A number of items in the collection of watches at Amgueddfa Cymru 'glow-in-the-dark'. The material that causes this glow (luminescence) is radium. As radium is radioactive, the watches in question now have to be treated with care, making their conservation, accessibility and display a big challenge.

Radium

1918 gent's wristwatch showing degraded and missing areas of radium paint

Marie Curie discovered Radium in 1898, and was the wonder of the new century - ironically thought to cure everything from arthritis to cancer. Mixing materials such as zinc sulphide and radium produces the glowing effect. In 1902, this luminescent material was first used to paint on the dials and hands of watches and clocks, allowing them to be seen in the dark.

Marie Curie eventually died from exposure to radium in 1934. Her notebooks, in which she was recording all her experiments are still too radioactive to handle today.

The Radium Girls

Glow-in-the-dark watches soon became popular with the mass market, and in the 1920s, production factories were set up where women would mix together glue, water, and radium powder into a glowing greenish-white paint that was then put onto the watches.

In order to paint neat and sharp numbers on the dials, the brushes needed a very fine tip. After a few strokes, the brushes would lose their shape, so the women "sharpened" the fine brushes by rolling the brush tips on their tongues to straighten the bristles, sometimes up to 6 times for every watch dial. Some even painted their teeth or applied glowing "makeup" as a novelty to show their friends. Many of these women would later die from cancer.

Testing for radioactivity at the museum

A radioactive contamination monitor (Geiger counter) was used to measure the radiation given off by the clocks and watches held in the collections housed at the museum. The highest readings showed dials to have a reading of 3000 counts per second against a naturally occurring level of 8 - 10 counts per second.

The measurable dose of Radium in a watch is apparently about 5 times the dosage from a standard chest X-ray.

The readings confirmed that the dials could be hazardous if exposure was not limited in some way. To combat this, the radioactive items were:

• Enclosed in a sufficiently dense material;
• Confined to a little used area of the stores;
• Warning signs displayed as to the nature of the hazard.

All objects containing radium that were on public display were identified and withdrawn and put into safe storage.

Radioactive Dust

Although the storage of these items can be controlled and managed properly, the conservation of these objects is of concern. Since the dials are anything up to 100 years old, the paint breaks down into dust resulting in an increased risk of contamination from exposure to the radioactive dust.

There is the possibility of breathing in this dust by carrying out work on the dials, such as working on the mechanism, cleaning the dial, hands or covers. As a result, all items in the Museum that pose a radioactive risk are handled with suitable precautions taken to prevent any harm done to the conservator.

Radioactive decay

Interestingly, tests show that the brightness of the dials is not related to the level of radioactivity. Even if the dial paint is dim or invisible in the dark, it could still give a high reading of radioactivity, since although the reactive luminous chemical might have broken down, the radioactive element, radium will continue to be hazardous for many generations to come.

The ‘Kalighat’-style paintings at Amgueddfa Cymru were brought over from India at around 1880. They represent a popular Indian art form that had died out by 1940. They are the work of professional artists called ‘patuas’ in Bengali and were sold for the equivalent of a penny each at markets and fairs in and around Calcutta, mostly at the gates of the famous temple at Kalighat, from where the style gets its name.

Storytelling

For centuries in Bengal, travelling professional artists known as &;lsquo;patuas’ or ‘chitrakars’ painted pictures or ‘pattas’ on cloth or handmade paper. These pictures were sewn together to make long scrolls of images. These artists toured rural villages, unrolling the images as they recited or sang the story. Patua families living in rural areas near Calcutta continue the tradition to this day.

Patuas move to the city

By 1806, some patuas had moved to the Calcutta – the biggest bazaar in Bengal. This new urban market had huge potential. In addition to residents, seasonal visitors to Calcutta wanted affordable souvenirs. With cheap machine-made paper and manufactured paints, the essential characteristics of the style emerged. Designs were kept simple, to be repeated as often as required according to the popularity of the picture. As demand increased, the detail in the scrolls was abandoned.

Traditions and religion

Certain Hindu traditions guided the painter. Each Divinity had a particular meditational formula – dhyan mantra – which the painters attempted to produce in line and colour. The traditional stories relate the appearance and actions of the gods and goddesses with their complexions, poses, mounts and weapons, which all had to be drawn correctly.

Hindu images and Muslim festivals

As Calcutta was extremely cosmopolitan, in addition to the Hindu images, the important Muslim festival of Muharram is also represented. It is possible that many Kalighat artists accepted beliefs from both the Hindu and Muslim faiths, as many of the scroll painters still do, having two personal names, one from each tradition.

The origin of the Kalighat Collection

The origin of the collection at the Museum is unknown before 1954. Assuming they form a single group, it is likely that they were acquired in Calcutta some time around 1873. The original owner was possibly French.

