Alma record. (Alma, Mich.) 1878-1928, 1902-01-10
COUNTERFEIT GOLD.
GLIDING POWDERS ARE MADE OF
COPPER AND SPELTER
How the Material Tint Gives the
shining. Metallic Finish Ia Mirror
and Picture Frames IL Produced.
Gold Leaf without Gold.

shining, Metallic Finish To Mirror
and Picture Frames Is Produced.
Gold Leaf without Gold.
How many persons who see the shin
ing gold in colored printing and on
mirror and picture frames know that
gold does not enter at all into the COM
position Of the stuff that produces these
golden efiectsf
i he shining metallic effect Is pro-
duced 10y fine powder made from n
mixture of bronze and spelter This
offers the cheapest and best means of
| giving the rich surface demanded in
wall papers. printing, photography, fres-
Going aud in vast range of manufac-
tured articles of wood, paper aud iron.
The material used Is so called Dutch
metal, an alloy of copper and spelter.
The relative proportions are varied to
produce different colors. The larger
the percentage of spelter the lighter or
more yellowish will be the tint of the
alloy.
The copper and spelter are smelted In
graphite crucibles containing about 400
pounds of metal, which, when com
pletely fused, Is run Off into molds,
forming half round ingots two feet
long by half an inch In thickness. Aft
or cooling these are bound into bundles
and sent TO the rolling mill, where they
are passed cold nine times through a
double set of steel rolls under enor-
nous pressure. This flattens them and
draws them out into thin ribbons from
so 10 60 feet long and something more
than one inch wide. Cold rolling I'M
der such extreme pressure makes the
metal brittle, so II passes to the an
healing furnace, which Is heated by
wood fire. as the sulphur In coal or
coke would be injurious to the ribbons
Having been softened and rendered
ductile by annealing, they are cleansed
I'm an acid bath. cut into lengths OF
about three feet and collected in bun
dies OF 40 or 30 strips each. They are
laid between sheets Of zinc and passed
under hammers which beat the metal
strips to the thinncss OF tissue paper.
This requires six successive beatlngs,
and great skill must be exercised to
produce a uniform and unbrOken foil.
| After the third beating the metal strips
are taken from between the sheets or
zinc loosened from each other and
clcanScd by immersion in q bath OF
tartrate Of potassium The cleaning Is
repeated after the last beating, and the
sheets are hung on lines TO dry. In the
beginning the rolled strips are duh
gray metallic color. IN the fourth beat
ing the yellowish color begins 10 show,
and after the sixth they are clear and
bright as gold.
The defective leaves are then thrown
out and the perfect ones cut into small
squares. which are laid together by
hand i'm packets Of several hundred
each and inclosed within an envelope
of sheet brass. The packets return 10
the annealing furnace. where they are
sOftened 10y heating and slow cooling,
and then 20 10 the beaters. where they
are reduced under fattening hammers
TO the thinncss Of real gold leaf, so thin
that II can be blown away by the
breath
The manufacture OF bronze powder
consists in grading, clipping and pull
yerZing the various bronze fOils TO an
even, impalpable powder and is an In
dustry OF comparatively recent date.
Ii began as means of using up and
utilizing the imperfect leaves which
came as waste from the heaters oil
gold. silver and bronze. These were
cut by hand into fine clippings and
then ground to powder In hand mills OF
simple construction. With the lapse OF
/ time and the spread of artistic indus
tries the uses Of bronze powder in
, creased until the demand far outran
the supply OF waste. and the leaf metal
is now made on large scale.
! The beating process flattens out d
pound OF copper and spelter alloy TO an
area OF about 500 square feet, and In
this condition the square sheets as they
| come from the brass envelopes are
, sheared into small fragments and rub
bed with olive oil through a steel sieve
having ten meshes to the inch and ther
passed TO the stamping and grinding
machines, where they are pulverized 10y
steam or water power to the bronze
powder OF commerce. The grinding
occupies from one TO four hours, &c
! cording TO the grade or quality or the
3 powder to be produced, which is OF
= four grades. from coarse to supertine
The superfuous oil Is removed by heat
Ing under pressure, and the powder
Is then carried into centrifugal clari
{ fcrs. or grading machines, which. turn
a ing at high speed, eXpel the powder
. through fine oritices in the form OF
dust. which settles on inclosed shelves
according To weight and tineness, Tho
finer particles at the top, the coarse'
:. below. and in this way the powder IL
I divided into its various grades.-New
{ York Press.
How Customs Vary.