A voyage to the world of Cartesius written originally in French, translated into English by T. Taylor, of Magdalen Colledge in Oxford.

The third Argument.

This third Difficulty is well grounded on M. Descartes's Principles, and brings such weighty Consequences against the System of his World, as though all the rest were insignifi∣cant, would alone unravel the finest Contexture in it. He supposes the Earth to have a Vortex particular to it self in the great Vortex of the Sun. A Priviledge also he confers on Jupiter, but denies the Moon. He explains this Suppo∣sition in a plain and very familiar way, exem∣plifying it by those great Whirl-pools we some∣times see in Rivers. In the midst of these great Whirl-pools there are several little ones, that at∣tend the Motion of the bigger, and are carryed round their Centre, and at once whirl Chips and Straws about their own. Nothing could be bet∣ter thought on for the making us understand how the Earth and Jupiter, when carried about the Sun by the Matter of the Grand Solary Vor∣tex, at the same time cause the other Planets to circuit about themselves; how the Moon is forc'd about the Earth, and four little Planets a∣bout Jupiter. But as Ill-luck would have it, ex∣amining that Hypothesis by the Principles of our Philosopher, we found it absolutely impossible.

[illustration]

The Demonstration.

Either the particular Vortex attributed to the Earth is the same with what it had, whilst yet it was a Star; or else it is a new one, made since the Destruction of the other. We maintain that neither the one nor the other can be said. Therefore it can have none at all.

It cannot be that it formerly had. For 'tis M. Descartes's Position that a Star degenerates into a Planet or a Comet, by the loss only of its Vortex. According to him, a Vortex is pre∣serv'd meerly by its Matter, having as much Motion and Resistance as the Matter of those a∣bout it; and its Matter loses that equality of Motion and Resistance, when the Star at the Centre can no longer communicate so much by

reason of the Scum that covers it. Now the Earth is a Star not only covered with a Scum or Dross, but with several thick Crusts of an un∣accountable Depth. So that it was incapable of preserving its Vortex, which must have been quite and clean destroy'd, and swallow'd up (as M. Descartes's Latin Word expresses it) by that of the Sun. Let us see then if the Earth was able to procure a new one since its removal near the Sun.

[illustration]

S the Sun. T the Earth. A B C D the little Vortex of the Earth. N A C Z the great Orb wherein the Earth is carried round the Sun.

M. Descartes takes this same course to com∣municate his Thoughts: He makes this Figure which represents the Vortex of the Sun, in which the Centre S is the Sun it self. The little Circle or Ellipsis design'd with C. D. B. A. represents the

little oval Vortex of the Earth which carries the Moon about the Earth T. The Circle N. A. C. Z. is that which the Earth describes in a twelve Months time about the Sun. The Circle B. and the Circle D. bound and terminate the least Dia∣meter of the oval Circle of the Earth. Moreover he supposes that though the Planets and Earth are carried about the Sun by the Celestial Matter, yet that Matter moves swifter than the Planets, as the Water of a River runs swifter than the Boats that glide along its Current.

From this Supposition he concludes, That the Celestial Matter ought not only to give the Pla∣nets a turn about the Sun, but also about their se∣veral Centres, and ought to form it self into little Heavens round about them, that shall exactly mimick the motions of the greater.

He makes this second Conclusion, That if two Planets chance to meet in the same Circle, one of which is little and consequently fleeter than the other, the least upon its Approach ought to fall in with the petty Heaven of the bigger and dance along with it an eternal round. And this (says he) is the fortune of the Moon in reference to the Earth.

Whereas now almost all the Physicks of M. Des∣cartes rowl upon this particular Vortex of the Earth, and since this is, as a Man may say, the prin∣cipal Wheel in his whole Machine, he had need so to strengthen and establish it, as to render it uncon∣troverted, and to suppose not the least thing there in danger to be call'd in Question, and that cannot be made good by most solid Reason and Argument: Let us see then how it answers expectation.

