-The Bronze art market is not so clean.
Posting the warning "caveat emptor"
(buyer beware) never has seemed more applicable than
it does today in regard to the market for 19th and
20th century bronze figurines and other art items that has been flooded
with at least 4,000 fakes.
The bronze art fakes are the handiwork of Guy Hain, a French
collector, dealer and publisher who has been
incarcerated in Besancon Prison since last summer,
serving a four-year sentence on conviction of a
faking scam worth more than $60 million.
Some bronze 2,500 molds, models and bronzes
found in Hain's
studio were confiscated, but some 4,000 finished pieces
are believed to have entered the art market through
dealers and auctions, according to French authorities.
They say Hain faked the work of 98
artists--including such modern masters as Constantin
Brancusi, Jean Arp and Alberto Giacometti--whose
sculptures fetch millions of dollars each in today's
market.
Nothing is new about fakes, posthumous castings and
just plain reproductions in the tricky business of
collecting art bronzes. The Rodin Museum in Paris
continues to produce legal productions of Auguste
Rodin's work long after his death, many of them
collected and given to American museums by financier
George B. Cantor and his wife, Iris.
Rodin was one of Hain's favorite artists when it
came to copying.
He also produced many
copies of works by Antoine Louis Barye, the foremost French
sculptor of animals, who sold the rights to his
work to a foundry in order to get out of debt. Others whose work he
copied were Jean-Antoine Houdon, Frederic Bartholdi (sculptor of
the Statue of Liberty), Honore Daumier, Jean-Baptiste Carpeaux,
Emil Antoine Bourdelle, Aristide Maillol and Camille Claudel.
|
In the case of Rodin,
Hain had access to original
bronze casts through his association with Georges Rudier,
whose family foundry was the official caster of
Rodin bronzes for many years. Hain would remove
Georges' mark from the sculpture and put on the mark
of his father, Alexis Rudier, in order to make the
casts seem to be originals made while Rodin still
was alive and able to supervise production of his
bronzes.
Hain
copied other sculptors' work
by using original
plaster models or by making after-casts from
finished bronzes, using flexible silicon molds. He
used foundries in remote parts of France, one to do
the casting, another the chasing and another the patination. He consigned the fakes to auction houses
through third parties, one of them his daughter's
father-in-law in Marseilles.
Exposure of the breadth of Hain's fakery has put the
entire market for 19th and 20th century bronzes in
jeopardy. Gilles Perrault, an art conservator and
adviser to the French Supreme Court, now believes
Hain may have made 6,000 sculptures over and above
those confiscated, only one-third of which have been
traced to date through sales at such venues as
Drouot, Paris's top auction |
|
house, and the
famous Maastricht Art Fair in the Netherlands.
Perrault and other art insiders advise collectors of
art bronzes to be more wary than ever and to consult
experts in the field before making purchases.
They
point out that under French law, an artist is
allowed to make only 12 copies of any bronze
sculpture, all to be numbered. If any more copies
are made, even in the artist's lifetime, they are
considered reproductions and must have
"reproduction" marked on them.
Hain never marked any of his bronze fakes as reproductions.
Instead he cast into the sculptures the signatures
of the artists and the founder's marks to which he
had no legal right, making their identification as
fakes difficult. Good provenance--especially being
able to prove bronzes were in known collections long
before Hain's activities began in the 1980s--is
important.
"Even so, two out of three pieces of bronze art I see today are problematic," Jerome Le Blay, senior specialist at Christie's auction house,
told United Press International. "It makes for huge
price differences depending on the piece. If all the
reassuring elements are there, then the highest
price can be made. If not, the price will be much
lower."
As an example, he cited the sale of an authentic Rodin
Eve from a long-established French collection
for $4.8 million at Christie's in New York in 1999.
"Without that provenance, the piece might only have
made $500,000," he said.
FREDERICK M. WINSHIP WRITES FOR UNITED PRESS
INTERNATIONAL.
