Showing posts with label metallurgy. Show all posts
Showing posts with label metallurgy. Show all posts

Tuesday, 2 October 2012

West African copper alloy technology: Wellcome Collection, London


 
23 September, 2012
 
For a trial period, the Wellcome Collection series The thing is … is being held on a Sunday afternoon at 3 PM.  A sneak peak at a mystery object with a tour of associated items within the Wellcome Collection is provided for the visually impaired.  For further details of this series, read on ... 
 
An Edinburgh friend accompanied me, and Catherine Walker showed us some examples of Yoruba art and objects.  We then had a preview of a copper alloy anklet which was to be discussed and were introduced to Steve Martin, a historian, writer and journalist and who was going to present the talk at 3 o’clock.   

I mentioned to Steve that I had been to the Bronze exhibition at the Royal Academy, where there were many objects from the Ife and Benin cultures.  Steve didn’t want to give too much away about the mystery objects in advance of his talk, but we had an interesting discussion about metallurgy in both West Africa and East Africa, where there have been some interesting findings regarding iron and steel production in Tanzania. 

The object itself is an anklet and has a diameter of about the size of a 12 inch LP, with a depth of about 2 inches.  An image of the object is below
 
 
Nigerian copper alloy anklet
Credit: Wellcome Collection, London


 
 
Steve was joined by Timandra Harkness, a writer and presenter.  The format is similar to the series with Quentin Cooper, with many fewer puns and though less inquisitorial, was possibly more discursive. 

The metal industry in West Africa has often had the tag diffusion attached to it.  There is always an assumption that indigenous African metal working was really a result of foreign introduction, whether from North Africa or Europe.  While many of the bronzes and Ife and Benin could be based on imported copper alloys, discoveries of the area to the east of the River Niger, i.e. south-eastern Nigeria, has shown the Igbo- Ukwu culture capable of producing bronze from local raw materials.  Apparently, there are tin deposits in the area of Joss, so a copper-tin i.e. classical bronze was made.

Traders from Europe, starting with the Portuguese, found that a money based system of ‘manilla’ could be developed.  The local Africans would use these as currencies among themselves, and these manillas were to become the trading system of much of the slave trade which was later developed by the north Europeans.  Manilla production went into serious industrialisation in first the Low Countries, then England, with Bristol and latterly Birmingham being the main source of copper alloys.  This was a shift to copper and zinc – a classic brass. 

Manillas, thus, were exported to West Africa, exchanged for slaves who worked the sugar plantations in the West Indies or the cotton plantations in the USA, with the commodities returning to western Europe.  October is Black History month and provides an opportunity for reflecting on the part base metal bashing played in part of the trade routes in the past. 

The role of the anklet viewed above was described by Steve, though whether this is a form of ornament or female enslavement within a community is debatable.  I’ve checked out a few blogs and while some proclaim that these anklets were a symbol of male dominance over the females, others appear to be more apologetic saying that ‘women liked to develop an attractive gait’.  This is a question beyond my pay grade, given my replacement hip joint (steel/ceramic) !

Steve mentioned the term ‘adala’ and the Pitt Rivers Museum in Oxford has examples of these: http://web.prm.ox.ac.uk/bodyarts/index.php/permanent-body-arts/reshaping-and-piercing/165-brass-anklets.html . 

Within the Wellcome Collection there is another spiral anklet which encompasses virtually the whole leg as far as the lower thigh and an image of this can be found on the Wellcome Image website, from which the image below has been taken:

 
Copper anklet, Ibo people, Nigeria 1880 - 1930
Credit: Wellcome Library, London
 

Conclusion

I found this a very stimulating object and talk and it neatly fits in with the Wellcome Elements series which covered gold, silver and bronze.  It also links in well with the precious metal - base metal combination raised in the recent Noble Art of the Sword exhibition at the Wallace Collection.  I attended a Study Day at the Wallace which included discussion of West  African iron production in a bloomery, with a funnel system to increase the air-flow and provide higher temperatures for iron smelting.  The current Bronze exhibition at the Royal Academy has many fine examples of West African bronze/brass work. 

