of the Sun and Solar Syjletn . 261 
Suppofe it now arrived at C. Here, by a mere mfpe&ion of 
the figure, it will be evident, that the ftars j, j, j, which were 
before feen at a, a, a, will now, by the motion of the fun from 
S to C, appear to have gone in a contrary direction, and be 
feen at b, b, b\ that is to fay, every {far will appear more or 
lefs to have receded from the point B, in the order of the let- 
ters ab , ab , ab . The converfe of this proportion is equally 
true ; for if the ftars fhould all appear to have had a retrograde 
motion, with refpeCt to the point B, it is plain, on a fuppofi- 
tion of their being at reft, the fun muft have a direct motion 
towards the point B, to occalion all thefe appearances. From a 
due conftderation of what has been laid, we may draw the 
following inferences. 
1. The greateft or total fyftematical parallax of the fixed 
ftars, fig. 2. will fill upon thofe that are in the line DE, at 
rectangles to the direction AB of the fun’s motion. 
2. The partial fyftematical parallax of every other ftar, 
5, s , s, not in the line DE, will be to the total parallax as the 
fine of the angle BSrf, being the ftars diftance from that point 
towards which the fun moves, to radius. 
3. The parallax of ftars at different diftances will be in- 
verfely as thofe diftances ; that is, one half at double the dif- 
tance, one third at three times, and fo on ; for the fnbtenfe SC 
remaining the fame, and the parallaClic angle being very 
fmall, we may admit the angle SjC, to be inverfely as the fide 
S s, which is the ftars diftante. 
4. Every ftar at reft, to a fyftem in motion, will appear to 
move in a direction contrary to that in which the fyftem is 
moving. 
Corollary. Hence it follows, that if the folar fyftem be car- 
ried towards any ftar fituated in the ecliptic : every ftar, whole 
angular- 
