in the relative Situation of double Stars. 369 
degrees disengaged, as related in my second Catalogue, the 
separation between them kept on increasing, and, on the 21st 
of April, 1795, they were \ diameter of the small star asunder. 
Feb. 5, 1804, with a power of 527, the vacancy between them 
was nearly 1 diameter of the small one. The position has 
likewise undergone a sensible alteration. Nov. 13, 1782, it was 
20 0 54' south-following. Feb. 4, 1802, 41 0 28'. Feb. 5, 1804, 
40° 17'. A mean of the two last measures, is 40° 53' The 
change, therefore, amounts to 19 0 59', in 21 years and 84 days, 
and is probably owing to a real motion of u Leonis ; for the 
effect of a parallactic motion would have shown itself in a con- 
trary alteration of the angle of position. 
•jr Arietis. I, 64. 
This star is marked as being treble ; and the third star, as it 
happens, is now of use, in verifying the measures which have 
ascertained the relative change in the situation of the other two. 
The position of and its adjacent star, Oct. 29, 1782, was 19 0 9' 
south-following ; and the third star was in the same line of that 
angle continued. Oct. 17, 1802, the position was 34 0 1 1' ; and, 
Feb. 6, 1804, by a mean of two measures, 31 0 15'; which gives 
a change of 12 0 6', in 21 years and 100 days. 
That this change has taken place gradually, is confirmed by 
two observations of the third star. Jan. 15, 1795, the distant 
star was observed to have remained a little behind, while the near 
one had advanced ; and, Oct. 17, 1802, it was again remarked, 
that the three stars were no longer in a line, and that the nearest 
small star had advanced according to the order of the signs, 
which had increased its angle of position. 
The multitude of small stars in this neighbourhood, and the 
3 B 2 
