Part 1

THE Celeſtial Worlds DISCOVER’D: OR, CONJECTURES Concerning the INHABITANTS, Plants and Productions OF THE Worlds in the Planets.

Written in Latin by CHRISTIANUS HUYGENS, And inſcrib’d to his Brother CONSTANTINE HUYGENS Late Secretary to his Majeſty King William.

The Second Edition, Corrected and Enlarged.

LONDON: Printed for James Knapton, at the Crown in St. Paul’s Church-Yard. Mdccxxii.

TO THE READER.

This Book was juſt finiſhed, and deſigned for the Preſs, when the Author, to the great loſs of the Learned World, was ſeized by a Diſeaſe that brought him to his Death. However he took care in his laſt Will of its Publication, deſiring his Brother, to whom it was writ, to take that Trouble upon him. But he was ſo taken up with Buſineſs and Removals, (as being Secretary in Holland to the King of Great Britain) that he could find no time for it till a Year after the Death of the Author: When it ſo fell out, that the Printers being ſomewhat tardy, and this Gentleman dying, the Book was left without either Father or Guardian. Yet it now ventures into the Publick, in the ſame Method that it was writ by the Author, and with the ſame Inſcription to his Brother, tho’ dead; in confidence that this laſt Piece of his will meet with as kind a Reception from the World as all the other Works of that Author have. ’Tis true there are not every where Mathematical Demonſtrations; but where they are wanting, you have probable and ingenious Conjectures, which is the moſt that can be reaſonably expected in ſuch matters. What belongs to, or has any thing to do with Aſtronomy, you will ſee demonſtrated, and the reſt ingeniouſly and ſhrewdly gueſs’d at, from the Affinity and Relation of the heavenly Bodies to the Earth. For your farther Satisfaction read on, and farewel.

THE PUBLISHER TO THE READER.

I Doubt not but I ſhall incur the Cenſures of learned Men for putting this Book into Engliſh, becauſe, they’ll ſay, it renders Philoſophy cheap and vulgar, and, which is worſe, furniſhes a ſort of injudicious People with a ſmattering of Notions, which being not able to make a proper uſe of, they pervert to the Injury of Religion and Science. I confeſs the Allegation is too true: but after Biſhop Wilkins, Dr. Burnet, Mr. Whiſton and others, to ſay nothing of the ancient Philoſophers, who wrote in their own Tongues; I ſay, after theſe great Authors have treated on as learned and abſtruſe Subjects in the ſame Language, I hope their Example will be allowed a ſufficient excuſe for printing this Book in Engliſh.

Concerning this Edition I can ſay, that I have taken care to have the Cutts exactly done, and have placed each Figure at the Page of the Book that refers to it, which I take to be more convenient to the Reader than putting them all at the End.

I have been careful to procure the beſt Paper, that I might in ſome meaſure come up to the Beauty of the Latin Edition, though this bear but half the Price of it.

And I hope the Tranſlator has expreſſed the Author’s Senſe aright, and has not committed Faults beyond what an ingenuous Reader can pardon.

NEW CONJECTURES Concerning the Planetary Worlds, THEIR INHABITANTS AND PRODUCTIONS.

Written by Christianus Huygens, and inſcribed to his Brother Constantine Huygens.

BOOK the Firſt.

