Evening journal., 1902-07-15
GLASS FOR WINDOWS
THE METHOD AND THE MATERIALS
OF ITS MANUFACTURE.

house ana the f0thOusc.
People who have glass windows in
their homes do not know that the glass
contains enough arsenic 70 make it
deadly poison Glaesmakers say that
the windows Of an ordinary home CON
tain enough of this poison to kin a reg.
iment of men. The popular supposition
that glass is made OF sand is n correct
one, but quantity of other articles en-.
ters into its 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.
tlcally 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 I'm pots.
After the fires are lighted and a 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
tanlkhouse for the reason that the heat
Is so 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 shoveled in ut the other
end.
The molten mass seethes ana
works" in a manner similar TO that Of
mash in a distillery. From the salt
cake comes a salt water that has 20 bo
separated from the mass. and the easl.
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
glass is then skinned by an automatic
SKINNER and II 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 bah OF glass gathers on
the end. This ball is partially cooled,
polished by being turned I'm a 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 a blower Is
through, the melted glass becomes a
perfect cylinder about feet long and
feet across. 1t then passes to a "snap-
per-" who takes 1t to rack and breaks
the roller loose from the blowpipe.
The snapper gathers a small lump
OF melted glass on the end or a 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 oi
melted glass cool In a few seconds
when they are removed. leaving a mar
row zone Of almost redhot glas,
around the rollers at each end. Then
taking a tool that resembles a soldering
iron, the snapper rubs 1t for a moment
E on his forehead, and when the point oI
It is moistened with perspiration h,
runs the iron around the rollers at th'
heated spot. The glass cracks auf
separates as cleanly as If cut with Z
diamond. the blowpipe is removed, anC
the closed cylinder has become a role
= and IS then ready to go 70 the fat
tener.
The flattener works IN another par
Of the building, where are located thl
hattening ovens. These ovens are heat
ed to temperature sufficient to softer
the glass so that It may be rolled on
into sheets. A series of fireclay table
placed in q circle like the spokes of I
wheel revolve IN the ovens, and ol
these tables the rollers are flattened
They are placed inside, allowed to be
come hot. and then a cold iron is rui
along the inside from end to end. Tn
contact Of the iron cuts the glass
which Is then Strengthened out upoi
the table.
The dattener has number OF billet
of green wood attached TO long iroi
handles. and with these billets. whlcl
are shaped in such q manner as 10 d
the work expected of them, he 'irons
the softened sheet of glass until it /
) perfectly fat and smooth. The table
inside the oven revolve. the 1attene
sheet Is carried away, and another roll
er is brought into position before III
flattener. As the fiattened sheets coo
they are lifted 10 place on a Ion
travelling rack. on which they are b.
stages removed from the ovens. bein
allowed to cool as they go. This is don
in order that the glass may not b
shattered by too quick an exposure I
the air.
When the sheets are taken from tn
fattening ovens. they are covered wit
b a greasy. dirty looking coat Of chen
icals-soda, potash. silicatcs Of the dii
ferent salts. etc.-which must be r,
moved. and for this purpose the roug
sheets are placed in an. acid bath con
posed of hydrochlorlc and sulphur
acids more or less diluted. After thel
immersion in this bath the sheets ar
taken 20 the cutting room. where worl
men cut them into sizes and max
them ready for the packers. Hardly
scrap of the glass except the roug
edges IS wasted. In fact. none is was
ed. as all refuse goes back to be mel
ed After the cutters have 6nishe
"a 4l,,f,. .,.o..f- tf, s.ia@e. &c r,uaf-nI la,