He explains his first Supposition, which is the main Support of all the rest, viz. That the Cele∣stial

Matter which carries the Planet round the Sun moves far swifter than the Planet. He ex∣plains, I say, this Supposition by the Simily of a Boat falling down a River, which goes on much slower than the Water that flows under it: A plausible comparison at first sight, but that has nothing solid in it: Since the reason of the Boats tardy Motion in respect of the Water that for∣ces it along, is wanting in the Planet, steer'd in the midst of the Celestial Matter. The reason is this, that part of the Boat, which stands a∣bove the Water, meets with the opposition of the Air, which bends its course differently from the Water, and consequently resists the Motion wherewith the Water influences the Boat. And the greater that resistance is, as in a contrary Wind, the slower is the Motion of the Boat, in comparison with that of the Water. And the less the resistance is, as when the Wind stands fair, the swifter is the motion of the Boat: But this is not to be found in the Planet, plung'd in the midst of the Celestial Matter: It pre∣serves intirely all that Motion the Celestial Mat∣ter can impress upon it, free from all external Opposition. Besides, being of it self indiffe∣rent to Motion, or to rest, to such or such a de∣gree of Motion, to this or that Determination, it offers no resistance, as M. Descartes himself speaks to the Matter of the Heaven.

He gives next the reason of that inequality of Motion of the Celestial Matter, and of the Planet carried by it; which is (says he) that though such little Bodies, as are the insensible parts of the Celestial Matter, conspiring all together to act confederately against a great one, may be as prevalent as that; notwithstanding they can ne∣ver

move it in all respects so swift, as they are mov'd themselves; 'cause though they are uni∣ted in some of their Motions which they com∣municate unto it, they infallibly disagree in o∣thers which they cannot communicate. Either we are mistaken, or this is a meer Gipsy-talk, at least in relation to the Business we are upon; and one of these Slights of Hand, we have observ'd M. Descartes from time to time to make use of, designedly to blind his Reader, and to conceal from him the Lameness and Imperfection of a Conclusion necessary to his System; which he is well aware of, but is unwilling any one else should see. 'Tis but bringing some pretty sort of Comparison that may prepare the Mind, and sooth and tame (if we may so speak) the Ima∣gination of his Reader, though commonly it never comes up to the stress of the Difficulty; and then clapping on it for a Confirmation some abstracted Reason, that few either can or will take pains to understand, and the Business is done; fore-seeing that being half-gain'd al∣ready by the Comparison, they will easily sur∣render themselves to the least appearance of Truth, which he shall give them a glimpse of in his reason, that often is a meer fallacy at bottom. And as for this before us: What matters it, though the little Bodies, that drive on a great one, should have several Motions? What tho' they do not communicate all these several Moti∣ons, provided they have still Strength enought to force it on, that the Body makes no resistance, that they all combine, as we suppose, with M. Descartes, to communicate the Motion requisite, and that we conceive them all pressing on its Surface, so as to push it towards the place where

they are push'd themselves? For certainly in all these Circumstances, we must conceive it going at as great a rate as they.

And yet from a Principle so weakly establisht as this, he concludes, That the Celestial Matter ought to move the Planet round its own Centre, and constitute a little Heaven about it, to turn at the same time as the great one. But not now to controvert that Supposition, as poorly prov'd as it is, let us persue him in his reasoning; and to see if it be good, let us imagine the Earth T. as it were suspended in a Void, and let us fancy a Circle of Celestial Matter as thick as the Diame∣ter of the Earth, that violently rushing like a Torrent, carries it suddenly away: But as we suppose this Torrent to be swifter than the Earth, methinks without having puzzled our Heads much with the Rules of the Determinations of Motion, we might readily conceive it, upon its violent dashing against the Earth, to be immedi∣ately divided in two Parts or Arms, whereof one should run above, the other below it; and whether we conceive this Stream of an equal, or a greater depth, than the Diameter of the Earth, it would diffuse it self round its Surface, above, below, and on every side. Whence it follows, that it would impress no Motion on it about its own Centre, but would moreover deprive it of that Motion if it had one; all the Lines of the Torrent counterpoizing one another, and resist∣ing the Determinations they should meet with in the Earth contrary to their own.

Here ought to be the foregoing Figure, p. 278.

Now methinks in explaining these things thus, it is not a bare Similitude that we offer, but a

perfect Idea of that which ought to happen in the Motion of the Celestial Matter, wherein the Earth is carried round the Sun,

Wherefore then will Descartes have the Cele∣stial Matter that carries the Earth, and insists a∣gainst its Superficies towards A, making greater haste than the Earth, bend its whole Current from A to B, not suffering half of it to run from A to D? For 'tis impossible for things to be, or to be conceiv'd otherwise. But if it ought to fall out thus, as questionless it ought, the Earth no longer has a Vortex; since the Matter flowing from A to D, prevents that which flows from A to B from returning by C. D. Nothing can be more plain and evident than this Demonstration.