COPYRIGHT News World Communications, Inc.& Gale Groups |
Bronze art a warrior rescues his love. Liberty
Bronze Collection, bronze-finish alabastrite.
photo by emedio1 order at website
www.eqmcorp.com |
- Cellini and
Bronze Sculptures
Every painter paints himself--and what of
the sculptor? Michael Cole's remarkable new book asks us to
apply the renaissance common-place about painting to the
practice of sculpture as exemplified by Benvenuto Cellini in the
sixteenth century. The self fashioning mapped by Cole occurs
less through the incorporation of Cellini's own Likeness in his
work than through the sculptor's technical processes--modeling,
casting, carving, and so on--that in Cole's words 'realize not
only the material, but also the artist'. This approach differs
markedly from discussions that have looked upon Cellini's
extensive writings as the most vital source of information on
his life available. Pope-Hennessy's classic monograph, for
example, describes the texts the artist wrote as 'our most
important source for knowledge of Cellini's work'. (1)
The new study by
literary scholar Margaret Gallucci attends to
Cenini prose and poetry as rhetorical performances
through which he crafted a transgressive persona, 'shap[ing]
words much in the same spirit as he molded gold or
bronze'. (2) Other recent efforts have explicitly
sought to tease apart the artist from the writer,
seeking to examine 'die Verschmelzung sowie die
Spannung zwischen der historischen Gestalt des
Kunstlers im Zusammenhang mit seinem Werk und dem
fiktiven "Cellini" der Autobiographie'. (3) Cole's
book instead fuses the making of sculpture with the
artist's own acts of self-disclosure.
The works of bronze art resulting from the sculptor's
processes, Cole argues, are 'self-referential'
because they 'seek to demonstrate the artistry
inherent in the various acts they represent, and to
relate that artistry to Cellini's own'. The
sculptures function in this way because Cole
presents Cellini as a natural philosopher intent on
the transformation of matter: molten ore to cast
bronze, seawater to salt, blood to coral. Even the
obdurate material of marble was described in his
Treatise on Sculpture as compounds of earth and
water, 'reduced to stone by means of the sun's
rays'. Seen in this light, transformations from one
material to another are the subject, as well as the
method of facture, of Cellini's art.
The discussion of Cellini Perseus, already"
rehearsed in a justly lauded essay in Art Bulletin,
is a prime example of such a self-referential Work.
(4) Cole returns to a previously murky term, the due gorgoni di Medusa, that appears in an inventory of
pieces of the monument cast after the main figure. A
more detailed inventory and a survey of period usage
of the term allow Cole to identify them not as extra
Gorgons' heads (as Eugene Plon, lacking the second
inventory, had in 1883) but as the two extrusions of
blood streaming or hanging from Medusa's severed
head. The ambiguity between streaming and hanging is
the crucial point: as Cole demonstrates with
reference to the Ovidian story of Perseus' rescue of
Andromeda as well as Pliny's description of
gorgonian corals, Medusa's liquid blood was
understood to color the shrub-like corals, which
solidified only when cut. The sculpture's pronounced
framing of the blood/corals, which Cole likens to a
colossal goldsmith's setting of precious stones, in
turn references the casting of bronze itself. In
Cole's words, the 'medium becomes vivid: In its
featured preciousness, and in its aptness to form,
the blood cure coral is as functional a token of
bronzes as any Cellini could have offered'.
The opening chapter on the Saltcellar for Francis
matches the richness of Cole's discussion of the Perseus. (5) The two intertwined figures, identified
by Cellini as Terra and Mare form 'an allegorical
picture of a seashore, the interpenetration of two
geological bodies'. Drawing together texts by
Aristotle, Giorgius Agricola, Pliny, and Ovid, Cole
reads the iconography of the Saltcellar to be the
making of salt: Neptune unbridles the waters,
represented by the sea horses behind him, with his
trident strikes the Earth, and she opens to allow an
inflow of sea water. Salt extracted by allowing
saltwater to penetrate land was typically collected
into a small boat, shallow enough to navigate the
saltbed. The vessel on the Saltcellar designed to
contain the condiment mimics this small boat in
seeming to carry the salt away from the land.
