But ſome may object, that this will not
conſiſt with that which was before deliver'd,
where I ſaid, that the thinneſt parts had leaſt
Light.
conſiſt with that which was before deliver'd,
where I ſaid, that the thinneſt parts had leaſt
Light.
If this were true, how comes it to paſs then
that this Air ſhould be as light as any of the
other parts, when as ’tis the thinneſt of all?
that this Air ſhould be as light as any of the
other parts, when as ’tis the thinneſt of all?
I anſwer, if the Light be receiv'd by Re-
flexion only, then the thickeſt Body hath moſt,
becauſe it is beſt able to beat back the Rays;
but if the Light be receiv'd by Illumination
(eſpecially if there be an Opacous Body be-
hind, which may double the Beams by Reſlecti-
on) as it is here, then I deny not but a thin
Body may retain much Light, and perhaps,
ſome of thoſe Appearances which we take
for Fiery Comets, are nothing elſe but a bright
Cloud enlightned; ſo that probable it is, there
may be ſuch Air about the Moon; and hence
it comes to paſs, that the greater Spots are
only viſible towards her middle parts, and
none near the Circumference; not, but that
there are ſome, as well in thoſe parts, as elſe-
where, but they are not there perceivable, by
reaſon of thoſe brighter Vapours which hide
them.
flexion only, then the thickeſt Body hath moſt,
becauſe it is beſt able to beat back the Rays;
but if the Light be receiv'd by Illumination
(eſpecially if there be an Opacous Body be-
hind, which may double the Beams by Reſlecti-
on) as it is here, then I deny not but a thin
Body may retain much Light, and perhaps,
ſome of thoſe Appearances which we take
for Fiery Comets, are nothing elſe but a bright
Cloud enlightned; ſo that probable it is, there
may be ſuch Air about the Moon; and hence
it comes to paſs, that the greater Spots are
only viſible towards her middle parts, and
none near the Circumference; not, but that
there are ſome, as well in thoſe parts, as elſe-
where, but they are not there perceivable, by
reaſon of thoſe brighter Vapours which hide
them.