Page 368 - Copper and Bronze in Art: Corrosion, Colorants, Getty Museum Conservation, By David Scott

Notes
ι Plutarch Moralia, the Oracles at Delphi no longer J. Pierpont Morgan, then by Henry E. Huntington,
given in verse 5.264-6 5 (Plutarch 1984). thereby reaching the collections of the Hunting­
2 This conclusion does not necessarily pertain to ton Library and Art Galleries in San Marino,
the golden surfaces of New World arsenical cop­ where this bronze resides today.
per or tin bronze objects, which may have been 16 Because of the togas worn by the figures, this
painted or altered before burial. Following exca­ relief fragment is often informally referred to as
vation, careful examination might need to be made the "Togati bronze."
to determine if the surface was altered before or 17 The microstructures of the pustule are discussed
after burial. in greater detail in Scott (1994a).
3 Pliny the Elder Natural History 34.40 (Pliny 1979). 18 The beta phase of the copper-tin system, which
4 Chios was on the island of Nisos, which is reputed occurs in bronzes of 21-24% tin, can be retained
to have been the home of Homer. by heating to 650-70 0 °C, followed by quenching
5 Pliny 34.9. in water. The metastable beta phase, usually acic­
6 Pliny 35.51. ular, is therefore retained by the quenching pro­
7 Presbyter Theophilus De diversis artibus 3.71 cess. The advantage of retaining the beta phase
(Theophilus i96i) . is that the alloy is hard but not brittle, since the
8 Arthur Beale, letter to the author, 22 January 1998. equilibrium alternative is delta phase with alpha
9 The ephebe of Marathon is a bronze statue of a infill, which is extremely brittle. The beta-phase
young boy by Praxiteles or one of his students, quenched alloys are particularly suitable for pol­
ca. 330 B . C . E . The sculpture was recovered from ished mirror surfaces. Some of the especially fine
the sea in the bay of Marathon, Greece, in 1926, and lustrous patinas on objects of this type are
and is widely considered to be one of the master- related to the kind of alloy employed and the
works of ancient Greece. very careful polishing they underwent.
10 The Zeus (or Poseidon) was found in 1928 off 19 Fire-refining is the process of heating a metal
Cape Artemision, Greece, in the wreckage of a or alloy, usually in a crucible, and removing the
ship. It is one of the few surviving masterpieces dross that forms on the surface. The alloy can be
of Classical sculpture. poured into another crucible or simply heated
11 The Riace bronzes, dating from the fifth century again in the original crucible and the dross
B . C . E . and recovered from the sea off Calabria, removed again. Repeating this process results
Italy, must have been in transit from Greece or in the gradual removal of many of the impurities
Magna Graecia by a boat that sank near Riace, associated with copper, such as iron, arsenic, anti­
taking these two bronze masterpieces to the deep mony, and zinc.
for 2,500 years. 20 Cf. Stambolov 1985: sec. 4.6.
12 Formerly in the collection of Sir Anthony Blunt, 21 Because artificial patinas generally have no ability
now in the J. Paul Getty Museum. to create a cuprite patina in depth, artificial pati­
13 A Renaissance nobleman's "cabinet of wonders," nas usually manifest a cuprite crust only a few
containing art objects and curiosities from the microns in depth, if at all. The malachite patina
natural world. was applied to this cuprite surface to attempt to
14 Donatello's David remains a masterpiece of free­ build up a convincing depth of corrosion, in the
standing bronze art, the first in Europe since the right sequence, that would have taken many hun­
fall of the Roman Empire. Vasari accused the artist dreds of years to develop on a buried bronze.
of having cast the figure from life, but this is com­ 22 These finishes were achieved with a variety of
pletely unfounded. Rodin was similarly accused polishing techniques demanding considerable
when he made The Age of Bronze, which was first skill in execution. After the instrument was filed,
exhibited in 1878. Water of Ayr stone would be used to matte the
15 The surface appearance of a work of art may surface, which was finished by rubbing on soft
change with ownership and personal tastes. gray slate stone. The Washemery and Fesh brands
Some details of the provenance of this bronze are of polishing papers were used where a bright fin­
known: by 1581 the object passed from the Niccolo ish was needed. The heads of screws and small
Gaddi collection to a London Gaddi sale of March turned parts would be finished with a burnisher
1764; by 1822 it is thought to have been sold to on a lathe.
an Alderman Beckford and William Beckford
of Fonthill; by 1844 the bronze passed by inheri­
tance to Alexander, tenth Duke of Hamilton; in
July 1882 it was bought by F. Davis in a Hamilton
Place sale; in 1917 the work was purchased by

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