A Man that is of Copernicus’s Opinion, that this Earth of ours is a Planet, carry’d round and enlighten’d by the Sun, like the reſt of the Planets, cannot but ſometimes think, that it’s not improbable that the reſt of the Planets have their Dreſs and Furniture, and perhaps their Inhabitants too as well as this Earth of ours: Eſpecially if he conſiders the later Diſcoveries made in the Heavens ſince Copernicus’s time, viz. the Attendants of Jupiter and Saturn, and the champaign and hilly Countries in the Moon, which are a ſtrong Argument of a Relation and Kin between our Earth and them, as well as a Proof of the Truth of that Syſtem. This has often been our Talk, I remember, good Brother, over a large Teleſcope, when we have been viewing thoſe Bodies, a Study that your continual Buſineſs and Abſence have interrupted for many Years. But we were always apt to conclude, that ’twas in vain to enquire after what Nature is doing there, ſeeing there was no likelihood of ever coming to any Certainty of the Enquiry. Nor could I ever find that any Philoſophers, either antient or modern, have attempted any thing upon this Subject. At the very Birth of Aſtronomy, when the Earth was firſt aſſerted to be Spherical, and to [Some have already talk’d of the Inhabitants of the Planets, but went no farther.] be ſurrounded with Air, even then there were ſome Men ſo bold as to affirm, there were an innumerable Company of Worlds in the Stars. But later Authors, ſuch as Cardinal Cuſanus, Brunus, Kepler, (and if we may believe him, Tycho was of that opinion too) have furniſhed the Planets with Inhabitants. Nay, Cuſanus and Brunus have allowed the Sun and fixed Stars theirs too. But this was the utmoſt of their Boldneſs; nor has the ingenious French Author of the Dialogues about the Plurality of Worlds carried this Matter any farther. Only ſome of them have coined ſome Stories of the Men in the Moon, juſt as probable as Lucian’s true Hiſtory; among which I muſt count Kepler’s, which he has diverted us with in his Aſtronomical Dream. But a while ago thinking ſomewhat ſeriouſly of this matter (not that I count my ſelf quicker-ſighted than thoſe great Men, but that I had the Happineſs to live after moſt of them) the Enquiry appeared not ſo impracticable, nor the Way ſo ſtopt up with Difficulties, but that there was very good room left for probable Conjectures. As they came into my Head, I put them down into common Places, and ſhall now try to digeſt them into ſome Method for your better Conception of them, and add ſomewhat of the Sun and fix’d Stars, and the Extent of that Univerſe of which our Earth is but an inconſiderable Point. I know you have ſuch an Eſteem and Reverence for any thing that belongs to the Heavens, that I perſwade my ſelf you will read what I have written with ſome Pleaſure: I’m ſure I writ it with a great deal; but as often before, ſo now, I find the Saying of Archytas true, even to the Letter, That tho’ a Man were admitted into Heaven to view the wonderful Fabrick of the World, and the Beauty of the Stars, yet what would otherwiſe be Rapture and Extaſie, would be but a melancholy Amazement if he had not a Friend to communicate it to. I could wiſh indeed that all the World might not be my Judges, but that I might chuſe my Readers, Men like you, not ignorant in Aſtronomy and true Philoſophy; for with ſuch I might promiſe my ſelf a favourable hearing, and not need to make an Apology for daring to vent any thing new to the World. But becauſe I am aware what weak Hands it’s likely to fall into, and what a ſevere Sentence I may expect from thoſe whoſe Ignorance or Zeal is too great; it may be worth the while to guard my ſelf beforehand againſt the Aſſaults of thoſe ſort of People.

There’s one ſort who knowing nothing of Geometry or Mathematicks, will laugh at it as a whimſical and ridiculous Undertaking. It’s an incredible Thing to them to talk of meaſuring the Diſtance and Magnitude of the Stars: And for the Motion of the Earth, they count it, if not a falſe, at leaſt a precarious Opinion; and no wonder then if they take what’s built upon ſuch a ſlippery Foundation for the Dreams of a fanciful Head and a diſtemper’d Brain. What ſhould we anſwer to theſe Men, but that their Ignorance is the Cauſe of their Diſlike, and that if they had ſtudied theſe things more, and viewed the Works of Nature nicely, they would have fewer Scruples? But few People having had an opportunity of proſecuting theſe Studies, either for want of Parts, Learning or Leiſure, we cannot blame their Ignorance; and if they reſolve to find fault with us for ſpending time in ſuch Matters, becauſe they do not underſtand the Uſe of them, we muſt appeal to properer Judges.

