Sullivan republican. [volume] (Laporte, Pa.) 1883-1896, 1890-01-24
A GLASS FACTORY.
How the Glass is Melted, Rolled
and Blown.
Liability of the Workmen to
Burns and BliSterS.

great central furnaces in which the
glass is melted. The most uno bservant
person will have noticed that ordinary
glass presents itself in three aspects
brown, green and stainless white or flint
glass. The former tints arc due to the
presence of IRON oxide in the sand,
which is one of the principal ingredi-
ents. When colerless glass is desired
the iron has to be eliminated, or the
color masked by suitable means, and it
is a noteworthy fact that proportion
of iron in the sand too small to be in
dicated by the most delicate assay will
impart distinct hue to glass. Differ
ent metallic oxides impart different
hues; thus tin or arsenic will render
the product white and Opaque; gold
will give a ruby red; copper, in the
form of black oxide with little iron
ore, will yield an emerald green prod
uct; cobalt t-oxide blue; manganese
purple; oxide of uranium yellow, and
SO on.
1t follows that where colorless glass is
desired the greatest care has to be
taken to insure the use of sand in
which the metallic oxides referred to
are distinguished by their absence.
The furnace takes up quite large
part of the room in a glass factory, and
is circular in form, to enable the opera
tors to approach the pots from all sides
AS these melting pots are of large size
(scme are 55 inches in diameter) and
have to withstand continuously heat
which will easily melt iron or steel, it
follows that they have to be made of
wel-kneaded, tempered and annealed
fire-clay. There is glorious uncer-
tainty about the life of melting pot.
1t may give way and break up in eight
hours or it may last for months. In
any case the sides wear through and get
thin, In the lapse of time, from the alb
sorption of the clay into the vitrifed
molten mass within. Just so long as
good pot can be patched up and forti-
fed it is kept in use, but when a pot
has to be removed, no matter under
what circumstances, it means a hot,
hard days work for all hands. The
first thing is to dislodge the broken
fragments of the pot, or the whole affair
bodily if not broken, by battering-ram
blows directed with gigantic crowbar
into the interior of a furnace heated
like unto that into which Shadrach,
Meshech and Abednego were cast in the
days of old. When the work Is COM
pleted the new pot, already annealed
and heated to whiteness, has to be
placed in position, and as the pot and
contents may weigh many hundred
pounds, the ordeal is necessarily severe
one. Burns and blisters are every day
occurrences in glass factory.
1t is busy scene, this interior of a
glass factory in full blast. About
hundred hands, men and boys in nearly
equal proportions, are employed. First
an operator sticks the end of a long
iron tube into a glowing white hole
and draws the instrument forth with a
glistening gelatipous looking mass at
the end. He rolls this mass actively
for few moments ON fiat slab called
"marver." The marver is placed in
slightly inclined position ON wooden
slab, and the rolling of the gl ass on
the surface, easy as it looks, is quite an
art.
While the glass is still in the soft,
pasty condition, the operator blows it
slightly and guides the lump into the
interior of a mold closed by treadle,
blowing it all the time. The trans
formation is almost ins tan taneous, and
when the pressure OF the treadle is re-
leased the tube is Withdrawn, with
'full blown bottle at the end of it.
As already remarked, this bottle mould
Is an American invention, and the saw
ing in the case of cheap goods is very
great. The bottles are annealed-a
process of re-heating and gradual cool
ing-and finished off at the necks, ETC..
by manipulation at the "glory-holes"
smaller furnaces.
In another part of the factory the
visitor witnessed the making of carboys,
or the huge jars employed to hold acids
and liquors in bulk, the final shape in
this instance also being given by press
ure in a suitable mold The carboy.
before being taken to the annealing
furnace, is detached fr ON the blowing