Archimedes Texts

56
sented by figures answerable to those which we see in the Moon:
I comprehend also, how the period of its illumination and varia
tion 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 un
apt 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 remain
der 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.

The eminencies
and cavities in the
Moon are illusions
of its opacous and
perspicuous parts.

SALV. If I have well apprehended what you have answered, it
seems to me, that there still remains in controversie between us, cer
tain 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 perspi
cuous. 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 ^{*} Saggiator and in the Solar Letters of our Com
mon Friend, hath profited nothing in your judgment, if haply
you have attentively read what he hath there written on this sub
ject.

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.