The Discovery of a World in the Moone Part 10

[Sidenote 1: _Progym. 1._]

[Sidenote 2: _l. 20. c. 5._]

It doth not proceede from the fixed starres, for then it would retaine the same light in eclipses, whereas the light at such times is more ruddy and dull. Then also the light of the Moone would not be greater or lesser, according to its distance from the edge of the earths shadow, since it did at all times equally partic.i.p.ate this light of the starres.

Now because there is no other body in the whole Universe, save the earth, it remaines that this light must necessarily be caused by that which with a just grat.i.tude repaies to the Moone, such illumination as it receives from her.

And as loving friends equally partic.i.p.ate of the same joy and griefe, so doe these mutually partake of the same light from the Sunne, and the same darkenesse from the eclipses, being also severally helped by one another in their greatest wants: For when the Moone is in conjunction with the Sunne, and her upper part receives all the light, then her lower Hemispheare (which would otherwise be altogether darke) is enlightened by the reflexion of the Sunne beames from the earth. When these two planets are in opposition, then that part of the earth which could not receive any light from the Sunne beames, is most enlightened by the Moone, being then in her full; and as she doth most illuminate the earth when the Sunne beames cannot, so the gratefull earth returnes to her as great, nay greater light when shee most wants it; so that alwaies that visible part of the Moone which receives nothing from the Sunne, is enlightened by the earth, as is proved by _Galilaeus_, with many more arguments, in that Treatise which he calls _Systema mundi_.

True indeed, when the Moone comes to a quartile, then you can neither discerne this light, nor yet the darker part of her body, but the reason is, because of the exuperancy of the light in the other parts. _Quippe ill.u.s.tratum medium speciem recipit valentiorem_,[1] the clearer brightnesse involves the weaker, it being with the species of sight, as it is with those of sound, and as the greater noise drownes the lesse, so the brighter object hides that which is more obscure. But they doe alwaies in their mutuall vicissitudes partic.i.p.ate of one anothers light; so also doe they partake of the same defects and darknings, for when our Moone is eclipsed, then is their Sunne darkened, and when our Sunne is eclipsed, then is their Moone deprived of its light, as you may see affirmed by _Maeslin_.[2]

_Quod si terram n.o.bis ex alto liceret intueri, quemadmodum deficientem lunam ex longinquo spectare possumus, videremus tempore eclipsis solis terrae aliquam partem lumine solis deficere, eodem plane modo sicut ex opposito luna deficit_,

"If wee might behold this globe of earth at the same distance as we doe the Moone in her defects, wee might discerne some part of it darkened in the Sunnes eclipses, just so as the Moone is in hers."

For as our Moone is eclipsed by the interposition of our earth, so is their Moone eclipsed by the interposition of theirs. The manner of this mutuall illumination betwixt these two you may plainly discerne in this Figure following.

[Sidenote 1: _Scal. exerc. 62._]

[Sidenote 2: _Epit. Astro. l. 4. part. 2._]

[Ill.u.s.tration as described in text: sun, crescent moon and gibbous earth]

Where A represents the Sun, B the Earth, and C the Moone; Now suppose the Moone C to be in a s.e.xtile of increase, when there is onely one small part of her body enlightened, then the earth B will have such a part of its visible Hemispheare darkened, as is proportionable to that part of the Moone which is enlightened; and as for so much of the Moone, as the Sun beames cannot reach unto, it receives light from a proportionall part of the earth which shines upon it, as you may plainly perceive by the Figure.

You see then that agreement and similitude which there is betwixt our earth and the Moone. Now the greatest difference which makes them unlike, is this, that the Moone enlightens our earth round about, whereas our earth gives light onely to that Hemispheare of the Moone which is visible unto us, as may be certainly gathered from the constant appearance of the same spots, which could not thus come to pa.s.se, if the Moone had such a diurnall motion about its own axis, as perhaps our earth hath. And though some suppose her to move in an epicycle, yet this doth not so turne her body round, that we may discerne both Hemispheares, for according to that hypothesis, the motion of her eccentrick, doth turne her face towards us, as much as the other doth from us.

But now if any question what they doe for a Moone who live in the upper part of her body? I answer, the solving of this is the most uncertaine and difficult thing that I know of concerning this whole matter. But yet I will give you two probable conjectures.

1. Perhaps, the upper Hemispheare of the Moone doth receive a sufficient light from those planets about it, and amongst these _Venus_ (it may be) bestowes a more especiall brightnesse, since _Galilaeus_ hath plainly discerned that she suffers the same increase and decreases, as the Moone hath, and 'tis probable that this may be perceived there without the help of a gla.s.se, because they are farre neerer it than wee. When _Venus_ (saith _Keplar_) lies downe in the Perige or lower part of her supposed Epicycle, then is she in conjunction with her husband the Sunne, from whom after she hath departed for the s.p.a.ce of ten moneths, shee gets _plenum uterum_, and is in the full.