A collection now in the Bodleian Library, Oxford, was purchased between 1860 and 1870, and contains similar images. The collection is also similar to the seventy-three items in the Victoria and Albert Museum, London, acquired in India between 1865 and 1893.

The fall of the Kalighat style

1870 seems to have been the time when the popularity of these paintings reached its peak. To speed production, some families tried using a lithographic outline during the 1840s, but did not survive many years. It was the chromolithograph, capable of even brighter colours and a huge print run, which ultimately undercut the hand-painting families and took over the market and by the 1930s this popular art form had died out completely.

Sadly, very few of the thousands of Kalighat pats produced during the nineteenth century survive in India today, either in museums or private collections. They were never bought by the rich, who considered them unworthy of the name of art. In the poorer homes, the lack of protection from both the humid climate and physical damage soon destroyed the inherently weak cheap paper on which the patuas had worked their art.

Further reading

W. G. Archer, Kalighat Paintings, London 1971
Balraj Khanna, Kalighat – Indian Popular Paintings, London, 1993
Hana Knizkova, The Drawings of the Kalighat Style, Prague, 1975

The Celts

The Late Iron Age harness piece from Alltwen

Study of 'Celtic' art styles on metalwork helps us to understand the peoples of the Iron Age in Europe. La Tène art, as it is more properly known, was used across Europe, from the late 5th century BC onwards. This was a form of art uniquely different from that of the classical Mediterranean world, employing natural forms in a free-flowing style.

Early La Tène styles were thought to have been made by the Celts, a people who shared common languages, societies and similar pagan religious beliefs. Recently, this view has been challenged; experts today believe that similar metalwork styles show that this art form was passed on across cultures and not necessarily retained within one common ethnic identity.

Wales has many fine metalwork discoveries decorated in La Tène art styles, examples of which are housed at National Museum Cardiff.

Glass enamels

Analysing the samples using an Scanning Electron Microscope

A technique mastered by British metalworkers from the 3rd century BC onwards was the application of red 'enamel' to decorated metalwork. It is in fact a type of glass applied by cutting pieces to shape; the pieces were then carefully heat softened and finally pressed into the metalwork. A specimen decorated with La Tène art, with red enamelling, has been discovered at Alltwen near Pontardawe (Neath Port Talbot) and purchased for Amgueddfa Cymru.

The discovery raises questions about Welsh enamelled and decorated artefacts from the Iron Age. How similar (or different) were the metal and glassworking traditions in north and south Wales? Did the Severn Estuary act as a barrier, or as a cultural focus for metalworkers between south Wales and south-west England during the later Iron Age? How do these 'enamels' (glasses) decay?

Removing samples for analysis

Crystals of cuprite within the glass matrix

The items chosen for the study include a piece of horse-harness from Cardiff, the Snowdon Bowl (Gwynedd) with its cat-like motif, and selected horse equipment from the Seven Sisters Hoard (Neath Port Talbot), in addition to the Alltwen find. Tiny samples of enamel were taken from the artefacts; these were mounted and polished on microscope slides. Analyses of samples were conducted using a Scanning Electron Microscope and X-ray analysis.

Additionally, the structure of the enamels was studied, through transmitted and incidental light, using a polarising light microscope.

Results from the analysis show 'soda-lime' glass, containing large amounts of lead and copper. These are responsible for the brilliant red colour and the opacity of these glasses. Their manufacture is technically advanced and can only be produced by careful control of both the ingredients of the glass and the furnace conditions.

Results show that enamelled artefacts from south Wales match reasonably well with those from south-west England; however the enamel on the Snowdon bowl from north Wales is markedly different from the others. This suggests differences in the manufacture of these glasses across different regions of Wales.

Watercolour by F.G. Newton, 1905

Removing one of the panels

In 1988, archaeological excavations of the council chamber in the basilica (assembly hall) of the Roman town at Caerwent revealed a fine wall painting that has since been removed for conservation and display.

The painted plaster or fresco, 5m long and 1m high, was still attached to the south wall of the chamber. It had been previously recorded in watercolour by F. G. Newton in 1905, and had been covered over again.

The fresco shows an architectural perspective, with yellow pillars above a brown veined pink dado. A dark brown area in the central pillar may be part of a decorated panel, possibly containing the torso of a man.

It was decided to remove the fresco to prevent further deterioration as the plaster was extremely fragile.

After carefully covering the delicate artwork with muslin and glue, the painting was cut into five panels. Each enclosed in specially-designed boxes.

A variety of saws and chisels were used to separate the painted plaster from the wall. Since access to the back of each panel was restricted to its top edge and one side, this process was difficult, needing extreme patience and ingenuity.

It took a total of nine days to remove the painting, with the subsequent conservation and rebacking taking several years, the fresco is now conserved and stored at the National Museum, Cardiff.

Background Reading:

Caerwent Roman Town by R.J. Brewer. Published by Cadw (2006).