduced ta 
real motions of no more than 2", 2 249. 
When first I proposed A Herculis as an apex for the solar 
motion, it may be remembered that a reference to future ob- 
servations was made for obtaining greater accuracy.* Such 
observations we have now before us, in the valuable Tables 
from which I have taken the proper motions of the six stars ; 
and I shall prove that, with their assistance, we may fix on a 
solar motion that will be considerably more favourable. 
We have already shown, that to ascertain the precise place 
of the best apex is attended with some difficulty; but from 
the inspection of the figure which represents the quantities of 
real motion required when A Herculis is fixed upon, it will be 
seen that, by a regular method of approximation, we may 
turn the line SP into a situation where all the angles of the 
* See Phil. Trans, for 1783, p. 373, line 8 ; and page 274, line 4. 
