вторник, 25 февраля 2020 г.

100 years of science and conservation

2020 marks 100 years since the creation of the 'Research Laboratory' – a space for developing and conducting scientific research and conservation on the British Museum collection. Museum staff were quick to recognise the value of the laboratory’s work and, over the past century, scientists and conservators at the Museum have performed painstaking, groundbreaking work to improve our understanding of the collection and to care for it for the benefit of future generations.

To kick-start our year of celebration, we’re pleased to share some of our favourite stories from recent years. We hope you enjoy them. Please keep an eye out over the coming months as we share recent conservation success stories, the latest applications of scientific research and report news of the latest work from both the Scientific Research and Collection Care teams.

Carl Heron, Director of Scientific Research and Sandra Smith, Head of Collection Care

Breaking down black 'goo'

Research Assistant Dr Kate Fulcher's analysis of the mysterious black 'goo' found in ancient Egyptian coffins, on the Museum podcast, makes for compelling listening. After analysing “crumbly black stuff” (her words) found in tombs at Amara West for her PhD, Kate was inspired to continue looking into unusual funerary substances, and so began to research mummy goo.

The goo – a black liquid that was applied to coffins during funerals – was poured over the outside of the coffin, the mummy case (the box between the mummy and the coffin), or the wrapped body itself. In some cases, the dead person had only a small amount of goo poured onto their face, in others a large amount was poured into their coffin.

Mummy of Pedihorpakhered in wooden coffin. Thebes, Egypt, 22nd dynasty (945 – 720 BC).

Gas Chromatography–Mass Spectrometry (a type of chemical analysis) revealed that the goo is made up of plant oils, animal fat, beeswax and bitumen. The analysis was performed on tiny samples, so Kate and her team were able to understand the components of the goo while still leaving the coffins entirely intact.

Mummy of Djedkhonsiufankh in wooden coffin. Egypt, 22nd dynasty (945 – 720 BC)

You can hear more about Kate's work on black goo in the May episode of the Museum podcast, or read her blog here.

Kate's research is funded by the Wellcome Trust.

Exploring X-rays

Not many people know that the Museum has its very own X-ray lab, headed up by Dr Dan O'Flynn – X-ray Imaging Scientist and self-styled Curator of Photons. It sits four floors down, in the bowels of the Museum, and was purpose-built with extra-thick walls to prevent X-rays leaking into the building. An incredible six metres tall, the X-ray room itself is large enough to house even the largest objects in the collection and the equipment can support weights of up to 2,000kg.

Dr Dan O’Flynn at work in the Museum’s X-ray lab.

Dan's findings include information about the assembly of the Townley Discobolus, showing how the limbs of the 800kg ancient Roman statue were attached to the body. This information is particularly pertinent to the statue’s outstretched throwing arm which comprises several fragments joined together and is otherwise unsupported. Identifying if and where metal dowels have been used inside a joint means that the stability of the object can confidently be assessed. This helps conservators determine what treatment the object requires so they can ensure its safety for future display.

The Townley Discobolus in the X-ray room.

But it's not just large objects that benefit from a trip to Dan's lair; X-ray imaging has revealed mummified snakes hiding inside an ornately wrapped ancient Egyptian bundle, the cuneiform writing on a 4,000 year-old tablet sealed in clay, and even the contents of a Kinder Surprise.

You can hear more about what it's like in the X-ray lab on the September 2019 episode of the Museum podcast.

CT-scanning Afghan sculptures

At the end of 2019, curator St John Simpson told us how the Museum is helping to identify and return looted objects to Afghanistan, Iraq and Uzbekistan. Among the 2,345 objects that the Museum has helped to return over the past decade are a group of Buddhist sculptures from Afghanistan. Seized as part of an operation involving the Art and Antiques Unit of the Metropolitan Police, the sculptures were brought to the Museum for identification. They date from between the fourth and sixth centuries AD, when Buddhism was the main religion in Afghanistan.

Seized Buddhist sculptures on temporary display in Room 53.

St John explained how scientific analysis – carried out by Dr Joanne Dyer – of the 1,500-year-old stone sculptures revealed the nature of the pigments used on the objects' heads. Through this work we were able to ascertain that the red pigment was made from iron-rich ore and applied over a carbon black layer to deepen the colour. The sculptures were also CT-scanned to determine how the heads were made. The scans revealed a two-layered construction: a centre of coarse clay, overlaid with a finer and more compact material which was then painted.

(L) Moulded and painted clay head of a female bodhisattva wearing a diadem (crown).
(R) Image highlighting the red pigment.
Decoding ancient tattoos

In 2018 the Museum made headlines around the world with the discovery of the oldest figurative tattoos in the world. Curator of Bioarchaeology Daniel Antoine (who works closely with the Department of Scientific Research) and his team used infrared scanning of two 5,000-year-old natural mummies – known as 'Gebelein Man A' and 'Gebelein Woman' – to reveal a range of tattoos on the pair.

Curator of Bioarchaeology Daniel Antoine explains how his team discovered the earliest known figurative tattoos in the world.

Both mummies were discovered around 100 years ago, but the markings on the pair remained unexamined. When Daniel's team re-examined them for signs of body modification, they found that Gebelein Man A has a tattoo of two horned animals on his arm. These have been identified as a bull and a Barbary sheep.

Detail of S-shaped tattoos on the Predynastic female mummy from Gebelein.

The Gebelein Woman has a series of 'S' shapes on her shoulder – a motif also found on pottery of the same period. Below it, on her arm, is a linear design, perhaps a baton for a ritual dance or a crooked stave, symbolising power.

More science and conservation stories

We'll be sharing our favourite Conservation projects and revealing new work from both the Department of Scientific Research and the Department of Collection Care over the coming year. Stay tuned to find out more about the amazing work that goes on behind the scenes here at the Museum to help us care for the collection and continue uncovering stories from history.

If you’d like to find out more about any of the terms used in this blog, head to our Scientific Research, Care of Collection and Conservation glossary.

To read the article in English. blog.britishmuseum.org

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