de guichen-nardi for getty newsletter 20 - luca isabella.pdf

7/27/2019 De Guichen-Nardi for Getty Newsletter 20 - Luca Isabella.pdf

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Mosaic conservation. Fifty years of Modern Practice

Gal de Guichen and Roberto Nardi

Mosaics conservation is a practice as old as the mosaics making itself. We can see today ancient

mosaics showing patches made as maintenance practice when the floors were still in use. We are alsoaware that restoration was an art widely used in the passed centuries with antiquary purposes. We

might also refer to brilliant examples of restorations implemented during the first decades of the 20th

century.

But in the 1950th we can observe a dramatic evolution in this sector due to the fact that if previouslyexcavations were mainly made on archaeological protected sites, the post war period saw numerous

constructions and reconstructions happening in Europe, with several discoveries of mosaics undergoingall around the countries. According to a study made by Claude Bassier at least 95% of the pavements

found in France where destroyed at the discovery .The remaining ones- when the subjects werefigurative and considered valuable- were according to the traditional techniques systematically

removed from the archaeological sites. The luckiest ones were relayed on concrete slab when theothers were abandoned in so-called deposit were they are still waiting today (See photo 1-2)

Two professional figures appeared in this period, Rolf Wihr in Germany, that worked in Colonia, andClaude Bassier in Perigueux. When the first one was a conservator/restorer working in a publicinstitution, the second owned a private enterprise .In case of a discovery, he was called all around

France on rescue excavations and was able to arrive within two days with lorries, a crate, a tent withheating systems ready to work in the middle of winter time.

They introduced:

- new practice of systematic documentation;- new supports: aluminium honeycomb instead of concrete;

- new products: the resins instead of glues and cement.

There is also to say that at that time they continued the practice of polishing the mosaic surfaces.

Together with those two figures "technologically advanced" we should recall Antonio Cassio from theIstituto Centrale del Restauro who being mosaicist by family tradition prefers a more sensitive and

controllable method for detaching the mosaics. He uses a system typical of the mosaic making, whichpermits to detach the mosaics in pieces of an average of one fourth of square meter. This method

dramatically reduced the cutting stresses and damages to the mosaics.

A part from those three main figures, the situation can be reassumed in 7 points:


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1. options were very limited when deciding a conservation strategy (detachment was the main option

available);2. Interventions were undertaken without adequate planning;

3. The workforce consisted mainly of artisans, craftsperson or carpenters;4. Practice was based solely on empirical knowledge;

5. Materials used were limited to cement, gypsum and glues;6. Documentation was lacking;

7. Practitioners worked in isolation without benefit of professional associations.

One must mention an exception in the late '50s: the completion of the excavation of the Villa delCasale in Piazza Armerina where, in front of the incredible mosaic collection, Cesare Brandi

introduced the solution of conserving the mosaics in situ and protecting all site.

10 years after, again in Italy, in a different field, the mural paintings, it was undergoing a theoreticaland practical reflection which will have several years after direct and important impact on mosaic

conservation: in 1968 ICCROM with the Istituto Centrale per il Restauro initiated a annual fourmonths course on conservation of mural paintings. At that time the highlight of the course was the

detachment of the wall paintings but very quickly it evolved toward in situ consolidation as the wall-paintings were considered integrated part of the buildings to which they belonged.

This evolution in the approach of mural paintings conservation lead to the publication in 1977 of the

Mora-Philippot publication "Conservation of mural paintings" which is still a fundamental book for theprofession.

Obviously all this was in the air when in 1977 was organized in Rome the first conference on mosaic

conservation. There were 45 participants ICCM (see photo 3) At the end of this conference a group of10 participants decided to create the ICCM (the International Committee for the Conservation of

Mosaics) and to act as the first Board

The publication of the acts of the meeting were called "Mosaic n 1" .It was addressed toarchaeologists, conservator-restorers, technicians, administrators and to the public. An other important

result was the a recommendation to launch a course on mosaics conservation.

This conference in Rome was the starting point for the long series of regular meetings of which the lastone in Hammamet is the number 9. At the end of each of those meetings the proceedings were

published: After 27 years ,11 volumes have been printed and distributed.

The following year, in 1978 Tunis hosted the second meeting the Institute National du Patrimoine andTunisia very soon become the country which most supported and very generously hosted meetings of

the ICCM board. Other meetings were in Aquileia (1983) in Italy; Soria (1986) and Palencia (1989) inSpain; Conimbriga (1993) in Portugal; Nicosia (1996) in Cyprus; Arles and Saint Roma in (1999) in

France; Thessaloniki, Greece, on 2002.

Together with the publication of the proceedings, 12 newsletters have been edited since. All those

represent for the profession, a basic source of information which was not existing 50 years ago.

