Chemical Composition: Body
XRF data from Tracer
Alloy: Bronze
Alloying Elements: copper, tin
Other Elements: lead, iron, silver, arsenic
XRF data from Artax 1
Alloy: Bronze
Alloying Elements: copper, tin
Other Elements: lead, iron, arsenic
Handle
XRF data from Artax 1
Alloy: Leaded Bronze
Alloying Elements: copper, tin, lead
Other Elements: iron, nickel, arsenic
XRF data from Tracer
Alloy: Leaded Bronze
Alloying Elements: copper, tin, lead
Other Elements: iron, nickel, silver, antimony, arsenic
K. Eremin, January 2014
Chemical Composition: ICP-MS/AAA data from sample, Leaded Bronze:
Point 1 (handle): Cu, 83.9; Sn, 9.26; Pb, 6.36; Zn, 0.01; Fe, 0.05; Ni, 0.07; Ag, 0.06; Sb, 0.07; As, 0.15; Bi, 0.054; Co, 0.016; Au, less than 0.01; Cd, less than 0.001
J. Riederer
Technical Observations: The original vessel was made up of at least two pieces: a cast handle and a raised body. The body would have been hammered out from a thicker-walled cast form with a thick, partially decorated lip. The fine beads may also have been formed with a punch. The guilloche and other decorative elements were cold worked into the surface. The sides of the top edge adjacent to the handle appear to have been hammered out and squeezed or pinched together to form the narrow protruding elements. The rows of round indentations at the center of the incised lines of the guilloche were punched. In several areas, the incised lines show very fine repeated marks of the chisel tip’s progression through the metal (visible only under magnification).
Only the top of the body remains; the part below the neck broke off due to weakening of the metal through mineralization. The surface of the vessel is very polished and a smooth light to dark green. The part of the handle that would have had the most exposure due to handling is darkest. The vessel’s surface reveals a fine fibrous, wavy linear structure that is also visible with the aid of magnification in the highly mineralized (and fragile) areas at the broken edges of the body. The pattern suggests that the metal underwent elongation as it was shaped and that the heterogeneous nature of the alloy accounts for differential corrosion. U. Peltz, conservator of metals at the Antikensammlung in Berlin, suggested that the lighter parts are the result of preferential corrosion of the tin-rich areas that formed metastannic acid.
The handle was cast separately by the lost-wax process, judging from the details and complexity of the shape. Much of the detail was already formed in the model but reworked in the metal (e.g., the strands of hair and beard). The silenus face on the top of the handle is much more worn that the one at its base. The handle was joined to the vessel by means of additional metal poured between the two parts, forming a mechanical join. One can see the space between the metals clearly on the proper right side of the top silenus head. A similar method was no doubt used to affix the attachment plate of the handle, as the inner surface is quite smooth and there are no visible holes or traces of some other method of joining. The ovoid impressions preserved in the inner surface of the vessel are formed by hammer blows, but they seem to be spaced too far apart to relate to the raising of the vessel.
The surface was clearly cleaned or scraped free of corrosion accretions during restoration. A number of small pitted areas of the same size on the proper right side of the neck and into the guilloche could reflect areas where the corrosion attacked the surface, or perhaps they could be the location of later damage during excavation. The surface also has a number of scratches and cracks emanating up from the broken edges. Evidence of deep scraping is particularly visible on sections of the handle. The dark brown accretions on the handle may be a mixture of burial accretions and wax, as the material is quite friable and the metal surface below it is matte and green. Remains of a light orange clay or earth are stuck to various parts of the vessel (e.g., inside of the vessel, bottom of the handle, parts of the guilloche decoration). The dark brown patch on the underside of the protruding element on the proper left side of the rim corresponds to an accretion of a tan material on the inner surface and looks like some kind of repair.
Francesca G. Bewer (submitted 2011)
