JAIC 2003, Volume 42, Number 2, Article 6 (pp. 261 to 278)
JAIC online
Journal of the American Institute for Conservation
JAIC 2003, Volume 42, Number 2, Article 6 (pp. 261 to 278)




In 1996, after 16 years on exhibit, the bull head was examined in preparation for a traveling exhibit, Treasures from the Royal Tombs of Ur. The head and plaque had been removed a number of times for study or travel, without difficulty and without damage to themselves, the mechanism, or the soundbox. A detailed examination by conservator Lynn A. Grant revealed no sign of deterioration either in the head core or in the beard support. The Plexiglas armature remained securely in place, in spite of the complex design and the lack of climate control in the gallery. The restored beard backing was painted a darker gray to satisfy the preferences of the exhibit curator, but no other work was needed to prepare the lyre for exhibit. When the objects are eventually reinstalled at the University Museum, a new mount will be constructed for the pieces of the original silver backing, which are also in excellent condition. The treatment, in fact, appeared to have been completely successful.

However, many aspects of the work are now somewhat embarrassing. The materials used reflect the practices of the 1970s and would be considerably different if the treatment had been carried out more recently. A contemporary treatment would reflect current safety practices, a wider ranger of available materials, and greater experience on the part of the conservators, including experience in keeping treatment records.

Most notably, toluene would not be used either as the solvent for the Paraloid B-72 or to clean the lapis tesserae. At that time, the laboratory purchased Paraloid B-72 not as dry pellets but in a toluene solution, which was then diluted further with toluene. At present, the resin is prepared from pellets and normally used in acetone or ethanol solution. The choice of ligroine (and, in one place, ethanol) for the wax removal reflects early efforts to reduce the use of xylene and toluene, though this reason was never made clear in the treatment report. Dimethylformamide (DMF) and methylene chloride were at the time, and remain today, solvents of last resort. Even in the 1970s they were used in a fume hood, with appropriate personal protection.

At that time, PVA-AYAF was normally used in the laboratory as a consolidant for pottery and other porous materials, as well as an adhesive, although Paraloid B-72 was generally employed for backings. This practice accounts for the initial choice of PVA-AYAF as the consolidant for the silver. By the mid-1980s PVA solutions had been almost entirely replaced by acrylics, and B-72 would have been the first material tried as a consolidant—which still might not have avoided the problem of incompatibility with a previous consolidant. An acrylic would also now be the adhesive of choice for the eyeball assemblies.

Emulsion adhesives would be used only a last resort, as they are now known to cross-link over time. At the time of the treatment, both Jade 403 and Rhoplex AC-33 were in common use, and Jade 403 was still thought to remain soluble in water.

The styrene foam pellets used in the wax fill were easily available from a local distributor (they were used at the time to fill bean-bag chairs), and the staff was not given a great deal of time to explore alternatives. The conservators were aware that the pellets were not a conservation-grade material and might not age well, although it was hoped that the fact they were in the dark would extend their life. The use of a material that could be easily dissolved (in acetone) would contribute to the potential ease of removal of the core, but the wax itself dissolves in warm water. If the treatment were carried out today, a different material would certainly be chosen. Shredded Ethafoam, which has recently become available, would be a possibility, along with glass and resin microballoons. The use of a hard water-soluble wax as the primary fill material still looks like a good choice.

There is, however, a notable discrepancy between the care taken to protect the back of the eye assembly and backing the beard tiles directly over the holes and wires. If this treatment were being done today, more effort would be put into finding a way to mount the beard tiles without completely coating the backs of the tiles with adhesive. In retrospect, it is also clear that the fragments of silver sheet should not have been backed until later in the treatment process; the author is less likely now to make assumptions in advance about the course of a complex treatment.

If done even 15 years ago, the photographic documentation would have been done primarily using black-and-white film, with color only as a supplement, instead of having been done largely with color slides. If the treatment were carried out today, digital photographs would also be taken. Moreover, more attention would be paid to specifying the exact materials used in the treatment and the reasons for their selection. The laboratory reports have detailed discussions of the properties needed for a particular material and procedure but often neglect to identify (or to identify adequately) the specific product that was finally selected. An example of this omission is the choice of facing materials, where the discussion is extended but the specific type of tissue and the wax chosen were not identified. From the author's recollection of what the laboratory was using at the time, the tissue was an uncoated long-fibered cellulose tissue similar to lens tissue, intended principally for mounting paper-based material. No further information on the microcrystalline wax could be located, except that it was made by Sunoco.

Still satisfactory in retrospect are the decision to use a heavy facing until the strength of the gold sheet was known, the use of a fiberglass–Paraloid B-72 lining for the gold, the care taken in the selection and testing of the fill for the head, the decision to mount the silver backing separately from the head, the ingenious design of the armature and mounting systems, and, above all, the meticulous and patient excavation of the beard backing.

Some of the work certainly reflects the unexpected expansion of the scope of the project and the fact that the conservation staff was under considerable pressure to finish the work as quickly as possible and without spending any money beyond that available in the normal laboratory supplies budget. Additional time for planning and research would have improved both materials and procedures. With additional years of experience, the staff might well have been able to successfully resist the pressure for speed and possibly have been able to secure additional funding, given the importance of the piece.

The Conservation Laboratory now has the experience to plan adequately for major projects, but access to analytical services is not much improved. Radiography can still be arranged through the generosity of the University of Pennsylvania Medical Center, but for almost all analytical work, it is necessary to have outside funding, as the laboratory budget will not support the expense even when facilities are available.

However, in spite of everything that would now be done differently, the treatment still looks like a success. After 21 years of exhibit, including one loan and a traveling exhibit with 10 venues, the head and beard appear to be as stable as they were immediately after the work was completed, and this is a satisfactory result by any standards.


The author would like to extend her thanks to the many people who participated in this project, especially the following (titles and affiliations are those of 1973 except as noted): Diane E. Davies (now Diane Davies Burke), assistant conservator, University of Pennsylvania Museum (currently at the Saint Louis Museum of Art), who was entirely responsible for the excavation of the interior of the beard and provided constant support in the running of the laboratory; in the Near East Section of the University of Pennsylvania Museum, Dr. Robert H. Dyson Jr., curator, now retired, Dr. Christopher Hamlin, assistant curator, Maude de Schauensee, assistant to Dr. Dyson, and Dr. Richard Zettler, currently associate curator; Victoria Jenssen, assistant conservator, University of Pennsylvania Museum; Shelley Reisman (now Shelley Reisman Payne), intern from the Winterthur/ University of Delaware Conservation Program (currently in private practice in Nashville), who assisted in dismantling the lyre and also made the arrangements for the radiography of the head; W. Thomas Chase, head of the Conservation Laboratory at the Freer Gallery of Art, Washington, D.C. (now retired), who cheerfully interrupted his own work to make imaginative and useful suggestions about the construction of the new armature; J. E. Curtis of the Department of Western Asiatic Antiquities of the British Museum and other members of the staff who searched diligently for information on Woolley's role in the first restoration; James House Jr., Mervin Martin, and Edward MacLean, who produced a soundbox both attractive to the eye and accurate as to details; and a second thank you to Mervin Martin, for the design and construction of the mounting mechanism for the head and plaque; Lynn A. Grant, conservator at the University of Pennsylvania Museum, who examined the lyre in preparation for the traveling exhibit and confirmed that the treatment had been surprisingly successful.

Copyright 2003 American Institution for Conservation of Historic & Artistic Works