The Bluffton news. [volume] (Bluffton, Ohio) 1875-current, 1940-08-01
Coal. Coke. Steel, Cement und Glass
Are Pennsylvania Greet Industries

Nowhere in industrial Pennsylva- .
MIA does one discover more progress
in processes than in the cement in
dustry. A pilgrimage through ce- .
ment plant 20 years ago was like
working at the "bunghole" of a
threshing machine before the days
of the straw blowers. There was
dust everywhere. AS one surveyed
the horizon of Lehigh and North
ampton counties, it seemed that
there were hundred whirlwinds
perpetually blowing and marking
the sites of the cement plants scat !.
tered over the countryside.
Today it is different. Now the
rock is crushed under streams Of
water and the final powdering of the
stone produces a sludge of about
the consistency of mush. This is
introduced into the big rotary kilns
some Of them as much as 40 feet
long and Is feet in diameter. -
Here it meets a stream of pow
dered coal under a flame that gives
temperature of from $500 to 5000
degrees Fahrenheit. The coal has
been SO finely ground that 95 per
cent of it will pass through a screen
that has 10000 meshes to the square
inch. When the powdered coal, the
sludge, the fiery heat, and regulat-
ed amount of air meet, glass-hard
clinkers are formed. 49,. .4s~.-e-.
These clinkers in turn are the in
termediate materials between ce-
ment rock and the finished product.
They are mixed with heavy steel
oval-shaped globules and conveyed
into rotary grinders. Round and
round these big machines turn hour
after hour until all the clinkers have
been ground almost to impalpable
dust, in which form it is Portland
cement.
Among all of Pennsylvania's dra-
matte industries there is none pos
sessing greater fascination than
plate-glass making. Such opaque
substances as salt cake, pure lime
stone, and quartz sand go into a
furnace in 3,500-pound patches, be-
come liquid, and then pass out as
continuous sheet of plate glass
which is cut, ground, and polished
until it is as transparent as thin aira
In a Plate Glass Plant.
Up the Allegheny river from Pitts
burgh stands the little village OF
Creighton. On its outskirts is tha
largest plate-glass plant in the
world. The company owns at its
back door the coal mine that sup
plies its fuel, for coal is used in
such quantities that such plant in
always located near its fuel supply
rather than close to its raw ma
terial.
Here are huge bins for storing
salt cake, soda ash, glass sand.
limestone, and other ingredients.
There is the giant furnace that
holds 1900 tons of molten glass.
With colored glass shield before
your eyes look into the fiery fur
mace. Here are little hills and tiny
mountains, survivals of the last
3,500-pound mouthful of material
dumped in. There you see minia-
ture lake of incandescent molten
mixture.
Twenty-one days of warming are
required to bring the temperature
of the furnace up to operating re-
Quirements. The marvel is that its
Innings can be made heat-resistant
enough to stand temperatures that
convert sand and limestone into iq-
uid and to take that punishment
for months on end.
At the rear of the furnace is a
giant lip out of which the molten
glass flows. Glowing hot, of doughy
consistency, it passes under tremen-
dous rollers, which convert it into a
ribbon about feet wide. Along
this it travels through an annealing
lehr for 400 feet. BY now it is cool
enough for the cutters who trim
off the edges, cut it into lengths,
and mark the defective spots.
Then a sort of mechanical spider
with vacuum-cup feet swoops down
on each piece, lifts it high over
head, and deposits it in a plaster-of-
paris film on the six-ton cast-iron
car that is to be its bed while pass
ing under the grinding machines,
where sand and emery smooth it
down.. From these grinders the
plate passes under the felt-footed
polishers where enough rouge to col
or the lips and cheeks of an army
of women is used to produce that
perfection of smoothness which
gives perfect vision through your
motor window.
After the glass has travelled 125
feet in the fiery furnace, 400 feet on
the cooling lehrs, 400 feet under the
grinders, and 400 feet under the pol
ishers, it is ready for its trip
through the Duplate works where
two pieces are cemented together
with a Dupont product and be-
come safety glass.