Tag: Antiquities

The Shrine Project

Discussion about replacing the old, worn plinth beneath the Egyptian Shrine (E.40.1902) in the Gayer Anderson Gallery began in 2017 (Fig. 1). We wanted to bring it into line with the other two plinths supporting the largest pieces of sculpture in this gallery.  Plinths provide an important protective function. In addition, they help to create a clearly defined, dedicated space which can offer visual emphasis to objects, like frames around paintings.

Fig. 1 The Egyptian shrine, E.40.1902

People had been observed passing this sculpture too closely, accidentally brushing against it. On one occasion, a boy had climbed up onto the front of the shrine and reversed himself neatly into the niche. Although this was an isolated incident, it increased the urgency to make the necessary improvements. Preservation of this ancient sculpture is vital: in widening the footprint of the plinth, a safer distance could be created between the sculpture and visitors.

I contacted the company who had built the two previous plinths, forwarding them a rough sketch to save time (Fig. 2). In follow-up communications, I included static label holders, required for each of the three main sculptures. To achieve design consistency, they were to match the material and design of those in our Greek gallery. For the plinth itself, we chose Corian, a hardwearing and versatile stone-like material, which was also used for the other main plinths.

Fig. 2 Initial sketch of the shrine and the plinth

The contractors visited to make a plywood template in four sections which needed to follow the meandering edges of the base very closely. The aim was to provide a snug fit but avoid contact with the surface of the object. They were confident that they had all the information they needed to proceed, but to ensure accuracy, I asked for a detailed, scale drawing – to quote an inherited mantra, ‘Measure twice, cut once!’.  After some tweaking, relating specifically to the angle and height of the label holders and how they connected to the plinth, we were able to agree on the plan and set a date for installation.

Work and time spent on the practical, planning stage of a project is mostly unseen and therefore largely unappreciated. Success, however, is apparent in a job well done. Mistakes can prove costly and exceed time limits, so clear, detailed communication with contractors is key. This technical drawing (Fig. 3), showing various angles, views, and elevations, illustrates the result of this process, which took several weeks.

Fig. 3 Detailed drawings of the final design

A structural restoration had been made on the reverse of the shrine using bricks and poorly applied cement mortar (Fig. 4). This was to enable safe, upright display and it continues to serve this purpose. The shrine was previously displayed up against a wall, so no consideration had been given to the appearance of this practical fix.

Fig. 4 Old structural restoration to the back of the shrine

When the Egyptian galleries were refurbished and reopened in 2006, the shrine was moved into the Gayer Anderson gallery and placed in a central space where it could be viewed from all sides. During this busy project, the decision was made to hide the unsightly restoration from view temporarily behind a white shadow board, set vertically into the base.

As technicians, our priorities regularly shift around to provide vital support to our rolling exhibitions and departmental needs. Projects can overlap or happen simultaneously so temporary measures are adopted when time is short. This can sometimes move into semi-permanent status, which is perfectly acceptable if the safety and condition of an object is uncompromised.

However, ten years on, with the imminent installation of a new plinth, it was time to remove the painted board from the shrine, and improve upon the ugly restoration beneath. Minimal intervention is always preferable and, as removing the cement would almost certainly have incurred risk to the shrine itself, the plan was to work with what was already there, making the best possible improvements. I estimated the project would take a couple of months to complete as this was gallery-based work and I was restricted to Mondays, when the Museum is closed to the public.

I enjoyed the opportunity and challenge presented and began to plan how I could achieve the best result. I reviewed all existing documentation on the shrine to see if I could find information that might reveal less obvious areas of fragility or cracks. I also needed to establish exactly where the actual object ended and where the restoration began. This would enable me to take the new infill just up to the edge of the object without creating too obvious a divide, but make the dividing line apparent on closer inspection. This was to keep in line with a general museum conservation rule-of-thumb that infills and repairs should be imperceptible from a distance of six feet, but clearly distinguishable from a distance of six inches.

After thorough examination and consideration, I collected the equipment and materials I would need.  These included:

  • A good task light and extension lead – essential for fine work in our darkened galleries
  • Dust masks and gloves, and something comfortable to sit on
  • Lots of sandpaper, an old chisel, blunt scraping tools, and various brushes (ranging from wide DIY types to thin fine bristle)
  • An inert, conservation-grade filler, called ‘Flugger’ (https://www.flugger.com/en) 
  • Paint, both acrylic and pigment, and a vessel for water
  • a Henry vacuum-cleaner
  • …and my personal playlist!

