Part 8

That their Diſtance is ſo immenſe, that the Space between the Earth and Sun (which is no leſs than Twelve thouſand of the Earth’s Diameters) is almoſt nothing when compar’d to it, has more Proofs than one to confirm it. And this among the reſt. If you obſerve two Stars near one another, as for example thoſe in the middle of the Great Bears Tail, differing very much from one another in Clearneſs, notwithſtanding our changing our Poſition in our Annual Orbit round the Sun, and that there would be a Parallax were the Star which is brighter nearer to us than the other, as is very probable it is, yet whatever Part of the Year you look upon them, they will not in the leaſt have altered their diſtance. Thoſe that have hitherto undertook to calculate their Diſtance, have not been able perfectly to compaſs their Deſign, by reaſon of the extreme Niceneſs and almoſt Impoſſibility of the Obſervations requiſite for their Purpoſe. The only Method that I ſee remaining, to come at any tolerable Probability in ſo difficult a Caſe, I ſhall here make uſe of. Seeing then that the Stars, as I ſaid before, are ſo many Suns, if we do but ſuppoſe one of them equal to ours, it will follow that its diſtance from us is as much greater than that of the Sun, as its apparent Diameter is leſs than the Diameter of the Sun. But the Stars, even thoſe of the firſt Magnitude, though view’d through a Teleſcope, are ſo very ſmall, that they ſeem only like ſo many ſhining Points, without any perceivable Breadth. So that ſuch Obſervations can here do us no good. When [A way of making a probable gueſs at the diſtance of the Stars.] I ſaw this would not ſucceed, I ſtudied by what way I could ſo leſſen the Diameter of the Sun, as to make it not appear larger than the Dog, or any other of the chief Stars. To this purpoſe I clos’d one End of my twelve-foot Tube with a very thin Plate, in the Middle of which I made a Hole not exceeding the twelfth Part of a Line, that is the hundred and forty fourth Part of an Inch. That End I turn’d to the Sun, placing my Eye at the other, and I could ſee ſo much of the Sun as was in Diameter about the 182d part of the Whole. But ſtill that little piece of him was brighter much than the Dog-ſtar is in the cleareſt Night. I ſaw that this would not do, but that muſt leſſen the Diameter of the Sun a great deal more. I made then ſuch another Hole in a Plate, and againſt it I plac’d a little round Glaſs that I had made uſe of in my Microſcopes, of much about the ſame Diameter with the former Hole. Then looking again towards the Sun (taking care that no Light might come near my Eye to hinder my Obſervation) I found it appeared of much the ſame Clearneſs with Sirius. But caſting up my account, according to the Rules of Dioptricks, I found his Diameter now was but 1⁄152 part of that hundred and eighty ſecond part of his whole Diameter that I ſaw through the former Hole. Multiplying 1⁄152 and 1⁄182 into one another, the Product I found to be 1⁄27664​. The Sun therefore being contracted into ſuch a Compaſs, or being removed ſo far from us (for it’s the ſame thing) as to make his Diameter but the 27664 part of that we every Day ſee, will ſend us juſt the ſame Light as the Dog-ſtar now doth. And his diſtance then from us will be to his preſent diſtance undoubtedly as 27664 is to 1; and his Diameter little above four Thirds, 4‴. Seeing then Sirius is ſuppoſed equal to the Sun, it follows that his Diameter is likewiſe 4‴, and that his Diſtance to the Diſtance of the Sun from us is as 27664 to 1. And what an incredible Diſtance that is, will appear by the ſame way of reaſoning that we uſed in meaſuring that of the Sun. For if 25 Years are required for a Bullet out of a Cannon, with its utmoſt Swiftneſs, to travel from the Sun to us; then by multiplying the Number 27664 into 25, we ſhall find that ſuch a Bullet would ſpend almoſt ſeven hundred thouſand Years in its Journey between us and the neareſt of the fix’d Stars. And yet when in a clear Night we look upon them, we cannot think them above ſome few Miles over our Heads. What I have here enquir’d into, is concerning the neareſt of them. And what a prodigious Number muſt there be beſides of thoſe which are placed in the vaſt Spaces of Heaven, as to be as remote from theſe as theſe are from the Sun! For if with our bare Eyes we can obſerve above a Thouſand, and with a Teleſcope can diſcover ten or twenty times as many; what bounds of Number can we ſet to thoſe which are out of the Reach even of theſe Aſſiſtances! eſpecially if we conſider the infinite Power of God. Really, when I have been reflecting thus with my ſelf, me-thoughts all our Arithmetick was nothing, and we are vers’d but in the very Rudiments of Numbers, in compariſon of this great Sum. For this requires an immenſe Treaſury, not of twenty or thirty Figures only, in our decuple Progreſſion, but of as many as there are Grains of Sand upon the Shore. And yet who can ſay, that even this Number exceeds that of the Fix’d Stars? Some of the Ancients, and Jordanus Brunus carry’d it further, in declaring the Number infinite: he would perſwade us that he has prov’d it by many Arguments, tho’ in my opinion they are none of them concluſive. Not that I think the contrary can ever be made out. Indeed it ſeems to me certain, that the Univerſe is infinitely extended; but what God has been pleas’d to place beyond the Region of the Stars, is as much above our Knowledge, as it is beyond our Habitation.