It is worthwhile to review the titles of those conferences because they well illustrate the evolution inthe mentality of this committee and, indirectly, reflect the trend in the professional principles:


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1977 Rome, Deterioration and Conservation

1978 Tunis, Conservation1983 Aquileia, Conservation in situ

1986 Soria, Conservation in situ1990 Palencia, Conservation in situ

1993 Conimbriga, Conservation, Protection, Presentation1996 Nicosia, Mosaic make a site

1999 Arles & SRG Mosaics: Conserve to Display?2002 Thessaloniki Wall and floor mosaic: Conservation, Maintenance and

Presentation2005 Hammamet, Lessons from the past

As we see the ICCM already in 1983 pointed out the importance of in situ conservation obviously

when it is possible. In this way it followed the track already opened by the mural painting specialists

One other principle that ICCM strongly supported is the refuse of the use of cement inconservation/restoration of mosaics. It was in fact clear since long time that the use of cement in

conservation of ancient monuments was representing a great factor of risk and damage. Even so anddespite the numerous evidences of destruction caused by the use of cement , this material is still in use

on mosaic and worse sometime still taught in some countries.

In answer to this, Giorgio Torraca launched a research to replace cement with a new material thatparadoxally is the oldest one: that is the lime based mortar. Even within the committee it took almost

10 years of ferocious battles to see lime commonly accepted and applied in direct contact to the mosaic,replacing the cement. The use of lime based mortar has allowed the development of in situ

consolidation and of the practice of maintenance in situ when possible.

An other important step ahead that can be assigned to the long work of reflexion during three ICCMconferences was the flexible approach to safeguarding mosaic floors that it has been now accepted by

the committee and by the practitioners. It can be represented by the 5 following options (see illustration4)

1. Destruction2. Backfilling

3. Lifting and transferred to a museum4. Lifting and relaying in situ and maintenance

5. Consolidation in situ and maintenance

The previous habit of leaving the mosaic on the site without protection or of lifting the pavement andof abandoning it into a deposit was clearly the result of non planning. It illustrated the attitude of

some archaeologists non sensitive to conservation who felt that their work ended the day they had donetheir publication. On the opposite, the diagram presents a systematic analysis of practical conditions

that can determinate different practices when planning and conserving a mosaic. Any of the optionschosen required serious planning before any implementation.

After the three conferences dedicated to in situ conservation, the four following ones were referring intheir titles to presentation to the public. Already in 1977 it was suggested in "Mosaic n1" to involve

the public "..so that specialists responsible for conservation receive support from individuals. It is thepublic, after all, that benefits and is served by the world-wide conservation movement.." This finally


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established in our field the recognition that our profession is aimed at presenting to the public the

meaning of the cultural properties which we are conserving.( See photo 5)

In order to influence the practice, those new ideas and approaches required adequate training but it took12 years to realized the first course which had been already requested by the first recommendation

made by the committee in 1977. A one month course was organized by ICCROM in 1989 in Rome andwas attended mainly by archaeologists. Some of them are today member of the board of the committee.

After that time several courses at various levels have been and are still organized. Despite the

generosity of the offer it exists certain doubts concerning their efficacy because either those sessionsare much too short -few weeks sometime- or the trainers have not always the teaching qualities

required. We have also to question if the production of new mosaics for selling to the public has to betaught in the same time as the conservation techniques.

One of the few exceptions of training adapted to the challenge faced is the program launched by the

GCI in 1998 in Tunisia. This is a long term involvement in training technicians in conservation andmaintenance of mosaics on site that has produced impressive results that can be appreciated directly on

the field in some sites of Tunisia.

CONCLUSIONS

The last 50 years represented for the mosaics conservation/restoration field a period of great changes

and maturation. The creation of ICCM has been a landmark and completed the work started by AIEMAand later developed by ASPROM in Great Britain and AISCOM in Italy.

It is evident today that the prospective that the profession faced is not anymore referred to a single

tessera or few square meters exhibited in a museum as 25 years ago, but it has greatly widen up toentire mosaic complexes or sites where thousands square meters of mosaics are in danger.

It is also clear that, today, several professional figures approach the common problem of mosaic

conservation. Among them the scientists are today more interested in proposing solution to the mosaicconservation globally and not anymore through the lens of a microscope.

The fact that 250 colleagues from 30 countries (see photo 5) with so many backgrounds attended the

9th ICCM conference held in 2005 in Hammamet, Tunisia, indicates that similar problems exist andthat the interest to solve them within a common platform is very high.

At the same time it is evident that there are still issues which have not been cleared and that a lot of

work has still to be done. For instance:

- the salvage at great scale of mosaics previously laid on concrete;- a systematic campaign to relay on support detached pavements abandoned in deposits;- a clear technical and financial evaluation and protocol for backfilling;

- a research on biological protection;- a comparative middle term study of the cost of maintenance in situ;

- a feasibility study of the necessity of training of archaeologists, conservators/restorers andtechnicians;


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- the publication of a major book on Conservation and Restoration of Mosaics

The above topics are only some of the challenges faced by the professionals having to conserve and

exhibit mosaics Their is still a long way to go. We would like to conclude with a note of optimismdictated by the great vitality that the profession, with the help of the ICCM, demonstrated until today

up to the point that some of the tasks that 30 years ago appeared almost unreachable have beenacquired today as the normal practice.

de guichen-nardi for getty newsletter 20 - luca isabella.pdf

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