234 Dr. Herschel on the Direction of the 
above mentioned Table of well ascertained proper motions will 
also enable us to enter rigorously into the necessary calcula- 
tions for ascertaining its direction, and discovering its velocity. 
When these points are established, we shall be prepared to 
draw some consequences from them that will account for many 
phenomena which otherwise cannot be explained. 
The scope of this Paper, wherein it is intended to assign 
not only the direction, but also the velocity of the solar motion, 
embraces an extensive field of observation and calculation ; 
but as to give the whole of it would exceed the compass of the 
present sheets, I shall reserve the velocity of the solar motion 
for an early future opportunity, and proceed now to a disqui- 
sition of the first part of my subject, which' is the direction of 
the motion of the sun and solar system. 
Reasons for admitting a solar Motion. 
It may appear singular that, after having already long ago 
pointed out a solar motion, and even fixed upon a star towards 
which I supposed it to be directed, I should again think it ne- 
cessary to show that we have many substantial reasons for 
admitting such a motion at all. What has induced me to enter 
into this inquiry is, that some of the consequences hereafter to 
be drawn from a solar motion when established, seem to con- 
dradict the very intention for which it is to be introduced. The 
chief object in view, when a solar motion was proposed to be 
deduced from observations of the proper motions of stars, was 
to take away many of these motions by investing the sun with 
a contrary one. But the solar motion, when its existence has 
been proved, will reveal so many concealed real motions, that 
we shall have a greater sum of them than it would be necessary 