Cole further suggests that the making of salt
bears directly on the goldsmith's work of composing
and recomposing metal. Various sixteenth century
writers understood salt to be interchangeable with
metal: the one could be used to generate the other.
The transformations of materials continue in the
enamel or colored glass, covering much of the base
of the Saltcellar, for glass was seen as a composite
of earth and water, and salt as a primary
constituent of glass. As Cole summarizes, Cellini
crafted his Saltcellar using 'a collection of
siblings (metal, glass, salt), a family of materials
related through common parentage'.
Cole aptly describes the Saltcellar's function
as a
conversation piece, serving to prompt table talk
about the etiology of salt and its family of
materials. In her study of Johann Joachim Becher,
Pamela Smith described such a conversation at the
Munich court of the Elector of Bavaria in the 1660s,
where Becher served as Hofmedicus and Mathematicus.
Given the task of discoursing on the table salt, a
visitor to the court spoke on its moral, physical,
theological and historical significance. Becher,
proclaiming himself the better orator:
- Began with an explanation of the nature of metals,
their relation to each
other, their growth and development in the earth,
and their mining, smelting and working techniques.
He went on to discuss the manufactures that produce
and market silver objects. He discussed silversmiths
and silver and gold beating ... and the tools of
these craftsmen, their technical vocabulary, what
raw materials they used, and finally he returned to
the salt cellar.
As he was about to return to the silversmith, the
restless diners finally asked Becher to stop. (6)
Cole's discussion shows us that, had Cellini
Saltcellar graced that Bavarian court's table,
conversations about the salt, its container, and the
container's maker could have been melded into one.
These compelling readings of Cellini Saltcellar
and Perseus and Medusa deftly reveal unanticipated
facets to these well-studied works. The chapters on
his lesser efforts, including the marble sculptures
and the designs for the seal of the Accademia del
Disegno, are perhaps inevitably slighter. To
describe Bernini's Apollo and Daphne as 'a sequel
to' Cellini's flawed Apollo and Hyacinth emphasizes
the thematic parallels to be round in two episodes
from Ovid's Metamorphoses rendered in the medium of
sculpture at the expense of the great formal and
technical differences between the two works
themselves.
|
The discussion of the bronze relief of the
Liberation of Andromeda, designed for the foot
of the Perseus by Cellini, similarly relies on textual sources.
Here Cole proposes that in the relief, two moments
from the Ovidian text are conflated, so that Perseus
is shown when Andromeda's 'eyes held his, and from
them an arrow pierced him with light, and as its
fire ran through his veins, he almost forgot to flap
his wings'. At the same time, Perseus 'took sword in
hand, and with fiery heart, vigorously flew towards
[Cetus]' (both passages from Ovid cited by Cole on
pp. 129-30). Perseus' double action, flying yet
turned towards Andromeda, is linked to the latter's
role as pretium et causa laboris, both the prize and
cause of his labor. Yet the relevance of the first
Ovidian passage remains in question, given
Andromeda's distinct profile away from Perseus, any
possible exchange of gazes shielded by her upraised
right arm.
Still, in this ambitious book, Cole effects no less
than a reorientation of the social status of the
artist vis a vis the sculptor. Standard discussions
of an evolution from craftsman to liberal artist
have focused on the move away from mechanical labor
based on handiwork. Proponents of painting in the
sixteenth-century paragon between painting and
sculpture commonly denigrated the sculptor's
physical efforts necessary to shape the material.
