Chemical Composition: ICP-MS/AAA data from sample, Mixed Copper Alloy
1957.68.A: Cu, 74.24; Sn, 2.8; Pb, 6.13; Zn, 16.22; Fe, 0.17; Ni, 0.1; Ag, 0.08; Sb, 0.06; As, 0.2; Bi, less than 0.025; Co, less than 0.005; Au, less than 0.01; Cd, less than 0.001
1957.68.B: Cu, 72.76; Sn, 1.93; Pb, 8.18; Zn, 16.08; Fe, 0.41; Ni, 0.19; Ag, 0.11; Sb, 0.03; As, 0.26; Bi, 0.044; Co, less than 0.005; Au, less than 0.01; Cd, less than 0.001
J. Riederer
Technical Observations: All the lamps in this group (1957.68.A-B, 1975.41.138, 1992.256.94, and 1992.256.227) are very dark, almost black, with a faint green cast. The surfaces are in good condition and are relatively free of corrosion products. 1992.256.227 is the one exception, and it shows some pitting and raised corrosion products. 1975.41.138 has a deep, pre-burial dent at the rim under the shell-shaped lid. All of the lamps have possible oil residues mixed with accretions and corrosion products in their interiors.
The lamps and lids are all cast. Although there is no visible evidence supporting the use of molds to make the wax models for the lamps, it seems likely that at least the wax model for the general shape of the body was cast. The interior surfaces do not reflect the shape of the feet, and the feet and handles were probably added manually to the cast wax bodies. The lids were cast separately and attached with a hinge held by a bronze pin, which is peened at both ends to hold it in place. The cruciform handle of 1957.68.A-B is not integral to the cast; it is instead held in place mechanically with a mortise and tenon joint. Grooves (0.1 cm wide at the top and bottom of the tenon) catch the edge of the mortise and help to hold this “removable” handle in place. Long striations visible in the better-preserved surfaces are burnish marks from finishing the surfaces during fabrication.
Lamps 1957.68.A-B and 1975.41.138 have tapered square holes at the middle of the bottom to insert the pin at the top of a stand such as 1975.41.141.A-C. These sleeves appear to have been formed by piercing the bottom of the wax model with a similar square pin and then building additional wax around that pin in the interior. With 1992.256.94, instead of a provision added in wax, a roll of sheet bronze was inserted into the hole to form the sleeve. It is not clear if this sleeve is held in place mechanically or if a solder is present.
Henry Lie (submitted 2001)