Or what if beyond ſuch a determinate Space he has left an infinite Vacuum; to ſhow, how inconſiderable all that he has made is, to what his Power could, had he ſo pleas’d, have produced? But I am falling, before I am aware, into that intricate Diſpute of Infinity: Therefore I ſhall wave this, and not, as ſoon as I am free of one, take upon me another difficult Task. All that I ſhall do more is to add ſomewhat of my Opinion concerning the whole World, as it is a Place for the Reception of the Suns or fix’d Stars, every one of which, I have ſhowed, may have their Planetary Syſtems about them.

[Every Sun has a Vortex round it, very different from thoſe of Cartes.]

I am of Opinion then that every Sun is ſurrounded with a Whirl-pool or Vortex of Matter in a very ſwift Motion; tho’ not in the leaſt like Cartes’s either in their Bulk, or manner of Motion. For Cartes makes his ſo large, as every one of them to touch all the others round them, in a flat Surface, juſt as you have ſeen the Bladders that Boys blow up in Soap-ſuds do; and would have the whole Vortex to move round the ſame way. But the Angles of every Vortex will be no ſmall hindrance to ſuch a Motion. Then the whole Matter moving round at once, upon the Axis as it were of a Cylinder, did not a little puzzle him in giving Reaſons for the Roundneſs of the Sun: which however they may ſatisfy ſome People that do not conſider them, really prove nothing of the Matter. In this æthereal Matter the Planets float, and are carried round by its Motion: and the thing that keeps them in their own Orbs is, that they themſelves, and the Matter in which they ſwim, equally ſtrive to fly off from the Center of this Motion. Againſt all which there are many Aſtronomical Objections, ſome of which I touch’d upon in my Eſſay of the Cauſes of Gravity. Where I gave another Account of the Planets not deſerting their own Orbs; which is their Gravitation towards the Sun. I ſhow’d there the Cauſes of that Gravitation, and cannot but wonder that Cartes, the firſt Man that ever began to talk reaſonably of that Matter, ſhould never meddle with, or light on it. Plutarch in his Book of the Moon above-mentioned ſays, that ſome of the Ancients were of Opinion, that the Reaſon of the Moon’s keeping her Orbit was, that the Force of her Circular Motion was exactly equal to her Gravity, the one of which pull’d her to, as much as the other forc’d off from the Centre. And in our Age Alphonſus Borellus, who was of this ſame Opinion in the other Planets as well as the Moon, makes the Gravitation of the primary Planets to be towards the Sun, as that of the Secondary is towards the Planets round which they move: Which Sir Iſaac Newton has more fully explain’d, with a great deal of Pains and Subtilty; and how from that Cauſe proceeds the Ellipticity of the Orbs of the Planets, found out by Kepler. According to my Notion of the Gravitation of the Planets to the Sun, the Matter of his Vortex muſt not at all move the 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.