327

Appendix.

( as we have shewn). It will also augment|| le Aberration of the Orbit from an El-lj ptic Form, on a double Account, viz. bothbecause it is not directed from P to T, anda lso because it is not inversely as the Squarethe Distance P T. For the Forces SM

'8n:: --L::S^ :S P*. These

jj SP J Sf

Errors therefore are least of all when the^ c ond and third Forces (especially the^ird) are so, the first Force remaining the

W.

*6. Let S N expound the Force by^fich the Body T is accelerated towards> then if the Forces S M and S N are5 )l u al, they, by attracting the Bodies T and^ Equally, and in parallel Lines, will cause110 Alteration in their Site or Positions inAspect of each other. But when the ForceM is greater, or S m lesser than the Force® the Difference N M, or N M, will bealone by which the Proportionality ofTimes and Areas, and also the Elliptic*°rm of the Orbit, will be disturbed. ElenceNM or N« is nothing, or least ofthe aforesaid Perturbations will vanish;is, when the Body P is nearly in theP °ints G and D of its Orbit.

. 17. We have hitherto supposed the Body pj ate* revolving about T in the fame Plane Otvni,Y 4 With 1£ ‘ 9 '