The other ſort, When they hear us talk of new Lands, and Animals, and Creatures endued with as much Reaſon as themſelves, will be ready to cry out, that we ſet up our Conjectures againſt the Word of God, and broach Opinions directly oppoſite to Holy Writ. For we do not there read any thing of the Production of ſuch Creatures, no not ſo much as that they exiſt; nay rather we read the quite contrary. For, That only mentions this Earth with its Animals and Plants, and Man the Lord of them: To ſuch Perſons I anſwer, what has been often urged by others before me: That it’s evident, God had no deſign to make a particular Enumeration in the Holy Scriptures, of all the Works of his Creation. When therefore it is plain that under the general Name of Stars or Earth at the Creation, are comprehended all the Heavenly Bodies, even the Attendants upon Jupiter and Saturn, why muſt all that Multitude of Beings which the Almighty Creator has been pleaſed to place upon them, be excluded the Privilege, and not ſuffered to have a Share in the Expreſſion? And theſe Men themſelves can’t but know in what Senſe it is that all things are ſaid to be made for the Uſe of Man, not certainly for us to look at through a Teleſcope, for that’s very abſurd. Since then the greateſt part of God’s Creation, that innumerable multitude of Stars, is placed out of the reach of any Man’s Eye; and many of them it’s likely, of the beſt Glaſſes, ſo that they don’t ſeem to belong to us; is it ſuch an unreaſonable Opinion to think, that there are ſome reaſonable Creatures who ſee and admire thoſe glorious Bodies at a nearer diſtance?

But perhaps they’ll ſay, it does not become us to be ſo curious and inquiſitive in theſe Things which the Supreme Creator ſeems to have kept for his own Knowledge: For ſince he has not been pleaſed to make any farther Diſcovery or Revelation of them, it ſeems little better than preſumption to make any inquiry into that which he has thought fit to hide. But theſe Gentlemen muſt be told, that they take too much upon themſelves when they pretend to appoint how far and no farther Men ſhall go in their Searches, and to ſet bounds to other Mens Induſtry; as if they knew the Marks that God has placed to Knowledge: or as if Men were able to paſs thoſe Marks. If our Forefathers had been at this rate ſcrupulous, we might have been ignorant ſtill of the Magnitude and Figure of the Earth, or that there was ſuch a Place as America. We ſhould not have known that the Moon is inlightned by the Sun’s Rays, nor what the Cauſes of the Eclipſes of each of them are, nor a multitude of other Things brought to light by the late Diſcoveries in Aſtronomy. For what can a Man imagine more abſtruſe, or leſs likely to be known, than what is now as clear as the Sun? Whence it follows, that vigorous Induſtry, and piercing Wit were given Men to make Advances in the Search of Nature, and there’s no Reaſon to put any Stop to ſuch Enquiries. I muſt acknowledge that what I here intend to treat of is not of that Nature as to admit of a certain Knowledge; I can’t pretend to aſſert any thing as poſitively true (for how is it poſſible) but only to advance a probable Gueſs, the Truth of which every one is at his own liberty to examine. If any one therefore ſhall gravely tell me, that I have ſpent my Time idly in a vain and fruitleſs Enquiry after what by my own acknowledgment I can never come to be ſure of; The Anſwer is, that at this rate he would put down all Natural Philoſophy as far as it concerns it ſelf in ſearching into the Nature [Conjectures not uſeleſs, becauſe not certain.] of Things: In ſuch noble and ſublime Studies as theſe, ’tis a Glory to arrive at Probability, and the Search it ſelf rewards the Pains. But there are many degrees of Probable, ſome nearer Truth than others, in the determining of which lies the chief exerciſe [Theſe Studies uſeful to Religion.] of our Judgment. But beſides the Nobleneſs and Pleaſure of the Studies, may not we be ſo bold as to ſay, they are no ſmall help to the Advancement of Wiſdom and Morality? ſo far are they from being of no uſe at all. For here we may mount from this dull Earth, and viewing it from on high, conſider whether Nature has laid out all her Coſt and Finery upon this ſmall Speck of Dirt. So, like Travellers into other diſtant Countries, we ſhall be better able to judge of what’s done at home, know how to make a true Eſtimate of, and ſet its own Value upon every Thing. We ſhall be leſs apt to admire what this World calls Great, ſhall nobly deſpiſe thoſe Trifles the generality of Men ſet their Affections on, when we know that there are a multitude of ſuch Earths inhabited and adorned as well as our own. And we ſhall worſhip and reverence that God the Maker of all theſe things; we ſhall admire and adore his Providence and wonderful Wiſdom which is diſplayed and manifeſted all over the Univerſe, to the Confuſion of thoſe who would have the Earth and all things formed by the ſhuffling Concourſe of Atoms, or to be without beginning. But to come to our Purpoſe.

