Giving objects a voice: conservation and the N. W. Thomas collection

UCL Conservation student conducting visual inspect of headdress collected by N. W. Thomas for condition report
UCL students conducting an inspection of objects from the N. W. Thomas collection at the Cambridge University Museum of Archaeology and Anthropology prior to their transfer to the UCL Conservation Lab. Photograph: George Agbo.

Among the many collaborations involved in the [Re:]Entanglements project is a partnership with the Museum Conservation programme at UCL’s Institute of Archaeology. Under the supervision of Drs Dean Sully and Carmen Vida, students on the graduate programme have been working on a selection of objects collected by Northcote Thomas during his anthropological surveys of Nigeria and Sierra Leone. Project coordinator, Carmen Vida, introduces some of the contributions of conservation in this the first in a series of posts from the UCL Conservation team.

Starting in February 2019, as part of the [Re:]Entanglements project, a selection of objects belonging to the N. W. Thomas Collection at the University of Cambridge Museum of Archaeology and Anthropology (MAA) have come to UCL’s Institute of Archaeology for conservation. The project is allowing us to interact with the collection in new ways and to approach, explore and elicit some of the past and present meanings of the archive Thomas put together. As a result, in many cases the objects in the stores are being studied for the first time and the cobwebs are being dusted off, sometimes quite literally.

Conservation has a particular role in the [Re:]Entanglements project: not only does it ensure that the objects are stable enough to be used by anyone interacting with them, but as a distinct form of engagement, it provides intimate knowledge of the objects and can shed light on their make-up and their biography. Due to the lack of contextualising documentary evidence, museum objects often appear to be ‘mute’. But even where there is documentary evidence, the histories and narratives that have reached us provide one side – often someone’s side – of the story. Conservation can help provide a voice to the objects themselves, which may sometimes corroborate, but at other times question, the established histories associated with the objects. In doing so, conservation affords present day audiences the possibility to re-engage with the objects, whilst exploring the way in which the archive came to be both from past and contemporary perspectives.

UCL Conservation student conducting visual inspect of mask collected by N. W. Thomas for condition report
Detailed documentation is essential in conservation practice. Here a student annotates photographs of a mask collected in Ibillo in present-day Edo State, Nigeria prior to conservation treatment. Photograph: George Agbo.

By the time the project is finished more than 40 objects will have been worked on at the Institute of Archaeology’s conservation lab and at the MAA. The objects being treated vary in type and size, and are but a small part of the N. W. Thomas Collection, which includes over 3,000 objects. Some will form part of upcoming exhibitions in London and Cambridge, whilst others are being conserved because, after over a century of existence, they have become unstable even when packaged away in a museum store. The work is being carried out both by professional conservators and students, and is allowing these students to develop their skills and further their training, another affordance of the project. We are also providing running some workshops for the Art Assassins, the youth forum of the South London Gallery, which is another collaboration within the [Re:]Entanglements project.

Fish trap collected by N. W. Thomas being reconstructed in UCL Conservation Lab
A fish trap collected by N. W. Thomas in Awgbu in present-day Anambra State, Nigeria undergoing reconstruction in the UCL Conservation Lab. Made from strips of bamboo, tied with plant fibres, this fragile trap was little more than a pile of sticks prior to conservation. NWT (2) 2, MAA Z 13941. Photograph: Paul Basu.

There is a whole array of tools and techniques that we use in conservation to better understand the objects and inform our treatments. Documentation is essential, starting with any existing historical information to which we can correlate the object itself: documents, photographs, previous museum information in the form of labels or markings on the objects. Labels are interesting things: sometimes informative, sometimes deceptive and indicative of misidentification at some stage. Our conservation work on the N. W. Thomas Collection includes the preservation of labels and museum numbers marked on the object, as they have by now become part of it and of its history.

Historical labels attached to a fish trap collected by N. W. Thomas
Documentation of labels associated with the fish trap being conserved.