But you'll reply, though _Venus_ may bestow some light when she is over the Moone, and in conjunction, yet being in opposition, she is not visible to them, and what shall they then doe for light?

I answer, then they have none: nor doth this make so great a difference betwixt those two Hemispheares as there is with us, betwixt the places under the poles, and the line, but if this bee not sufficient, then I say in the second place that

2. Perhaps there may be some other enlightened body above the Moone which we cannot discerne, nor is this altogether improbable because there is almost the like observed in Saturne, who appeares through this gla.s.se with two lesser bodies on each side, which may supply the office of Moones, unto each hemispheare thus:

o O o

So in this world also there may be some such body, though wee cannot discerne it, because the Moone is alwaies in a streight line, betwixt our eye and that. Nor is it altogether unlikely that there should bee more moones to one Orbe, because _Jupiter_ also is observed to have foure such bodies that move round about him.

But it may seeme a very difficult thing to conceive, how so grosse and darke a body as our earth, should yeeld such cleare light as proceedes from the Moone, and therefore the Cardinall _de Cusa_[1] (who thinkes every Starre to be a severall world) is of opinion that the light of the Sunne is not able to make them appeare so bright, but the reason of their shining is, because wee behold them at a great distance through their regions of fire which doe set a shining l.u.s.tre upon those bodies that of themselves are darke.

_Vnde si quis esset extra regionem ignis, terra ista in circ.u.mferentia suae regionis per medium ignis lucida stella appareret._

"So that if man were beyond the region of fire, this earth would appear through that as a bright Starre."

But if this were the onely reason then would the Moone bee freed from such increases and decreases as shee is now lyable unto.

[Sidenote 1: _De doct. ig. l. 2. c. 12._]

_Keplar_ thinkes that our earth receives that light whereby it shines from the Sunne, but this (saith he) is not such an intended cleare brightnesse as the Moone is capable of, and therefore hee guesses, that the earth there is of a more chokie soyle like the Ile of _Creete_, and so is better able to reflect a stronger light, whereas our earth must supply this intention with the quant.i.ty of its body, but this I conceive to be a needlesse conjecture, since our earth if all things were well considered, will be found able enough to reflect as great a light. For

1. Consider its opacity, if you marke these sublunary things, you shall perceive that amongst them, those that are most perspicuous, are not so well able to reverberate the Sunne beames as the thicker bodies. The rayes pa.s.se singly through a diaphanous matter, but in an opacous substance they are doubled in their returne and multiplyed by reflexion.

Now if the moone and the other Planets can shine so clearely by beating backe the Sunne beames, why may not the earth also shine as well, which agrees with them in the cause of this brightnesse their opacity?

2. Consider what a cleare light wee may discerne reflected from the earth in the middest of Summer, and withall conceive how much greater that must bee which is under the line, where the rayes are more directly and strongly reverberated.

3. Consider the great distance at which wee behold the Planets, for this must needs adde much to their shining and therefore _Cusa.n.u.s_ (in the above cited place) thinkes that if a man were in the Sunne, that Planet would not appeare so bright to him, as now it doth to us, because then his eye could discerne but little, whereas here wee may comprehend the beames as they are contracted in a narrow body. _Keplar_ beholding the earth from a high mountaine when it was enlightned by the Sunne confesses that it appeared unto him of an incredible brightnesse, whereas then the reflected rayes entered into his sight obliquely; but how much brighter would it have appeared if hee might in a direct line behold the whole globe of earth and these rayes gathered together? So that if wee consider that great light which the earth receives from the Sunne in the Summer, and then suppose wee were in the Moone, where wee might see the whole earth hanging in those vast s.p.a.ces where there is nothing to terminate the sight, but those beames which are there contracted into a little compa.s.se; I say, if wee doe well consider this, wee may easily conceive, that our earth appeares as bright to those other inhabitants in the Moone, as theirs doth to us.

Proposition 12.

_That tis probable there may bee such Meteors belonging to that world in the Moone, as there are with us._

_Plutarch_ discussing this point affirmes that it is not necessary there should be the same meanes of growth and fructifying in both these worlds, since nature might in her policy finde out more waies then one how to bring about the same effect. But however he thinks its probable that the Moone her selfe sendeth forth warme winds, and by the swiftnesse of her motion there should breathe out a sweet and comfortable ayer, pleasant dewes and gentle moysture, which might serve for the refreshing and nourishment of the inhabitants and plants in that other world.

