The Indianapolis journal. [volume] (Indianapolis [Ind.]) 1867-1904, 1884-09-20
WINDOW GLASS.
Description of the Interesting Process by
Which 1t Is Manufactured.

Description or the interesting Process Dy
Which 1t Is Manufactured.
Milwaubee Wisconsin.
This forenoon a large number of people visited
the factory of the Wisconsin Glass Company, To-
Gated at Bay View, a few blocks north of the
Whitehil Sewing-machine works, for the pur-
pose of witnessing the process of making window
glass. Superintendent Slimm, who, In his
younger days, worked at a w~indow-glass furnace,
took the first bali of molten glass out of the
furnace, and did the principal work of making
the first sheet of window glass ever manufactured
in Wisconsin,. A large quantity of window
glass was made afterward, and by Friday next
the home maze article will be upon the market.
By experts the glass is pronounced second to
none made, and orders from dealers are already
commencing to be received. As stated yesterday,
the Wisconsin Glass Company, which is now the
only glass company in the State, has spentabout
$100,O0O in making preparations for the manu-
facture of glass. The building occupied by the
melting and blowing furnace is Ito feet square.
new and brick-veneered. The annealire and
hattening ovens are located in another brick
veneered building, the dimensions of which are
ll0x50feet, The most improved and convenient
arrangements have been made for the manu-
facture of the glass, and everything has worked
very smoothly from the start. The new build
ings are models of the kind, and were planned
by VIM. Slimm, the assistant superintendent,
under the supervision of Superintendent Joseph
Slimm, who is his father.
How is window glass nader asked a Wiscon-
sin reporter who visited the factory this fore
noon of Superintendent Slimm. For reply Mr..
Slimm conducted his interrogation to the build
ing containing the melting and the blowing
furnaces. The former, a large brick affair, is
located in the center of the building. 1t con
tains ten large pots, where the sand, lime, soda
ash and salt, etc, of which glass is made, are
melted to a thin liquid state at a temperature of
about ,000 degrees. The sand used in making
the glass is obtained at Clayton, Iowa, and is
very fine, pure and white. Lake sand can not
be used for the purpose. The lime used is OBJ
faInn % .-l L. oN~.--
from England and the salt from Michigan. The
proportion of the four principal ingredients used
is about as follows: To every 100 pounds of
sand, 40 pounds of soda, p of lime and 2 of salt
are added. Other chemicals are used, but in
smaller proportion. The ingredients are all
thoroughly mixed together and then the furnace
is charged with the mixture. In about
eighteen hours it is in a fit condition for a
further change.
The next step is to blow it into the shape of a
cylinder. A lump of melted glass of the required
weight is gathered from the poi, which is fifty
seven inches IN diameter and thirty three inches
deep, on the end of a blow-pipe. This lump is
gathered by a series of accretions, the ~blow-pipe
being first inserted, a lump of glass obtained by
twirling it, and then Withdrawn and allowed to
assume a dull red color, when tits again inserted,
and the operation is repeated until the lump is
of the required size. This mass, when cool
enough, is placed inside a wooden cylinder,
where, while a stream of water is playing upon
it, it is revolved and blown until it assumes the
shape of a pear. with the diameter of the larg-
est part, which is that of the finished cylinder,
Immediately at the end Of the biow-pipe. 1t is
next taken to the blow furnace, where, after be-
ing heated, it is blown by the workman into a
perfect cylinder about four feet long usually. and
a foot In diameter. This cylinder, being closed
at one end and attached to the blow-pipe at the
other, is filled with air, and the aperture is closed
and the end exposed to The heat Of the furnaces
which expands the air in the cylinder, and the
end, being the softest part of the glass, bursts
4@.,2 = - - 49,
cylinder at the furnace-hole, and the glass is
then laid upon a wooden rest the blow-pipe is
detached from the pear-shaped neck by the lat
ter part of the cylinder being touched with a
piece of cold iron, and the rest of this cap is
taken on by winding a thread of hot glass
around it, and touching the circuit covered by
the hot thread with cold iron. All of these re-
suits. as can easily be seen, are effected by a
practical application Of the laws of heat and
cold. After the other end of the cylinder has
been trimmed with a diamond. the glass is split
with a rcd hot iron, which is rubbed up and
down, and causes it to crack open in a straight
line.
The cylinder, having been split, is taken to
the fattening oven, for it must be ~lattened be-
fore it can be cut into panes The split side is
uppermost, and the cylinder, after being put
into the oven, where it is placed upon a rotary
furnace, is first conveyed to a warm furnace.
where it gradually spreads out, and then to a
hot furnace, where it fattens right out. Quite
a large number of sheets always go through this
oven together. The operation just described is
next repeated in inverse order, after which the
glass is taken to the annealing oven and tenn
pered. About fifteen hours are usually required
for the work of f1attening and annealing. Both
the fattening and annealing ovens are seventy
five feet long. TIL glass is now in perfect sheets
and is taken to the cutting and packing rooms,
which together are fifty feet square, and cut
into any required sizes on se~lf-mcasuring tables,
and then packed into boxes for shipmen The
entire process, from beginning to end, is one of
the most interesting than can be imagined.
There is another method of making window
glass, and glass made in this manner is called
crown glass. The difference lies in the manner
in which the workmen treat the glass in blow
ing it. Grown glass is blown into a fiat circular
disk, instead Of into a cylinder. 1t is the more
difficult method and no more satisfactory result
is reached.
HOW WE REMEMBER Things.