Chemical Composition: XRF data from Tracer
Alloy: Leaded Bronze
Alloying Elements: copper, tin, lead
Other Elements: iron, silver, antimony
Comments: There are small patches of gold on the back of the neck of the object.
K. Eremin, January 2014
Chemical Composition: SEM-WDS data from sample, 1956.19.B, Leaded bronze:
Overall Alloy: Cu, 76.2; Sn, 8.2; Pb, 15.6; Zn, 0.13; Fe, nd; Ni, nd; Ag, nd; Sb, 0.17; As, 0.13; Co, nd
Copper phase around lead inclusions: Cu, 90.2; Sn, 8.6; Pb, 0.62
Comments: Copper sulfide inclusions. Large region SEM/EDS analysis used to indicate overall lead content of alloy.
R. Newman, June 2015
Chemical Composition:
Lead Isotope Analysis (Pb, 15.6%):
Pb206/Pb204, 18.58825; Pb207/Pb204, 15.66532; Pb208/Pb204, 38.73287; Pb, 207/Pb206, 0.84275; Pb 208/Pb206, 2.08373; Pb208/Pb207, 2.47252
P. Degryse
Technical Observations: The removal of burial accretions from much of the interior surface of this portrait revealed numerous drip marks and a close conformation between interior and exterior surfaces. The interior also exhibits two vents connecting the tear duct areas of the eyes to the upper portion of the forehead. The vents, which measure 0.65 cm in diameter, would have been added as wax rods to the wax model to reduce the chances of air bubble flaws forming at the eyes. These features indicate that the bronze was produced using an indirect casting procedure. The incised lines in the hair and the finer features in the eyes appear to have been added directly to the wax model. The iris and pupil portions of the eyes are depicted in a shallow relief that would not have retained inlay material.
Many areas of the neck exhibit coarse scrape and scratch marks that predate the formation of corrosion products and appear to be related to the original finishing of the bronze casting. Unlike the broader scrape marks associated with the finishing of the Running Boy at the Walters Art Gallery (1) and the Statue of a Youth at the Toledo Museum of Art (2), these scratches measure only about 0.15 cm or less. Traces of a gilt layer, some of which are embedded in the corrosion layers, are present at the back and proper left side of the neck. The band of light gray patina (2 – 3 cm wide) at the lower edge of the neck appears to be the remains of lead that was added at this location to secure the head to a torso. The bronze at this leaded surface exhibits a higher concentration of scratch marks related to surface preparation than is present at other areas of the neck. The patina covering the exterior surface is a varied green with areas of brown burial accretions. The distortion of the nose and most of the ragged break at the top and reverse sides predate the formation of corrosion products.
Chaplet holes are visible at the lower ears, the proper left and possibly the proper right sides of the neck, the lower front edge in the leaded area, and under the chin. All of these holes are fairly square and measure between 0.20 and 0.45 cm. The ear chaplets, which are positioned in a manner that may have assisted in holding earrings, and the chaplet at the proper left side of the neck were never patched. The proper left ear chaplet hole shows a substantial flanged periphery at the interior, which is indicative of piercing a soft wax or using a warm chaplet. The wall thickness of the casting at points in the region of the neck above the lead residue measures 0.17, 0.27, 0.15, 0.26, 0.28, 0.11, and 0.19 cm. Areas in the upper portion of the forehead measure 0.17, 0.08, and 0.07 cm. The thinness of the casting in this critical area emphasizes the need for the internal vents noted above to help prevent flaws.
NOTES:
1. Inv. no. 23.71; see C. C. Mattusch, The Fire of Hephaistos: Large Classical Bronzes from North American Collections, exh. cat., Arthur M. Sackler Museum, Harvard University; Toledo Museum of Art; Tampa Museum of Art (Cambridge, MA, 1996) 247-51, no. 28.
2. Inv. no. 1966.126; see ibid., 232-36, no. 24.
Henry Lie (submitted 1997)