And now becauſe the chief Argument for the Proof of what we intend will be taken from the Diſpoſition of the Planets, among which without doubt, the Earth muſt be counted in the Copernican Syſtem, I ſhall here firſt of all draw two Figures. The firſt is a Deſcription of the Orbs the Planets move in, in that order that they are placed round the Sun, drawn as near as can be in their true Proportions, like what you have ſeen in my Clock at home. The ſecond ſhows the Proportions of their Magnitudes in reſpect of one another and of the Sun, which you know is upon that ſame Clock of mine too. In the firſt the middle Point or Center is the Place of the Sun, round which, in an order that every one knows, are the Orbits of Mercury, Venus, the Earth with that of the Moon about it; then thoſe of Mars, Jupiter and Saturn: and about the two laſt the ſmall Circles that their Attendants move in: about Jupiter four, and about Saturn five. Which Circles as well as that of the Moon are drawn larger than their true Proportion would admit, otherwiſe they could not have been ſeen. You may eaſily apprehend the Vaſtneſs of theſe Orbits by this, that the diſtance of the Earth from the Sun is ten or twelve thouſand of the Earth’s Diameters. Almoſt all theſe Circles are in the ſame Plane, declining very little from that in which the Earth moves, call’d The Plane of the Ecliptick. This Plane is cut obliquely by the Axis upon which the Earth turns it ſelf round with reſpect to the Sun in 24 Hours, whence ariſe the Succeſſions of Day and Night: The Axis of the Earth always keeping the ſame Inclination to the Ecliptick (except a ſmall Change beſt known to Aſtronomers) while the Earth itſelf is carried in its yearly Courſe round the Sun, cauſes the regular Order of the Seaſons of the Year: as you may ſee in all Aſtronomers Books. Out of which I ſhall tranſcribe hither the Periods of the Revolutions of the Planets, viz. Saturn moves round the Sun in 29 Years, 174 Days, and 5 Hours: Jupiter finiſhes his Courſe in 11 Years, 317 Days, and 15 Hours: Mars his in about 687 Days. Our Year is 365 Days 6 Hours: Venus’s 224 Days 18 Hours: and Mercury’s 88 Days. This is the now commonly received Syſtem, invented by Copernicus, and very agreeable to that frugal Simplicity Nature ſhows in all [Arguments for the Truth on’t.] her Works. If any one is reſolved to find fault with it, let him firſt be ſure he underſtands it. Let him firſt ſee in the Books of Aſtronomers with how much greater Eaſe and Plainneſs all the Motions of the Stars, and Appearances in the Heavens are explained and demonſtrated in this than either in that of Ptolomy or Tycho. Let him conſider that Diſcovery of Kepler, that the Diſtances of the Planets from the Sun, as well of the Earth as the reſt, are in a fix’d certain proportion to the Times they ſpend in their Revolutions. Which Proportion it’s ſince obſerved that their Satellites keep round Jupiter and Saturn. Let him examine what a contradictory Motion they are fain to invent for the Solution of the Polar Star’s changing its Diſtance from the Pole. For that Star in the end of the little Bear’s Tail which now deſcribes ſo ſmall a Circle round the Pole, that it is not above two Degrees and twenty Minutes, was obſerved about 1820 Years ago, in the Time of Hipparchus, to be above 12: and will within a few Ages more be 45 Degrees diſtant from it: and after 25000 Years more will return to the ſame Place it is now in. Now if with them we allow the Heavens to be turned upon their own Axis, at this rate they muſt have a new Axis every Day: a Thing moſt abſurd, and repugnant to the Nature of all Motion. Whereas nothing is eaſier with Copernicus than to give us Satisfaction in this Matter. Then he may impartially weigh thoſe Anſwers that Galilæus, Gaſſendus, Kepler, and others have given to all Objections propoſed, which have ſo ſatisfied all Scruples, that generally all Aſtronomers now-a-days are brought over to our Side, and allow the Earth its Motion and Place among the Planets. If he cannot be ſatisfied with all this, he is either one whoſe Dulneſs can’t comprehend it, or who has his Belief at another Man’s Diſpoſal.

