Salusbury, Thomas, Mathematical collections and translations (Tome I), 1667
page |< < of 701 > >|
1Volumes; and yet not ſo much as one of the infinite admirable
concluſions that thoſe his writings contain, hath ever been
ſerved, or underſtood by any one, before Our Friend made
them out.
An intire and
new Science of the
ning local motion.
SAGR. You make me loſe the deſire I had to underſtand
more in our diſputes in hand, onely that I may hear ſome of
thoſe demonſtrations which you ſpeak of; therefore either give
them me preſently, or at leaſt promiſe me upon your word, to
appoint a particular conference concerning them, at which
plicius alſo may be preſent, if he ſhall have a mind to hear the
paſſions and accidents of the primary effect in Nature.
SIMP. I ſhall undoubtedly be much pleaſed therewith, though
indeed, as to what concerneth Natural Philoſophy, I do not think
that it is neceſſary to deſcend unto minute particularities, a
ral knowledg of the definition of motion, and of the
ction of natural and violent, even and accelerate, and the like,
ſufficing: For if this were not ſufficient, I do not think that
ſtotle would have omitted to have taught us what ever more was
neceſſary.
SALV. It may be ſo. But let us not loſe more time about
this, which I promiſe to ſpend half a day apart in, for your
faction; nay, now I remember, I did promiſe you once before to
ſatisfie you herein.
Returning therefore to our begun
tion of the time, wherein the grave cadent body would paſs from
the concave of the Moon to the centre of the Earth, that we may
not proceed arbitrarily and at randon, but with a Logical method,
we will firſt attempt to aſcertain our ſelves by experiments often
repeated, in how long time a ball v. g. of Iron deſcendeth to the
Earth from an altitude of an hundred yards.
SAGR. Let us therefore take a ball of ſuch a determinate
weight, and let it be the ſame wherewith we intend to make the
computation of the time of deſcent from the Moon.
SALV. This is not material, for that a ball of one, of ten, of an
hundred, of a thouſand pounds, will all meaſure the ſame hundred
yards in the ſame time.
SIMP. But this I cannot believe, nor much leſs doth Ariſtotle
think ſo, who writeth, that the velocities of deſcending grave
bodies, are in the ſame proportion to one another, as their
vities.
SALV. If you will admit this for true, Simplicius, you muſt

lieve alſo, that two balls of the ſame matter, being let fall in the
ſame moment, one of an hundred pounds, and another of one,
from an altitude of an hundred yards, the great one arriveth at the
ground, before the other is deſcended but one yard onely: Now
bring your fancy, if you can, to imagine, that you ſee the great