The discovery of a world in the moone

by John Wilkins

Suppose A B to be a Hemispheare of one earth, C D to be the upper part of the highest region, in which there might be either a contracted vapour, as G, or else a dilated one, as H I. Suppose E F likewise to represent halfe the heavens, wherein was this appearing Comet at K. Now I say, that a contracted vapour, as G, could not cause this appearance, because an inhabitant at M could not discerne the same starre with this brightnesse, but perhaps another at L, betwixt which the vapour is directly interposed. Nor could it be caused by a dilated vapour, as H I, because then all the starres that were discerned through it would be perceived with the same brightnesse.

Tis necessary therefore that the cause of this appearance should be in the heavens. And this is granted by the most and best Astronomers. But, say some, this doth not argue any naturall alteration in those purer bodies, since tis probable that the concourse of many little vagabond starres by the union of their beames may cause so great a light. Of this opinion were Anaxagoras and Zeno amongst the ancient, and Baptista Cisatus, Blancanus, with others amongst our moderne Astronomers. For, say they, when there happens to be a concourse of some few starres, then doe many other flie unto them from all the parts of heaven like so many Bees unto their King. But 1. tis not likely that amongst those which wee count the fixed starres there should be any such uncertaine motions, that they can wander from all parts of the heavens, as if Nature had neglected them, or forgot to appoint them a determinate course. 2. If there be such a conflux of these, as of Bees to their King, then what reason is there that they doe not still tarry with it, that so the Comet may not be dissolved? But enough of this. You may commonly see it confuted by many other arguments. Others there are, who affirme these to be some new created stars, produced by an extraordinary supernaturall power. I answer, true indeed, tis possible they might be so, but however tis not likely they were so, since such appearances may be salved some other way, wherefore to fly unto a miracle for such things, were a great injury to nature, and to derogate from her skill, an indignitie much mis-becomming a man who professes himselfe to be a Philosopher, Miraculum (saith one) est ignorantiæ Asylum, a miracle often serves for the receptacle of a lazy ignorance which any industrious Spirit would be ashamed of, it being but an idle way to shift off the labour of any further search. But here’s the misery of it, wee first tie our selves unto Aristotles Principles, and then conclude, that nothing could contradict them but a miracle, whereas ’twould be much better for the Common-wealth of learning, if we would ground our Principles rather upon the frequent experiences of our owne, then the bare authority of others.

Some there are, who thinke that these Comets are nothing else, but exhalations from our earth, carried up into the higher parts of the Heaven. So Peno, Rothmannus & Galilæus, Tycho Progym. l. 1. cap. 9. but this is not possible, since by computation ’tis found that one of them is above 300 times bigger than the whole Globe of Land and Water. Others therefore have thought that they did proceed from the body of the Sun, and that that Planet onely is Cometarum officina, unde tanquam emissarii & exploratores emitterentur, brevi ad solem redituri: The shop or forge of Comets from whence they were sent, like so many spies, that they might in some short space returne againe, but this cannot be, since if so much matter had proceeded from him alone, it would have made a sensible diminution in his body. The Noble Tycho therefore thinkes that they consist of some such fluider parts of the Heaven, as the milkie way is framed of, which being condenst together, yet not attaining to the consistency of a Starre, is in some space of time rarified againe into its wonted nature. But this is not likely, for if there had beene so great a condensation as to make them shine so bright, and last so long, they would then sensibly have moved downewards towards some center of gravity, because whatsoever is condenst must necessarily grow heavier, whereas these rather seemed to ascend higher, as they lasted longer. But some may object, that a thing may be of the same weight, when it is rarified, as it had while it was condenst: so metalls, when they are melted, and when they are cold: so water also when it is frozen, and when it is fluid, doth not differ in respect of gravity. But to these I answer: First, Metalls are not rarified by melting, but molified. Secondly, waters are not properly condensed, but congealed into a harder substance, the parts being not contracted closer together, but still possessing the same extension.

And beside, what likely cause can we conceive of this condensation, unlesse there be such qualities there, as there are in our ayre, and then why may not the Planets have the like qualities, as our earth? and if so, then ’tis more probable that they are made by the ordinary way of nature, as they are with us, and consist of exhalations from the bodies of the Planets. Nor is this a singular opinion; but it seemed most likely to Camillus Gloriosus, Th. Campanella, Fromondus, De Comet. l. 5. c. 4.
Apolog.
Meteor. l. 3. c. 2. Art. 6.
Iohan. Fabr.
Carolus Malaptius de Heliocyc.
Scheiner. Rosa Vrsina. with some others. But if you aske whither all these exhalations shall returne, I answer, every one into his owne Planet: if it be againe objected, that then there will be so many centers of gravity, and each severall Planet will be a distinct world; I reply, perhaps all of them are so except the Sunne, though Cusanus thinkes there is one also, and later times have discovered some lesser Planets moving round about him. But as for Saturne, he hath two Moones on each side. Jupiter hath foure, that incircle his body with their motion. Venus is observed to increase and decrease as the Moone. Mars, and all the rest, derive their light from the Sunne onely. Concerning Mercury, there hath beene little or no observation, because for the most part, he lies hid under the Sunne beames, and seldome appeares by himselfe. So that if you consider their quantity, their opacity, or these other discoveries, you shall finde it probable enough, that each of them may be a severall world. But this would be too much for to vent at the first: the chiefe thing at which I now ayme in this discourse, is to prove that there may be one in the Moone.

It hath beene before confirmed that there was a spheare of thicke vaporous aire encompasing the Moone, as the first and second regions doe this earth. I have now shewed, that thence such exhalations may proceede as doe produce the Comets: now from hence it may probably follow, that there may be wind also and raine, with such other Meteors as are common amongst us. This consequence is so dependant, that Fromondus De meteor. l. 3. c. 2. Art. 6. dares not deny it, though hee would (as hee confesses himselfe) for if the Sunne be able to exhale from them such fumes as may cause Comets, why not then such as may cause winds, and why not such also as cause raine, since I have above shewed, that there is Sea and Land as with us. Now raine seemes to be more especially requisite for them, since it may allay the heate and scorchings of the Sunne, when he is over their heads. And nature hath thus provided for those in Peru, with the other inhabitants under the line.

But if there be such great, and frequent alterations in the Heavens, why cannot wee discerne them?

I answer:

1. There may be such, and we not able to perceive them, because of the weaknesse of our eye, and the distance of those places from us, they are the words of Fienus, as they are quoted by Fromondus in the above cited place,[8] Possunt maximæ permutationes in cœlo fieri, etiamsi a nobis non conspiciantur, hoc visus nostri debilitas & immensa cœli distantia faciunt. And unto him assents Fromondus himselfe, when a little after hee saies, Si in sphæris planetarum degeremus, plurima forsan cœlestium nebularum vellere toto æthere passim dispersa videremus, quorum species jam evanescit nimia spatii intercapedine.

If we did live in the spheares of the Planets, wee might there, perhaps, discerne many great clouds dispersed through the whole Heavens, which are not now visible by reason of this great distance.

2. Mæslin and Keplar affirme, that they have seene some of these alterations. The words of Mæslin are these (as I finde them cited.) Disser. 2. cum nunc. Galil.[9] In eclipsi Lunari vespere Dominicæ Palmarum Anni 1605, in corpore Lunæ versus Boream, nigricans quædam macula conspecta fuit, obscurior cætero toto corpore, quod candentis ferri figuram repræsentabat; dixisses nubila in multam regionem extensa pluviis & tempestuosis imbribus gravida, cujusmodi ab excelsorum montium jugis in humiliora convallium loca videre non rarò contingit.