Macon beacon. [volume] (Macon, Miss.) 1859-1995, 1878-03-23

assay Office to
oIP. Int pure, or 999 fine,
which IS about as pure as silver can be-,
1t is sent in large bars, and when
received at the mint is melted and
alleged with copper. Coin silver is 900
fine. After being melted and alleged
the metal is cast into ingots, which are
simply bars of a convenient size for
handling, The metal is then assayed to
determine whether it is exactly of the
standard fneness. Assaying is done by
what is known as the dry or
humid process. Samples for assay
are taken while the silver is in a
fused condition, and two assays are
made Of every specimen, The silver
ingOts then go to the coiner, They are
then rolled into strips, and as the rolling
process is apt to make the metal brittle,
it is annealed to soften it. Silver ia
aunealed simply by heating in an open
wood fire, and then being allowed to cool
gradually. The silver dollar strips are
passed through the rolls nineor ten times
before the annealing and four or FIVE
times atterward. Then the process of an
healing is repeated. Alter the annealing
the strips are run through cutters which
divide them into drafts of the proper
thickness for the coins, and these, in
their return, are run though a steam
punching machine which cuts p~lanChets
the proper sieze for the coin. From 1850
to 200 are cut in a minute. As the metal
gets greasy during the process, the plan.
chefs are dipped into a bath of diluted
sulphuric acid, which is too weak to act
upon the surface, but effectively removes
all foreign matter. The planchets are
adjusted; that is to say, they are carefully
weighed, and all that are lacking in
weight are cast aside; such pieces are
called lights" and the "heavies " are
the pieces which weigh too much and are
filed off. The adjusting is done by women
1t is a process which requires much
delicacy, and scales are used which are
sensitive to one siXty>fourth of a grain.
After the adjusting is finished, the next
operation is the milling, which is done
with a curious sort of a machine. The
edges of the coin are thrown up and
grooyed by this process. After another
cleaning with sulphuric acid the coins are
ready for the die. The stamping is done
on a screw press, and both sides of the
com are stamped at the same time. The
dies are cylindrical blocks of steel, upon
which are carved the designs to be trans
ferred by pressure to the coins. Art ola
high order, as well as fine mechanism, is
conspicuous in this part of the coming
process. The designer in the case of the
new silver dollar, Mr.. Morgan, first draws
his design on paper, from which is made
a model in wax, of which a plaster cast
is taken, and from this cast an electrotype
is taken, upon which careful revision
is made with the graver. This
el~ectrotype, like the model and cast
which preceded it, is three or four times
larger than the impression which appears
on the dollar. The design is transferred
to a steel die Ivy using Hills reducing
machine, constructed on the principle of
the pantograph. One arm of this instru.
ment, with a blunt point, follows the
lines on the e%lectrotype, while the other
arm, to which is attached a strong and
rapidly revolving drill, reproduces the
same lines on a smaller scale upon a steel
block. By means of a press this i'm.
preston is transferred to another block
in intaglio and thence upon another
block, which is the parent die. After
each transfer the lines are carefully i'm
proved with a graver. Steel of the same
quality as that of which the parent die
Is made is used for the coming dies.
They are annealed, and trued on both
ends. Two or three blows in the screw
press, which is worked with a large
wheel, ecures a perfect impression, and
both the diverse and the reverse of a
coin are struck at once Machinery places
the planchets between the dies, and af-
terwarG drops the completed coin in a
box. Two or three pieces of each coin.
age are reserved for the annual govern
ment assay,
The processes of melting, refining and
assaying gold and silver are carried on
in the assay office, in this city, on quite
as large a scale as at the Philadelphia
mint. Not only government work is
done here, but large deposits are made
daily of gold and silver bullion by pri.
waite individuals. Gold is always found
alleged with silver, and it is never found
with any other alloy. To separate the
silver from the gold, the bullion is boiled
in sulphuric acid, which removes the
alloy; the gold is then reboiled and re.
duced to a coarse powder resembling
clay. Its purity then is 1893 and 999.
The silver, mixed with copper, is run into
watts on the lower floor, and is purified
and graduated, when it resembles pine
clay. The granulated gold and silver
are pressed into large cheeses in a nv
draulic press. A cheese of gold, twelve
inc az in diameter and three inches thick,
10 worth $4,000; a silver cheese of the
same SIZE Is worm 500. The suiphunc
acid, after it is used, produces a sediment
of blue v%itriol, which is much prettier
than either the gold or the silver seen in
the assay Office. The vitriol and the
weak acid are both sold for as much
money as the original acid costs,
The substitution of sulphuric
acid for nitric acid has caused
a saving to the New York Assay Office
alone OF 100000 a year, Depositors