New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1877-10-26
BRONZE WORK.
LETTERS FROM AN EXPERT.

only u the mouf made OF sand. Zinc can be moulded
I'm copner mould and that IL thc principal cause OF me
low price spclcror sttucttes known IN the trade
as imitation or French bronze. Tho real bronze ~ an
alloy Of copper zinc and tin the two latter metals i"r
ing very small part Of the combination, the object OF
which f. RE production Of metal harder thIn the pure
conner would be, ami consequently more rapabe %
standing action of time and also less brittle am H"t
than zine alone would be. Let NJ follow statue te
through the differ processes through when u haS 10
pass the time leaves the hand'o Of the artist who
has molld it to that when it reaches the store where
is to BE- sold
The original statuette is generally finished in plaster
The manu- curers operation j. 10 hayei cnt in such
pieces as viii the mouder. the mounter and The
chaser very sta'ueites cast all In one
piece and legs generally put on aferi the body
is finished The next operation l. Ia reproduce The an r
parts IT the fyrIe IN metal For this the molIder
takes II in hand prepare the mould IL begins by select
ing rectangular frame. technically termed flask,
Jorge enough for the figure u lie in easily. To this
Frame which is from two TO six inches deep another SINH
ar frame be fastened by bolts and eyes arranged on
the outside that several Of these frames snper
posed sort of box The workman places the plaster
statuctte, which his pattern" bed Of SOFT
moulding sand inside The rsr iron frame The sand used
10Y nou d-mafng OF peculiar nature, ITS principal
quality beng due TO TIE presence OF agncsia. Only in
one locality in the world is found the be sand that Is
at Foncn lyaux-R lses arw miles from Paris in France
This sand. when slightly damp, sticks together very
easily nd is well fitted take the impression OF the pat
tern.
O zee the pattern imbedd,d in the sand the workman
ikes small lump Of sane. which be presses against the
side Of the fl .rc covering certain portion Of it, Next
to this piece he presses another ing small wooden
maet to the perfect adhesion OF the nd to th"
p1tien Each OF these .ecr OF sand is trimmed of
and hight layer OF potatofour busted both over the
pattern and the dit rent parts ~ the mould TO prevent
them from adherng together In course OF time the en-
tire part Of the pa eft above the first bed Of sand
on which n has been placed will be covered with these
pieces ~ sand which beaten hari enough 90 keep
together Loose sand is thrown over this element
airy brckwork OF sand II may be called, and sec
ond ron frame boed tOthe first one 20 ho the sand To-
gether which, when beaten down, will form ease hold
ing The elementary sand pieces the mould IN place
The workman now his mould over and removes he
loose san which formed the original bed of the pttern
and replaces by beaten pieces just he has done or
the upper side.
W. can now easily conceive that II the mould Is
opened the pastcr pattern be removed and that II
on tue piece, OF sand repl iced they were shall
have hollow space iusilc the mould which will be ex
acty The space previously occupied by the pattern II
We pour melted metal into ia space IL will h IL exnc'ly
and consequently when solicited by cooling, reproduce
exactly the plaster pattern. For small pieces nis will
answer very well hut large pieces must be hollow
II they were cast solii, tn metal IN cooling
would and the surface wOuld present cracks AMI
holes dih,Ilt . fll. To make casting hol ov,
i. is necessary suspend Inside tie mould an inner
mould or core, Irayiag it and the inner
faca of the FIRST mould regular space, which Is that
ich will be filed by tho metal when IL il poured IN
This c,re Is made o. sand, aud suspend IN the mould
by cross wires iron rods, according 10 the
Importance OF the pi'ce. A method often used
IN preparing a mould named by the French
cire perd,te VIII help to illustrate this The arrS'
first takes a rough clay image Of the IL rt he wants
"a produce. This viii be the OF the mould; he Gov
rs it with coatngo; ul1dEg-wax OF equal tuc mess
an on this he finishes the modelling OF his figure
The mou'd,r now makes his sandmould the WAX
and when 1t completed by blking the m0ul in SUIT
able furnace the ol leaving exactr the space
10 be lei up by the metal The celebrated statue "
Perscu by Bcnyeuuto C'llni, cast in this way.
IL IS very frequently employed by the Jap1neso and chi
ncsc. Sometimes IL animals or BASKETS i'll
bcdied in the mould after the hakin tire ashes 60
which they have been reduced are either washed or
blown ont make for the metal This can easily
he done throu lh the jets cft for thr m't -
enter the mould, ana through tho ceHtIDeS provided
for the escape u air aud sasses.
when The moul has cooled 1t IS broS 80 remove the
casting il contains and here l. the reason WHY real
bro r. x1ensive than thr speiter int
tltion. For each bronze new san In 'uld must he
m.da vho the zine or spelter be poured In metal
moulds watch Will last forever. In this the pieces
are pro lucel with bit little moce LABOR than that r.
oured to manufacture lead bullets These pieces, of
course do not receive the same expensive finish tn
real brOnzes. When the casting Is taken ONT OF tAe
mould it the mounler, who trims It or files The
base rue prepares tho which 10 receive
other pieces to be mounted and hands the
piece to The work Of this ART san consists 10
removing from the surface Or 70 metal such 'duai'S
.ani-m juld may nave left aud IN finishing the
surface OF the meta Is best suits tie piece Inc amount
OF work * lfu chaser lay out piece IS uniim
.lt. Tar pf u
pro luced on the surface oi the metal rl' m'ie of
chasin . calel I'm French chars and in EngliSh. skin
finish" is of course, only found on work or the best
class Sometimes pieces are finished with slight cross
touches similar TIE cros-hatcnns OF engraving rms
style hni-h, which IL much esteemed ny conhOlsseuF
j.. named crosr ii rib0tie. Aftcr the chaser
has hnished mia the piece rrtuns T. the mounsef
who doantycy the elements OF the piece In their
places
The next process ia that OF bron1ng The color known
rs "bronze" Is that which piece OF that metal would
take through the natural process OF atmo'phorca ox
dizrment II II exposed TO dry atmosphere at IN
even temperature. But manufacturer, not being able
10 wat Tor tao slow action Of nature, calls chemistry to
his aid and By different processes produces on the su
face of the piece metallic oxyde Of copper which. ne
cor,ing taste fashion varies from blacG to red
winch are the TWO extreme coors OF copper oXyd. The
discovery OF old brouzoS buried for centuries ~ damp
earth aud covered vertde-Srs, suggested The color
known ~ vert antique. which ia easily produced ON new
metal by the action Of acetc sulphuro acid In the
ii teenth century tue Florentne artisans Produced
be,utfu color on their by smoking them over
fire OF greasy rags and straw This color which very
Ike that mahogany, Is still known as Florenuhe or
smoked bronze. ONE also be plated WITH gold and
.yer nickel aud platinum, Ike oy nv other metil bnt
ia this lett object has been TO explain the manufrc
tIre OF bronze its most simple fothAt is. without
drawing on any other metals for s hlish and decora
ton. fkEDEHlo 'ohs'