On removal of the painted backboard, it was a nice surprise to discover a more modern piece of history – a handwritten note by  my retired colleague, Bob, on the underside (Fig. 5).  I posted a photo of it to him, but we are still wondering what he had meant by ‘No 50 pm’!

Fig. 5 A message from Bob

My first job was to cut away a random, brittle piece of Formica, protruding from the base of the object (Fig. 6). Use of a Stanley knife proved futile, but a quick trip to our friendly Maintenance team produced an essential, sharp, electrical cutting tool. The Formica had been filing a small void at the base of the object, so I made a new fill from pieces of card (Fig. 7).

Figs. 6-7. A scrap of Formica had been used to fill a void at the base of the object (left). I used card to make a new fill after the Formica had been removed (right).

Next came the use of the filler. The crude surface of the old bricks and cement needed to be covered evenly to reintegrate the area with the sculpture visually, so it was important to make the texture match well with the original surface.

Flugger can shrink a little on drying so needed to be applied quite thinly in stages. It was important to allow it to dry fully before applying the next layer. This fitted well with the rhythm of access that framed the job. At the end of the day, I would re-attach the white board back over my work and have little choice but to allow it the entire week to set before adding another layer.

Regular sanding back of rough, crusty edges (Figs. 8 and 9) and the repeated application of Flugger continued for some time. This resulted in a lot of fine white dust and the regular need to vacuum. Although smoother than the surface of the object, the end goal was not to disguise or confuse but to create a subtle distinction between the object and the new fill.

Figs. 8 and 9. Sanding back the filler to create a neat fill (left), and building up the new infill (right).

Once I had completed this stage, I needed to decide on a suitable colour match. I took time to examine the  landscape of textures and differing earth tones on the shrine (Figs. 10 and 11). This  was a tricky decision, particularly because, when viewed from the side, several different colours and tones were apparent. I made colour tests with a mixture of acrylics and  earth pigments, adding a matting solution to prevent surface shine. On comparison of the results, I decided on a muddy combination of them all.

Figs. 10 and 11. The surface of the shrine has a great variety of textures and colours (left). The base coat of colour on the infill, on which further layers were built up to create the appearance of depth and texture (right).

I applied a base coat to the entire area and then began building up layers, stippling with a wide brush to create depth and texture. Challenges arose with the difference in colour of wet, freshly applied paint in comparison to its appearance when dry. This is a common issue, especially with pigments. In order to check on progress with the colour I had to switch off my task light regularly and stand back to judge the effect of how my work would normally be seen by visitors, under the controlled light of the gallery during open hours.

Mixing up a big enough batch of paint and covering it with clingfilm to use at the next weekly application became a helpful time-saver. Although enjoyable, colour matching can sometimes seem never-ending, with a constant potential for improvement; but the fast-approaching date for the plinth installation provided me with a deadline.

Having completed my part of the project, it was great to see the four sections of Corian arrive and fit neatly, jigsaw-style, around the object (Figs. 12 and 13). The contractor made small adjustments where needed and filled the joins, sanding back the filler to an impressive invisible finish.

Figs. 12 and 13. Fitting the new plinth (left) and sanding the filler in the joints to give a perfect finish (right).

Now standing on its smart new plinth, complete with a built-in label holder, the shrine has an improved, balanced aesthetic and is better protected from general contact (Fig. 14).

Fig. 14 The shrine on its new plinth

Louise Jenkins, Senior Chief Technician, Antiquities Department

Study and conservation of a miniature Egyptian coffin

In 2016 the Fitz made the headlines with a remarkable discovery: a miniature Egyptian coffin (E.43.1907) that had been thought to hold mummified organs was found to contain an embalmed human foetus, probably the youngest ever known to be buried in Ancient Egypt.

Figure 1. The miniature coffin featured in The Guardian.

The coffin had been X-rayed in preparation for the Death on the Nile exhibition, but when the results appeared inconclusive it was decided to CT-scan 1 its contents. This revealed a mummified foetus only 18 weeks into gestation, its arms ritually folded over its chest. It was wrapped in bandages, over which molten back resin had been poured before the coffin was closed.

Figure 2. Detail of the face and right ear.

The coffin that holds the bundle is of interest in itself. Excavated in Giza by the British School of Archaeology in 1907, it came to the Museum in the same year. Though the wood is poorly preserved and the painted surface entirely lost, surviving details of the face and ears show that it was skilfully carved. Measuring only 43cm in length, it is a fine example of an anthropoid coffin of the Late Period (664-525 BC), built on a tiny scale.

Figure 3. Diagram of a mortise with a loose tenon (copyright Geoffrey Killen and The Fitzwilliam Museum). Tenons in this coffin are pegged, meaning that a small dowel holds them in place from the side.

