1leſcope upon the ſunne; but alſo when a
large and well defin'd image of the ſunne
is by the ſame teleſcope brought into a
roome and caſt upon a ſheet of white pa
per. But to inſiſt on this were to digreſs:
and therefore I will proceed to experi
ments of another kind.
large and well defin'd image of the ſunne
is by the ſame teleſcope brought into a
roome and caſt upon a ſheet of white pa
per. But to inſiſt on this were to digreſs:
and therefore I will proceed to experi
ments of another kind.
IT has been admir'd by very ingenious
Men, that if the exquiſitly poliſh'd
ſurfaces of two flat peeces of marble be ſo
congruous to each other that from their
mutuall application there will reſult an
immediate contact, they will ſtick ſo faſt
together, that he that lifts up the upper
moſt, ſhall, if the undermoſt be not ex
ceeding heavy, lift up that too, and ſuſ
taine it aloft in the free aire. A proba
ble cauſe of this ſo cloſe adheſion we have
elſewhere endeavour'd to deduce from the
unequall preſſure of the Air upon the un
dermoſt ſtone; For the lower ſuperficies
of that ſtone being freely expos'd to the
Air is preſſ'd upon by it, whereas the up
permoſt ſurface, being contiguous to the
ſuperiour ſtone, is thereby defended from
the preſſure of the Air which conſequent
ly preſſing the lower ſtone againſt the up-
Men, that if the exquiſitly poliſh'd
ſurfaces of two flat peeces of marble be ſo
congruous to each other that from their
mutuall application there will reſult an
immediate contact, they will ſtick ſo faſt
together, that he that lifts up the upper
moſt, ſhall, if the undermoſt be not ex
ceeding heavy, lift up that too, and ſuſ
taine it aloft in the free aire. A proba
ble cauſe of this ſo cloſe adheſion we have
elſewhere endeavour'd to deduce from the
unequall preſſure of the Air upon the un
dermoſt ſtone; For the lower ſuperficies
of that ſtone being freely expos'd to the
Air is preſſ'd upon by it, whereas the up
permoſt ſurface, being contiguous to the
ſuperiour ſtone, is thereby defended from
the preſſure of the Air which conſequent
ly preſſing the lower ſtone againſt the up-