Conservation

Conservation

Conservation - a word that seemed to blossom in the 1980's and will hopefully come to fruition in the 1990's.

The conservation implied, however, is usually ecological but there is another type of conservation, that of Archaeological Conservation. This is a subject equally complex, with an important role to play in the quality of life in the future.

The conservation of archaeological and historical objects, in which we include buildings as well as artifacts is a comparatively new branch of science. This does not mean to say that some form of conservation was not practiced in the past. Romans, Greeks, Egyptians and other early people took an interest in and displayed artifacts found in their times. In later centuries, particularly Eighteenth and Nineteenth centuries, people became almost obsessed with the past and collected vast quantities of artifacts from many sites. Much of this was deposited in storerooms, never to see the light of day again.

The scientific methods of conservation used today developed and became increasingly important as public awareness and interest in details of the past grew.

Being a Conservator is like being a doctor of antiquities!

We try to understand the condition of an object in terms of the materials of which it has been made, the techniques employed to make it and the environment in which it has been in the past, stored in the present and will be subjected to in the future.

One of the projects upon which I am currently engaged is that of First Aid conservation to Uppark House, the National Trust property that burnt down last Summer. Here it definitely feels like being Florence Nightingale to a building site, with patients lying burnt, waterlogged and wounded in a network of field hospitals.

The materials of which an object is made may be organic such as bone, skin, wood, textiles, or, inorganic such as metals like iron, gold or lead. They may be ceramic in the form of bowls, tiles or bricks while many things are made of stone of one kind or another. However, the object is likely to be made of more than one type of material.

The condition of an object when presented to a conservator for analysis and work will be determined, not so much by its age but by the environments in which it has been and the chemical and physical influences that may have acted on its microstructure. I have worked on an 8,000 year old basket that didn't look a day over 50 years old, mainly due to the conditions in which it had been stored for the 7,950 years prior to its excavation.

Environments may range from marine or fresh water, dry hot conditions of desert regions, the hot steamy atmosphere of the tropics, cool temperate dampness to the bitter cold of Arctic snow and ice. Many environments have the added hazards of air laden with sea salt or industrial chemicals. While these environments are indicative of geographical locations it isn't necessary to range the world in search of them.

Desert conditions can easily occur in a room where there is central heating and sunlight streaming through a window and there is many a steaming jungle atmosphere within the realms of kitchen or bathroom.

On locating and excavating new archaeological sites one of the main public misconceptions is that it has been 'saved' from the ground. The precious and everyday objects can now be put safely on display, locked away in cellars or storage rooms. They have been 'saved' from the nasty, damp, dark soil in which they have been hidden for perhaps thousands of years. Unfortunately this is far from the truth - from the moment the first trowel enters the ground many of the objects awaiting discovery are doomed to destruction.

Why should this be so? If it has lasted anything from 100 to 5,000 years or more why shouldn't it last so that it can be seen by people of the Twentieth and Twenty-first centuries? The nature of the deterioration will depend on the stability of the materials involved. Ceramics on the whole tend to be of stable material chemically and their breakdown is usually caused by physical stress. An unwittingly placed trowel perhaps, or crushed under the weight of overburden. They may be broken by pressure that has developed within their porous network, caused by the growth of crystals that may develop in environments where there are fluctuating conditions of saline solutions and drying air. Recent investigations have even recorded the sound of such crystals growing and the subsequent pressure they create in the ceramic body. Metals on the other hand, will, given the right environment, try to revert to their most stable form - which in most cases is the ore from which they were extracted in the first place. Some metals, like gold and silver are very stable and change little with time. The silver spoon from the KAS Plaxtol excavation was as bright and shiny when found as the day it was lost nearly 2,000 years previously.

Organic materials are naturally part of the carbon cycle and, given the right conditions will continue to be so, as the Dry Rot fungus will readily indicate to an unsuspecting houseowner.

The moment the resting place of an archaeological object is disturbed, so too are the conditions to which it has stabilized over the centuries. So how can a Conservator help?

An object is taken into the care and custody of a Conservator. An array of chemical and electrical gadgetry is used to help determine the present condition of the object. The environmental conditions of the past are gleaned from archaeological records and geographical information of the area. There is also a need to know the likely environmental conditions of its immediate and long term future.

Work is begun on an object. It is first photographed and then possibly drawn. A detailed examination is made using a microscope or hand lens to look for flaws, cracks, corrosion, paint or gilding, etc., traces of things that could be associated with its original owners or burial customs. For example, layers of textiles, encrusted and mineralized within the details of a Saxon brooch can shed light on fabrics and weaving techniques of that time. An object may require an X radiograph to determine what might be hidden within thick encrustations of corrosion material. Soil, dirt and corrosion encrustations may be removed slowly and carefully with scalpels, bristle brushes and dental tools - though some encrustations may be so hard they need carefully controlled power-assisted tools to prise them from the surfaces. When cleaning is completed some metal objects may need chemical stabilizing to help delay further corrosion processes taking place.

If an object is to be displayed, it might require gap filling where there are large gaps that would detract from the presentation. Pottery frequently has sherds missing; a gap fill not only allows better presentation but often imparts strength and stability to an otherwise fragile object. However, a gap fill is never intended to fake the original but blend with it, to please the eye when looking at the whole. The observant will always be able to detect the filling.

After completion of conservation work there are more photographs, detailed reports are written giving whole treatments including chemicals used, recommendations for storage conditions, lighting and display environments best suited to the object, bearing in mind the materials of which it is made. All treatments and materials used in the course of conservation are aimed at being reversible so that should better techniques and materials be developed in the future, previous treatment can be removed.

However, we have been considering perfect conditions, where objects will have well-equipped laboratories to hand. Such is not always the reality and Conservators may be asked to work in a variety of strange locations, under unfavorable conditions, with the minimum of equipment. Necessity is the Mother of Invention - Conservators are very inventive. A very effective solar panel was once made from a fishing umbrella, a piece of card and a length of baking foil - to assist in the drying of a wet decorated plaster wall that had been excavated in a very remote location. Then there was Orkney! Here we lifted pottery that was so fragile and friable that it resembled biscuit crumbs that had been rolled flat, in a landscape that was so bleak that gale force winds were the norm and the laboratory had to be held down with steel hawsers.

Nearer to home, lifting the neck of a Twelfth-century kiln in Canterbury was hardly a comfortable job. It was a particularly wet location, not far from the river and several feet below its bed level, where the delicate task of undercutting and lifting was made while lying in liquid mud.

I am particularly interested in building conservation, using the knowledge of materials and their interactions, as applied to artifacts, to help stabilize the buildings. As you can imagine these pose particular problems concerning access and working conditions on a much larger scale than those involving artifacts. We may be asked to look at medieval painting, plasterwork, deteriorating stones that are in walls and timberwork only accessible by walking across open joists, balancing on planks of wood or high on scaffolding - invariably on cold days!

There is a great deal of satisfaction from being able to find inscriptions hidden under centuries of overlying paint using infra-red photography and then having the knowledge and techniques to be able to reveal them to the eye, for all to see again. However, there is also the heartache of seeing an old building, lovingly cared for by its owners who are unwittingly using modem materials that will lead to the destruction of the very thing they are trying to save.

If you are lucky enough to have in your care an article of antiquity, whether artifact or building - be aware of its needs, seek the cause of problems - you are not the owner, merely a custodian in time.

Maureen Lovering