Visual analysis of the objects can be extremely revealing for a trained eye. We use microscopes to examine the surface of the objects, looking for evidence of damage and instability, but also for clues as to the history of the object: manufacture materials and techniques, damage and/or repairs (whether before or after collection), evidence of rituals or of use are all things we will be looking for in our work. All these tell stories and give the object a new voice. Some of the objects treated so far exhibit extensive pest damage, and microscopy has helped us find evidence of the pests themselves, which will be later used by expert entomologists to identify the species and give us a good idea of where the damage might have occurred. The insect damage in some of the objects reflects their places of origin in West Africa (termites) as well as their later history (wood boring insects that can be found in the UK).

Horned mask collected by N. W. Thomas exhibiting insect damage
Horned mask, described by Thomas as ofulu mpi, collected in Awgbu, present-day Anambra State, Nigeria in 1911. Conservators use microscopes to inspect the insect damage: top-right: insect carcass; bottom-right: insect eggs. These will be sent to an entomologist for identification. NWT (2) 375, MAA Z 14231.1.

But conservators do not rely on visual inspection alone and we are trained to use most of our senses as part of our work, not just our eyes and hands. Smell, for instance, can help us identify fungal infestation, or certain materials used in the past. And by listening to the sound when we very gently tap a surface, we can ascertain the extent to which it may be hollow under the surface as a result of pest activity. One sense we are definitely not encouraged to use is taste! – not least because of the toxic materials earlier conservators may have used to treat objects.

Other techniques we use help us to identify materials whether original or introduced by repairs done in the past. Ultraviolet fluorescence, for instance, can reveal the presence of modern adhesives and materials in objects. Chemical tests can help identify binders and pigments used in their decoration. Elemental analysis with portable technology such as p-XRF (portable X ray fluorescence, which detects inorganic elements such as metals and minerals) can help us identify not just what the objects are made of, but also, for instance, if they were treated with pest treatments no longer used such as arsenic or mercury salts. And we can use Fourier-transform infrared spectroscopy (FTIR) to identify organic compounds. In this way we were able to establish, for instance, that a white deposit on one of the masks (Z 13728) was paraffin wax. This identification helped us both clean it safely by using the right solvents, but also to speculate that the mask may have received some treatment, possibly soon after arrival at the Museum of Archaeology and Anthropology in Cambridge. Paraffin wax was often used as a filler and protective coating treatment for wooden objects from the end of the 19th century and into the first half of the 20th century. In this case, our findings support documentary evidence from the museum’s Annual Reports in the years shortly after acquisition that the objects were cleaned, mended and restored.

Horned mask collected by N. W. Thomas showing parafin deposits
Mask described by Thomas a onye kulie collected in Nibo, present day Anambra State, Nigeria in 1911. Using FTIR techniques, conservators were able to identify the white deposit evident on parts of the mask as paraffin wax, likely to have been used to treat the mask at the Museum of Archaeology and Anthropology soon after it was accessioned. NWT (2) 428, MAA Z 13728.
Excerpt from Cambridge Report of the Antiquarian Committee, 1913
Excerpt from the Annual Report of the University of Cambridge Antiquarian Committee, 1914. The report notes that much of the museum assistant’s time ‘has been devoted to cleaning, mending and restoring’ objects collected by Thomas, many of which had been damaged in transit from Nigeria. The report also notes that Thomas himself spent a week at the museum ‘classifying and labelling his collections’. This would have been during the period of leave between his third and fourth tours.