I recently re-examined the object with the aim of completing its technical study and assessing the condition of the fragile surface.

X-ray examination confirmed that box and lid are each carved out of a single piece of cedar wood2, joined by four pegged tenons on each side (Figs. 3 and 4). The deterioration of the wood is so severe that deep crevices are visible in X-rays of the box (Fig. 4).

Figure 4. X-ray image of the upper half of the box. Deep crevices are visible in the degraded wood. Four rectangular tenon holes can be seen around the edges, each one with lateral holes for pegs.

A powdery white material can be seen on the ears, face, chest and feet (Fig. 5), particularly in recessed areas. This shows that the surface would have been covered in a white preparation layer (typically calcite mixed with animal glue), applied over the wood to create a smooth surface for painting. Traces of black resin are also visible, which may be unintentional splashes from when the burial bundle was coated.

Figure 5. Detail of the feet, showing remnants of the white preparation layer and traces of black resin.

Although to the naked eye the surface appears to be bare wood, microscopic examination reveals occasional loose pigment particles. The main colour visible is blue, seen on the wig and the collar. This is likely to be Egyptian blue3, a glassy, copper-based frit4 commonly used in the ancient world, and one of the earliest synthetic pigments. Red, yellow, and green pigment particles are also visible under the microscope, but it is hard to be sure that these are original.

Figure 6. Fingerprint in black resin, visible on the outer surface of the coffin, on the proper right side. Microscopic image by Jennifer Marchant.

Close examination also reveals signs left by craftsmen at the time of manufacture: a fingerprint in black (Fig. 6), probably left at the time the coffin was closed after the molten resin was applied within; and chisel marks on the wooden surface around the head (Fig. 7), which might have served to roughen the surface before the preparation layer was applied.

Figure 7. Raking light reveals chisel marks around the head of the coffin. Image by Jennifer Marchant.

The surface was investigated further with an imaging technique known as Visible Light Induced Luminescence5 photography (VIL), used to detect the pigment Egyptian blue, and ultraviolet6 light (UV), which helps reveal the presence of varnishes and resins, but no further traces of the original decoration could be seen.

The fibrous structure of the wood is severely weakened by what appears to be brown-rot, a type of fungal degradation, also responsible for the pronounced fracturing of the surface (known as ‘cubing’). Entire sections of the surface are lost, particularly on the sides, but the head is better preserved. The surface layer easily crushes and powders on touch, a symptom of degradation of the wood structure at a cellular level.

Figure 8. The author carrying out consolidation treatment of the highly degraded surface under magnification.

The conservation treatment aimed to reinforce particularly degraded areas of the surface to avoid further losses. After cleaning with a soft brush, smaller wood fragments and highly deteriorated, fibrous areas were consolidated with a cellulose-based adhesive7, selected after testing due to its compatibility with wood and the fact that it did not change the appearance of the surface. Larger fragments were secured in place by inserting tabs of a long-fibre paper tissue soaked with a strong cellulose starch paste8. The powdery plaster and pigment residues had to be consolidated without touching the surface, as any contact with a brush would have picked up the loose particles. This was achieved by applying a consolidant9 in a mist using a nebulizer. For this treatment I chose Funori, a polysaccharide derived from dried red algae that has been used in Japan as an adhesive for over 300 years and is known for its excellent ageing properties and suitability for matte surfaces.

Though the coffin remains one of the most fragile objects in the Antiquities collection, the surface is now significantly stronger and less prone to losses, allowing for the coffin to be moved safely when needed for further examination and display.

 

Flavia Ravaioli
Objects Conservator, Research Associate
Fr306@cam.ac.uk

 

Acknowledgements

The mummified foetus was discovered by Helen Strudwick, Associate Curator (Egyptian Antiquities), and Julie Dawson, Head of Conservation, both from the Fitzwilliam Museum, in collaboration with Dr Tom Turmezei, Honorary Consultant Radiologist at Addenbrooke’s Hospital in Cambridge, and Dr Owen Arthurs, Academic Consultant Paediatric Radiologist at Great Ormond Street Hospital, London. Technical investigation of the coffin was carried out by the author and by Jennifer Marchant, Conservator of Antiquities and Assistant Keeper at the Fitzwilliam Museum. The wood species was identified by Caroline Cartwright, Senior Scientist at the British Museum, in 2006.

 

References

Jillian, H. and Z. Wyszomirska-Noga, ‘Funori: The use of a traditional Japanese adhesive in the preservation and conservation treatment of Western objects’, in Adapt & Evolve 2015: East Asian Materials and Techniques in Western Conservation. Proceedings from the International Conference of the Icon Book & Paper Group, London 8-10 April 2015. London: The Institute of Conservation, 2017. 69–79.

