311131That the Earth may be a Planet.
ſuch thing as a right Motion, whether of Aſ-
cent or Deſcent, in a ſtreight Line.
cent or Deſcent, in a ſtreight Line.
I anſwer:
The moving of heavy or light
11Sol. Bodies, may be conſidered in a double rela-
tion.
11Sol. Bodies, may be conſidered in a double rela-
tion.
1.
According to the ſpace wherein they
move, and then we grant their Motions not
to be ſimple, but mixed of a direct and cir-
cular.
move, and then we grant their Motions not
to be ſimple, but mixed of a direct and cir-
cular.
2.
According to the Body or medium
wherein they move, and then they may pro-
perly be ſaid to have right motions, becauſe
they paſs through the medium in a ſtreight
Line; and therefore it is, that unto us they
ſeem directly to aſcend or deſcend. Ariſto-
tle himſelf would not deny, but that Fire
may aſcend in a ſtreight Line unto its Sphere,
and yet participate alſo of that Circular
Motion which he ſuppoſes to be communica-
ted from the Heavens, unto the upper part
of the Air, and its own Region. So like-
wiſe muſt it be for the deſcent of any thing.
Suppoſe a Ship in its ſwifteſt motion, and a
Man in it, having ſome Veſſel filled with Wa-
ter, ſhould let fall into it a little Ball of
Wax, or ſome other matter which may be
ſlow in its ſinking, ſo that in one minute it
ſhould ſcarce deſcend the ſpace of a Cubit,
though the Ship (it may be) in the ſame
time may paſs at leaſt a hundred Cubits;
yet would this ſtill ſeem unto the eye to de-
ſcend in a ſtreight Line; and the other mo-
tion, which is communicated unto it by the
Ship, would not at all be diſcernable to it.
wherein they move, and then they may pro-
perly be ſaid to have right motions, becauſe
they paſs through the medium in a ſtreight
Line; and therefore it is, that unto us they
ſeem directly to aſcend or deſcend. Ariſto-
tle himſelf would not deny, but that Fire
may aſcend in a ſtreight Line unto its Sphere,
and yet participate alſo of that Circular
Motion which he ſuppoſes to be communica-
ted from the Heavens, unto the upper part
of the Air, and its own Region. So like-
wiſe muſt it be for the deſcent of any thing.
Suppoſe a Ship in its ſwifteſt motion, and a
Man in it, having ſome Veſſel filled with Wa-
ter, ſhould let fall into it a little Ball of
Wax, or ſome other matter which may be
ſlow in its ſinking, ſo that in one minute it
ſhould ſcarce deſcend the ſpace of a Cubit,
though the Ship (it may be) in the ſame
time may paſs at leaſt a hundred Cubits;
yet would this ſtill ſeem unto the eye to de-
ſcend in a ſtreight Line; and the other mo-
tion, which is communicated unto it by the
Ship, would not at all be diſcernable to it.