sented by figures answerable to those which we see in the Moon: I comprehend also, how the period of its illumination and variation of figure, would be monthly, albeit the Sun revolves round about it in twenty four hours: and lastly, I do not scruple to admit, that the half onely of the Moon seeth all the Earth, and that all the Earth seeth but onely half of the Moon. For what remains, I repute it most false, that the Moon can receive light from the Earth, which is most obscure, opacous, and utterly unapt to reflect the Suns light, as the Moon doth reflect it to us: and as I have said, I hold that that light which we see in the remainder of the Moons face (the splendid crescents subducted) by the illumination, is the proper and natural light of the Moon, and no easie matter would induce me to believe otherwise. The seventh, touching the mutual Eclipses, may be also admitted; howbeit that is wont to be called the eclipse of the Sun, which you are pleased to phrase the eclipse of the Earth. And this is what I have at this time to say in opposition to your seven congruities or resemblances, to which objections, if you are minded to make any reply, I shall willingly hear you.
Salv.If I have well apprehended what you have answered, it seems to me, that there still remains in controversie between us, certain conditions, which I made common betwixt the Moon & Earth, and they are these; You esteem the Moon to be smooth and polisht, as a Looking-glass, and as such, able to reflect the Suns light; and contrarily, the Earth, by reason of its montuosity, unable to make such reflection: You yield the Moon to be solid and hard, and that you argue from its being smooth and polite, and not from its being montuous; and for its appearing montuous, you assign as the cause, that it consists of parts more and less opacous and perspicuous. And lastly, you esteem that secondary light, to be proper to the Moon, and not reflected from the Earth; howbeit you seem not to deny the sea, as being of a smooth surface, some kind of reflection. As to the convincing you of that error, that the reflection of the Moon is made, as it were, like that of a Looking-glass, I have small hope, whilst I see, that what hath been read in the * Il Saggiatore, & Lettere Solari, two Treatises of Galilæus.* Saggiator and in the Solar Letters of our Common Friend, hath profited nothing in your judgment, if haply you have attentively read what he hath there written on this subject.
Simpl.I have perused the same so superficially, according to the small time of leasure allowed me from more solid studies; therefore, if you think you can, either by repeating some of those reasons, or by alledging others, resolve me these doubts, I will hearken to them attentively.
Salv.I will tell you what comes into my mind upon theinstant,
