you shall perceive it by degrees to make _perpendicularly_ toward the
nearest part of the side, and the nearer it approaches, the faster to be
moved, the reason of which _Phænomenon_ will be found no other then this,
that the Air has a greater pressure against the middle of the
_superficies_, then it has against those parts that approach nearer, and
are _contiguous_ to the sides. Now that the pressure is greater, may (as I
shewed before in the explication of the third _Figure_) be evinced from the
flatting of the water in the middle, which arises from the gravity of the
under _fluid_: for since, as I shewed before, if there were no gravity in
the under _fluid_, or that it were equal to that of the upper, the
terminating Surface would be _Spherical_, and since it is the additional
pressure of the gravity of water that makes it so flat, it follows, that
the pressure upon the middle must be greater then towards the sides. Hence
the Ball having a stronger pressure against that side of it which respects
the middle of the _superficies_, then against that which respects the
_approximate_ side, must necessarily move towards that part, from whence it
finds least resistance, and so be _accelerated_, as the resistance
decrease. Hence the more the water is raised under that part of its way it
is passing above the middle, the faster it is moved: And therefore you will
find it to move faster in E then in D, and in D then in C. Neither could I
find the floating substance to be moved at all, until it were placed upon
some part of the _Superficies_ that was sensibly elevated above the height
of the middle part. Now that this may be the true cause, you may try with a
blown Bladder, and an exactly round Ball upon a very smooth side of some
pliable body, as _Horn_ or _Quicksilver._ For if the Ball be placed under a
part of the Bladder which is upon one side of the middle of its pressure,
and you press strongly against the Bladder, you shall find the Ball moved
from the middle towards the sides.

Having therefore shewn the reason of the motion of any float towards the