The evening telegraph. [volume] (Philadelphia [Pa.]) 1864-1918, 1869-12-24

locked by two men. each one having key. The
metal ls then placed in pots and melted 1t is then
poured into moulds, and when cool Is again car
red TO the deposit and reweighed, after which
a small piece, weighing about three dwts, is cut Off
from each deposited lot by the Assayer. From this
small piece the 1neness OF the whole lot (perhaps
$4,000 WORTHY is ascertained its value calculated
and the deposter paid.
The gold in its rough state is then ready to be
transferred to the melter and renner to be refined
and rendered nt for coinage.
The Cabinet.
Passing to the second story OF the building you
register your name and residence In a book provided
for the purpose, and then pass on to the Cabinet
Here much will be found OF interest to the visitor.
Portraits OF the different gentlemen who have acted
as Directors OF the institution at different times grace
the walls, while arranged in cases. around and about
the room, collections of medals and coins. Each
OF the medals has an interesting history attached 10
IL, as commemorating some important event In
the annals OF this and other nations. Specimen
coins OF all the nations in the world will
here be found. Among these are those
OF ancient Rome, A. ID. III to 222; Greek Republic,
TO b. c.. together with collection OF Oriental
China, and Japan. Passing on round the room, a
plaster cast OF Oliver Cromwell is 1t is said to
be good likeness A machine for asserting coins
attracts considerable attention on account OF the
delIcacy OF Workmanship. 1t is not in use. large
and most elegant collection OF agates, petrihed
wood, together with specimens Of gold in its native
state will be found here. At the opposite end OF the
room, among collection Of odd and rare COINS VIII
be seen the ''widow's mite" the smallest OF all
ancient coins and which is spoken OF in the Bible.
The visitor will find much in this department which
8 entertaining and instructive
The Directors Room, Etc.
just outside OF the exit door OF the cabinet Is seen
in glass case fine specimen Of the American eagle,
stuffed, with outstretched WINGS as though In the
act OF flying. facsimile OF this bird will be found
upon the diverse of the first nickel cents that were
coined.
To the right, looking down the STAIRS is the Drec-
tors Office Here this offlcer receives his visitors
and transacts the business OF his office. The next
door, on the same side, is the Chief Clerks room.
Further is the private Office Of the Chief Coner.
This room has fine library of scientific and his
torical works On the left is the messengers room,
back OF which are the medal and other departments
for the transaction of business.
Passing the Chief Coner's room, and thence out
upon the gallery, which runs completely around the
building, the machine shop is reached This depart
ment is stocked with lathes .and all the necessary
tools for doing the light work OF the establishment
Back Of this, and adjoining it, are the engravers
apartments. Here the dies used by the Mint are
engraved. The dies for all the different branch
mints are also made here.
The Adjusting Room.
Leaving the engravers' department, we pass I'M
medately into the adjusting room. The work OF
this room is done entirely by ladies. The planchets
of gold and silver are conveyed to this room. Here
they are weighed by the ladies.
There is a certain deviation in the weight allowed
by law. If planchet Is found too light, IL Is
thrown aside and is melted over again. If too heavy,
but very the weight allowed by law, 1t Is taken
in hand and small particle filed oil the edges;
If too heavy to admit of filing, 1t Is thrown aside
with the light ones, and melted again into ingots.
If the planchet is found to be of the proper weight
it is then ready for the coming press. The base
coins nickel, etc. are not taken to this room. 1t
belongs to the Chief Coiners department
The Separating Room.
Occupying greater part OF the west side OF the
building second noor) is the Separating Room.
Here the gold and silver used by the Mint in the
manufacture Of coin and fine bars are separated
from each other, or whatever other metals may be
mixed with them, and purified. 1t goes to this room
after having been once melted and assayed
In separating and purifying gold it is always ne
cessary to add to it certain quantity OF pure silver
The whole is then immersed in nitric acid, which
dssolves the silver into a liquid which looks like
pure water The acid does not dissolve the gold,
but leaves it pure The silver solution is then
drawn off, leaving the gold at the bottom of the tub
1t is then gathered up into pans, washed, and dried
after which it is ready for the use Of the godmelting
room. The silver used in this process in its liquid
state is then into tubs prepared for it, and 'pre-
cpitated" rendered into partially hard state, by
being mixed with common salt water. After being
'precipitated" II is called chloride" and resembles
very closely newlyslacked lime, or ''smearcase." BY
putting spelter zinc on the precipated chloride
it becomes metallic silver, and only needs washing
and melting to make the purest virgin metal
The process OF refining silver Is OF two kinds, that
of melting 1t with saltpetre, ETC., which known
some thousands OF years since, and the modern pro-
cess of dissolving it in nitric acid just like the
method OF extracting it from gold in the above de-
scribed operation.
The Assay Rooms.
Passing along the gallery We enter the building at
the assay rooms In the back room are the fires
stills, and other appliances necessary to performing
all the work OF the department.
In the front room are the delicate scales referred
TO in the description of the deposit room. These
scales 'Dalances" are incosed in glass cases. and
when the Assayer is engaged in weighing the gold
they kept closed that the air may not reach them
and thereby influence either side.
The Process of AssayiBg Gold.
The gold is placed in a black lead crucibe and
covered with boraX to assist the uxing and to pre-
vent oxidation OF the alloy. 1t is thus melted down
and stirred by which complete mixture is effected,
so that an assay piece may be taken from any part
OF the bar cast The piece taken for this purpose
is rolled out for convenience OF cutting 1t is then
taken to an assay balance Sensible to the ten
thousandth OF half gramme less), and from it
is weighed a half gramme which is the normal ASSAY
weight for gold being about ~ grains troy. This
weight is stamped 1000; and all the lesser weights
afterwards brought into requistion) are decimal
divisions OF this weight, down TO ten-thousandth
part
Silver is next weighed out for the quartation; and
as the assay piece, II standard should contain 300
thousandths OF gold, there be three times this
weight or 200 thOusandths OF silver; and this is
accordingly the 0uantity used,