But let us suppose per impossibile, that the Mat∣ter when arriv'd at A, should entirely make a double, to run towards B. Would it make a Vortex? No by no means. For advancing from B. to C. and arriving at C. it ought to deviate from the Centre of its Motion, and continue its Progress towards Z. The Reason given for it in the Principles of Descartes, is, That this is the very place in all the little Circle it had begun to describe, where it finds least resistance. First, because the Matter it meets in that same Point is already on its Motion towards Z. and freely re∣signs its place. Secondly, because that which is below it, that is to say betwixt D. and C. resists it, and hinders its Descent, being more weighty, according to M. Descartes. And thirdly, because the Circle C Z. is its natural place, according to the same Philosopher. It will flow therefore more to∣wards Z. than D. and consequently make no Vortex.

But let us farther suppose a Vortex made, and the Matter continuing its round, from A. to B.

from B. to C. and from C. to A. would this Vor∣tex last? Not at all. For we must suppose one of these three things: Either that it is stronger than the Vortex of the Sun, that is, its Matter has a stronger bent and tendency from its Centre, than the Matter of the Sun's Vortex has from his, or that it is weaker; or that they both are equal. If it is weaker it must be destroy'd by the Vortex of the Sun. If stronger it must ruin his. It re∣mains then that its Strength be equal with the Suns: And M. Descartes must unavoidably sup∣pose it: But how will he prove it to us, I say not by a Demonstration (we will not put him on so hard a Task) but how will he bring the least Conjecture to give this Supposition a pretence to probability? Cannot we on the other side pro∣duce several Reasons to destroy this Supposition? Cannot we shew, in case the Vortex of the Earth was as strong as that of the Sun, and the little Glo∣bules wrested themselves as forcibly from the Cen∣tre of their Vortex, that the Earth it self would appear a Sun, and so would Jupiter to boot? Since that which makes the Centre of a Vortex to us seem luminous, is only the vehement Motion of its Matter? Though Descartes says the Centre would be drain'd of all its Matter, might not we however, imitating the Stile of that Philosopher, compare the Vortex of the Sun quite from S. to D. to a vast Ocean, whose boystrous Tide swel∣ling against the Stream of a little River, by which we illustrate the Vortex of the Earth, obli∣ges it to fall back again, and adds a Determina∣tion to its Waters quite contrary to its former? But with Descartes for a Vortex to be destroy'd, and for the Matter of the Vortex to take the Mo∣tion and Determination of another, is one and

the same thing. Let M. Descartes but prove his Vortex of the Earth with the least part of the rea∣son we have brought against it, or by as natural a Comparison as we have us'd to demonstrate it a meer Chimera, and he need not fear to stand the Test, Sallies and Assaults, of the best of his Adversaries.

What now if we should fall to examining the Difficulties that may be gather'd from the little Planet in particular, I mean the Moon consider'd in the petty Vortex of the Earth? Should we probably find less Matter of Objection?

Here ought to be the foregoing Figure, p. 278.

We advance no more than this, that suppo∣sing the Moon when arriv'd at A. was carried on towards B. she ought to deviate from her Vortex in C. For first, That's the external Superficies of the little Vortex, as M. Descartes will not deny. Secondly, She Attempts to leave her Vortex, by his grand Principle of circular Motion. He pretends she cannot make her escape towards B. because the Matter of the Solary Vortex in that place is more light and active, and repels her towards the Centre. Nor can she, according to him, make downwards towards K. for that, says he, the Celestial Matter on that side is hea∣vier than the Moon, and equally opposes her Descent: But we say she will get out of her Cir∣cle at C. and continue her Progress toward Z. For being in C. she finds no resistance, since the Matter of C. Z. is that of her own Circle, which is already on its March, and willing to give up its place. Besides, being in that place, she actu∣ally makes an Attempt to get rid of the Centre

of her Motion, that is to say, of T. she therefore will accomplish her escape, since there is no Ob∣stacle in that as is found in the other Points; and being cast out of her Circle, she will be oblig'd to continue her Journy towards Z. by the Mat∣ter plac'd above, and below her in the Circle, for the self-same Reasons as are given by M. Des∣cartes.

