The Democratic advocate. [volume] (Westminster, Md.) 1865-1972, 1890-12-13
Plate Glass.

H. C. Hovey in the Scientific American.
The remarkable advantages furnished by
the discovery of natural gas at Kokomo,
Ind, have induced numerous manufactur-
ing companies to invest capital there, the
most important of which is the Diamond
Plate Glass Company, whose plant now
covers eight acres. The company control
20 wells of their own, together with large
tract of gas territory. They have invested
$4,000, 1000, and employ from 600 to 1000
men. The location is only mile from
the city, and the intervening space is being
rapidly built up with a superior class of
houses The officers of the company at
present are A. l.. Conger, President; NJ.
Seiberling, General Manager; NJ. p. FL
liott, Superintendent; f. NJ. Atterholt and
w. L. Clause, Secretaries, and 4. G.
Keith and A. G. Seiberling, Treasurers.
The list of stockholders is large, and the
whole business is on firm foundation,
with degree of prosperity such as to in
duce them to duplicate their Kokomo
works at Elwood, . point 20 miles south.
At Elwood the water supply will be from
artesian wells, but at Kokomo water is
drawn from the adjacent Wildcat river by
a huge pump, with capacity of 3,OOO,-
900 gallons per diem. The engine by
which power is supplied for the works was
built by E. P. Allis & Co., of Milwaukee,
and has capacity of 600 horse power.
The materials used are those that orli-
narily enter into the composition of plate
glass of fine quality, namely, white sand,
ground lime, sulphate of soda, arsenic and
charcoal, mixed in special proportions.
The melting pots are made of Missouri
fire clay that comes prepared in barrels.
Having been properly mixed, it is trodden
by men barefoot until it gets the right
consistency, when it is divided into
small rolls, and piled up for use. One
man has eighteen pots under manipulation
at once, building up each by "spells' of
six inches day, and taking twelve days to
finish the lot This rather tedious process
is necessary in order to allow time for the
clay to harden as it is built up.
No machinery has yet been devised
competent to be substituted for the human
hand in this important process. When it
is remembered that a pot is required to
hold from 1000 to $500 pounds of
molten glass while being handled by
dozen men, it is clear that the greatest care
and thoroughness must be demanded in
its manufacture Every pot bears the
initials of its maker, as well as the date of
making, and all are allowed to stand for
seasoning considerable time before being
used. The average life of pot in con-
slant use is about thirty days. Tuiles and
shoppers are also made in the same pot
terry, but of different grade of fire clay.
There are two large furnace rooms. One
room has three furnaces, with a capacity
for 20 pots each, while the other has two
furnaces for 16 pots each. By recent i'm
proyements there is a great saving Of fuel,
as we'll as a material reduction ip the time
required for melting, and hence cores
ponding diminution of the cost of manu-
facture. The required heat is 10000 Fab.
The natural gas is supplied from the wells
by large mains, from which service pipes
90 to the several furnaces. 1t is impossi-
bic to tell the exact amount of gas daily
consumed, but an estimate has been made
of about 100000 cubic feet. When the
glass in any pot is properly melted the pot
is run out of the furnace room on tram
way to the annealing room, lifted by a
crane, meanwhile being steadied by great
tongs, and the contents emptied directly on
the casting table. This is heavy, fat
table of iron, somewhat larger than the
largest plate that may ever have to be
east upon it. At one end is a heavy cast
iron roller, the full breadth of the table,
and fitted so as to roll the entire length Of
the table by means of gearing along its
sides. Narrow strips along the edge de-
termine the height at which the roller runs
above the table, and this again determines
the thickness of any given plate of glass.
An adjustable apparatus also fixes the
breadth of the plate. The semifued mass
poured from the melting pot on the table
is pushed before the roller, leaving uni
form layer between the moving surface of
the latter and the casting table. The glass
does not instantly solidify, hence the edges
have rounded appearance. A bar press
ed against the end farthest from the oven
thickens the plate for few inches to
enable its being pushed along without
wrinkling. The roller having been rolled
back to its carriage is trundled out of the
way, the casting table is moved up to the
edge of the annealing oven, whose heat has
been carefully raised to a required temper
ature, and then by means of long iron
pushers the red hot plate is showed to its
place. All this work has to be done with
the greatest rapidity, and by men who may
have been idle for an hour waiting for the
turn of their gang.
timed one operation as performed by
gang of 10. 1t took one minute and a
quarter to run the melting pot to the
casting table, and in two minutes and a
half more it had been lifted, emptied, the
glass rolled, the roller withdrawn and the
plate run into the oven. Total time, three
minutes and three-quarters.
This was extraordinarily rapid work, the
usual time allowed for each operation being
about nine minutes, and the time for hand
ling 90 pots being on an average three
hours. The men are well paid, and seem
to be vigorous and in good health. l was
assured that serious accidents rarely hap
pen, although slight injuries from the
scorching heat or from the bits of broken
glass are frequent.
Four plates may be laid at time in
each oven, and seventy-two plates may be
cast in day. There are forty-eight
ovens in all, each measuring % by 40 feet
in size; from which it will be seen that the
annealing house must be very large, es-
pecially as ample space must also be allow
ed for manipulating the castings. When
the plates have been in the oven for four
or FIVE days, the temperature meanwhile
having been slowly reduced to that Of the
ordinary atmosphere, they are Withdrawn.
At this stage they have a rough, undulat-
ing appearance, and seem to be opaque,
however pure and clear they may be in
fact They are NOW insnected for Hawa