It ſhould have been ſaid, that whenf' S 1 the Moon is in any place of its orbit, ſuppoſe ſomewhere at N, in that half of the orbit which is next the Sun, it then being nearer the Sun than the Earth, has thereby a greater gravity to the Sun, than the Earth: which exceſs of gravity, according to Sir I/bac Nefwton's method, coniifts of two arts; one acting in the line N IC paraiiel to that which joins the Earth and Sun; and the other acting, in the line If B directed to the Earth, and theſe two forces, being compounded into one, make a force directed in the line NB; which is in proportion to the force of gravity, as that line NB is to TB nearly. Wherefore, as there is a force conſtantly impelling the. Moon, ” fpmewhere towards the point B, this force is ſuppoſed to iniiect the motion of the Moon into a curve line about that point; for the ſame reaſon as the gravity of it to the Earth, is ſuppoſed to infiect its motion into a curve line about the Earth: not that the Moon can actually have ſo many diftinct motions, but the one ſimple motion of the Moon round the Sun is fitp ofed to ariſe »frotn a compoſition of theſe ſeveral motions, In