(7) Pointing to the example of Cellini, Cole
suggests that 'the kind of practical reason that the
Arts totelian tradition had long associated with the
mechanical arts is the kind of thinking that really
matters'. |
Perseus by
Cellini |
|
This emphasis on the bronze artist's hand has
significant implications for the idea of
artistic authorship. As Cole points out, Cellini sculptures are 'about the
invention or discovery of an executive agency',
though this issue is not further pursued. In an
appendix, 'On the Authorship of the Bargello Marble
Ganynrede', Cole reviews the scholarly literature
and period documents on Willem van Tetrode. (8) His
final conclusion is that though Tetrode was recorded
as carving marble in the Cellini workshop in the
period during which work on the Ganymede was done, 'Cellini
himself had covered the cost of materials and hired
the hands to help work them; it would have been
conventional to designate the work ... as his'. This
assessment is true enough; yet a deeper analysis of
what Henri Zerner called (in reference to Raphael) a
'colonization of the talent of others' would be
welcomed For then both Cellini's personal hand in
his work and his enmeshment in a social network of
making would be joined as well. |
Michael W. Cole Cambridge University Press, 2002.
ISBN 0 521 81321 2. 60 [pounds sterling]
(1) John Pope-Hennessy, Cellini, New York, 1985, p.
15.
(2) Margaret A. Gallucci, Benvenuto Cellini:
Sexuality, Masculinity, and Artistic Identity in
Renaissance Italy, New York, p. 20.
(3) Alessandro Nova and Anna Schreurs (eds.),
Benvenuto Cellini: Kunst und Kunsttheorie im 16.
Jahrhundert, Cologne, 2003, p. 1. This collection of
essays presents the papers given at a symposium in
Frankfurt in 2000. Since that quintcentennial year
of Cellini's birth, other contributions, including
for example Denise Allen's paper, 'Crafting a
Profession: Cellini and the Gold smith-Jewelers in
Rome', given at the conference Il nostro bel
Cinquecento: Italian Sculpture of the Sixteenth
Century held at the Isabella Stewart Gardner Museum
on 8 November 2003, have aim enriched the
literature.
(4) 'Cellini's Blood', Art Bulletin vol. 81, no. 2,
1999, pp. 215-35, was awarded the Arthur Kingsley
Porter Prize.
(5) The Saltcellar was stolen from the
Kunsthistoriches Museum, Vienna, on 11 May 2003, and
a ransom demand was reported three months later.
(6) Pamela H. Smith, The Business of Alchemy:
Science and Culture in the Holy Roman Empire,
Princeton, 1994, pp. 87-88.
(7) On the paragone generally see Leatrice
Mendelsohn, Benedetto Varchi's Due Lezzioni:
Paragoni and Cinquecento Art Theory, Ann Arbor, Ma,
1978; Claire Farago, Leonardo da Vinci's Paragone: A
Critical Interpretation with a New Edition of the
Text in the Codex Urbinas, Leiden and New York,
1992; Rona Goffen, Renaissance Rivals: Michelangelo,
Leonardo, Raphael, Titian, New Haven and London,
2002. On the paragone in connection to Cellini, see
Alessandro Nova, 'Paragone-Debatte und gemalte
Theorie in der Zeit Celllnis', pp. 183-202, and
Stefan Morel 'Der paragone im Spiegel der Plastik',
pp. 203-16, in A. Nova and A. Schreurs (eds.),
Benventao Cellini: Kunst und Kunsttheorie, Cologne,
2003, p. 1.
(8) Two exhibitions and their respective catalogues,
postdating the completion of Cole's text, have added
tremendously to the scholarship on Tetrode: Stephen
Goddard and James Ganz, Goltzius and the Third
Dimension, exh. cat., Sterling and Francine Clark
Art Institute, Williamstown, MA 2002; and Frits
Scholten, Willem van Tetrode, Sculptor (c.
1525-1580), exh. cat., Rijksmuseum, Amsterdam, and
the Frick Collection, New York, 2003.
