Archimedes Texts

79
of the Sun capable to penetrate the substance of the Moon, he
makes her in part diaphanous, as is v. g. the transparence of a cloud,
or crystal: but I know not what he would think of such a tran
sparency, in case the solar rayes were to passe a depth of clouds
of above two thousand miles; but let it be supposed that he
should boldly answer, that might well be in the Cœlestial, which
are quite other things from these our Elementary, impure, and
feculent bodies; and let us convict his error by such wayes, as
admit him no reply, or (to say better) subter-fuge. If he will
maintain, that the substance of the Moon is diaphanous, he
must say that it is so, whilest that the rayes of the Sun are to pe
netrate its whole profundity, that is, more than two thousand
miles; but that if you oppose unto them onely one mile, or
lesse, they should no more penetrate that, than they penetrate
one of our mountains.

The Author of the
Book of conclusi
ons, accommodates
the things to his
purposes, and not
his purposes to the
things.

SAGR. You put me in mind of a man, who would have sold

me a secret how to correspond, by means of a certain sympathy of
magnetick needles, with one, that should be two or three thou
sand miles distant; and I telling him, that I would willingly buy
the same, but that I desired first to see the experiment thereof,
and that it did suffice me to make it, I being in one Chamber, and
he in the next, he answered me, that in so small a distance one
could not so well perceive the operation; whereupon I turn'd him
going, telling him, that I had no mind, at that time, to take a
journey unto Grand Cairo, or to Muscovy, to make the experi
ment; but that, if he would go himself, I would perform the
other part, staying in Venice. But let us hear whither the dedu
ction of our Author tendeth, and what necessity there is, that he
must grant the matter of the Moon to be most perforable by the
rayes of the Sun, in a depth of two thousand miles, but more
opacous than one of our mountains, in a thicknesse of one mile
onely.

A jest put upon one
that would sell a
certain secret for
holding correspon
dency with a person
a thousand miles
off

SALV. The very mountains of the Moon themselves are a
proof thereof, which percussed on one side of the Sun, do cast
on the contrary side very dark shadows, terminate, and more di
stinct by much, than the shadows of ours; but had these moun
tains been diaphanous, we could never have come to the know
ledg of any unevennesse in the superficies of the Moon, nor have
seen those luminous montuosities distinguished by the terms which
separate the lucid parts from the dark: much lesse, should we see
this same term so distinct, if it were true, that the Suns light did
penetrate the whole thicknesse of the Moon; yea rather, accord
ing to the Authors own words, we should of necessity discern the
passage, and confine, between the part of the Sun seen, and the
part not seen, to be very confused, and mixt with light and