Yet in spite of all this, it cannot be deny'd, but that M. Descartes had good reason to order his Suppositions of these things as he did. His System was too far advanc'd to think of stop∣ping at so small an Obstacle as a Moon. All the Grandee-Planets were plac'd severally, according to the Quality and Preeminence their Solidity had given them. Madam Luna too was seated in the Circle of the Earth. There was only one little Inconvenience in the case, which was, that she must necessarily take a turn about the Earth, and consequently must be sometimes in the Earths own Circle, and sometimes out of it. She must therefore have a little Vortex of her own. And this is the best, as also only reason that can be given for his making one on purpose: And setting this aside, the Laws of Staticks alone could never have prevail'd with his Frugality, to put it self to that extraordinary Ex∣pense.

We had not insisted so long upon this Article, had not we consider'd it as the capital Point in the Cartesian System; and as the Founda∣tion of that prodigious Edifice, which has been taken in our days by so many, for the compleatest Mastery of a Human Mind. Let us see the Importance of our Demonstration by the Corollaries drawn from it.

Consequences of the preceding De∣monstration.

The first Consequence belongs to Astronomy and the Phenomena of the Planets. For first of all, there being no such thing as a Vortex, the Moon turns no longer round the Earth, since, accord∣ing to M. Descartes, the only reason of her cir∣cuiting is the Vortex that carries her aloft. Se∣condly the four Satellites of Jupiter, must be cashier'd of their Dignity and Employment, which they only injoy on account of the conti∣nual Centry they keep about him, and that by means of a particular Vortex attributed to that Planet, as well as to the Earth, in the grand Vor∣tex of the Sun. For all that we have said of the Vortex of the Earth and of the Moon, ought to be apply'd to Jupiter and his garde du Corps.

These two Particulars in Astronomy are consi∣derable enough to assure us that the World of M. Descartes is not that of Gods own making, which we live in, but of a very different Archi∣tecture and Contrivance.

The second Consequence respects almost all the principal Phenomena's of the lower World in general, whereof wee'l only concern our selves with the most considerable and easiest to be un∣derstood. 'Tis by the means only of the Vortex of the Earth, that the Cartesians, following their Master, explain the gravity of Bodies, and ac∣count for the Motion which they have towards the Centre of the Earth. For to instance, say they, when you cast a Stone up in the Air, it forces below it a Mass of the second Element, and Air equal to its bulk: But that same Mass has a far

greater agitation, and is better dispos'd for Mo∣tion, and consequently has more power to spring fromward the Centre of its Vortex than the Stone that scarce contains any thing but the Matter of the third Element; and therefore must be compell'd by the Matter of the second, to de∣scend towards the Centre of the Vortex, which is to say, the Centre of the Earth. We may tru∣ly say then, that without a Vortex heavy Bodies would not fall downwards, on the contrary they would naturally fly upwards, and thus we should see Miracles and Wonders.

According to the new System, the Sun as far out of Gun-shot of the Earth as he is, could not warrant his own Security, in case there should be a People that inrag'd at the heat and scorch∣ing of his Rays, should sometime joyn to give him an innumerable flight of Arrows. For these Arrows shot from the Earth, against the Sun, would fall in the circumference of his Vortex, and in the midst of the Matter of the second Ele∣ment, which strugling all it can to get farther from the Centre of its Motion, would constrain the Bodies less capable of Motion than it self, to descend towards the Centre, that is to say, the Sun. Now these Arrows would be Bodies far less capable of Motion than the Matter of the se∣cond Element, therefore it would constrain them to fall towards the Sun: Undoubtedly a very surprizing thing. And now we may easily give a reason for the Experiment that Father Mersen∣nus formerly assur'd M. Descartes he had made; that in discharging a Musquet perpendicularly towards the Zenith,* 1.1 the Bullet never came down again; for it must have infallibly been carried to the Sun.

