CASE STUDY799

Conservation and Restoration of the Historic Furniture from the "Laboratorio Chimico"

of the University of Coimbra

Methodology and Intervention Criteria

By Carlos José Abreu da Silva Costa

Intervention period: June 2005 - August 2006
Worksite coordinator: Carlos José Abreu da Silva Costa, conservator-restorer,
Atelier Samthiago conservation enterprise
Supervision: Margarida Cavaco, Conservation Department – Furniture,
Portuguese Institute of Conservation and Restoration

Abstract

The University of Coimbra is one of the oldest universities in Europe and, at the moment, a candidate to the UNESCO World Heritage List. The intervention of conservation and restoration of the historic furniture of the "Laboratorio Chimico" from the University presents great interest in what concerns the identified pathologies, the interpretation of the previous interventions and the new solutions found for its preservation. For 335 days more than 30 furniture pieces were under intervention, among which 11 laboratory fume hoods and an impressive 18th century painted amphitheatre.

Introduction

Located in the centre of Portugal, the University of Coimbra is one of the oldest Higher Education institutions dating back to the 13th century, more precisely to the 1st of March 1290, when the "Scientiae thesaurus mirabilis" document was signed in Leiria by the Portuguese King D. Dinis who established the University and asked confirmation from the Pope. Initially  installed in Lisbon, the University was transferred to the city of Coimbra in the year 1308.
During more than seven centuries of existence the University has grown, first across the uptown of Coimbra and later a bit throughout the entire city. The city of Coimbra and its university have played an important role in the dissemination of the Portuguese culture in the world and are now applying to the UNESCO World Heritage List.

The Laboratorio Chimico (the Chemistry Laboratory), built between 1773 and 1775 at the behest of the Marquis of Pombal, is the oldest chemical laboratory in the world built for this precise purpose as an independant building that has been preserved to our days with the same function. This neoclassical building, typical of the Pombaline reforms, was made by the architect Guilherme Edsen and is located in Largo Marquis of Pombal.

Until 1998 the building was occupied by laboratories and classrooms. After this date, the University of Coimbra took the first steps to create a Museum of Science to house a collection of more than 200 thousand objects. The musealisation project took off and today the museum is a world reference. The Laboratorio Chimico is only the first phase of an ambitious project which will involve the conversion into a museum of more than 12 thousand square meters of the former College of Jesus. Beyond its scientific collections and historical objects, the museum displays its entire integrated heritage, including its furniture. The amphitheatre from 1855 built in loco and the furniture from the18th century were designed and ordered from an English workshop and transported by sea to the Portuguese coast, with the sole purpose of serving in the chemistry laboratories.

Historic Furniture – Intervention Methodology

The conservation and restoration of the historic furniture from the Laboratorio Chimico had as main challenge the search of solutions that would allow to preserve and stabilize the degradation caused either by extensive use or by chemicals and reagents to which the pieces have been subjected. These chemical products created problems to the structure and paint layer and in some cases the replacement of some parts was necessary in order to safeguard the nearby elements still in reasonable
state of conservation.

Another challenge was to identify accurately the historical consecutive interventions carried out on the building and, in particular, on the furniture, either as structural interventions and overpaintings or as temporary interventions.

A fundamental principle of the current conservation concept was used in this project: the principle of minimum intervention. As such, the choices and options were made according to this concept. The options of intervention were properly studied, analyzed and discussed between the involved entities: the owner - the University of Coimbra; the supervisory authority - the Portuguese Institute of Conservation and Restoration; and the company responsible for the conservation works - Atelier Samthiago.

One of the main considerations under discussion was the preservation of the oak wood imitation painting present in most parts of the furniture. If in most of the pieces this paint layer seems to be original and contemporary with the furniture making (most of the fume hoods, benches, etc.), in other pieces its application is of great historical interest and artistic value even though they are not original (such as the amphitheatre or the large cabinets of the laboratory).

Thus, given its historical and artistic importance, the decision to keep the furniture's vein painting was taken, either by its preservation and removal of the overpainting or by recreating a new decorative layer based on existing examples, such as the amphitheatre and the classroom fume hoods.

For the structural intervention it was decided to treat and strengthen those parts that lost their function or that on a short/medium-term could have been lost or could have advanced into such state of deterioration that would have induced the loss of the contiguous parts.

