THE CONSERVATION-RESTORATION OF ARCHITECTURAL STATUARY IN ACCORDANCE WITH THE ETHICAL REQUIREMENTS FOR SCULPTURE AND ARCHITECTURE

Between the conservation-restoration of several disciplines like sculpture and that of architecture differences in the application of the general ethical guidelines exist. Because some “objects” like architectural statuary cannot be classified under one specific discipline this paper attempts to outline the parallels between the applicable disciplines and to point out any inconsistencies, thus encouraging an environment in which the cross-pollination of the principles of a minimal, reversible and stable intervention can thrive and bridging the existing gap between the different fields. Two case studies undertaken by KIK-IRPA Brussels of the treatment of architectural statuary from around 1900 in Brussels are used to illustrate some of these aspects.


Introduction
In the past, our profession has developed ethical guidelines for treatments that optimise a range of requirements that take the aesthetic and technical considerations into account. These universal codes are largely adopted by conservator-restorers. Comparison of the recent conservation-restoration history of sculpture and architecture reveals that the importance given to the different considerations differs significantly depending on the subgroups in which they are classified, such as architectural decorations, contemporary art, and stone, wooden, terracotta or polychrome sculpture, etc. In architecture, it is broadly accepted to repaint interior as well as exterior surfaces in their original colours. A good example is Fallingwater, the house designed by Frank Lloyd Wright in 1935. The stucco-covered concrete has always been painted and its original light ochre colour was even specified by the architect himself in 1937 (Fallingwater, 2006). Between 1937 and 2006, the house was repainted at least seven times, using a variety of paint manufacturer products. In the case of polychrome wooden sculpture, it is common knowledge that in the past, the rich polychromy was often scraped off. Johannes Taubert and Paul Philippot however argued that the colour of polychrome sculpture is in service of the sculpted forms and they became role models for conservators of this type of artworks (Philippot, 1970). In general, we can say that in current-day Belgium polychrome wooden sculpture is highly valued and examined and conserved with much respect. Contrary to architecture, repainting or retouching large parts of a statue is absolutely unacceptable and would even be classified as a forgery. On the other hand, polychrome terracotta and stone sculpture, especially outdoor pieces, are often stepmotherly treated. Next to the complexity of the conservation of outdoor sculpture, this might also be due to a lack of attention for the study of polychromy during the education and therefore a gap in the know-how of interpreting observations. While sampling is often carried out to define the number of overpaintings, observation windows are rarely made to discover how different polychrome interventions really looked like (Fig. 1). Furthermore, for sculptures in stone and stonelike materials, it is also largely accepted to repaint the statuary in brick red, beige or white, as long as it slightly resembles a terracotta or stone imitation. This often resulting in a situation that never existed before. Sometimes a polychrome detail, such as partial gilding or a detail in another colour, is added based on an incomplete study of the paint layers. As a result, the sculpture is then repainted in a combination of colours that were never visible at the same time. It is clear that there is a difference in the study and conservation-restoration activity of a sculpture and architecture, whether polychrome or not. Different opportunities and constraints arise even if the properties of materials are similar. Are the standard ethics and principles of the conservationrestoration profession then insufficient or inappropriate to meet the needs of architectural polychrome statuary? Jonathan Ashley-Smith presented a method to stimulate people to think about the ethics of the treatment of objects and proposed a framework for documenting local attitudes to different aspects of decision-making about treatments (Ashley-Smith, 2017). The point is that the conservator-restorer, who is aware of the general ethical guidelines for conservation-restoration, develops a bespoke code of ethics for this type of case, in co-operation with the stakeholders (architects, owners and city). To develop this bespoke code, Renée van de Vall appeals to conservators to analyse how principles have been applied in paradigmatic case studies to arrive at appropriate decisions for works under their care (van de Vall, 2009). Unfortunately, surveys of modern architecture tend not to pay particular attention to the statuary so there is hardly any documentation about their conservation-restoration. The conservators-restorers, the owners and the architect are therefore dependent on themselves to decide about conservation-restoration decisions. Recently, the stone sculpture conservation studio of the Royal Institute for Cultural Heritage (KIK-IRPA, Brussels) has dealt with two cases of architectural statuary in terracotta from around 1900 in Brussels. In both cases the conservation-restoration treatments were approved by the same commission composed of the architects of the Monuments and Sites Agency of the Brussels-Capital Region, the owners and the team of KIK-IRPA's Stone sculpture studio. Despite these similarities, the outcome of the decision-making about the treatments differs significantly.

