35 2 Dr. Hersohel’s Account of the Changes that have happened 
time I have taken notice of the angle of position and distance 
of the small star, will amount to a change of nearly 2", 47. 
Then, if we enter the short Table I have given in No. 2, with 
the motion « P, we find, that in the first quadrant, where the 
small star is placed, the distance between the two stars will be 
diminished, and the angle of position increased. But since it ap- 
pears, by my observations, that the distance of the stars is not 
less now than it was in 1780 ; and that, instead of an increase in 
the angle of position, it has actually undergone a diminution of 
nearly 22 degrees ; it follows, that the motion of a. Geminorum 
in right ascension, will not explain the observed alterations in 
the situation of this double star. If, according to Mr. De la 
Lande’s account,* we should also consider the annual proper 
motion of a in declination, which is given o",i2 towards the 
north, we shall find, by entering our Table with the motion «N, 
amounting to 2"82, that the distance of the two stars will be 
still more diminished ; but that, on the contrary, the angle of 
position will be much lessened; and, by combining the two 
motions together, the apparent disks of the two stars should 
now be a little more than one-tenth of a second from each other, 
and the angle of position 35 degrees south preceding. But, since 
neither of these effects have taken place, the hypothesis cannot 
be admitted. 
( c) That the sun has a proper motion in space, I have shown 
with a very high degree of evidence, in a paper which was read 
at the Royal Society about twenty years ago/f The same 
opinion was before, but only from theoretical principles, hinted 
at by Mr. De la Lande, and also by the late Dr. Wilson, of 
# See page 2 1 1 of the treatise before referred to. 
-{- See Phil. Trans. Vol. LXXIII. page 247. 
