In 2018, conservators, curators and scientists had the challenge of preparing an imposing Tahitian mourning costume for display and long-term preservation.
Head of Organic Conservation Monique Pullan talks us through the lengthy process.
Reimagining a Tahitian mourning costume
One of the star objects in our 2019 exhibition Reimagining Captain Cook: Pacific perspectives was this 'chief mourner's costume' from Tahiti, in the Society Islands. The costume (known as a heva tu papa'u) was worn during the mourning ceremonies following the death of a chief in 18th-century Tahiti, and is one of the most important objects in the British Museum's collections.
Collected by Cook in 1774, the outfit is believed to be one of approximately ten he brought to Europe in 1775. Today, only a handful survive, making the British Museum's near complete assemblage an important document of a now-lost Tahitian practice – particularly in light of the exciting discoveries that were made during conservation.
It is constructed from a range of ritually significant materials – barkcloth (a material made from tree bark), pearl shell, feather, and coconut shell. For many years the costume stood 'dressed' on a painter's easel, which posed the first conservation questions.
Records show the costume was displayed on the easel in the Museum's South Seas galleries in the early 19th century, and the use of plaited coconut fibre string to tie elements onto the easel suggested that it might have been mounted like this while still in the Pacific, perhaps on board the HMS Resolution – Cook's ship.
The conservation process began by carefully documenting and removing each component of the costume from the easel. It was fascinating to peel away the layers, as we could examine and document each element closely.
It was only when we had fully undressed the costume that we made our most significant discovery. Thought initially to be extra padding, a large bundle of fine barkcloth was found tied to the easel. We decided to carefully unroll it, revealing not one, but two hidden treasures.
The first was a large rectangular sheet of finely beaten barkcloth. It was covered in reddish-brown splashes – identified as hand and finger prints. Although probably not part of the costume itself, its presence suggested another association with the mourning ceremony. Descriptions of the ceremony in Cook's journals following his first visit to Tahiti in 1769 tell of ritual self-mutilation, suggesting that the marks could be blood, and although on further investigation and analysis these marks turned out to be dye, this piece could still be a representation of a blooded cloth from the ceremony, which itself would have been too sacred for Tahitians to give to Cook.
The second discovery was a barkcloth poncho style garment, called a tiputa, very similar, but smaller, to the one already on the costume. Creasing and distortions matching the shape of the easel showed that this had undoubtedly once been part of the assembled outfit. The un-faded, bold red stripes suggested it had hadn't seen much light since being brought to Europe in the 1770s, and gave us an understanding of the former colour of the now-faded costume.
The vivid black, red and yellows shown in contemporary depictions of mourner's costumes drawn by Herman Diedrich Sporing (below) and the Tahitian Tupaia (the high priest and navigator) during Cook's first voyage began to make sense. Once we started looking, we found evidence of red and yellow dyes on several other pieces.
Although faded, all of the barkcloth elements of the costume remained in remarkably good condition. The main deterioration has been the absorption of dirt, and creasing and distortion caused by being wrapped around the easel, which required surface cleaning and humidification treatments. Cleaning of the barkcloths was carried out using specialised sponges and cloths, and their creases relaxed with humidification techniques.
Most fragile of all the pieces was perhaps the long feather cloak hanging down the back of the costume, and conserving it was painstaking work.
The black feathers, split down the central shaft to make them twist, were bound together in groups and tied onto a plant fibre mesh to form the cloak. The feathers were individually repaired using narrow strips of paper, glued along the shaft in order to reinforce them. Feathers always present a challenge to conservators – they are intrinsically fragile and many had become detached. They are also vulnerable to pest damage – especially from the larvae of clothes moths and carpet beetles.
The long black feather pendants, hanging either side of the breast plate, had suffered particularly from pest damage which had left obvious bald areas. Conservator Sophie Rowe was able to create 'feather toupees' from feathers that had become detached from the pendants to hide the bald spots, matching similarly sized and shaped feathers, and grouping them into bundles.
Multiple bird species have been used throughout the costume and British Museum scientist Chris Mussell is currently working with bird expert Hein van Grouw from the Natural History Museum to identify the species.
Conserving shell elements
Completing the costume were the distinctive breast plate and face mask. The curved wooden breastplate is decorated with five large pearl shells, and with nearly 1,000 tiny rectangular shell plaques suspended below. The craftsmanship of cutting and drilling each plaque without metal tools is quite incredible.
The mourner's face would have been completely covered by the shell mask, and there's only one very small eye hole. Topped with a crest of long white tropic bird feathers, the mask exaggerates the wearer's height, making an awe-inspiring figure.
One of the large shells making up the mask had broken down the middle, and had been repaired in the 1960s using an epoxy adhesive. This glue had left unsightly hard, yellow residues on the surface of the shell. Using innovative laser cleaning techniques, conservator Tania Desloge was able to break down the epoxy. Although normally used in the cleaning of stone artefacts in the Museum, this was the first time laser cleaning technology had been employed in the treatment of organic materials.
Working closely with scientist Lucia Melita preliminary experiments were conducted using mock up samples of pearl shell and aged epoxy resins to ensure the success and safety of the treatment. The radiation energy from a special Er:YAG laser softened the aged epoxy so it could be picked off with tweezers. Needless to say applying this laser technique to the real object required great care! The shell was then reinforced in a way that could be reversed in the future – using Japanese paper and fibreglass sheets impregnated with an acrylic adhesive.
Displaying the costume
After lengthy discussions with curator Julie Adams, in consultation with visiting experts from Tahiti and the UK, and having carried out research to compare other remaining mourners' costumes in the UK, Hawaii, Italy and Germany, it was decided to make some significant alterations to the presentation of the costume when reassembling it following the 2018 conservation. This included removing it from the easel mount.
We wanted to display the costume as it would have been perceived during the ceremony, worn by a person. This was particularly important for visiting Tahitian curator Theano Guillaume Jaillet, who felt that the time had come to move away from feeling constrained by the easel's possible association with Captain Cook.
The development of a new, custom designed mannequin was critical to the costume's display and long-term preservation. Supportive undergarment now give shape to each part of the costume and carefully fitted mounts hold the breast plate and face mask in place. During display, light levels will be carefully monitored to prevent fading and deterioration of the fibres. After display, the costume will remain on its mount, in an environmentally controlled store with optimal temperature and humidity levels.
Scientific investigations are still ongoing – with dyes, feathers and fibres being identified. The discovery of two previously unknown and extremely well-preserved components, as well as never-before-seen decorative elements was a cause for great excitement. Close interaction between the Museum's curatorial, conservation and science teams, and external Tahitian specialists, has given us a deeper understanding of the importance of this unique object as a record of Tahitian culture, and of early European contact with Tahiti.