ſame way, but after ſuch a manner as to have its Parts carry’d different ways on all Sides. And yet there is no fear of its being deſtroyed by ſuch an irregular Motion, becauſe the Æther round it, which is at reſt, keeps the Parts of it from flying out. With the Help of ſuch a Vortex as this I have undertook in that Eſſay to explain the Gravity of Bodies on this Earth, and all the Effects of it. And I ſuppoſe there may be the ſame Cauſe as well of the Gravitation of the Planets, and of our Earth among the reſt, towards the Sun, as of their Roundneſs: A Thing ſo very hard to give an Account of in Cartes’s Syſtem. I muſt differ from him too in the Bigneſs of the Vortices, for I cannot allow them to be ſo large as he would make them. I would have them diſperſed all about the immenſe Space, like ſo many little Whirl-pools of Water, that one makes by the ſtirring of a Stick in any large Pond or River, a great way diſtant from one another. And as their Motions do not all intermix or communicate with one another, ſo in my Opinion muſt the Vortices of Stars be placed as not to hinder one anothers free Circumrotations. So that we may be ſecure, and never fear that they will ſwallow up or deſtroy one another; for that was a mere Fancy of Cartes’s, when he was a ſhowing how a fix’d Star or Sun might be turn’d into a Planet. And ’tis plain that when he writ it, he had no Thoughts of the immenſe Diſtance of the Stars from one another; particularly, by this one Thing, that he would have a Comet as ſoon as ever it comes into our Vortex, to be ſeen by us. Which is as abſurd as can be. For how could a Star, which gives us ſuch a vaſt Light only from the Reflection of the Beams of the Sun, as he himſelf owns they do; how I ſay could that be ſo plainly ſeen at a diſtance Ten thouſand times larger than the Diameter of the Earth’s Orbit? He could not but know that all round the Sun there is a vaſt Extenſum; ſo vaſt, that in Copernicus’s Syſtem the magnus Orbis is counted but a Point in compariſon with it. But indeed all the whole Story of Comets and Planets, and the Production of the World, is founded upon ſuch poor and trifling Grounds, that I have often wonder’d how an ingenious Man could ſpend all that pains in making ſuch Fancies hang together. For my part, I ſhall be very well contented, and ſhall count I have done a great Matter, if I can but come to any Knowledge of the Nature of Things, as they now are, never troubling my ſelf about their Beginning, or how they were made, knowing that to be out of the reach of human Knowledge, or even Conjecture. FINIS. NOTE [1] The Author invented the Pendulum for Clocks.