Strudwick, H. and J. Dawson (eds.) Death on the Nile. Uncovering the Afterlife of Ancient Egypt. The Fitzwilliam Museum, Cambridge. London: Giles, 2016.

 

Glass Iridescence – Deliberate or deterioration?

I’ve recently enjoyed making an interesting connection between our Roman glass collection and a beautiful display of Tiffany and Loetz glass that is part of the Frua-Valsecchi collection. You can see this for yourself in our Cypriot gallery.

Valsecchi glass display in the Cypriot gallery

Much of the Roman glass in our collection displays a pearlescent sheen known as iridescence. Although beautiful, and copied by 19th and 20th century glassmakers such as Tiffany and Loetz, this wasn’t deliberately produced by ancient glassmakers, it is the result of the deterioration of the ancient glass.

Iridescent glass vessel
Early Roman bowl found in Leukolla Cyprus, GR.101.1876

What is Roman glass?

The major component of glass is silica, found in sand. The melting point of silica is 1600-1713oC, which is too high for production in simple glass furnaces (about 800oC) so an alkali is added to reduce the melting point. In Roman glass this was soda, which is found in many naturally occurring salts. Lime is also needed to stabilise the material. This is found in many sands. Soda-lime-silica make a very stable form of glass.

Much Roman glass is slightly blue or green; this is caused by small quantities of iron in the natural materials used in glass making. Other colours could be produced by choosing particular sources of sands that contain different minerals.

Deterioration

Although largely stable, our Roman glass has had to contend with many challenges to survive to the present day. Vessels may have been physically damaged during use, at the point of burial or during excavation. Prolonged contact with water is also a significant challenge to the chemical stability and surface appearance of the material (take a look at a previous blog post where one of our conservation students worked on part of the glass collection).

Water leaches the alkali (soda) from the surface of the glass, especially in slightly acidic burial environments. This leaves behind fine layers of silica that can flake off the surface. The iridescence is purely a visual effect; in the same way that water droplets in the air cause rainbows, light is bent and split into its separate colours as it passes through the thin layers of deteriorated glass and air.

Surface of deteriorated glass showing pitting and flaking

Copying history

Tiffany – Louis Comfort Tiffany was an American artist and designer well known for his work in stained glass. In 1865 Tiffany travelled to Europe and visited the Victoria and Albert Museum (then the South Kensington Museum). Here he was struck by the colours of the Roman and Syrian glass collections, reflecting on the “rich tones” achieved without the use of paint. It is likely that Tiffany did not recognise the impact of deterioration on the appearance of this material.

Vase, Favrile glass. Louis Comfort Tiffany. Lent to the Fitzwilliam Museum by Massimo and Francesca Valsecchi.

The Tiffany Glass Company was established in 1887 in New York, but he was working with glassmakers at more than one Brooklyn based glassworks prior to this. In the early 1890s, Tiffany patented the Favrile glass making technique, which was heavily influenced by the appearance of ancient material. Multi coloured iridescent glass was produced by mixing different colours of glass together and spraying metal solutions onto the hot surface of the glass before the vessels were blown. The glassmaker Arthur J. Nash developed this method, passing it on to his son Leslie Nash. They kept the recipe a closely guarded secret that even Tiffany did not know.

Iridescent vase. Loetz, Austria. Lent to the Fitzwilliam Museum by Massimo and Francesca Valsecchi.

Loetz – A glassworks was established in Klostermühle (today called Klášterský Mlýn) in 1836. This changed hands several times until it was bought by Frank Gerstner and his wife Susanne Loetz in 1851. Loetz was the widow of a glassmaker and ran the business for 20 years after the death of her second husband in 1855. The business was then transferred to Loetz’s son-in-law Maximilian von Spaun in 1879. Working with the glassmaker Eduard Prochaska, he modernised the factory and developed new glassmaking techniques.

In 1897, von Spaun, saw Tiffany Favrile glass exhibited in Bohemia and Vienna. This inspired him to focus production on Art Nouveau style glass, which led to the most artistically significant and profitable period of the company’s history.

 

Being able to make this type of comparison of objects from widely separated time periods is one of the joys of working somewhere like the Fitzwilliam Museum. Come and take a look for yourself in our Cypriot Gallery.

