32

b

Appendix.

Y Which it is attracted towards the Sun S.N take S L : S K : : S K* : S P 1 , and S / :

:: S* k : S^ 1 ; then shall S L, or S /, ex-v, n d the accelerative Attraction in any.^stance of the Satellite SP or S p. Thats the Force at P is to the Force at p as

I H

:

is to S /; for S K = S and S K 3

0 >< S P 1 = S / x S f ; therefore S L : S /::V : S P-.

lei

*2. Join PT and p T, and draw paral-

8 / :

thereto the Lines L M and /w, meeting

in M and m. And the Attraction S L,> ' ! s resolvable into two others SM and^ and S m and / m. Hence the Bodyf / S urged with a Threefold Force; viz.j. That by which it is attracted or tends^ards T, arising from the mutual At-^ion of the Bodies T and P. (a.) The° rc e L M, or Im, by which it is likewise^Ted towards T. (3.) The Force S M,^ by which it is urged towards S, or^ a( Ted in Directions always parallel to

t * 3 * By the first of these Forces the Sa-I *te ought to describe an Ellipsis about T°ne of its Foci, and therefore Areas pro-‘ tlQ nal to the Time, as is evident fromwas demonstrated in An not at. CXI..lls is upon Supposition tjhe Body T wasY 1 fixed :

PlateLXVIIIFig. 8,