Knoxville journal. [volume] (Knoxville, Iowa) 1874-1986, 1875-05-13
Unbeatable Glass.

81 =
A Paris correspondent Of the Philadel-
phia Bullsttn writes: Some curious ex-
periments in glass, which were quite
novel to myself, though ] cannot say
whether they may be so to what Is tech
nically called the trade, took place be-
fore the French Academy Of Sciences at
the Institute last week, and seem de-
serving of some mention. If ] am re-
peating only what is well known already,
or has been even carried to q further
extent by American manufacturers of
the article IN question, must apologize
for my ignorance; but what was exhib-
tied at the French Institute seemed very
extraordinary, and was regarded by all
present as representing something which
has been considered as hitherto unattain-
able. There was brought In what is re-
garded in most French domestic estab-
lishments as an article of IndispeGsar
BILE household necessity, familiar under
the name of Verre d'E0at, and which
consists of stand water-bottle, two
glasses, and sugar basin, all of glass,
to which is generally appended smaller
bottle for feur d0rdnge, the whole being
intended, of course, for the fabrication
of that most universal of drinks
amongst all classes OF French peO-
pie, from the orator in the trib-
une to the concierge's wife in her
lOge, glass of can sucree. Well,
all these different objects--water-bo
tie, glasses, sugar-basin, stand itself
were taken up separately by Nj. de Lu-
bac, the well-known member OF the So
ciety for the Encouragement of French
Manufactures, and on the responsibility
of the inventor, M. de la Bastie, pitched
one after the other to considerable dis
lance, and, to our no small establishment
without giving rise TO any occasion for
"picking up the pieces They all, in
fact, remained unbroken and uninjured.
The secret of unbreakable glass; that
great boon to the peace Of families and the
nerves of housekeebers, seemed to be
solved. There were several ladies look
ing on, and you may imagine the deep
interest they took in discovery which
promised security to many of the most
cherished objects of their clt1nabre-d a couch.
en- and their dinner tables. Even bobeches,
or sconces for candles, Of the very light
est and thinnest description, were thrown
down upon the floor, from which they re-
bounded again without the slightest inju-
ry. The secret Of imparting this invaual-
able property to glass does not, 1T APP
pears, consist In any particular method OF
fabrication. Any sort OF glass can be
rendered unbreakable by subsequent
process to which it has to be submitted
for this purpose. The process consists
in 9 tempering" or hardening" the glass
after it is made (tremper is the French
word used to express the operatlon) by
immcrsing it in a solution at the heat at
which it usually melts. The composition
of the solution and the heat at which IL
is to be applied vary with the quality of
the glass which Is to be submitted to it.
| OF what the composition consists, the
exact mode of using it and of procuring
its results, the inventor, of course, told
us nothing; but a large usine de trenapdge,
or glass works, Is now in
course OF erection at Pont d'Ain, in the
Ain, near Bourg, for carrying on the
| process on large scale. l am told that
at the Society for the Encouragement OF
Manufactures itself the experiments
| were lately exhibited In still more re
markable manner, and that while plates
of ordinary glass there broke to pieces
by a fall Of one yard, those of tenn
pered" glass fell uninjured from height
of four yards, and when even struck
violently with hammer broke only like
flint or granite.