According to this System, when we have a mind to make a Voyage, I do not say to the Globe of the Moon as did Cyrano de Bergerac, but to the Sun it self, it will be the easiest thing to be accomplish'd of a thousand. We need but turn our Head perpendicularly towards the Sun, then give a little Spring to put our selves in Motion, and to make room for the Matter of the Solary Vortex, that would come bounce against the Earth, to give our Heels a hoise, and this is all; For, according to the Principles of Descartes, it would give us such a flirt, as in a trice would dart us to that Luminary. In short, heavy Bodies would no longer make towards the Earth, but all would be upon the gallop to the Sun.

What shall we say of the Flux and Reflux of the Sea; which is one of the choisest places in all M. Descartes Philosophy, and on which account there's no one but ought to lament the Misfor∣tune of the Vortex? For by the assistance of that Vortex, M. Descartes and M. Rohault speak Marvels upon that insearchable Phenomenon of Nature. Which not only depends upon the Vortex it self, but upon the very Figure of it, which was made oval on purpose, and singularly for it, though probably it was not at first in the intention of the Philosopher. For never did Tragick Poet better and more artificially prepare the Incidents of his Piece, than M. Descartes has contriv'd his Conclusions. It would surprize one to see, in his deducing them, that one word, which he let fall careless by the way, and one would think without Design, should have been big with such an Infinity of Delicate Conse∣quences. A Man wonders in the third part of his Principles, to see the figure of that Vortex,

which is no better grounded than the Vortex is it self: But when in the fourth he sees the ne∣cessity M. Descartes had of it, to explain the Flux and Reflux of the Sea, he cannot choose but commend his Foresight and Precaution. Not but that, for all these pretty and specious Expli∣cations of the Phenomena of the Flux and Re∣flux of the Sea, the Cartesian System may be de∣monstrated false in that very Particular. We are convinc'd of this by those Reflections and Observations we have drawn from the best Ma∣thematicians since M. Descartes's time. They de∣monstrate by the Observations of the Distances of the Moon, determin'd by her apparent Dia∣meters, that that Planet is as remote in many of her Conjunctions and Oppositions, as in some of her Quadratures, and as near in some of her Qua∣dratures, as in several Conjunctions and Oppositions. Hence it is false that the Apogy of the Moon is al∣ways in her Quadratures, and the Perigy in her Conjunctions and Oppositions. Wherefore it can∣not be suppos'd that the Moon being in Conjun∣ction and Opposition, is always in the little Diame∣ter of the Elliptick Vortex, and in her Quadra∣tures always in the Great one.

And yet it is upon this only Supposition that M. Descartes explains, and can explain, the ine∣quality of the Tides in the Conjunctions and Op∣positions, and in the Quadratures, as also of those we see in the Equinoxes and Solstices.

Again, if when the Moon pass'd our Meridian, the pressure of the Air was remarkably so much stronger, than in an other Hour of the Day, it would be perceivable by the ordinary Experi∣ments of Torricellus his Tube. Yet this diffe∣rence has never been observ'd, though it must be

very great: We could still give many other weighty Reasons against this System: But let it be how it will, take away its Vortex, and the Flux and Reflux must needs follow it.

Lastly, according to M. Descartes it is the Ce∣lestial Matter of this Vortex, that having more Motion than is necessary to turn in twenty four Hours time about the Earth, imploys the re∣mainder to diffuse it self all manner of ways, and together with the Matter of the third and first Element causes that great variety of Effects and Bodies which we so much wonder at. So the Vortex being ruin'd, all goes to Wreck and Confusion, and returns to its Native Chaos. Wherefore it makes not only for the glory of M. Descartes, but for the Interest of all Man∣kind to save this Vortex. For what remains, we protest we should be wonderful glad to see the Solution of the Difficulties we have pro∣pos'd against this and the other Points, upon which we shall resign our selves intire and sincere Proselytes to Cartesianism.