First Case Study
The first case study concerns the polychrome terracotta statue of Saint Anthony from Padua ( Fig. 2) from Georges Houtstont (Paris, 1832-Brussels, 1912, the leading ornamentalist in Brussels during the second half of the nineteenth century. The artist started his career in Paris where he was born in 1832. He executed amongst others decorative work at the Palais du Louvre. When he was 30 years old, he moved to Brussels where he became professor in sculpting at the Academy of Fine Arts in Saint-Josseten-Noode and ran a very active workshop. He collaborated with the main architects of his time, such as Henri Beyaert and Joseph Poelaert. He died in Brussels in 1912. The 138-centimetre-tall statue of Saint Anthony is conserved outdoors in its original niche at a height of 8 meters. It makes part of a completely preserved neo-Gothic site in Brussels, consisting of a church and a convent created by architect P.J.H. Cuypers (16 May 1827 -3 March 1921) in 1868. Saint Anthony, patron of the church community, is represented in a typical way and with his usual attributes. He is wearing the Franciscan habit, with a rope belt and a large rosary hanging from his robe. He holds the Infant Jesus in his hands. After an outdoor exposure of 150 years, the conservation state of the sculpture was problematic. The most badly weathered parts are situated at the bottom of the right arm and at the base. Infiltration of rainwater and rising damp in combination with frost action provoked a series of small cracks and delamination resulting in material loss. The terracotta surface of the sculpture was largely unprotected as a large part of the paint layer was missing. Stratigraphic investigation however showed that the sculpture was originally finished with a paint layer. The realistic effect of the statue was emphasized by this elaborate polychromy. The soutane resembled black velvet with a yellow-brown rosary and the Infant Jesus wore a light blue loincloth. The original polychromy is well preserved on the flesh tones but largely disappeared on the robes vestments, especially on the front side. The statue was overpainted twice. First in colours similar to the original polychromy and later with a whitish paint layer. The binding media were not fully identified. However, there is evidence that all the paint layers were bound in an oil medium. It is obvious that the priority of the conservation treatment is to stabilize the terracotta support. The cracks where rainwater could infiltrate were filled and the statue's partly broken base was consolidated. To keep the intervention to a minimum, broken parts that do not have a supporting function such as the monk's sleeve and the Child's limb have not been restored. Since the expression of the face of Saint Anthony was completely lost, we decided to test the possibility of removing the whitish overpaint. The result was aesthetically very satisfying (Fig. 3). Unfortunately, this approach could not be applied on the other parts of the sculpture as the polychromy had largely disappeared. On the front side of Saint Anthony's robe for example, there were hardly any remains of the original paint layer. An important element in the decision-making on the conservation-restoration treatment is the location of the sculpture, as both the owners and the architect were strongly in favour of keeping the sculpture in its original niche. However, because the statue must be replaced outside, a protection of the damaged surface against severe weathering conditions was an absolute necessity. The fragile terracotta support definitely needed a protective coating. Therefore, we decided to remove the whitish overpaint on the flesh tones and recover the vestments with reversible conservation paint products in their original colour scheme (Fig. 4). The remains of the original polychromy were preserved underneath this new layer of paint, as a historical witness. As new painting materials a ground layer ("Gesso", an acrylic coloured ground layer from Golden) and paint (Golden MSA) were used 1 . They have both been tested at the KIK-IRPA during a 10-year period with very good results: good colour, good attachment, no peeling and perfectly reversible. To conclude we can resume that the statue that represents Saint Anthony in a very classic way with the usual attributes and original polychromy, cannot be valued as an innovative masterpiece, despite the fact that Houtstont was an important sculptor in nineteenth century Brussels. Therefore, there is no need to overprotect it by placing it in a museum context. As a depiction of the patron of the church and the convent, the polychrome statue has a very high religious value. Partially repaint the statue has, next to an aesthetic and iconographical function, also a very important protective function against the severe weather conditions.

