The Jackson standard. [volume] (Jackson C.H., Ohio) 1847-1888, 1869-05-06
JACKSON STANDARD.
THURSDAY, MAY 6, 1869.
How Common VVTmdOw-GsIaws Is
- III Made.
BIZ J. T. TRowDRIDeE.

Hf . ID - - AkOAbhADNhs
S.There is another process" continu-
ed gafer, 4'by which our common win
dow-glass is made. By the way, if ever
yon visit Pittsburg, in Pennsylvania
you must go into the window-glas
factories there; you will ind them
very curious. Their furnace, in the
first place, is built in the ancient style;
it has no chimney, and the smoke
from the bituminous coal they burn,
pours out in a cloud into the room.
There are openings in the roof for it to
escape through, and a continual
draught of air from the doors carries it
upward, SO that it is not SO bad for the
workmen as one would think. Besides,
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 row, blowing all at once, with the
regularity of file of soldiers exercis-
ing. Each gather thirty or forty
pounds of metal on his pipe, which is
very long and strong They stand on
platforms, to get room to swing the
glass, as they blow it. The five men
begin to blow and swing all together.
Each blow a great globe of glass, which
is stretched out gradually by the swing
ing motion into a cylinder, or roller, as
it is called, FIVE feet long. Then the
five rollers are swung up towards the
furnace-holes, and FIVE other soldiers
spring toward with their guns.-which
in this case are iron bars, that they set
upright under the five blowing pipes
toisupport 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 holes to pre-
vent the air from rushing out again in
the meanwhile the end of the roller ie
softened, so that at last the air, forced
in and expanded by the heat, bursts il
outwards. The glass is then a cylin-
der, open at one end. It's whirled in
the heat until the edges become true
then brought away FIVE iron sup
ports dropping to the ground with a
simultaneous clang. The cylinders are
laid on tables, where the imperfect
spherical end about the blowing pipe is
cracked off from the rest by a stripe ol
melted glass drawn around it. The
cylinder is then cracked from end to
end on one side by means of red-hot
iron passed through it.
"In an adjoining building is what is
called the dattening oven. The cylin-
ders brought there are lifted on the
end ofa lever, passed in through a cir
Cular opening just large enough to
admit them, and laid on tlattering
stones on the oven bottom, with the
crack uppermost. The oven bottom il
circular, and it revolves horizontally,
AS the glass softens, it separates at the
crack, and lays itself down gently and
gradually on the stone. The long cyl.
inder is then a fiat sheet, three feet
wide and nearly five feet in length.
There are four openings around the
sides of the oven; at one the glass is
put in, through another a workman
sweeps the stone for it, a third work
man smooths it down with a block as
it comes round to him, and q fourth, at
the last opening, which is close to the
one at which it was put in, lifts the
sheet-partly cooled by this time
upon a carriage in the oven. This he
does by means of lever furnished
with sharp, broad blades at the end
which he works in under the glass
When the carriage is full, it is rur
through an annealing oven beyond
a''The opposite end Of the annealing
oven opens into the cutting-room.
There the carriages are pushed along
a central track, and unloaded at the
stalls Of the cutters. The cutter has
8 table before him, with measure
marks on its edges He lifts one of
the sheets, lays 1t on the table, and
commences ruling ii faster than a
sohool-boy rules his slate. His ruler
is q wooden rod, five feet long, and bis
pencil point is diamond. Every
stroke is a cut, Not that he cuts the
glass quite apart; indeed, he seems
scarcely to make a scratch, Yet that
scratch has the effect Of cracking the
glass quite through, so that it breaks
clean offat the slightest pressure. In
this way. the sheets are cut up into
panes ofthe requisite size"
~ should think the diamonds would
wear out, said Lawrence.
81 remember" replied tho gaffer,
"one workman told me that a single
diamond wonld last him two or three
years. II has fifteen or sixteen differ
ent edges, and when one edge is worn
out he uses another. South American
diamonds, such as he used, cost, he
told me, from six to thirty dollars eachi
and, when they are worn out for his
purpose, he sells them for jewels to be
put into watches. Our Young Folks
for March
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