Daily Kennebec journal. [microfilm reel] (Augusta, Me.) 1870-1975, 1875-06-26
NO. 151.
Mistellatifpus.
TOUGHENED GLASS-THE NEW DiEC0V.
ERY.


ERY.
The London Standard of May IS prints
the following:
There are few substances which form
SO material a part of our surroundings as
does glass. To discover method of rem
dering it practically unbreakable would
be to confer benefit upon humanity.
Until now all efforts in this direction have
failed. Patience and perseverance will,
however, do much, and a discovery has
been lately announced which will revolu-
tionize the manufacture and increase to a
fabulous extent the uses of glass. This
discovery has been made by a French
gentleman, M. Francois De la Bastie, and
is the result Of years of experiment and
labor. By the kindness Of Messrs Rey,
OF Mincing lane, the agents of NJ. De Ia
Bastie, we have been enabled to inspect
this invention, and to be present at the APP
| plication of tests which are absolutely de-
cisive as to its success. The brittleness of
glass is caused by the want of cohesion OF
| its particles. This absence of cohesion is
| so great that a sudden change of tempera-
ture is sometimes sufficient to make it fly
to pieces, and delicate glass is shivered by
the slightest shock. 1t has long been
known that gradual process of cooling
adds to the cohesion of the particles Of
glass; and plate glass. and indeed all
kinds of superior glass. are cooled very
gradually in what are termed annealing
ovens. The idea occurred to NJ. De la
Bastie that by some modification Of the
process a far better result might be OBJ
tanned, and after many experiments he
| found that sudden plunge into a bath of
oil ria nt
heat appeared entirely to change its prop
critics.
| At first he could only succeed in occasional
instances in rendering the glass unbreaka-
| BILE, but by slow degrees and endless ex-
periments as to the exact degree of heat
required he succeeded in establishing an
unfailing rule. Thus he found that were
the glass cooled in the slightest degree in
its passage from the oven to the oil bath,
| the required effects were not obtained. In
practice. therefore, he tips the glass di-
| rectly from its stand in the oven into the
bath placed beside it. The process in no
way alters the appearance OF the glass.
nor detracts from its clearness or trans
parancy. To the eye the glass remains as
before but its properties. indeed, it may be
said its very nature is changed. We saw
watch glasses and sheets of window glass
thrown high into air and fall upon the
ground with a crash some in falling came
half across wooden chair in a way which
would have snapped the strongest and
thickest ordinary glass had it fallen from
one-fitth of the height; we saw delicate
glass plates thrown recklessly on to the
floor, and window-glass placed under foot
and trodden upon. The glass might, no
doubt, have been broken with hammer,
but it would defy all ordinary risks of
breakage. Not only We're the properties
of the glass changed, but its very nature
was, as has been said, altered. 1t had ac-
quired so great hardness that it could no
longer be cut with a diamond. 1t had lost
much of it's power of conducting heat,
and when broken by deliberate force ii
split up into thousand fragments, which
were so destitute Of the ordinary sharp
ness of glass that one could plunge ones
hand into box full of them and bring out a
handful without fear of cutting the fingers.
Hence it was evident that the whole
moleclar arrangements OF the particles
composing il had been modified. This
loss of conducting power and this change
in fracture testified alike to the fact that
the alteration was not mere surface
change, but was extended through the
whole body of the glass; and this was fur
ther conclusiyely proved by the fact that
some plate glass. treated in the rough
state, and aiterward ground down 10 liale
more than halt its original thickness,
| could not be cut with the diamond No
change of temperature subsequent to the
| alteration affects the glass, OF deprive il
of its strength.
We saw an ar9and chimney which had
been over and over again heated almost
to redness at one end. while the tempefa-
ture at the other remained unaltered, and
vet it was as unbreakablc as nj first. We
saw water boiled in a rough and very
thick glass bowl on the fire, and then
taken off and lett to cool, and the expert
ment had been repeated dozens OF times
without impairing its properties. The
success OF the invention is indeed com
plete and unquestionable. Although il
cannot be cut with the diamond, the glass
can be engraved with the sand blast, and
can be ground in the same manner as
other glass. The fact of its resisting the
diamond is Il draw back, as it would have
to be cut into the sizes required for win
dows before being treated in the oil bath.
but experiments are at present being made
which seem to promise q favorable result
in cutting it by some other method. Huh
erto the invention has not been worked
upon Il large scale, the whole OF the glass
at present operated upon having been
treated by Nj. de la Baste, who is fortu-
nately possessed Of ample private means,
| in his laboratory. Works are at present in
course of erection in France to work the
invention commercially.
The advantages of this invention and
the new fields which it opens for the en-
ployment of glass are immense. OF the
benefit to house-keepers by the rendering
OF all the table glass. windows, and pier
glasses unbreakable, We need say nothing.
for this will be apparent to every reader.
In the article of glass chimneys alone the
consumption is at present enormous. We
should be afraid to mention the number OF
millions of chimneys for lamps which we
have heard are manufactured yearly in
France alone. Short indeed is the life OF
a chimney at present, and the constant
hreakage is one reason why lamps are not