Fit for a queen: a secretaire made by Jean-Henri Riesener for Marie-Antoinette's private apartments at Versailles in 1780 has recently been conserved by the Wallace Collection, using innovatory techniques developed by the museum. As Yannick Chastang and Eleanor Tollfree explain, this delicate project has revealed significant information about Riesener's practices

Apollo, Oct, 2004 by Yannick Chastang, Eleanor Tollfree

Although the technique must have been familiar to Benneman when he restored the secretaire in 1788, it was obviously unknown to one of the early restorers of a similar secretaire made by Riesener for Louis XVI at the Petit Trianon, now at Waddesdon Manor. (17) In this case, the restorer, encountering difficulties, simply cur through the original bronze fixings by sliding a metal saw blade between the mounts and the marquetry. This treatment resulted in slight damage to the surrounding veneer decoration and also in visible screws having to be fitted through the front of the mounts. (18) In the case of the early twentieth-century repairs to the Wallace Collection secretaire, small pieces of veneer were cut out to reveal the fixings inside the drop-front and the lower doors (Fig. 15). When they were replaced, however, they no longer matched.

[FIGURE 15 OMITTED]

As yet, there is no evidence of other makers of the period using this difficult, impractical and very costly technique, which must have been reserved for the most expensive royal furniture. Even Riesener himself, who is well-known for having restored examples of his own furniture, must have encountered the same difficulty when dismantling his own earlier work.

As part of the conservation treatment, the bronze mounts were cleaned using an appropriate solvent and chelating agent applied in the form of fumes and poultices, a method developed in the last few years at the Wallace Collection that, while cleaning gilt bronzes of their dirt and corrosion, preserves the original patina on the back. The various products used during the cleaning of the bronzes were carefully formulated to suit the varying corrosion problems found among the gilt-bronze mounts and to control as far as possible their cleaning effect.

New techniques to conserve the marquetry

Re-laying eighteenth-century marquetry decoration is an extremely complex task. Practices that were once common, such as the complete removal of the marquetry or the use of a spatula pushed under loose marquetry to introduce new glue, are now generally regarded as overly interventionist and would have been inappropriate for the size of the areas being treated on this piece. Lifting marquetry by Riesener or his contemporaries can indeed prove disastrous, as the acids used to colour the woods during the original dyeing processes can make the marquetry elements extremely fragile and liable to crumble when disturbed. The Wallace Collection has helped to pioneer the use of a rehydration process by which a reversible adhesive made of sturgeon (fish) bladder, called isinglass, is introduced underneath the lifted marquetry, a technique successfully used on this desk. The glue is gently massaged and pushed into the cracks and crevices of the marquetry and drawn underneath by means of vacuum clamping. (19)

The practice of using woods with opposing grains for the interior construction of furniture is often cited as the principal reason for cracking and damage to marquetry. It was decided to take X-ray photographs of the sides, lower doors and the drop-front in order to gain a better understanding of how this particular piece had been constructed. Numerous little rectangular holes in the carcase, situated in line with the design of the veneer border of the drop-front and the purpleheart fretwork of the marquetry on the side of the desk, and invisible once the marquetry is glued in position, could be seen in the X-ray photographs (Fig. 17). This is consistent with the process of laying marquetry described in an important eighteenth-century guide to furniture-making, L'Art du menuisier by Andre-Jacob Roubo. (20) Roubo described the use of small hand-made nails or rectangular veneer pins which would have been fixed alongside a piece of veneer or a border strip, to stop the piece sliding out of position when glued and clamped. These pins were removed after the glue had dried and the next piece of veneer was then glued over the holes. (21)