But in answering us let no one think to put upon us, nor quote a place in M. Descartes, to convince us he has not contradicted it in ano∣ther; when 'tis a plain and notorions Case. That Wheedle might take with those that have but perfunctorily read his Works, but must shew them the Contradiction in a clearer Light, that shall take pains to compare the opposite pla∣ces. We farther desire succinct and neater Answers, than the generality of those himself hath formerly given to those many Objections, propos'd against his Metaphysicks. Those very Answers raise in our Minds more Scruples than they cure: And yet because they have been

Printed, set off and tinsell'd with High-strain'd Praises of the Author, because he gives them a Magisterial and usually a disdainful Air, and we never see any Replies affix'd to them, many are habituated to reverence them as second Oracles, wherewith he hath confirm'd and explain'd those former of his own pronouncing. We shall not be such tame Asses, as to be impos'd on by M. Descartes's Reputation and Authority, no more than we would be Vassals to the esteem we have for some of his Disciples. We praise and highly approve the Advice he gives those who are on the Inquest after Truth, to beware of Prejudices, and shall put in Practice. These, Monsieur, are the chiefest of the things contain'd in my Peripatetick Memoir. They added some few others by word of Mouth, as for Instance; That you would have been most horribly pester'd if any one would have track'd you step by step, in the fourth Part of your Book of Principles, especially from Number 32. to 45. where you are so particular, in posturing and disposing those parts of the third Element, of which you form your Earth: That there were many things there unsatisfactory to the Mind, and that there was not a Page wherein it might not be reason∣ably again and again demanded, why such a thing ought to be rather so than otherwise, with∣out your being able to give a tolerable Reason for it: That they believ'd that piece of your Physicks was one of those that had most con∣tributed to make your Philosophy pass with ma∣ny for a perfect Fable, ill-digested and not well hung together: And that your Adversaries, without troubling themselves to refute the Pro∣positions that you make there, the Discussion

whereof must needs be very tedious, had no more to do, than to refer your Readers to the place, to make them as ill-satisfied with you as can be wish'd.

[illustration]

They proceeded farther to say, you us'd to at∣tribute Properties to your Elements, which you was sure to take away again when they were not for your purpose. They gave me an Instance in the Matter of the first Element: You attribute as a Property to that Matter a great facility of division and readiness to change its Figure, so as easily to insinuate its self in every place, and sill all sort of Space whatever. But when 'tis brought for the Explication of the Nature of the Loadstone, that Propriety growing disad∣vantagious, Descartes thinks fit to change it for a contrary. There is occasion for a little Vortex of chamfer'd Matter round the Earth, and about each particular Loadstone, to give a Reason for

the Qualities of that miraculous Stone. These chamfer'd parts belong to the first Element.* 1.2 It formerly was nothing to them to accommodate themselves with the Figure of a Skrew, to pass and repass betwixt the Globules of the second Element. And now in issuing from the Earth, or from a Loadstone, the parts of Air are able to detain them. Instead of breaking and pro∣portioning themselves to the Figure of the Parts of Air, and second Element mingled with it, they flock and settle in heaps about the Earth and about the Loadstone, where they constitute a Vortex. Those that enter by the Southern Pole are incapable of passing by the Northern, since their Figure can no longer be adapted to that Passage; and they farther demanded, upon that occasion, how it was possible those Snail-work'd Parts, confin'd and stopt thus in a definite Space, having an intricate and confus'd Motion, one a∣mongst another, approaching the Pole of the Earth, or Magnet that was proportion'd to them, could so conveniently turn themselves an end, and present so cleverly their Point against the Pores, in order to their entrance in those Bodies. They pretended the contrary was more likely, and that generally the parts would present them∣selves across, and thereby make a Confusion ca∣pable of stopping all the rest, and damming up the Pores of the Earth and Magnet, so as to fru∣strate all those admirable Effects we see there. They advanc'd one Paradox more, which was a good Humour enough. Hitherto, said they, the most rational Philosophers have acknow∣ledg'd, that no Physical Argument could be brought against Copernicus, to prove the Earth was not turn'd about its Centre. But M. Des∣cartes

who sides with that Astronomer in his Hy∣pothesis, has furnish'd us with a very conclusive one against that Motion. His topping Princi∣ple is, That every Body circularly mov'd, at∣tempts to wheel off the Centre of its Motion: This Principle is true: He thence concludes, that the Earth turning on its Axle, would fly in Pieces, unless the Bodies, of which it is com∣pos'd, were closely press'd, and squeez'd against one another by the Matter of the second Element. This Consequence is moreover evident in his System: But now let us see if that pressure of the Matter of the second Element is strong enough to overpower the Effort which the Parts of the Earth make to disengage themselves and get fur∣ther from their Centre. This difficulty, said they, falls only on M. Descartes: For the School-Opinion is so far from owning such a Propensity in the parts of the Earth, to deviate from the Centre, as to suppose a quality and inclination that naturally buckles them unto it. Now upon comparing the pressure of Terrestrial Bodies one against another, by the Matter of the second Element, with the Effort Terrestrial Bodies make to get far off the Centre, the Effort must surmount the pressure: For the Effort is as great as the Motion that causes it, and the Motion is very great indeed, that can carry the Earth seve∣ral Leagues each Minute; and on the contrary, Experience shews there needs but a very little Effort for the conquering the pressure, since no greater is requisite, than that a Child of four years old imploys in Walking, to lift his Foot and separate it from the Ground, whereto the pressure of the second Element did fasten it. Wherefore it seems to be reasonably concluded,

