The Tucson citizen., 1902-07-22
GLASS FOR WINDOWS
rHE METHOD AND THE MATERIALS
OF ITS MANUFACTURE.


nm Ordinary House to XIII a ReEi-
ment of Men-ProceSs of the Tank
house and the POthouse.
People who have glass windows In
their homes do not know that the glass
contains enough arsenic to make 1t
deadly poison. Glassmakers say that
the windows of an ordinary home con-
tain enough of this poison to kill reg
iment of men. The popular supposition
that glass Is made of sand is correct
one, but n quantity of other articles en-
tiers into It's composition.
Window glass factories are divided
into I, departments, a tankhouse and
n pothouse. The F@pcess OF glassmak-
Ing In one of these departments Is prac-
tically the same as In the other. In the
tankhouse the glass Is all melted In i'm
mense tanks which will hold thou
glass Is made In pots.
After the fires are lighted and tank
is heated the glass mixture Is shoveled
In. 1t includes glass left over from the
former season. glass refuse, sand and
salt cake. Arsenic Is not used IN the
tankhouse for the reason that the heat
Ia SO intense that the drug In volatilized
and escapes into the air without enter
ing the mixture AS one mixture melts
and flows to one end of tank fresh
supplies are shoveled In at the other
end.
The molten mass seethes and
''works" In manner similar to that or
a mash In a distillery. From the salt
cake comes salt water that has to be
separated from the mass. and the easl.
est way TO remove 1t 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 10 destroyed by the In
tense heat from the glass. The melted
glass Is then skinned by an automatic
skinner, and 1t is ready for the gath.
erer.
A gatherer thrusts a long steel blow
pipe into one OF the rings at the lower
end Of the tank. He twists and turns
1t until a small ball OF glass gathers ON
the end. This ball is partially cooled,
polished by being turned iu box OF
sawdust and then passed on TO the
blower. who heats Ii again until II be-
comes like taffy. The blower swings
the ball over a pit that is twelve feet
deep and rapidly blows II into an elon-
gated pear shape. When blower is
through, the melted glass becomes
perfect cylinder about b feet long and
2 feet across. 1t then passes TO snap
per-" who takes Ii to q rack and brea KS
the roller loose from the blowpipe.
The snapper gathers small lump
| OF melted glass on the end OF rod
aud dexterously runs narrow ribbon
roller, both at the blowpipe end and
| the closed end. The little ribbons OF
melted glass cool in a few seconds.
when they are removed. len wing a mar
row zone of almost redhot glass
around the rollers at each end. Then.
taking a tool that resembles u soldering
| iron, the snapper rubs IL for moment
on his forehead and W hen the point Of
1t is moistened with perspiraton be
runs the iron around the rollers at the
heated spot The glass cracks and
separates as cleanly as II cut with a
diamond. the blowpipe Is removed, and
the closed cylinder has become roller
and Is then ready to so to the fat
tener.
The aattener works In another part
OF the building. where are located the
fiattening 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 freciay tables
placed IN circle like the spokes Of a
wheel revolve In the ovens, and on
these tables the rollers are 6attened.
They are placed inside. allowed to be-
come hot. aud then 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 Hattener has number OF billets
OF green wood attached to long iron
handles, ard with these blllets, which
are shaped In such manner as to do
the work expected OF them. he irons"
the softened sheet OF glass until II is
| perfectly fiat and smooth. The tables
inside the oven revolve. the fattened
sheet is carried away. and another roll
er Is brought into position before the
| iattener. As the fattened sheets cool
they are lifted TO a place on a long
travelling rack, on which they are by
| stages removed frop. the ovens. being
allowed to cool as they go. This is done
In order that the glass may not be
shattered by too quick an exposure to
| the air.
When the sheets are taken from the
fiattening ovens, they are covered with
a greasy. dirty looking coat of chem
icals-soda, potash. silicates Of the diff
ferent salts, etc.-which must be re-
moved, and for this purpose the rough
sheets are placed In an acid bath COM
posed Of hydrochloric and sulphuric
acids more or less diluted. After their
immersion in this bath the sheets are
taken to the cutting room, where work