Apollo by Lisa Pon
- Ways the Romans used antique Bronze
Bronze age, for about 2,000 years, from around 3,000 BC to 1,000 BC, bronze
was the most important metal used by people for industrial
purposes. Although the use of tools made of iron began to
increase after 1,000 BC, in the Roman world bronze continued to
be an essential medium. Like the Greeks and Egyptians before
them, the Romans used bronze in numerous ways. Roman cooks used
bronze pots and pans; some furniture was made of bronze, as were
belts and brooches for fastening clothes, and bronze armor and
other equipment was used by Roman military personnel.
Additionally, in private homes and gardens and in public places
like the Roman Forum, bronze figurines and statues of gods,
athletes, heroes, and government officials were ubiquitous.
Writing in the first century AD, Pliny the Elder discusses the
use of bronze for statues:
"Bronze-working came generally to be associated with statues of
gods. I find that the first image cast in bronze at Rome was
that of Ceres....The art then passed from representations of
gods to statues and likenesses of men in a variety of forms....
"Likenesses of men were not usually made unless they deserved
lasting commemoration for some outstanding reason, such as a
victory in the sacred games-particularly those held at Olympia
where it was customary to dedicate statues of all winners. When
an individual had won three times, exact likenesses were made of
him and these were known as 'portrait statues'.
The first portrait statues erected at public expense in Athens
were probably those of
|
Bronze age
artifacts at castle museums in Linz ( Upper
Austria ). Archeological collection: Bronze age
sword, found in a river. |
|
the tyrannicides Harmodius and
Aristogiton. This happened in the same year as the expulsion of
the kings of Rome. Out of a most civilized sense of rivalry, the
setting up of statues was afterwards adopted by the whole world.
The custom arose of having bronze and other statues adorn the
forums in all municipal towns, and-so that such
records should not be seen only on tombs-the
memory of men was perpetuated by inscribing
rolls of honor on statue bases to be read for
all time." (Pliny, Natural History 34.15-17) |
There were surely thousands of bronze smiths working throughout
the Roman Empire, and bronze technology was very sophisticated.
Unfortunately, there is no detailed account of the techniques
used in Roman bronze foundries and no technical manual on the
design, production and casting of bronze statues. Nevertheless,
although the ancient bronze workers probably did not fully
understand the chemistry of metallurgy, they had a 3,000
year-old tradition and they knew their craft. The objects they
produced give us the best evidence of the techniques used in the
manufacturing process. Like many craftsmen today, the Roman
bronze workers may not have been able to explain the theory, but
their products indicate that they understood the process very
well, indeed.
Bronze is an alloy, which is "an intimate blend-not a mechanical
mixture-of one metal, known as the 'parent' or 'base' (in the
sense of basic) metal, with other metals or non-metals. Its
elements are miscible with each other when in the molten state
and do not separate into distinct layers when solid. Some metals
cannot, therefore, be alloyed." (Healy 1978, p. 199) The primary
components of the bronze used by Greek and Roman craftsmen to
make statues are copper, tin, and lead. Prior to being included
as part of an exhibit in 1996 at the Harvard University Art
Museums, fifteen large-scale bronze statues were analyzed by
technicians at the Straus Center for Conservation between 1994
and 1996. The other thirty-seven large-scale bronze statues in
the exhibit were analyzed at their home institutions or
collections between 1989 and 1995. All fifty-two statues
contained copper, tin, and lead in varying proportions. The
copper content in twenty-six objects ranged from 70-80% and it
ranged from 80-90% in another twenty objects. Over two-thirds of
the objects had a tin content ranging from 5-10%. The lead
content for nearly two-thirds of the bronzes tested ranged from
10-20%, but all of the objects had some lead (Lie and Mattusch
1996, pp. 174-5). These figures seem to support Pliny's formulae
for bronze. He states:
|
- "The composition of bronze for statues, as well as for sheets of
metal, is as follows:
the ore is melted and to the melt is added
a third part of copper scrap-that is, used, second-hand copper.