Concerning the alterations of the forms, it was decided to restore all those elements that would allow a better understanding of their construction or function, such as the sash windows replacement of the fume hoods or the removal of the boards added to the amphitheatre in the beginning of the 20th century. The remaining alterations were maintained, subject to the  understanding of their function and as a document of interest to the perception of the evolution, history and use of the building, for example, the maintenance of the benches’ doors subdivision as a result of the progressive increase of the students’ number.

Imitative Decorative Layer - Integrity and Replacement?

During the 18th and 19th centuries the decorative art started to be implemented in Portugal as integral part of the civil or religious building, assuming a perfect relationship with the architecture, sculpture or painting.
The decorative painting techniques, particularly those with imitation purposes, were brought to Portugal from Brazil: for example, the stone imitation techniques (marmoreados) and the European wood imitation. For the painting of decorative wood veins, an imitation of oak wood to hide a structure built in less noble wood (softwood) was common.
This imitation, made while the paint was still fresh and using oil binders or pigments in varnish (forming a sort of velatura layer over a base colour), was achieved through the use of ordinary tools: fish-bone, fins (the cod fin, for example, allowed to obtain a very realistic vein) and bird feathers among other objects.

These decorative layers, often resin-based, become very difficult to treat because with the removal of adjacent layers, many of them already high polymerised, the thin and weak underlying layers would be easily attacked. Tests for extensive overpainting removal were carried out in order to ascertain the possibility of a safe intervention maintaining the integrity of the decorative layer or to establish whether it was necessary to create a new layer, reversible and in accordance with the original model.

If from a formal point of view, the conservation and restoration of the amphitheatre classroom and other elements that undertook minor intervention is of great rejoicing, from the conservation point of view the intervention brought us no novelty or complicated ethical issues to resolve, summarizing the simple procedures of fixation, consolidation, cleaning and chromatic integration. The same can not be said for other interventions where to reach the 1800s decorative surface, successive overpaint layers would have to be removed - sometimes up to 6 or 8 layers, 10 times thicker than the layer to preserve.

Although a general and consistent result was aimed, the means to achieve it were not the same, thus it was required to find a solution to each particular case. The owner, the inspection team and the company have mutually agreed in order to better preserve the historic and aesthetic unity of the overall, to remove successive overpaint layers or to remake them according to existing models and methodologies by reversible means where the preliminary research proved that the safeguarding of the decorative layer integrity was not possible.

We may state that today, the historic furniture of the Laboratorio Chimico of the University of Coimbra is historically and artistically valorised. In fact, beyond the central function of creating an environment and an historic experience, the furniture is an integral part of the museological heritage of the University of Coimbra. In terms of conservation, and at a methodological and ethical level, important decisions were taken which became possible only after intense and careful discussion.
Since it is not possible to entirely describe here how interesting and complex this experience was, we hope that this can be seen as a starting point to better understand what is now the Museum of Science at the University of Coimbra.

Image 1. Example of an English workshop signature found in the furniture: V DE;
Images 2, 3 and 4. Overview of the amphitheatre at the beginning of the 20th century, before and after the conservation treatment – paint layer reattachment, wood consolidation, structural reinforcement, cleaning and volumetric and chromatic reintegration of the lacunas;
Images 5. Micro sample, cross-section obtained by optical microscopy - layer no. 8 (intermediate decorative layer – wood surface imitation) represented the objective of the overpainting removal;
Image 6. Tests for the removal of the overpainting;
Images 7 and 8. One of the fume hoods before and after the conservation and restoration intervention. In some cases only the restoration of the decorative layer, according to existing models, allowed to regain the historical and artistic dignity, while safeguarding the integrity of the original materials.

MUSEU DA CIÊNCIA - Laboratorio Chimico
Largo Marquês de Pombal 3000-272 Coimbra
Phone: +351 239 85 43 50 | Fax: +351 239 85 43 59
www.museudaciencia.pt | geral@museudaciencia.pt

ATELIER SAMTHIAGO | CONSERVAÇÃO E RESTAURO DE OBRAS ARTÍSTICAS

Rua da Bandeira, 87 - 2º Sala TG – 4900-560 Viana do
Castelo - PORTUGAL
Phone: (00351) 258 825 385 | Fax: (00351) 258 825 385
Mob.: (00351) 964 108 812
www.samthiago.com | geral@samthiago.com