Evening star. [volume] (Washington, D.C.) 1854-1972, 1906-06-24
M TAKING GOLD COIN
PROCESSES THROUGH WHICH
PRECIOUS METAL PASSES.
How the Bright Discs Are Turned Out
at a United States Mint
Tricks of Rogues.

From the Van Norden Magazine.
piece of gold after being received at n
mint of the United States will be entered
in at least twenty accounts. subjected to
four assays and passed through thirteen
operations before 1t is finally Issued as a
finished coin ready for circulation. For
that reason, and because gold coins are
perhaps our most attractive, even of not
the most handily carried form Of circulat-
ing medium (perhaps on account Of the In
frequency with which most of us view
them), 1t may not be without interest to
note some Of the steps In their making
and the vicissitudes through which they
pass.
Gold reaches the rnints In various forms.
such as foreign and domestic coins, bars,
plate, Jewelry and the like. these represent
ing all degrees Of fineness. 1t is estimated
that among its receipts the mint at Phil
adelphia takes in annually about one and
one-half million dollars worth of jewelry,
dental leaf and old gold
Under the law a certain loss Of weight on
accepted gold coin Is permitted and pro-
gided for By By special appropriation n,a from ON
example, Is about one-tenth OF a grain an
nually, the coin itself weighing 616 grains.
This loss. which Is caused by abrasion and
otherwise. is deducted from the value of
all gold ccin received by the government
unless 1t Is within the tolerance allowed
by law. BY tolerance" is meant the
amount by which the coin Is allowed to
vary above or below the legal weight In
grains.
All gold pieces deficient in weight when
presented to subtreasuries or minis are
stamped with the letter L." meaning
light. The owner can either secure the
actual value Of the coin in gold or take
away the defaced piece.
When It Is remembered that the pres
ence of one-hundredth of one per cent
of either lead or antimony will make the
metal SO brittle that 1t cannot be rolled,
it will be seen that all the old gold re-
cetved at the mint must be purified before
working. This IL accomplished by an cleo
trical refining process known as electricity
sis, by means of which the metal Is puri-
fed to 500 and sometimes 1000 fine. The
gold then has added to it the amount Of
copper necessary to give 1t proper con-
sistency, Is melted in q gas furnace and
cast into ingots twelve inches long, one and
one-half inches wide and one-half Inch
thick, which are then subjected to process
Of rolling. which congresses them to the
thickness desired for the denomination Of
coin in hand and elongates them to six feet
For this process OF reduction there Is re-
CURED a fifty horse power motor, and the
pressure to which the metal Is thereby sub
jected tends to harden 1t in a compare
lively short time. To restore 1t to work
applied. This Is accomplished by means OF
automatic furnaces supplied with gas.
Annealing.
Following this last process, which is
known as annealing. the strips are cut into
blanks by a cutting press run at speed
Of one hundred and ninety-five revolutions
per minute. The blanks are then upset, .
a process which consists of rolling up the
edge In order to fill up the raised border
Of the die This operation tends to harden
the edge Of the blanks In the same manner
as rolling hardens the strips. AS the bor-
der Is the weakest part of the die, 1t Is
necessary to have the edge of the blanks
soft and plfable, and anneaiing is again re-
sorted to, this time in a rotary furnace
having q capacity of six tons Of metal per
day.
This rotary annealing furnace consists
OF an iron cylinder revolving in e. fire heat
ed brick chamber. The blanks are fed into
the mouth of the furnace carried along the
heated cast-iron surface by means of an
internal spiral and dropped into water.
After being washed in a dilute solution of
sClphuric acid and dried. they are ready for
the final operation-the stamping.
The large stamping or coming presses
are driven by motors of seven and one
half horsepower. By means Of these
presses the coins are struck at q pressure
ranging from fifty TO one hundred and
eighty tons, and the largest denominations
are turned out at the rate of eighty-five
per minute. the capacity of the press for
100000 per day OF double eagles.
When the blanks are presented to the
coming press they are fitted into q tube
in the front OF the press and placed auto
maticaIly in steel collar located between
the dies. The inside OF this collar is milled,
and the pressure exerted on the dies causes
the metal to flow into the grooves and gives
to the edgo Of the coin the milIed appear
ance with which we are ell familiar.
After the coins have been placed In cir
culation they are subject to a certain
amount OF wear and tear Az indicated In
the foregoing. the LOGS Of metal by abrasion
may, under the law. b az great as one-
tenth OF a grain per annum. Should coin
show an amount Of abrasion greater than
training or cara prompts them to refuse =
coin which does not measurs the full nura-
Der Of grains required.
. In addition 70 the ordinary wear and teax
coins are subject 20 the imitafi0a and a.
lacks OF various members Of society WHO