But since they have all things alike with us, as sea and land, and vaporous ayer encompa.s.sing both, I should rather therefore thinke that nature there should use the same way of producing meteors as she doth with us (and not by a motion as _Plutarch_ supposes) because shee doth not love to vary from her usuall operations without some extraordinary impediment, but still keepes her beaten path unlesse she be driven thence.

One argument whereby I shall manifest this truth, may be taken from those new Starres which have appeared in divers ages of the world, and by their parallax have beene discerned to have been above the _M_oone, such as was that in _Ca.s.siopeia_, that in _Sagittarius_, with many others betwixt the Planets. _Hipparchus_ in his time tooke especiall notice of such as these,[1] and therefore fancied out such constellations in which to place the Starres, shewing how many there were in every asterisme, that so afterwards posterity might know, whether there were any new Starre produced or any old one missing. Now the nature of these Comets may probably manifest, that in this other world there are other meteors also; for these in all likelihood are nothing else but such evaporations caused by the Sunne, from the bodies of the Planets. I shall prove this by shewing the improbabilities and inconveniences of any other opinion.

[Sidenote 1: _Plin. nat. hist. l. 2. c. 26._]

For the better pursuite of this 'tis in the first place requisite that I deale with our chiefe adversary, _Caesar la Galla_, who doth most directly oppose that truth which is here to bee proved. Hee endeavouring to confirme the incorruptibility of the Heavens, and being there to satisfie the argument which is taken from these comets, He answers it thus:

_Aut argumentum desumptum ex paralaxi non est efficax, aut si est efficax, eorum instrumentorum usum decipere, vel ratione astri vel medii, vel distantiae, aut ergo erat in suprema parte aeris, aut si in clo, tum forsan factum erat ex reflectione radiorum Saturni & Jovis, qui tunc in conjunctione fuerant._

"Either the argument from the paralax is not efficacious, or if it be, yet the use of the instruments might deceive either in regard of the starre or the _medium_, or the distance, and so this comet might be in the upper regions of the aire, or if it were in the heavens, there it might be produced by the reflexion of the rayes from _Saturne_ and _Jupiter_, who were then in conjunction."

You see what shifts hee is driven to, how he runnes up and downe to many starting holes, that hee may find some shelter, and in stead of the strength of reason, he answers with a mult.i.tude of words, thinking (as the Proverbe is) that hee may use haile, when hee hath no thunder, _Nihil turpius_ (saith [1]*_Seneca_)

_dubio est incerto, pedem modo referente, modo producente._

"What can there bee more unseemely in one that should be a faire disputant, then to be now here, now there, and so uncertaine, that one cannot tell where to find him."

He thinkes that there are not Comets in the heavens, because there may be many other reasons of such appearances, but what he knowes not, perhaps (he saies) that argument from the parallax is not sufficient, or if it be, then there may be some deceit in the observation. To this I may safely say, that hee may justly be accounted a weake Mathematician who mistrusts the strength of this argument, nor can hee know much in Astronomy, who understands not the parallax, which is the foundation of that Science, and I am sure that hee is a timorous man, who dares not believe the frequent experience of his senses, or trust to a demonstration.

[Sidenote 1*: _Epist. 95._]

True indeed, I grant tis possible, that the eye, the _medium_, and the distance may al deceive the beholder, but I would have him shew which of all these was likely to cause an error in this observation? Meerely to say they might be deceived is no sufficient answer, for by this I might confute the positions of all Astronomers, and affirme the starres are hard by us, because 'tis possible they may be deceived in their observing that distance. But I forbeare any further reply; my opinion is of that Treatise, that either it was set forth purposely to tempt a confutation, that hee might see the opinion of _Galilaeus_ confirmed by others, or else it was invented with as much haste and negligence as it was printed, there being in it almost as many faults as lines.

Others thinke that these are not any new Comets, but some ancient starres that were there before, which now shine with that unusuall brightnesse, by reason of the interposition of such vapors which doe multiply their light, and so the alteration will be here onely, and not in the heavens. Thus _Aristotle_ thought the appearance of the milkie way was produced, for he held that there were many little starres, which by their influence did constantly attract such a vapour towards that place of heaven, so that it alwaies appeared white. Now by the same reason may a brighter vapor be the cause of these appearances.

But how probable soever this opinion may seeme, yet if well considered, you shall finde it to be altogether absurd and impossible: for,

1. These starres were never seene there before, and tis not likely that a vapour being hard by us can so multiply that light which could not before be at all discerned.