That the Earth turns not on its Axis, since if it did, we should all be hurl'd in the Air, pur∣suant to M. Descartes's Principle, which yet at bottom is true in sound Philosophy. Thus this System affords an excellent Argument against that of Copernicus.

They yet farther observ'd to me some peculiar Places and Points of your System, of the great∣est Importance, which you advance, as they pre∣tend, not only stript and naked of all Proof, but against all Reason in the World; they particu∣larly intreated me to read considerately and without prepossession, the second Number of the fourth Part of your Book of Principles, where ha∣ving explain'd how the Vortex of the Earth was destroy'd, and how there grew round that cak'd and crusted Star, a spacious Fleece of Air, you not only plunge it a great depth in the Solary Vortex, but also make that Sphere of Air keep pace, and wait upon it thither, and ever incom∣pass it as it still descends. They pretend that Supposition which you throw in Gratis, and without all Confirmation, is inconceivable; and yet if it be false, it were impossible at present to have Air about our Earth: It is inconceiva∣ble, say they: For, according to M. Descartes, the Air is nothing but an heap of the Parts of the third Element, exceeding small, and very loose and disunited from each other, and extra∣ordinary obsequious to the Motions impress'd on them by the Globules of the second Element, in which they swim. But this being so, how comes it to pass the Earth, traversing those im∣mense Spaces quite from its setting out, at the brink of the Solary Vortex, to the place in which it is, should still so preserve all. the Air about it?

How by the Principles of that Philosopher could that Mass of Air, being far less solid than the Mass of Earth, have the same Motion, the same Determination, and same Swiftness as the Earth? How chance those little Parts so loose and inde∣pendent of each other, and so obedient to the Motions of the Celestial Matter, have not been dispers'd by the rapidness of that Matter, which they stemm'd, as the Dust is scatter'd by the Wind? But added they, how is this Mass of Air at present driven along with the Earth by the Celestial Matter? How has it all the same Motions? Is it against the Body of the Earth, or against the Globe of Air the Celestial Matter presses, to give both one and the other a Diurnal and an Annual Motion? Would not a Copernical Cartesian be hard put to't to unperplex himself of this Affair?

I omit, Monsieur, many other Difficulties whose Solution probably I may find in the An∣swers your Goodness will, I hope, vouchsafe the others I have already noted in this Letter. But for what remains, I desire you to take the earn∣estness wherewith I write to you, as an effect of that passionate Love you have inspir'd me with, of Truth, and especially to put a favourable Construction on my meaning. I have only tran∣scrib'd your Adversaries Memoire in their own proper Terms and Language, and I presum'd the respect I ow'd you, could not warrant my concealing or dissembling their insulting way of arguing. Which will serve to let you know how much it is for my Interest, and the Honour of our Sect, not to suffer them to triumph long.

The great and important Business, the pro∣duction of a new World at present finds you, joyn'd to the indifference you have always had, and still have more than ever, for the Opinions and Thoughts of Men, might reasonably make you neglect and despise these mean and trifling Things. But those extraordinary Instances you have given me of your Favour, encourage me to hope you will have some Consideration of my Honour, and will not deny me your Hand to raise me from the Ground, where I must own my self a little foil'd and disheartned. I desir'd the Reverend Father Mersennus to imploy his Credit with you, to obtain this Favour, and at once to assure you, as I here do, with all the Sub∣mission and respect I am capable of, that I am with all my Heart and Soul,

MONSIEUR,

Your most humble, and most obedient Servant, and most zealous Disciple.

Notes

• * 1.1

  Let. 3. Tom. 2.
• * 1.2

  Part 3. princip.