368 Dr. Herschei/s Account of the Changes 
appears to be inconsistent, it ought to be recollected, that the 
cause of this apparent motion remains to be investigated. If the 
largest of the two stars should pass closely by the smallest, 
which, on account of its supposed great distance from us, may 
appear fixed, a very great and quick alteration in the angle of 
position will take place;* but, in a short time the change will 
become very moderate, and not long after insensible. The same 
appearances may also happen, although the small star should 
not be fixed, but revolve about the large one; for, if its orbit 
were in a plane with the line of sight, it would be seen to move 
with great velocity, about the opposition, and soon after appear 
to be almost stationary. That either one or the other of the 
stars has really had a motion approaching to a straight line, is 
ascertained from an alteration of the distance ; for, in the year 
1781, the vacancy between the two stars, witn 460, was 3 dia- 
meters of the large one. But, April 2, 1804, with 527, their 
distance was greater than estimations by diameters can deter- 
mine ; and, comparing g with tt Bootis, I found that the stars of 
g were farther asunder than those of 7r ; notwithstanding, in the 
year 1782, the former was placed in the 2d class, and the latter 
in the 3d. The change of the angle of position, if it were 
owing to a parallactic motion, would have been direct, instead of 
retrograde. 
u Leonis. I, 2 6. 
In a note added to this star, which is the 26th in my second 
Catalogue, a suspicion is expressed, that the two stars which 
compose this very minute double star, were receding from each 
other * This has since been completely verified ; for, having 
seen the two stars close upon one another, and afterwards by 
• See Phil. Trans. Vol. LXXV. Part I. page 48. 
