in the relative Situation of double Stars, &c. 379 
lengthened, or rather wedge-formed star ; after which, I took a 
measure of the position of the wedge. 
Our temperature is seldom uniform enough to permit the use 
of very high powers; however, on the 11th of April, 1803, I 
examined the apparent disk, with a magnifier of 2140, and found 
it, as before, a little distorted ; but there could not be more than 
about -f of the apparent diameter of the small star wanting to a 
complete occultation. Most probably, the path of the motion is 
not quite central ; if so, the disk will remain a little distorted, 
during the whole time of the conjunction. Our present observa- 
tions cannot determine which of the stars is at the greatest 
distance ; but this will occasion no difference in the appearance ; 
for, if the small star should be the nearest, its light will be 
equally lost in the brightness of the large one. 
The observations I have made on this star, are not sufficient 
to direct us in the investigation of the nature of the motion by 
which this change is occasioned. 
We may however be certain, that with regard to 
Single Motions , 
( a , b ) Neither x nor f can be supposed to be the only 
moving bodies, without contradicting the highly probable argu- 
ments for the sun’s motion. 
(c, d ) If we admit the sun to be the moving body, the stars 
f and x being at rest, we may calculate the effect of the solar 
parallax upon them, as follows. Let O move towards x Herculis, 
with the annual velocity 1, as in the case of a, Geminorum ; then, 
from the situation and magnitude of the large star of f Herculis, 
which we will suppose 4m, the effect of the solar motion at f 
will be only ,0522 ; and, at x, supposed to be at the distance 5m, 
