The Motions of the ſix Primary Planets round the Sun is So adjuſted, that the Square of the Times of their peroidical [sic] Revolutions are as the Cubes of their Diſtances from the Sun : And the ſame thing is found by all Aſtronomers to be true, with Regard to the Motions of the Secondary Planets or Satellites round their primary ones. … But if the Orbit of the Satellite Planet, inſtead of being a Circle be an Ellipſis, in whoſe Focus the Primary Planet is ſuppoſed to be placed, then will the greater Axis of this Elliptical Orbit, twice advance forward, viz. in the 2 Quadratures, and twice recede backward, viz. in the 2 Syzygies, of every Revolution of the Satellite round the Planet.