Iowa voter. [volume] (Knoxville, Iowa) 1867-1874, 1870-07-07
How Common Window. Glass Is Made;


sylvania, you must 60 into the window
glass factories there; you will find them
very curious. Their furnace, in the first
place, is built in the ancient style; It has
no chimney, and the smoke from the BIZ
luminous coal they burn pours out tn .
cloud into the room. There are openings
IN the roof for 1t to escape through, and q
continual draught of air from the doors
carries 1t upward, 50 that it Is not so bad
for the wOrkmen as one would think. Be-
sides. they do not begin to blow until the
smoke Is all burnt off.
There are five pots on each side of the
furnace and you will see FIVE men in q
row, blowing all at once, with the regulari-
ty of file of soldiers exercising Each
gathers 80 or 40 pounds of metal on his
pipe, which Is very long and strong.
They stand on Platforms to get room to
swing the glass, a. they blow it. The
Ave men begin to blow and swing all to-
gether. Each blowsa grea' globe of glass,
which is stretched out gradually by the
swinging motion into cylinder, or roller,
as 1t is called, Eve feet long. Then the
five rollers are swung up toward the fur
mace holes, and FIVE other soldiers spring
forward with their guns,-which in this
case are iron bars, that they set upright I'M
der the five blowing pipes to support them
while the rollers are being reheated in
the necks of the pots. The blowers blow
in the necks of the pipes with all their
might, then clap their thumbs over the
hole to prevent the air from rushing out
again in the meanwhile the end Of the
roller is softened, 90 that at last the air,
forced in and expanded by the heat, bursts
1t outward. The glass Is then cylinder,
open at one end. 1t IL whirled in the heat
until the edges become true, then brought
away,-the I've iron supports dropping
TO the ground with Simultaneous Clang.
The cylinders are laid ON tables, where
the imperfect spherical end about the
blowing pipe IL cracked of from the rest
BY strip Of melted glass drawn around
It. The cylinder 10 then cracked from
end to end on ono side By means Of .
red hot iron passed through IT.
In an adjoining building 10 what 10
called the fiattening oven. The cylinders
brought there are fifted ON tho end Of
ing just large enough TO admit them, and
tom, with the crack upperm0sA. The oven
zontally. Az the glass sOltens, II separates
at the crack, and lays itself down gently
and gradually on the stone. The long
cylinder 10 then fiat sheet, three feet
wide and nearly Eve feet inlongth. There
are four openings around the sides Of the
oven at one the glass isput In, through
another q workman sweeps the stone for
IL, third workman smooths h down with
a block as II comes round to him, and .
fourth, at the last opening, which 10 close
TO the one at which II was put In, HIS the
sheet-pArtly cooled by this time-up0n
carriage in the oven. This he does BY
means Of lever furnished with sharp,
broad blades Ut he ends, which he works
In under the glass. When the carriage 10
full, il IL run through an annealing oven
beyond.
The opposite end Of the annealiDg oven
opens into the cutting room. There the
carriages are pushed along central track.
and unloaded at tho stalls OF the cutters.
The cutter has Q table before him, with
measure marks o. Ito edges. He Lifts ono
Of the sheets lays h on , table, and COM
mcnCas ruling It faster than Q sehOOl-bOy
rules his slate. His ruler b . wooden rod,
i've feet long, and his pencikpOint 10
diamond. kvevy gtroke 10 cut Not
that he cuts the elass quite apart indeed,
he seems scarcely to mako . scratch. Yee
that scratch has the ef3De4 Of cracking the
glass quite through, % that It breaks
clean OF at the slightest pressure. In this
way the sheets are sus up into panes Of
the requisite aze.
remember, one workman told ne that
q single diamond would last him two or
three years. Il las fifteen OF sixteen diff
ferent eaEes, and when ono edge b worn
out he uses another. South American