1times bigger than the naked and real body: and a like or greater
augmentation doth the image of the Sun make, which you ſee in
that glaſs. I ſay greater, for that it is more lively than the ſtar,
as is manifeſt from our being able to behold the ſtar with much
leſs offence, than this reflection of the glaſs. The reverberation
therefore which is to diſpere it ſelf all over this wall, cometh from
a ſmall part of that glaſs, and that which even now came from
the whole flat glaſs diſperſed and reſtrain'd it ſelf to a very ſmall
part of the ſaid wall. What wonder is it then, that the firſt
flection very lively illuminates, and that this other is almoſt
perceptible?
augmentation doth the image of the Sun make, which you ſee in
that glaſs. I ſay greater, for that it is more lively than the ſtar,
as is manifeſt from our being able to behold the ſtar with much
leſs offence, than this reflection of the glaſs. The reverberation
therefore which is to diſpere it ſelf all over this wall, cometh from
a ſmall part of that glaſs, and that which even now came from
the whole flat glaſs diſperſed and reſtrain'd it ſelf to a very ſmall
part of the ſaid wall. What wonder is it then, that the firſt
flection very lively illuminates, and that this other is almoſt
perceptible?
The ſmall body of
the ſtars fringed
round about with
rays, appeareth
ry much biggerthan
plain and naked,
and in its native
clarity.
the ſtars fringed
round about with
rays, appeareth
ry much biggerthan
plain and naked,
and in its native
clarity.
SIMPL. I find my ſelf more perplexed than ever, and there
preſents it ſelf unto me the other difficulty, how it can be that
that wall, being of a matter ſo obſcure, and of a ſuperficies ſo
poliſh'd, ſhould be able to dart from it greater light, than a glaſs
very ſmooth and polite.
preſents it ſelf unto me the other difficulty, how it can be that
that wall, being of a matter ſo obſcure, and of a ſuperficies ſo
poliſh'd, ſhould be able to dart from it greater light, than a glaſs
very ſmooth and polite.
SALV. Greater light it is not, but more univerſal; for as to
the degree of brightneſs, you ſee that the reflection of that ſmall
flat glaſs, where it beamed forth yonder under the ſhadow of the
penthouſe, illuminateth very much; and the reſt of the wall which
receiveth the reflection of the wall on which the glaſs is placed,
is not in any great meaſure illuminated, as was the ſmall part on
which the reflection of the glaſs fell. And if you would
ſtand the whole of this buſineſs, you muſt conſider that the
ficies of that wall's being rough, is the ſame as if it were
ſed of innumerable ſmall ſuperficies, diſpoſed according to
numerable diverſities of inclinations: amongſt which it
rily happens, that there are many diſpoſed to ſend forth their
reflex rays from them into ſuch a place, many others into another:
and in ſum, there is not any place to which there comes not very
many rays, reflected from very many ſmall ſuperficies, diſperſed
throughout the whole ſuperficies of the rugged body, upon which
the rays of the Sun fall. From which it neceſſarily
eth, That upon any, whatſoever, part of any ſuperficies,
oppoſed to that which receiveth the primary incident rays,
there is produced reflex rays, and conſequently
nation. There doth alſo follow thereupon, That the ſame
body upon which the illuminating rays fall, beheld from
whatſoever place, appeareth all illuminated and ſhining: and
therefore the Moon, as being of a ſuperficies rugged and
not ſmooth, beameth forth the light of the Sun on every
ſide, and to all beholders appeareth equally lucid. But if
the ſurface of it, being ſpherical, were alſo ſmooth as a glaſs, it
would become wholly inviſible; foraſmuch as that ſmall part,
from which the image of the Sun ſhould be reflected unto the eye
the degree of brightneſs, you ſee that the reflection of that ſmall
flat glaſs, where it beamed forth yonder under the ſhadow of the
penthouſe, illuminateth very much; and the reſt of the wall which
receiveth the reflection of the wall on which the glaſs is placed,
is not in any great meaſure illuminated, as was the ſmall part on
which the reflection of the glaſs fell. And if you would
ſtand the whole of this buſineſs, you muſt conſider that the
ficies of that wall's being rough, is the ſame as if it were
ſed of innumerable ſmall ſuperficies, diſpoſed according to
numerable diverſities of inclinations: amongſt which it
rily happens, that there are many diſpoſed to ſend forth their
reflex rays from them into ſuch a place, many others into another:
and in ſum, there is not any place to which there comes not very
many rays, reflected from very many ſmall ſuperficies, diſperſed
throughout the whole ſuperficies of the rugged body, upon which
the rays of the Sun fall. From which it neceſſarily
eth, That upon any, whatſoever, part of any ſuperficies,
oppoſed to that which receiveth the primary incident rays,
there is produced reflex rays, and conſequently
nation. There doth alſo follow thereupon, That the ſame
body upon which the illuminating rays fall, beheld from
whatſoever place, appeareth all illuminated and ſhining: and
therefore the Moon, as being of a ſuperficies rugged and
not ſmooth, beameth forth the light of the Sun on every
ſide, and to all beholders appeareth equally lucid. But if
the ſurface of it, being ſpherical, were alſo ſmooth as a glaſs, it
would become wholly inviſible; foraſmuch as that ſmall part,
from which the image of the Sun ſhould be reflected unto the eye
zoom in
zoom out
zoom area
full page
page width
set mark
remove mark
get reference
digilib