Second Case Study
The second case study is the group of three reliefs from Pieter Braecke (1858-1938), a student of Georges Houtstont. It concerns architectural decorations made for the street façade of the private house in Woluwe-Saint-Pierre (Brussels) of the Symbolist painter Emile Fabry (Verviers, 1865(Verviers, -1966. The reliefs were added to the façade shortly after the house was built in 1902 by the architect Emile Lambot . The group consists of two reliefs representing kneeling women at both sides of the door and the portrait relief of the painter Fabry above the door (Fig. 5). The pieces represent the personal style of the artist Pieter Braecke. During our inspection, it appeared that only one of the three reliefs from the façade was still the original made out of red baked terracotta. Apparently, the two others were replaced by replicas in a terracotta-coloured mortar. It was only during our study that the landlords informed us about an unexpected and interesting fact: another copy of the central figure was kept in their garden. After our examination it appeared that the 'garden relief ' was not a copy, but the original terracotta representing the portrait of the painter (Fig. 6). So instead of three original terracotta reliefs on the façade, there was only one original on the façade, one original in the garden and furthermore two replicas on the façade. Unfortunately, the original terracotta from the second female figure has disappeared. 1 The ground layer ("Gesso", an acrylic coloured ground layer from Golden) and paint (Golden MSA) were tested at the KIKIRPA for 10 years. The good colour aging, good attachment, no peeling ensure that the products offer good protection for the support. Moreover, they are perfectly reversible.

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The deterioration of all four of them was advanced. The deterioration pattern of the two terracotta reliefs is mainly determined by the presence of cracks and delamination resulting in material loss on the entire surface. This damage was, as with the statue of Saint Anthony in our first case study, provoked by the combination of water seepage and frost. The thinner parts, such as the flowers in the hair of the left female character seemed to be very sensitive to this process as they were severely damaged. Furthermore, a lot of previous restorations were aesthetically disturbing. Lacunae were filled with gypsum or cement-based mortars. Apart from the colour difference with the terracotta their composition is inadequate for outdoor use or incompatible with the original material. Concerning the two mortar copies we can say that, despite their formal compatibility with the original sculptures, their state of conservation wasn't satisfactory either. The indefinite mortar was damaged by physical and chemical degradation, resulting in an uneven surface. Furthermore, we could observe black crusts. It was decided that the original reliefs in terracotta were too fragile to be exposed outside in the future. The old mortar copies wouldn't be re-used either because they are also not suited to be exposed in an outdoor situation. Therefore, we proposed to make three new replicas with a lime-based mortar 2 in a terracotta colour for the decoration of the façade and preserve the original reliefs in a protective environment. At the moment, the discussion concerning the future place of conservation of the originals is still ongoing. In fact, two options have been suggested. Firstly, as the reliefs were especially specifically designed for this house, conserving them inside this house could be a possibility. Another option would be to display the reliefs in a public space. The originals could be exhibited in the town hall of Woluwe-Saint-Pierre or at the museum of the CIVA foundation in Brussels, specialized in architecture.

Conclusion
Despite the similarities in the type of statuary and condition the treatment and choice of conservationrestoration environment were completely different. The main purpose is to preserve the art objects in such a condition that future generations may experience and study their value. Another aim is to follow the principles of minimal, reversible and stable intervention. In our two case studies all these conditions are fulfilled but applied in different ways. The Saint Anthony of Padua was polychromed and appreciated for his religious character. Applying partially a new polychromy was essential to recognize the subject as a Franciscan monk and for the conservation and protection of the object at his original site. Braecke's reliefs were not polychromed and they have suffered a lot of damage from their creation onwards. In fact, the reliefs are not suited to be placed on a façade. If we want to preserve the reliefs, it is indispensable to preserve them indoor.

Ackowledgements
Many thanks to the conservation-restoration team of the Stone Sculpture Conservation Studio, particularly Marie Herman, Nicolas Verhulst and Sam Huysmans. Furthermore we wish to thank architect Françoise Boelens for her continuous support.

Author contributions
Camille De Clercq, senior conservator at the stone sculpture conservation studio took the lead in writing the paper with support from Judy De Roy, head of the stone sculpture conservation studio. Both authors discussed the results, commented on the manuscript and guided the discussions of the commission. Camille performed the conservation-restoration of the statue of Saint Anthony from Padua. Judy helped supervise the project. 2 In order to manufacture the replicas, we tested several types of "Parthena moulage". THE CONSERVATION-RESTORATION OF ARCHITECTURAL STATUARY [...]