Our work so far has also allowed us to interrogate and qualify some of the other knowledge resulting from the [Re:]Entanglements project’s collections-based research. Thomas’s correspondence, for instance, indicates that – in stark contrast to the current practice in his time – he commissioned some of the objects he collected to be made or else bought them at markets. One of the objects conserved at UCL in 2019 is an Igbo maiden spirit mask. The initial visual examination of the mask identified a number of historical repairs, including an iron sheet stabilising one of the bird figure on the proper right of the headdress, an iron staple across a crack on the proper left side of the headdress, and a plant fibre tie on the same area as the staple but further down. In the case of the iron staple and the fibre ties, they are covered with the same pigment used on the rest of the mask, suggesting they are original repairs. Checking the current condition against Thomas’s field photographs showed that the iron sheet repair securing the bird was already there when the mask was photographed by Thomas, presumably at the time of acquisition. These repairs could both be indicative of use prior to collection, in which case the mask would had had a previous life and not been simply commissioned by Thomas, or else be repairs carried out during the process of manufacture, not an uncommon occurrence. Currently we have not been able to resolve the matter of previous use in relation to this object, but nevertheless this conservation work has raised the question, allowing us to continue looking for evidence of previous use in other objects. That is one of the research questions we will be looking to find evidence for when treating other objects.

Maiden spirit mask collected by N. W. Thomas showing historical repair
Maiden spirit mask collected by N. W. Thomas showing historical repair
Maiden spirit mask described by Thomas as isi abogefi collected in either Agukwu-Nri or Nibo, present-day Anambra State, Nigeria, in 1911. Thomas also photographed the mask in the field (top right), revealing that the repair to one of the bird decorations was made prior to acquisition. A close examination of the the iron staple and fibre tie used to repair a split on the proper left of the mask shows that they are covered in the same pigment used on the rest of the mask, suggesting that the repair was done during the making of the mask. NWT (2) 390, MAA Z 13689.

To date, nine objects have received treatment, and conservation of the remaining objects is underway. In this and subsequent conservation-themed blogs we will be sharing some of the stories that are coming to light as a result of the conservation work.

As noted above, many of the objects undergoing conservation and being discussed in this series of posts will be exhibited at the [Re:]Entanglements exhibition at SOAS’s Brunei Gallery, London (October to December 2020) and subsequently at the University of Cambridge Museum of Archaeology and Anthropology (2021, dates to be confirmed).

Archival Soundscapes with Onyeka Igwe

Northcote Thomas wax cylinder records at British Library
Wax cylinder recordings made by Northcote Thomas stored in their original cases in the British Library Sound Archive.

[Re:]Entanglements is collaborating with the Art Assassins, the young people’s forum of the South London Gallery in Peckham. As part of the project, the Art Assassins are working with a number of London-based artists and researchers with connections to West Africa. The idea is for each artist or researcher to use their creative practice to help the Art Assassins explore the Northcote Thomas collections and archives, and consider its relevance for young people in South London today. The Art Assassins’ work will culminate in an exhibition at the South London Gallery in May 2020, which they will curate themselves.

The first artist to collaborate with the group is Onyeka Igwe. Onyeka is a filmmaker, programmer and researcher. She is widely known for her video work which uses dance, voice, archive and text to expose hidden narratives. Her work explores the physical body and geographical place as sites of cultural and political meaning. Onyeka won the 2019 Berwick New Cinema Competition for her film the names have changed, including my own and truths have been altered. The film explores three interconnected narratives – a story of the artist’s grandfather, one of ‘the land’, and another detailing an encounter with Nigeria.

Onyeka Igwe, still from 'the names have changed'
Onyeka Igwe. Still from her prize-winning film the names have changed, including my own and truths have been altered.

For her project with the Art Assassins, Onyeka has been exploring the sound recordings made during Northcote Thomas’ anthropological surveys in Nigeria and Sierra Leone. The work is ongoing, so here we report on our activities so far and our plans for developing this strand of the project over the coming months.

Listening to the archive

At an initial workshop with Onyeka, the Art Assassins explored the [Re:]Entanglements SoundCloud site, at which the complete set of Northcote Thomas’ digitised sound recordings have been made available. They spent time listening to a selection of the recordings on high quality speakers in the South London Gallery’s Clore Studio. Participants were struck by the texture of the phonograph recordings and how the crackles and pops created their own rhythms. This led into a discussion about how the recordings were made and Onyeka explained more about the wax cylinder recording process employed by Thomas. To give a more contemporary context, Onyeka set up a vinyl record player so the group could get hands on with the analogue sound equipment and learn how sounds can be manipulated.