In the other Figure you have the Globes of the Planets, and of the Sun, repreſented to your Eyes as placed near one another. Where [The Proportion of the Magnitude of the Planets, in reſpect of one another, and the Sun.] I have obſerved the ſame Proportion, of their Diameters to that of the Sun, that I publiſhed to the World in my Book of The Appearances of Saturn: namely, the Diameter of the Ring round Saturn is to that of the Sun as 11 as to 37; that of Saturn himſelf about as 5 to 37; that of Jupiter as 2 to 11; that of Mars as 1 to 166; of the Earth as 1 to 111; and of Venus as 1 to 84: to which I ſhall now add that of Mercury obſerved by Hevelius in the Year 1661, but calculated by my ſelf, and found to be as 1 to 290.

If you would know the way that we came to this Knowledge of their Magnitudes, by knowing the Proportion of their Diſtances from the Sun, and the Meaſures of their Diameters, you may find it in the Book before-mentioned: And I cannot yet ſee any Reaſon to make an Alteration in thoſe I then ſettled, altho’ I will not ſay they are without their Faults. [The Lamellæ more convenient than Micrometers.] For I can’t yet be of their Mind, who think the Uſe of Micrometers, as they call them, is beyond that of our Plates, but muſt ſtill think that thoſe thin Plates or Rods of which I there taught the Uſe, not to detract from the due Praiſes of ſo uſeful an Invention, are more convenient than the Micrometers.

In this proportion of the Planets it is worth while to take notice of the prodigious Magnitude of the Sun in compariſon with the four innermoſt, which are far leſs than Jupiter and Saturn. And ’tis remarkable, that the Bodies of the Planets do not increaſe together with their Diſtances from the Sun, but that Venus is much bigger than Mars.

Having thus explained the two Schemes, there’s no Body I ſuppoſe but ſees, that in the firſt the Earth is made to be of the ſame ſort with the reſt of the Planets. For the very Poſition of the Circles ſhows it. And that the other Planets are round like it, and like it receive all the Light they have from the Sun, there’s no room (ſince the Diſcoveries made by Teleſcopes) to doubt. Another Thing they are like it in is, that they are moved round their own Axis; for ſince ’tis certain that Jupiter and Saturn are, who can doubt it of the others? Again, as the Earth has its Moon moving round it, ſo Jupiter and Saturn have theirs. Now ſince in ſo many Things they thus agree, what can be more probable than that in others they agree too; and that the other Planets are as beautiful and as well ſtock’d with Inhabitants as the Earth? Or what ſhadow of Reaſon can there be why they ſhould not?

If any one ſhould be at the Diſſection of a Dog, and be there ſhewn the Intrails, the Heart, Stomach, Liver, Lungs and Guts, all the Veins, Arteries and Nerves; could ſuch a Man reaſonably doubt whether there were the ſame Contexture and Variety of Parts in a Bullock, Hog, or any other Beaſt, tho’ he had never chanc’d to ſee the like opening of them? I don’t believe he would. Or were we thoroughly ſatisfy’d in the Nature of one of the Moons round Jupiter, ſhould not we ſtraight conclude the ſame of the reſt of them? So if we could be aſſur’d in but one Comet, what it was that is the Cauſe of that ſtrange Appearance, ſhould we not make that a Standard to judge of all others by? [Arguments from their Similitude, of no ſmall weight.] ’Tis therefore an Argument of no ſmall Weight that is fetch’d from Relation and Likeneſs; and to reaſon from what we ſee and are ſure of, to what we cannot, is no falſe Logick. This muſt be our Method in this Treatiſe, wherein from the Nature and Circumſtances of that Planet which we ſee before our Eyes, we may gueſs at thoſe that are farther diſtant from us.

And, Firſt, ’tis more than probable that the Bodies of the Planets are ſolid like that of our Earth, and that they don’t want what we call Gravity, that Virtue, which like a Loadſtone attracts whatſoever is near the Body to its Center. And that they have ſuch a Quality, their very Figure is a Proof; for their Roundneſs proceeds only from an equal preſſure of all their Parts tending to the ſame Center. Nay more, we are ſo skilful now-a-days, as to be able to tell how much more or leſs the Gravitation in Jupiter or Saturn is than here; of which Diſcovery and its Author you may read my Eſſay of the Cauſes of Gravitation.

