And this will make probable my next Position, That _the parts of the Glass
are under a kind of tension or flexure, out of which they indeavour to
extricate and free themselves_, and thereby all the parts draw towards the
Center or middle, and would, if the outward parts would give way, as they
do when the outward parts cool leisurely (as in baking of Glasses) contract
the bulk of the drop into a much less compass. For since, as I proved
before, the Internal parts of the drop, when fluid, were of a very rarified
Texture, and, as it were, tos'd open like a Lock of Wool, and if they were
suffered leisurely to cool, would be again prest, as it were, close
together: And since that the heat, which kept them bended and open, is
removed, and yet the parts not suffered to get as neer together as they
naturally would; It follows, that the Particles remain under a kind of
_tension_ and _flexure_, and consequently have an indeavour to free
themselves from that _bending_ and _distension_, which they do, as soon as
either the tip be broken, or as soon as by a leisurely heating and cooling,
the parts are nealed into another posture.
And this will make my next Position probable, that _the parts of the Glass
drops are contignated together in the form of an Arch_, cannot any where
yield or be drawn inwards, till by the removing of some one part of it (as
it happens in the removing one of the stones of an Arch) the whole Fabrick
is shatter'd, and falls to pieces, and each of the Springs is left at
liberty, suddenly to extricate it self: for since I have made it probable,
that the internal parts of the Glass have a contractive power inwards, and
the external parts are incapable of such a Contraction, and the figure of
it being spherical; it follows, that the superficial parts must bear
against each other, and keep one another from being condens'd into a less
room, in the same manner as the stones of an Arch conduce to the upholding
each other in that Figure.
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