This scrap contains an intrinsic, seasoned brightness, since it
has been subdued by friction and tamed by use. Tin is also
alloyed with it, in the proportion of one part of tin to eight
of copper.
"Then there is the bronze referred to as 'suitable for moulds';
this is very delicate because a tenth part of lead and a
twentieth part of |
|
silver-lead is added; it
is the best way to impart the color called Grecian...." (Natural History 34.97-98)
The antique
bronze alloy was most likely discovered by accident sometime
before 3,000 BC. Prior to that, around 4,000 BC, people living
in Mesopotamia (the Near East) were mainly using three metals:
gold, silver, and copper. Copper was probably the first metal
used for industrial purposes, that is, for making weapons and
tools. It could be hammered into various shapes. However, like
silver and gold, copper becomes brittle after it is hammered for
a while. It must be 'annealed' or softened again by heating it
until it glows red and then allowing it to cool. In time
craftsmen learned that copper would melt if heated long enough
at a high enough temperature. To make tools and weapons, liquid
or molten copper was poured into molds, which were perhaps first
made of carved stone and later of baked clay formed around
models probably made of wood or wax.
While about 3,000 BC the
people in Mesopotamia began to use bronzes, the Egyptians
continued to use copper in the way described until around 2,000
BC. The reason the Egyptians did not use bronze as early as
others is most likely the fact that there was virtually
|
Antique Bronze |
|
no tinstone
available in Egypt. (Hodges 1970, p. 92)
Unlike iron, which never occurs naturally, lumps of metallic
copper can be found among copper ores. Although it is difficult
to determine for sure, the melting of native metal may have
preceded the smelting of ore (Forbes 1966, p. 73). The type of
furnace used for the two processes is different. While the
smelting of copper ore could be done in a pit furnace, the
melting of copper and its alloys required more protection so
that the molten metal would be suitable for pouring into a mold.
Presumably, industrial furnaces evolved over time from cooking
fires in pits and baking ovens. |
Pottery was likely first fired
in pits, but by about 4,000 BC true pottery kilns were appearing
in Mesopotamia, and by 3,500 BC the making of pottery was
becoming a complex industry (Hodges 1970, pp. 65-70). At this
point it appears from the limited evidence that there was a
standard kiln arrangement which included a firing chamber pit at
the lowest level which was roofed and separated from the
ceramics by the floor of a stacking chamber above. The divider
had holes that acted as vents to allow hot gases to rise. At the
base of the firing chamber was a stoking pit where a workman
could stand to stoke the charcoal fire through an archway into
the firing chamber (Brown 1976, p 84). Some archaeologists
believe that these kilns had a dome-shaped cover with a vent at
the top, although no complete kilns have been found at any
ancient site. From the remains which have been found, it appears
that pottery kilns used in antiquity were usually built of clay
and sometimes had outer walls of stone or brick (Brown 1976, p.
84; Hodges 1970, p. 65). These pottery kilns could most likely
reach temperatures in the range of 1050-1200o C. (Brown 1976, p
86; Forbes 1966, p. 70). (See Figures 1-6 for several examples
of reconstructions and representations of pottery kilns.)
By using blowpipes made of reeds or metal tubes with clay tips
to direct a stronger air-blast to a specific point, ancient
metalworkers discovered that the temperature of a charcoal fire
could be raised high enough to melt metal (Forbes 1966, pp.