Rehousing the Egyptian Organics

The Fitzwilliam Museum is well known for its large and diverse collection and the Department of Antiquities alone holds 27,000 objects. The public galleries represent approximately one tenth of this, with other objects packed away in storage areas. The best and most interesting of these are swapped onto display, many other objects, including small items such as pottery sherds and beads, are accessed by researchers whilst in storage. As Departmental technicians, one aspect of our job, is caring for the objects, both on display and in storage, and working alongside the conservators and curators to ensure that they are housed a suitable way, which will help guarantee their longevity and condition.
In the Antiquities stores, as with many museums, space is limited. With many objects kept in storage, it is an on-going job to rearrange both store and the objects, so that the collection can be best accommodated into the minimum amount of space, but remain accessible to researchers. A recent project that is part of this reorganisation is the Egyptian Organics.
As the name suggests, these are Egyptian objects, varying in types of organic material and design. They are extremely sensitive to changes in environmental conditions and insect pest attack, so it is best for them to be stored together, where we can keep a close check on these factors. They have been stored in temporary tray-stacks in several different places, and we were keen to get them repacked, documented and rehoused together.

How are we doing it?
There is quite a bit of work that will go into rehousing this material, it is not a simple case of just transporting them to a new cupboard or box. Each object is assessed individually through a multi-stepped process.

How the objects have been stored previously.

Up until now, the organics have been stored in these large trays. They are lined with inert foam and acid free tissue, however some objects were not as well supported as we would like and we were keen to refresh the tissue and reduce some of the cramped storage. Some objects had also become separated from their information or component parts.
Each object was taken out, photographed and assessed for its conditions and needs. Information on each object is imported into a spreadsheet, which includes details such as the museum number, a brief description of what the object is, what types of deterioration are present, whether there are old repairs, or metal components. We also gave it a condition grade out of 5, with 1 being in the best condition (similar to the condition of the objects out in the galleries) and 5 being the worst, meaning it might need immediate treatment.


Organics being photographed, documented on the spreadsheet and labelled up.

The museum number is usually written somewhere on the object itself. It may seem strange to permanently mark the object, but it is the best way to ensure the number remains attached, as labels and tags can easily fall off and become disassociated. These days, when marking an object we do it in a way that is reversible and not harmful to the object, but pieces that arrived in the collection in the past sometimes have the number directly applied to the surface. The museum number is how we identify the object, it links it to all its records and documentation, including information on when and where it was found, and how it came to be part of our collection.

An object like this would be hard to identify if we didn’t know its museum number. Luckily it has survived and is still legible.

This tells us that this object came into the museum in 1943, and it was the 5842nd object to be accessioned that year. It means we can easily access all the documentation and provenance for this object. By looking at the online database, we can find out that E.GA.5842.1943 is a figure of a Pygmy with a monkey on its shoulder.

Once you know what the object is supposed to be, it is a lot easier to recognise.
When all his information is recorded, and his label is attached, he is nestled into new acid free tissue paper and placed into a lidded plastic tray.

Even though his museum number is clear to read, giving him a second visible label means we do not have to handle him to check his number in future, thus minimising further damage.

Sometimes, due to the condition of the object (or the handwriting!) the legibility of the number can become a problem. If we are not sure of the number, we can check it against our Slip Books. For many, but not all of the objects, these Slip Book records were created at the time the objects were given a number. They contain lots of useful information, including drawings and sketches of the objects (as this was before cameras were readily used) which can be used to match the object correctly.


Object with its Slip Book entry and drawing.

These drawings are extremely helpful as we can determine what state the objects where in when they arrived and how they are faring now in comparison. It is important to note that the condition of most of these objects has barely deteriorated since they arrived at the Museum. Some objects, especially the tomb model figures, were found to have remnants of newspaper attached to them. As many of the Slip Books entries also make note of it, we can determine that it is likely this newspaper was wrapped around them, as packing material when they were first shipped to the UK after excavation. The newspaper has adhered itself to the surface of the object and became embedded within the grain, making it potentially a tricky (and long) job for a conservator to tackle.

Any object that does not have a number and we cannot straight away identify from the Slip Books, we assign an ‘Unknown’ number. Currently over 100 of these ‘unknown’ numbers have come out of this project.

All these unknown organics will have to be identified through investigation through both our online database and our Slip Books, some unfortunately might take a bit of work to identify!

However, as they are all now safely packed and documented, the conservators can get to work on any that require immediate treatment whilst we investigate!

Rehousing all these artefacts safely is only the first step. There are still many phases of conservation, research, and documentation to be carried out, along with more permanent housing for those that need stabilising. However they can now all be easily accessed and identified, as well as safely packed away.

Projects like these allow us to look at our collection in depth, building up a good picture of the nature and the condition of the objects. It is also one of the most enjoyable parts of our job, as you never know what you might come across next…