276 SOLAR MOTION, 



Investigation By the contents of this Table, Fig 5 is drawn with the 

 motioa of^the ^^^^^ contained in the third column and the angles of the 

 sun. fourth ; the scale of it is that of the 5th and 3d figures; 



and it represents the directions and angular quantities of 

 the real motions that are required to compound with the 

 parallactic effects of the second column, so as to produce 

 those annual proper motions which are established by 

 observation. 



Fig. 6 is drawn on the reduced scale of the 2d and 4th 

 figures. The lines make the same angles with the direc- 

 tion of the solar motion as before, but their lengths are 

 in the proportion ©f the Telocities contained in the last 

 column. 



Remarks that lead to a necessary Examination of the 

 Cause of the sidereal Motions, 



The first particular that will strike us when we cast 

 our eye on Fig. 5, is the uncommon arrangement of the 

 stars. It seems to be a most unaccountable circumstance 

 that their real motions should be as represented in that 

 figure; indeed, if we except only ten of the stars, all the 

 rest appear to be actuated by the- same influence, and, 

 like faithful companions of the sun, io join in directing 

 their motions towards a similarly situated part of th« 

 heavens. 



This singularity is too marked not io deserve an exa- 

 mination ; for unless a cause for such peculiar directions 

 can be shown to exist, I do not see how we can reconcile 

 them with a certain equal distribution of situations, 

 quantities, and motions, which our present investigation 

 seems io demand. In order to penetrate as far as we can 

 into this intricate subject, we shall take a general view of 

 the causes of the motions of celestial bodies. 



A motion of the stars may arise either from their mu- 

 tual gravitation toward each other, or from an original 

 projectile force impressed upon them. These two causes 

 are known to act on all the bodies belonging to the solar 

 system, and we may therefore reasonably admit them to 

 p.xert their influence likewise on the stars. But it will 

 aoi be^ sufficient to know a general cause for their mo- 

 tions, 



