Salusbury, Thomas, Mathematical collections and translations (Tome I), 1667

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1do reduce its ſelf to its natural diſpoſure, and return to exerciſe

its pure ſimple inſtinct given it by nature.
it's neceſſary, that at leaſt that part of the Air which is beneath the
greater heights of mountains, ſhould be tranſported and carried
round by the roughneſs of the Earths ſurface; or that, as being
mixt with many Vapours, and terrene Exhalations, it do
turally follow the diurnal motion, which occurreth not in the
from the ſhip to the Tower hath not the force of an illation;
becauſe that ſtone which falls from the round top of the Maſt,
entereth into a medium, which is unconcern'd in the motion
of the ſhip: but that which departeth from the top of the Tower,
finds a medium that hath a motion in common with the whole
reſtrial Globe; ſo that without being hindred, rather being aſſiſted
by the motion of the air, it may follow the univerſal courſe of the
Earth.
The diſparity
tween the fall of a
ſtone from the
round top of a ſhip,
and from the top
of a tower.
*That you may not
ſuſpect my
tion, or wonder
what Oars have to
do with a ſhip, you
are to know that
the Author intends
the Gallies uſed in
the Mediterrane.
The part of the
Air inferiour to
the higher
tains doth follow
the motion of the
Earth.
SIMPL. I cannot conceive that the air can imprint in a very

great ſtone, or in a groſs Globe of Wood or Ball of Lead, as
ſuppoſe of two hundred weight, the motion wherewith its ſelf is
moved, and which it doth perhaps communicate to feathers, ſnow,
and other very light things: nay, I ſee that a weight of that
ture, being expoſed to any the moſt impetuous wind, is not
by removed an inch from its place; now conſider with your ſelf
whether the air will carry it along therewith.
The motion of the
Air apt to carry
with it light things
but not heavy.
SALV. There is great difference between your experiment and
our caſe.
You introduce the wind blowing againſt that ſtone,
ſuppoſed in a ſtate of reſt, and we expoſe to the air, which already
moveth, the ſtone which doth alſo move with the ſame velocity;
ſo that the air is not to conferr a new motion upon it, but onely
to maintain, or to ſpeak better, not to hinder the motion already
acquired: you would drive the ſtone with a ſtrange and
natural motion, and we deſire to conſerve it in its natural.
If
you would produce a more pertinent experiment, you ſhould ſay,
that it is obſerved, if not with the eye of the forehead, yet with
that of the mind, what would evene, if an eagle that is carried by
the courſe of the wind, ſhould let a ſtone fall from its talons;
which, in regard that at its being let go, it went along with the
wind, and after it was let fall it entered into a medium that
ved with equal velocity, I am very confident that it would not be
ſeen to deſcend in its fall perpendicularly, but that following the
courſe of the wind, and adding thereto that of its particular
vity, it would move with a tranſverſe motion.
SIMPI. But it would firſt be known how ſuch an experiment
may be made; and then one might judg according to the event.
In the mean time the effect of the ſhip doth hitherto incline to
vour our opinion.