83-84). For copper to melt, the temperature must reach about
1084o C. (1983o F.). This could be achieved in an open-hearth
pit fire given a sufficient amount of time. If copper ore was
mixed with charcoal, it could be and very likely was smelted
this way (See Figure 7). Over the course of perhaps a day, with
continuous blowing by workers, a mass of copper would settle to
the bottom of the fire pit and a glassy slag would form above
it. The slag could be chipped away and discarded. The remaining
lump of copper would most likely be full of blow holes that
could be removed in two ways. First, the metal could be
cold-worked, that is, hammered and annealed. Alternatively, the
blistered mass of copper could be broken up, placed in a clay
crucible shaped like an open jar, reheated either in the pit
forge or in a pottery kiln until liquid, and cleared of
impurities by raking off the surface with some implement. Once
it was refined in this way, the molten copper could be poured
into a mold of some kind (Hodges 1970, pp. 71-73). (See Figures
8 and 9.) In the absence of definitive evidence to the contrary,
it is reasonable to assume that the technology used for smelting
copper ore and for melting copper, and later bronze, for casting
did not change for many hundreds of years. In Greek and Roman
foundries, the use of bellows instead of blowpipes to raise the
temperature in a furnace was probably the primary advance in
technology.
Clay crucibles evolved from the potter's art and their use
required a different type of furnace. While crucibles could be
and no doubt were used in open-hearth charcoal fires, as
metalworkers improved smelting techniques, crucibles were
primarily used for refining purposes. Since a crucible full of
hot metal would be more stable if placed on a firm base, it is
reasonable to assume that special crucible furnaces were
developed from the two-part potter's kiln. In such a furnace a
crucible of molten metal could be protected from direct contact
with combustion gases which might affect the properties of the
metal (Forbes 1966, p. 75) and could probably be handled more
easily during the casting process. The production of clay
crucibles was most likely a specific industry in classical
times. Pliny tells us that "tasconium (from the Spanish tasco,
crucible or cupel) is a white earth like potter's clay, which is
the only substance which can endure the combined efforts of the
blast, the heat of the fire and the glowing charge of the
crucible." (Natural History 33.69 in Forbes 1966, p. 75). One
might speculate whether or not this special white fire clay was
a type of kaolin, or China clay, which the Chinese employed so
skillfully in making porcelain. No comments regarding this have
appeared in the works reviewed. In any case, such clay crucibles
were used in both the metal-casting and the glass-making
industries. As previously noted, fragments of crucibles have
been found around the casting pits on the Agora at Athens.
Additionally, crucibles have been found at the third to early
fourth century glassworking site at Titelburg in Luxemburg.
These crucibles, used for melting glass in a furnace, measured
10-13 inches in diameter and are estimated to have been at least
12 inches high. They would have held about 33 lb. of glass
(Price 1976, 115). A calculation performed independently*
indicates that a similar crucible with a 10 inch overall
diameter by 14 inches high would hold around 150 lb. or two
gallons of molten bronze composed of 90% copper and 10% tin.
This is the maximum amount that can be handled efficiently by
two men and poured successfully into a casting mold (Hemingway
1996, p. 3).
|
- How Big Were Those Crucibles? |
*The following information on crucible size was provided by
Gregory B. Young, Director; University of North Carolina at
Chapel Hill Biomolecular Nuclear Magnetic Resonance Laboratory:
|
|
"For bronze composed of 90%
copper and 10% tin, the density is 0.318 lb./in3. The
volume of 150 lb. of bronze is:
150 lb./0.318 lb./in3 = 472 in3 times 0.00433 gal/in3 = 2.04
gallons.
Assuming a cylindrical crucible 7 inches in diameter:
472 in3 = 12.25(Pi times height), so height = 12.3 inches.The crucible (ignoring the expansion with heating) must be
larger than 7 inches in diameter by 13 inches high inside. A
reasonable size would probably be (allowing 1 inch thick walls
and bottom) 10 inches OD by 14 inches high. For reference,
McMaster Carr sells a graphite crucible that holds 134 lb. of
red brass (density 0.316 lb/in3) for $84.00 with a lid for
$23.00 (1988 prices). This crucible is 10 1/8 inches OD by 12
3/8 inches tall." By Sara M. Malone |
|