But now to carry the Search farther, let us ſee by what Steps we muſt riſe to the attaining ſome knowledge in the deeper Secrets concerning the State and Furniture of theſe new Earths. And, firſt, how likely is it that they may be ſtock’d with Plants [Have Animals and Plants.] and Animals as well as we? I ſuppoſe no Body will deny but that there’s ſomewhat more of Contrivance, ſomewhat more wonderful in the Production and Growth of Plants and Animals, than in Lifeleſs Heaps of inanimate Bodies, be they never ſo much larger; as Mountains, Rocks, or Seas are. For the Finger of God, and the Wiſdom of Divine Providence, is in them much more clearly manifeſted than in the other. One of Democritus’s or Cartes’s Scholars may venture perhaps to give ſome tolerable Explication of the Appearances in Heaven and Earth, allow him but his Atoms and Motion; but when he comes to Plants and Animals, he’ll find himſelf non-plus’d, and give you no likely account of their Production. For every Thing in them is ſo exactly adapted to ſome Deſign, every part of them ſo fitted to its proper Uſe, that they manifeſt an Infinite Wiſdom, and exquiſite Knowledge in the Laws of Nature and Geometry, as, to omit thoſe Wonders in Generation, we ſhall by and by ſhow; and make it an Abſurdity even to think of their being thus happily jumbled together by a chance Motion of I don’t know what little Particles. Now ſhould we allow the Planets nothing but vaſt Deſerts, lifeleſs and inanimate Stocks and Stones, and deprive them of all thoſe Creatures that more plainly ſpeak their Divine Architect, we ſhould ſink them below the Earth in Beauty and Dignity; a Thing very unreasonable, as I ſaid before.

Well then, we have gain’d the Point thus far, and the Planets may be allowed ſome Creatures capable of moving themſelves, not at all inferior to ours; and theſe are Animals. And if this be allowed, it almoſt neceſſarily follows, that there muſt be Herbs [Not to be imagin’d too unlike ours.] for Food for them. And as for the Growth and Nouriſhment of all theſe, ’tis no doubt the ſame with ours, ſeeing they have the ſame Sun to warm and enliven them as ours have.

But perhaps ſome Body may ſay, we conclude too faſt. They will not deny indeed but that there may be Plants and Animals on the Surface of the Planets, that deſerve as well to be provided for by their Creator as ours do: but why muſt they be of the ſame Kind with ours: Nature ſeems to love variety in her Works, and may have made them widely different from ours either in their matter or manner of Growth, in their outward Shape, or their inward Contexture; ſhe may have made them ſuch as neither our Underſtanding nor Imagination can conceive. That’s the Thing we ſhall now examine, and whether it be not more likely that ſhe has not obſerv’d ſuch a Variety as they talk of. Nature ſeems moſt commonly, and in moſt of her Works, to affect Variety, ’tis true; But they ſhould conſider ’tis not the Buſineſs of Men to pretend to ſettle how great this Difference and Variety muſt be. Nor does it follow, becauſe it may be Infinite, and out of our Comprehenſion and Reach, that therefore Things in reality are ſo. For ſuppoſe God ſhould have pleaſed to have made all Things in the reſt of the Planets juſt as he has here, the Inhabitants of thoſe Places (if there are any ſuch) would admire his Wiſdom and Contrivance no leſs than if they were widely different; ſeeing they can’t come to know what’s done in the other Planets. Who doubts but that God, if he had pleaſed, might have made the Animals in America and other diſtant Countries nothing like ours? yet we ſee he has not done it. They have indeed ſome difference in their Shape, and ’tis fit they ſhould, to diſtinguiſh the Plants and Animals of thoſe Countries from ours, who live on this ſide the Earth; but even in this Variety there is an Agreement, an exact Correſpondence in Figure and Shape, the ſame ways of Growth, and new Productions, and of continuing their own Kind. Their Animals have Feet and Wings like ours, and like ours have Hearts, Lungs, Guts, and the Parts ſerving to Generation; whereas all theſe Things, as well with them as us, might, if it had pleaſed Infinite Wiſdom, have been order’d a very different Way. ’Tis plain then that Nature has not exhibited that Variety in her Works that ſhe could, and therefore we muſt not allow that Weight to this Argument, as upon the Account of it to make every Thing in the Planets quite different from what is here. ’Tis more probable that all the Difference there is between us and them, ſprings from the greater or leſs diſtance and influence from that Fountain of Heat and Life the Sun; which will cauſe a Difference not ſo much in their Form and Shape, as in their Matter and Contexture.