Nashville union and American. [volume] (Nashville, Tenn.) 1868-1875, 1875-04-24
RECOVERY OF A LOST ART.
Glass without NEUTRALITY-SUSPICIOUS. In
VenfiOn OF q French EngtReeE-Im-
pOFtant Results.
London Times.

Seven years since, II. Francis de Ia Bas-
lie, French engineer, after long and pa
tient investigation into the subject, discov-
cred a simple means Of rendering glass
practically unbrittle, and at the same time
of preserving its transparency. There
were many delicate conditions involved in
the process by which he obtained this re-
suit, but on endeayoring to repeat the sue
eeSsful experiment he failed signally. For
two years more NJ. de Ia Bastie, who pos
sesSes ample means, stroye without avail
70 rediscOver the secret Of his success. At
length, however, he succeeded in so doing,
and has since been engaged in perfecting
his invention and in developing a labOra-
tory experiment into practical working.
The process Of conversion in. the
main is a very simple one, so
simple that it seems singular it was
never thought Of before. Broadly
stated, it consists in heating the glass at a
certain temperature and ~plunging it while
hot into a bath consisting Of a heated Olea-
ginOus compound. There are, however,
many conditions in connection with the de-
tails Of the process upon which a s~atisfac-
tory result depends, and the neglect Of any,
even in a slight degree. constitutes the diff
ference between success and fsilure. Thus,
the glass may be U~nderheated and will not
be susceptible to the effect Of the bath, or it
may be overheated and it will then loose
It's shape, or, again, it may be rightly heat
ed and yet be spOilt in the course Of trans
ference to the bath. Moreover, the Oleagin-
Gus constituents Of the bath and their tenn
peratUre have an important bearing upon
the ultimate result. These and numerous
other points of detail have all been salts
f~actOrily settled by NJ. de la Bastie, who
has designed furnaces and baths by means
Of which his tOugheniDg process can be
carried out practically without fear Of mis-
chance. The time occupied in the actual
process Of temPering is merely nominal,
for directly the articles are brought to the
required temperature they are plunged into
the bath and instantly Withdrawn. The
cost Of tempering, too, is stated TO be very
small.
A number of ~toughened glass articles at
the offices of MesSrS. Abel Rev Il Bros, %
Mincing lane, consisting of watch-glasses,
plates, dishes, and sheet glass, both colOred
and plain. Neither transparency nor color
is affected at all, and the ring or sOund only
slightly. These aTtIcles-some Of them
being exceedingly thin-were thrown in
Discriminatory across a room against a wall
and fell spinning on the deal floor. Water
was boiled IN a saucer over a FIRE and the
saucer was quickly removed to a COMPARE
lively cold place, and was unaffected by the
sudden change Of temperature. One cor
ner Of a piece Of glass was held by the
hand IN q gas flame until the VI be-
came exceedingly hot, but the heat was
not communicated 10 the other portion Of
the glass, neither was l. cracked from I'M
equal expansion. A comparative expert
meHt was then made with a piece Of ordi-
nary pate glass, and d similar piece Of
tOugEeued glass, in order 10 show their re-
spective powers Of resistance to fracture,
from the force Of impact by a falling
weight. In each case the glass was abOUt6
inches square, and was placed IN q frame,
the weight being dropped upon its centre.
With the ordinary glass, a 2-Ounce brass
weight falling on it from a height of l.
and is inches respectively did no damage,
but at - inches the glass was broken into
several fragments. With a thinner piece
Of t~Oughened glass no impression was made
10y the same weight, falling from heights
ranging from 2 to 10 feet, the weight sim
ply reDOuudiDg from eli the glass. An
S-ounce iron weight tried > and ( feet re-
spectiyely gave similar results. Upon the
height being increased 70 9 feet, however.
the glass broke. But here another siugI-
lar result was produced; instead Of break
ing into about q dozen pieces, as did the
ordinary glass, it was literally smashed To
atoms. The largest fragments measured
about half N inch in length and breadth,
and these were easily reduced by the I'm
gers 70 atoms varying in size from that Of
a pins point 10 that Of a large pins head.
The lines Of fractures in the fragments pre-
sented 10 the eye the appearance Of irregu-
lar lace work.
The applications which suggest them
Sc yes are inuumerable, and above and be-
youd tie usefulness Of the process with re-
gard 10 articles of domestic use come I'M
pOrtaut considerations affecting the applied
sciences, especially in connection with
chemical manufactures and similar indus
tries, where 4 material, alike u~ninluenced
by the action Of heat or acids, has been so
I long and so vaiuly sought fJr-u0lably In
connection with yitriOl chambers I'm the
manufacture Of sulPhUric acid, and for
piping in chemical works. For the present
there remains one purpose to which tOu-
eued glass cannot be so easily applied, and
that is TO window glazing III odd sizes, in
aSmuch as il cannot be cut by . diamond
or other ordinary means. The glass how
7 ever, IS readily engraved either by fuoric
acid in the usual way, or by Mr.. Thigh
mans elegant sand-blast process.
"
EMPEROR WILLIAM, by a decree,
last month, ordered thirtynew fortress
es and more ground to be bought for
the enlargement Of certain works Of
ratification now existing on the side Of
the Empire looking toward Russia.
THE unknown quantity in Massa-
chusetts politics, this year, is-as usual
"a person Of the name Of Butler. ANY
professional or amateur cipheTer who
ignores "the General viii be liable to
find that the sum doesn't add up right.