The Tucson citizen., 1902-10-04
GLASS FOR WINDOWS
THE METHOD AND THE MATERIALS
OF ITS MANUFACTURE.


house and the Pothouse.
People who have glass windows In |
their homes do not know that the glass |
contains enough arsenic to make 1t a |
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 a correct |
one, but quantity of other articles en- |
ters into It's composition.
Window glass factories are divided
into t, departments, tankhouse and
d pothouse. The ra@ocess 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
sands of tons. In the pothouse the
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 heaa
is so intense that the drug is volatilizcd
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 a manner similar to that OF
mash in distillery. From the salt
cake comes salt water that has to be
separated from the mass, and the easi-
est way to remove it is to burn it 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
class is then skinned by an automatic
skinner, and it is ready for the gath
erer.
A gatherer thrusts long steel blow
pipe into one of the rings at the lower
end of the tank. He twists and turns
it until small ball of glass gathers on
the end This ball is partially cooled,
polished by being turned in box OF
| saWdust and then passed ON to the
| blower, who heats it again until it be-
comes like taffy. The blower swings
| the ball over a pit that is twelve feet
| deep and rapidly blows it into an elon'
| gated pear shape. When q blower is
through. the melted glass becomes q
perfect cylinder about feet long and
2 feet across. 1t then passes to snap
| per-" who takes it to rack and breaks
the roller loose from the blowpipe.
The snapper gathers a small lump
| of melted glass on the end of rod
and dexterously runs narrow ribbon
OF the stuff around the ends of the
| roller, both at the blowpipe end and
| the closed end The little ribbons OF
melted glass cool i'll few seconds,
when they are removed. leaving a mar
row zone of almost redhot glass
around the rollers at each end. Then,
taking Il tool that resembles q soldering
iron, the snapper rubs it for moment
on his forehead, and when the point OF
1t is moistened with perspiration lie
runs the iron around the rollers at the
| heated spot. The glass cracks and
separates as cleanly as if cut with a
diamond, the blowpipe Is removed. and
the closed cylinder has become roller
aud is then ready to go to the tat'
| tener.
The f0ttener works i'm another part
of the building, where are located the
dattening ovens. These ovens are heat.
ed to temperature sufficient to soften
the glass SO that it may be rolled out
into sheets. A series of fireclay tables
placed in circle like the spokes Of q
wheel revolve in the ovens, and on
these tables the rollers are hattened.
They are placed inside, allowed to be-
come hot, and then u 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 tiatteLer has a number of billets
OF green wood attached to long iron
handles, and with these billetG. which
are shaped in such a manner as to dc
the work expected Of them. he irons
the softened sheet Of glass until it ID
perfectly flat and smooth. The tables
|
sheet is carried away. and another roll
er is brought into position before stnt
tlattener. As the tiattened sheets COO
they are lifted to place OH a Ions
travelling rack. on which they are b!
stages removed froDA the ovens being
allowed to cool as they 20. This is done
, in order that the glass may not b'
. shattered by too quick an exposure Il
the air.
| When the sheets are taken from th'
! hattening ovens, they are covered will
| Il greasy, dirty looking coat Of ehc1n
. lcals-soda, potash, silicates Of the dit
fercnt salts. etc.-which must he re
j moved. and for this purpose the rougl
/ sheets are placed in an acid bath com
. posed Of hydrochloric and suIphuri
acids more or less diluted. After thei
: Immersion In this bath the sheets ar
8 taken to the cutting room. where work
= men cut them into sizes and max