The Stourbridge Observer, Cradley Heath, Halesowen & District Chronicle.
Stourbridge, West Midlands, England, 1875-06-12 00:00:00

TOUGHENED GLASS.

In London, on Wednesday evening in last week, a
paper was read before the Society of Arts, by Mr.
Perry F. Ntu-sey, C.E., on toughened glass, a subject
which has of late attracted considerable attention.

The chair was taken by COlone-f-§Witi;,-FIE.-§7,- ";11'd
the subject attracted a crowded audience.

Mr. Nursey commenced by referring to the impor-
tant part glass had played in promoting the advance-
ment of civilization and to the antiquity of its manu-
facture, which he showed there was reason to believe
was known to the children of Israel in their bondage.
The origin of glass, he stated, had been attributed
by Pliny to the Phamicians, who happened to use
some lumps of natron on the river shore for resting
their cooking pots on, when the fire fused the
netron and the sand together and formed glass. It
was more probable, he observed, that the idea was first
suggested by the -vitreous formation attendant upon
the firing of bricks and pottery and the reduction of
metallic ores. After touching briefly upon the de-
velopment of the glass manufacture in later times in
Venice, France, and England, the author pointed out
that we were now producing glass which did not differ
materially as regarded its physical features from that
made in the days of Pharaoh. He then described the
physical features of Prince R ipert drops and the
Bologna phials, with the object of showing that they
and toughened glass were in no way analogous, but
opposite; the drops being produced by dropping
melted glass into cold water, and toughened glass
being made by dipping the heated glass into a heated
oleaginous compound. Both the drops era the
phials flew to pieces if the skin were scratched,
while toughened glass was unaffected by being
scratched by the diamond or cut with the wheel.
Mr. Nursey then described the toughened glass of M.
de la Bastie, its method of manufacture, and its pecu-
liar characteristics, together with such physical features
as had developed themselves so far as investigation had
yet gone. As a full description of toughened glass
has already been published, it will only be necessary
to observe that the process of toughening consists in
heating ordinary glass and while hot dipping it into a
heated bath of oleaginous matter. When used by
glass manufacturers, the process of dipping would be
substituted for the ordinary annealing process, whereby
a great saving in time and cost for fuel and breakages
would be effected. The author stated that the
value of the invention had been appreciated by
some of our leading glass manufacturers, who
were negotiating for licences to work M. de la
Bastie's English patent. The author concluded his
paper by observing that the invention was BO remark-
able, so unique, and apparently so fraught with import
to the arts, sciences, and manufactures, as to render it
probable that the name De in Bastie would one day
occupy no mean position among those of men by whose
genius science had been enriched, and the nations prac-
tically benefited. At the concluson of the paper, Mr.
Nursey experimented with toughened and untoughened
glass articles, showing the infinitely greater resistance
to the force of impact possessed by the former over the
latter. A square of ordinary plate glass fin. by sin.
by tin. thick, was broken by a weight of 4oz. falling
on it from a height of 12in. The same weight was then,
dropped upon a square of toughened glass of simi-
lar dimensions from a height of 10ft., hut without
breaking the glass. A weight of Boz. was then sub-
stituted with similar results. Mr. Nursey then threw
the weight several times on the glass with great force
without breaking it, but he ultimately smashed it
with a hammer. • Watch glasses, glass plates, coloured
and plain, were then put to the test by being thrown
violently on the bare floor without damage. One plate
was dropped from a height of sft. on to an iron
grating and rebounded into the air intact.
An animated discussion then followed upon the
merits of the invention, but which was of necessity
rather theoretical than practical, the author, in his
reply, meeting all the objections raised.
The meeting was brought to a close by a cordial vote
of thanks to the author for what the chairman ob-
served was a highly interesting -paper.