The Red Cloud chief., 1902-08-22
GLASS FOR WINDOWS
THE METHOD AND THE MATERIALS
OF ITS MANUFACTURE.
Enough Arsenic In the windows of
an Ordinary House TO XIII IA Regi-
ment of Mcn-Process Of the Tank
house and the p~OthOusc.

IpOplc WHO nave PlilSS III
their homes do not know that the glass
contains enough arsenic to make 1t a
deadly poison. Glassmakcrs say that
the windows of an ordinary home con
tain enough of this poison to kill n reg.
iment of men. The popular supposition
one, but n quantity Of other articles en-.
tiers into It's composition.
Window glass factories are divided
Into two departments, n tankhouse and
a pothouse. The process of glassmak-
Ing In one Of these departments Is prac.
tically the same as In the other. In the
t%ankhousc the glass is all melted in i'm
mense tanks which will hold thou.
sands Of tons. In the pothouse the
glass is made In pots.
After the fires are lighted and a tank
Is heated the glass mixture Is shoveled
In. 1t includes glass left over frNI the
former season, glass refuse, sand and
salt cake. Arsenic Is not used In the
farmhouse for the reason that the heat
Is 80 Intense that the drug Is volatilized
and escapes into the air without enter.
Ing the mixture. As one mixture melts
and flows to one end Of a tank fresh
supplies are sboveled In ut the other
end.
The molten mass seethes and
"works" In a manner similar to that of
a mash In n distlllery. From the salt
cake comes a salt water that has to be
separated from the mass, and the east.
est way to remove it Is to burn II out.
This Is done by throwing stove wood
Into the tank on top of the molten
glass. The water is converted into
steam, which Is destroyed by the in.
tense heat from the glass. The melted
glass Is then skinned by an automatic
skinner, and ii Is ready for the gath
erer.
A gatherer thrusts a long steel blow
pipe n one of the rings at the lower
end of the tank. lie twists and turns
1t until a small ball OF glass gathers on
the end. This ball is partially cooled,
polished by being turned in a box of
sawdust and then passed on to the
blower. who heats it again until 1t be-
comes like taffy. The blower swings
the ball over q pit that is twelve feet
deep and rapidly blows it into ain elon.
gated pear shape. When a blower is
through, the melted glass becomes q
perfect cylinder about 8 feet long and
z feet across. 1t then passes to q ''snap-
who takes it to a rack and breaks
the roller loose from the blowpipe.
The snapper gathers q small lump
or melted glass on the end Of a rod
and dexterously runs a narrow ribbon
OF the stun around the ends Of the
roller. both ut the blowpipe end and
the closed end. The little ribbons Of
melted glass cool In a few seconds.
when they are removed, leaving a mar.
row zone Of almost redhot glass
around the rollers at each end. Then,
hiking a tool that resembles a soldering
IRON. the snapper rubs 1t for n moment
On his forehead, and when the point Of
Il IL moistened with perspiration he
runs b Iron around the rollers ut the
heated spot. The glass cracks and
Ieparates as clearly as If cut with a
diamond, the blowpipe Is removed, and
closed cylinder has become a roller
ana IL then ready to go to the fat.
tener.
The f%attener works In another part
Or the building, where are located the
nattening ovens. These ovens are heat
ed to a temperature sufficient to soften
the glass so that 1t may be rolled out
INTO sheets. A series of fircclay tables
in a circle like the spokes of a
Wheei revolve In the ovens, and on
these tables the rollers are ilattened.
They are placed inside, allowed to be.
hot, and then a cold iron Is run
along the inside from end To end. The
contact of the iron cuts the glass,
which Is then Strengthened out upon
the table.
The Hatcher has n number of bIllets
OF green wood attached to long iron
handle ara with these billcts. which
are shaped in such n manner rs to do
he work expected of them, he irons
softcncd sheet of glass until il is
perfectly flat and smooth. The tables
inside the oven revolvc, the tlattened
sheet Is carried away, and another roll.
- piouSul lntO position De1Orc the
hattencr. AS the flattened sheets cool
they are lifted to a place on a long
travelling rack, on which they are by
stages removed from the ovens, being
allowed to cool as they go. This is done
IN order that the glass may not be
by too quick an exposure to
the air.
When the sheets are taken from the
nattenins ovens, they are covered with
a greasy, dirty looking coat of chem.
l~eals-soda. potash. silicates of the diff.
rerent salts, etc.-which must be re.
moved, and for this purpose the rough
sheets are placed In an acid bath com
posed or hydrochloric and sulphuric
ACIDS more or less diluted. After their
immersion In this bath the sheets are
taken to the cutting room, where work
meh cut them into sizes and make
them ready for the packers. Hardly a
scrap or the glass aycapt tho ro,~h