The Stourbridge Observer, Cradley Heath, Halesowen & District Chronicle.
Stourbridge, West Midlands, England, 1875-05-15 00:00:00

TOUGHENED GLASS.

The Paris Correspondent of The Times, writing to tha \
Journal under date biay 9, says :
"You gave an account a few weeks ago of the dis-
covery by M. Francois del a Bastie, a French engineer,
of a process by which glass while retaining its trans-
parency practically ceases to be brittle. Yesterday
evening M. Victor de Luynes' who, with M. de Bastie's
sanction, has for some weeks been making experiments
at a glass manufactory, delivered a lecture on the
subject at the annual meeting of the SociAt4 de Secants
des Amis des Sciences. M. Dumas, the distinguished
chemist and permanent secretary of the It cacl4mie des
Sciences, presided, and the large amphitheatre of
the Faculty of Arts at the Sorbonne was crowded,
most of the members of scientific bodies and
the chief glass manufacturers being among the
audience. M. de in Bastie himself was also pre-
sent. M. de Luynes explained the expansion and
compression of the exterior and interior parts caused
by immersing glass heated to a certain tempeaature in
an oleaginous bath, and he gave some highly interest-
ing proofs of the success of the process. Thus he
applied some vigorous blows with a hammer to a piece
of glass which in its ordinary condition must have
been broken into fragments, but which sustained this
violence without being any the worse for it. A small
tube of thin twisted glass being fastened in a vice, he
endeavoured to break off the extremity of it with a
pair of pincers, but it was only after several attempts
and by dint of much evident muscular exertion that he
succeeded in doing so. A furnace, moreover,
was brought into the hall, and a number of
small globes and pieces of sheet glass were
submitted to the toughening process. M. de
Luynes then threw some of them on .the floor to
show that they could bear the shock. The globes were
fastened by strings to staves of wood at various heights,
and an assistant mounting a ladder and setting fire to
the string, they fell on the table with considerable
force, thence rebounding on the floor, but only one or
two of them were fractured, and those only when fall-
ing four or five yards. The assistant also mounted on
a curved plate of glass placed on the table so as to re-
present an arc of a Arcle, but though the portion of the
glass on which he stood was an inch or two above the
table it bore the whole weight of his body. A similar
experiment with much thinner glass was not so suc-
cessful, but M. de Luynes stated that it had previously
borne the strain though it had been necessary for the
assistant to mount upon it somewhat carefully so as
to equalize the pressure as much as possible. Of
course M. de is Bastie, as M. de Luynes explained,
does not pretend that glass thus tempered is absolutely
free from danger of breakage, but he claims that it
will bear 80 or 100 times the strain of ordinary glass,
and last night's experiments afforded conclusive
evidenee of the value of the discovery. The glass,
moreover, it is stated, can be cut under certain
conditions as easily as common glass. By means
of the electric light M. de Luynes gave some in-
teresting experiments of the optical prcperties of
glass the distribution of the colours, which were
very brilliant, depending on the shape given to the
object. The audience showed the utmost interest in the
experiments and explanations, the fOrmer evoking fre-
quent applause. The greater durability of glass articles
will obviously be a disadvantage to the trade, but
again 4 this must be set the use of glas for many pus-
from which'its brig.lo.w.j4asi ,lititkr.to excluded
it. Not only will it be aPplied t!i—many domeetic wzr-
peaeo. but in ebras branclaU ol rasufactuie it is likely