2i8 Dr. Herschel on the Quantity 
which the stars are moving ; if so, it would not be impro- 
bable that the sun, being situated among this group of stars, 
should partake of a motion towards the same part of the 
heavens. 
Our next remark concerns the velocity of the sidereal 
motions; and therefore we must have recourse to Fig. 2, 
where we perceive that the greatest motions are not confined 
to the brightest stars. For instance, the velocity of /3 Virginis 
is but little inferior to that of Arcturus, and exceeds the velo- 
city of Procyon. Likewise the velocities of @ Aquilse, Librae, 
and od Capricorni, surpass that of Sirius ; and an inspection of 
the rest of the figure will be sufficient to show how very far 
the velocities of Capella, Lyra, Rigel, a Orionis, Aldebaran, 
and Spica, are exceeded by those of many other stars. 
If we look at the arrangement of the stars with respect to 
the direction of the solar motion, we find in Fig. 3, that a 
somewhat different scattering of them has taken place ; but 
still most of the stars appear to be affected by some cause 
which tends to lead them to the same part of the heavens, 
towards which the sun is moving ; and the directions of the 
greatest number of them are not very distant from the line 
of the solar motion. 
The whole appearance of this figure presents us with the 
idea of a great compression above the centre, arising from 
some general cause, and a still greater expansion in the 
lower part of it. The considerable projection of a few stars 
on both sides, is however a plain indication that the com- 
pressing or dilating cause does not act in their directions. 
When the velocity of the stars, represented in the same 
point of view in Fig. 4, is examined, we find a particularity 
