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

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1fail, and the ball runs tripping along the ground, or rebounds leſſe
than uſual, and breaketh the time of the return.
Hence it is

that you ſee, thoſe who play at ^{*} Stool-ball, when they play in
a ſtony way, or a place full of.
holes and rubs that make the ball
trip an hundred ſeveral wayes, never ſuffering it to come neer the
mark, to avoid them all, they do not trundle the ball upon the
ground, but throw it, as if they were to pitch a quait.
But
cauſe in throwing the ball, it iſſueth out of the hand with ſome
roling conferred by the fingers, when ever the hand is under the
ball, as it is moſt commonly held; whereupon the ball in its lighting
on the ground neer to the mark, between the motion of the
jicient and that of the roling, would run a great way from the
ſame: To make the ball ſtay, they hold it artificially, with their
hand uppermoſt, and it undermoſt, which in its delivery hath
a contrary twirl or roling conferred upon it by the fingers, by
means whereof in its coming to the ground neer the mark it ſtays
there, or runs very very little forwards.
principal problem which gave occaſion for ſtarting theſe others; I
ſay it is poſſible that a perſon carried very ſwiftly, may let a ball
drop out of his hand, that being come to the Earth, ſhall not
onely follow his motion, but alſo out-go it, moving with a
er velocity.
And to ſee ſuch an effect, I deſire that the courſe
may be that of a Chariot, to which on the out-ſide let a
ning board be faſtened; ſo as that the neither part may be towards
the horſes, and the upper towards the hind Wheel.
Now, if in
the Chariots full career, a man within it, let a ball fall gliding
long the declivity of that board, it ſhall in roling downward
quire a particular vertigo or turning, the which added to the
motion impreſſed by the Chariot, will carrie the ball along the
ground much faſter than the Chariot.
And if one accommodate
another declining board over againſt it, the motion of the
riot may be qualified ſo, that the ball, gliding downwards along
the board, in its coming to the ground ſhall reſt immoveable,
and alſo ſhall ſometimes run the contrary way to the Chariot.
But
we are ſtrayed too far from the purpoſe, therefore if Simplicius
be ſatisfied with the reſolution of the firſt argnment againſt the
Earths mobility, taken from things falling perpendicularly, we
may paſſe to the reſt
*A Game in Italy,
wherein they ſtrive
who ſhall trundle
or throw a wooden
bowle neereſt to an
aſſigned mark.
SALV. The digreſſions made hitherto, are not ſo alienated
from the matter in hand, as that one can ſay they are wholly
ſtrangers to it.
Beſides theſe argumentations depend on thoſe
things that ſtart up in the fancy not of one perſon, but of three,
that we are: And moreover we diſcourſe for our pleaſure, nor
are we obliged to that ſtrictneſſe of one who ex profeſſo treateth
methodically of an argument, with an intent to publiſh the ſame.