The Indianapolis journal. [volume] (Indianapolis [Ind.]) 1867-1904, 1886-04-11
MAKING A GLASS.
Results Obtained by Using Natural Gas-Hov
the Glass Is Made.

Results Obtained by Using Natural Gas-How
the Glass L. Made.
Cincinnati sun.
There is a plate of glass 66x54 inches, which
Is the largest size made in this country, re-
marked a prominent glass merchant of this city
to a reporter yesterday, as he was engaged in SUI
perintending the unpacking of a large box.
at was made in a Pittsburg mandatory, with
natural gas as fuel, and is much superior to that
made by coal, since the sulphur, even in the
best and purest coal, blurs and coats the glass
with patches. while if smoke comes in contact
with it in the soft state a permanent stain Is
caused. Besides, when coal fuel is used, the
best Of care can not prevent ashes, dust and
solid particles from the furnace falling onto the
molten glass and making flaws.
Gas fuel, however, has changed all of that,
and has given Pittsburg a great advantage. and
glass can be made so much better and cheapef
there that all of the factories have found them,
selves forced TO go to Pittsburg or 60 to pieces
In a short time America can compete with
French and German plate glass, where manu-
featured gas is used.n
How is this glass made?" asked the newsman.
well, the hardest and most interesting part
is the blowing" was the reply. 1.-THE entire
mass of molten material must be blown into
shape by the breath. Messrs. Appert, of Clichy,
France, claim to have discovered a process that
will make glass blowing by the mouth unneces-
sary, and it is to be hoped that they have, as the
process is very painful, and the men after a few
years become pale-faced, with their cheeks hang
AH5 AhP AZ soiNSs ohN SOhO hosO 70
known where their cheeks have worn 80 thin
that they actually cracked"
what are the materials used to make the
glass;" was the next question of the reporter.
"One hundred parts of sand, thirty parts of
lime, forty parts of alkali, and some pulverized
charcoal are put in the friedrich pot, which is
set in a furnace heated to an intense heat by gas
and are brought to a molten state. A workman
then plunges a long wrought-iron tube with a
wooden handle and mouth piece into the white
hot mass. and by alternately cooling and rolling
it finally has a ball of glass many
pounds in weight adhering to the end. He turns
it about until it becomes pear shaped, and then
hands it to the blower, who blows gently into ii,
at the same time constantly turning 1t until it
becomes the shape of a huge bottle. 1t takes a
very strong man to do this, since for a plate of
this size the molten material will weigh thirty
pounds.
After it has been blown into the right
shape" the speaker went on. 1.-THE end Of
the pipe is closed up, and the air, ex
banded by the heat, breaks a small hole in
the end of the bottle, which the blower ~enlarges
by twisting his tube around and putting his
breath into it until at length the bottle becomes
a cylinder. A string of red-hot glass drawn over
the upper part of the cylinder breaks it off even
ly and it is then cracked open lengthwise by q
red hot iron. Each side Is heated, fattened out.
tempered and polished, and finally becomes a
great sheet of clear plate glass;"