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Properties of Glass
Amid ancient texts there nestles a subtle reflection
of how, over the period of the late 6th century B.C. to the mid
8th century A.D., inquiring minds came to grips with the distinctive
physical and technical properties of glass. The philosophical insight
of Aristotle gave way to the puzzlement of Lucretius; the empirical
perceptiveness of Pliny gave way to the scientific certainty of
Agricola:
"...for in some cases, if we saw we should
not seeknot on the grounds that we knew by seeing, but that
we grasped the universal by the seeing. For example, if we saw the
glass [hyalos] to be perforated and the light coming through
it, it would be clear why it does, even if seeing occurs separately
for each piece of glass while comprehending grasps from one time
that it is thus in every case." (Aristotle, Posterior Analytics
I.31)
"But when the opposed object is bright and
compact, as particularly a mirror [speculum], nothing happens
of the sort; for the image cannot pass through as through glass
[vitrum], nor again can they be broken; so much safety the
smoothness never forgets to afford." (Lucretius, On the
Nature of Things IV.150)
"...and yet glass globes [vitreae pilae]
containing water become so hot when they face the sun that they
can set clothes on fire. Pieces of broken glass can, when heated
to a moderate temperature, be stuck together, but that is all. They
can never again be completely melted except into globules separated
from each other." (Pliny the Elder, Natural History
XXXVI.199)
About halfway along that path to scientific understanding,
the Romans created an industry out of a craft.
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Faceted beaker from
Pompeii
Mid 1st century A.D.
Ht.,17.0 cm
Globular jar with
collared rim
Early 2nd century A.D.
Ht., 15.7 cm
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