214 Dr. Herschel on the Quantity 
we must fix upon the probable relative distance of the rest of 
the stars, in the same manner as we have done with the first 
six. In this I have thought it advisable to distinguish the stars 
that, from their lustre, may be called principal, and have 
limited their extent to the brightest of the second magnitude, 
on account of the uncertainty which still remains about their 
progressive distances. For though it appears reasonable to 
allow that the bright stars of the second magnitude may be 
twice as far from us as those of the first, it will admit of 
some doubt whether this rule ought to be strictly followed 
up to the 3d, 4th, 5th, and 6th magnitude ; especially when 
it is not easy to ascertain the boundaries which should limit 
the magnitudes of very small stars. 
The number of these principal stars is 24. The remaining 
12 are also arranged by admitting that their magnitudes ex- 
press their relative distances ; and notwithstanding the doubt- 
fulness we have noticed, their testimony with respect to the 
proper quantity of a solar motion, though it should be received 
with some diffidence, must not be neglected ; some consi- 
derable alteration in their supposed distances, however, would 
have but little effect upon the conclusions intended to be 
drawn from their velocities. 
The following Table contains the result of the calculations 
that relate to the permanent quantities. In the first and 
second columns, we have the names of the stars, and their 
assigned relative distances. The third gives the apparent 
angular motions, and the fourth their direction. The fifth 
contains the direction of the same motions, with respect to 
the parallactic motions arising from the given solar direction ; 
and the sixth gives the velocity of the stars which produce 
the quantity of the apparent motions. 