Onyeka Igwe and the Art Assassins listening to Northcote Thomas recordings at SLG
Onyeka Igwe and the Art Assassins listening to a selection of the digitized Northcote Thomas recordings in the Clore Studio, South London Gallery.
One of the first recordings made by N. W. Thomas. Recorded in Benin City on February 2nd, 1909, a few days after his arrival in Nigeria, this song is performed during the Ugie Ewere festival to bring ‘Ewere’ blessings to all homes.

Visiting the archive

The group visited British Library Sound Archive in Kings Cross to find out more about its huge collection of historical ethnographic and ethnomusicological wax cylinder recordings. The British library holds over 700 discrete recordings made by Thomas between 1909 and 1915. It was also responsible for producing the digitised versions of the recordings that the Art Assassins were able to access online. Dr Janet Topp Fargion, Lead Curator of World and Traditional Music, hosted the visit. After travelling down several floors deep into the basement of the British Library the Art Assassins were amazing to find themselves face-to-face with shelves of Thomas’ original wax cylinders. They were then introduced to the team responsible for digitising the wax cylinders and witnessed a live demonstration of the process.

Janet Topp Fargion showing the Art Assassins the Northcote Thomas wax cylinder records at the British Library
Dr Janet Topp Fargion showing the Art Assassins the Northcote Thomas recordings in archival storage at the British Library.
Janet Topp Fargion showing the Art Assassins the Northcote Thomas wax cylinder records at the British Library
The Art Assassins gained an insight into the work of conservators and researchers at the British Library Sound Archive.
Wax cylinder phonograph recorder at the British Library
The British Library’s sound conservation department has a large collection of historical recording equipment, including this wax cylinder phonograph recorder similar to the one Northcote Thomas would have used during his anthropological surveys of Nigeria and Sierra Leone, 1909-15.
In order to digitize the wax cylinders, the British Library had this bespoke machine built for them. British Library sound conservators demonstrated the digitization process.

Making an audio archive

Back at the South London Gallery, Onyeka and the Art Assassins started to plan how they might create their own archive of sounds reflecting their own lives. Relating back to the Thomas’s work, Onyeka asked the group to consider the categories he had used in his anthropological reports. Would these same categories work for understanding young people living in London today? The group debated this and offered up other categories to guide their sound recording process.

Onyeka Igwe and the Art Assassins discussing Northcote Thomas recordings at SLG
Onyeka Igwe and the Art Assassins back at the South London Gallery, reflecting on what they have learnt about sound archives and considering how they might include sound recording in their response to the Northcote Thomas collections.

The group are continuing to build up their own archive of sound recordings ranging from everyday sounds and actions to capturing their own and their families’ accents and phrases. They will also be conducting oral histories with people living the UK with a connection to Nigeria and Sierra Leone which will become part of their larger archive.

Onyeka Igwe and the Art Assassins discussing Northcote Thomas recordings at SLG
Comparing the categories that Northcote Thomas used to order his anthropological data and collections with the Art Assassins’ lists of topics that reflect their own experiences in contemporary South London, and which will guide their sound collecting work.

In preparation for the exhibition in at South London Gallery in May, the group will be working with Onyeka to explore how this developing sound archive can take shape as an artwork. Some of the early ideas are to draw on the technologies and techniques of sound systems and other urban music cultures, using sampling and remixing to produce new arrangements of sound.


The Art Assassins are making a film to document their project. As part of this they are interviewing each other about their experiences. In this clip Art Assassin, Sam Baraitser Smith, reflects on the visit to the British Library and some of the issues raised engaging with the sound archives.