I have also visited the British Museum to ‘see’ for myself the Benin bronzes in the collection on display.  The Benin bronzes were taken as booty in 1897 and examples of manillas can also be found in the British Museum. 

Little work has been done on checking the metal content of some of the alloys.  It should be easier to check copper alloys in a non-destructive way, unlike steel. 

The next talk in The Thing Is ... series is on 14th October. More information is available on:  http://www.wellcomecollection.org/whats-on/events/the-thing-is-mad-dogs-bite.aspx

To book a place or for more information, you can email access@wellcomecollection.org or call 020 7611 2222.

Wednesday, 26 September 2012

Royal Academy - Bronze exhibition

*** update 25/11/12

My 3rd and 4th visits to this exhibition are discussed in a special access post on the Royal Academy’s access programme for the Bronze exhibition, here:


These allow for further study of the subject as well as specialised access to the show.

*** end of update



*** update 7/10/2012

29th September 2012

I made my second visit to the Bronze exhibition.  Having teamed up with Marian at the National Gallery I navigated the pair of us via Haymarket, Jermyn Street, a coffee at St James, Piccadilly and then the Royal Academy.  We were both offered the audio sets and I could remember where all the described objects were. 

Marian can use a monocular and was able to read some labels, otherwise we stopped at those I could remember my friend Stephen describing and as a result, remembered so much more. 

The bronze of Perseus and Medusa is so huge that it is worth going round the plinth where the dead Medusa is sprawled out.  The lighting allows the shadow and silhouette of Perseus to sharpen up the image.   The animal section is great fun and we both enjoyed the Ram (Catalogue No 45, Roman, 2nd century CE) as it had the same pose as the Bull calf in the Veronese painting we had just viewed.  This time round, we spotted the Danish treasure from the bronze age (Catalogue No 7, The Chariot of the Sun, Trundholm, Zealand, Early Bronze Age, 14th century BCE) and I found the Krodo again.  

The exhibition was fairly busy but there were no bottlenecks apart from the entrance where visitors get used to the subdued lighting of the Dancing Satyr.  (Tip- move round slowly and if you have peripheral vision this sculpture dances.)

I got the catalogue (Bronze, edited by David Ekserdjian) which has many details and essays on the exhibition.  We spent some time on the reliefs and skipped through the Gods and Portraits.  An excuse for a third visit.

*** end of update

20th September 2012


This is a fascinating show.  It works on so many levels and there are many objects to be studied, a few to touch and some audio described items on a manageable audio system (I managed it).

My friend Stephen took me round and we spent about 3 hours going round the objects and listening to the section where the processes for casting bronze were on show.  For this exhibition the curators have used themes for bronzes rather than categorise by region, history or even genre.  If it is an animal it fits in the animal section, likewise for the human body, groups, objects, reliefs, gods and portraits. 

Some of the bronzes are huge, some are quite small but many have the ability to project a clear line which my peripheral vision picked out.  The exhibition is very well lit and many of the objects can be “viewed” as they would have been in their original setting.  The curators and the Royal Academy have statues on plinths, and Koons’ basketball is at a basket height- more or less. 

On entering the exhibition, I was offered a complimentary audio set and given instructions on how to use it. (If in doubt pressing 55 will guide you back again)  Stephen had planned my visit and we spent some time with the Satyr in the darkened (relatively) octagon.  This is a marvellous piece of sculpture and seems to defy gravity.  The satyr has lost 3 of his limbs but the other pieces have been put together and on circling the object it continues to dance.  This statue was found after centuries of being lost.  This shows the resilience of bronze as a medium for art; and several of the objects had survived volcanic eruptions by being covered in volcanic dust, debris and mud flows.  Many bronzes were carried off in war booty and melted down and some disappeared from the country of origin in a process euphemistically described as diffusion.

We then visited the process and technology section which neatly covers the art and craft debate between artist and founder.  Many artists continue to this day to take a mould to a foundry for a bronze casting.  Where the artistry begins and ends can be a pointless debate.  The skills and artistry employed in the “lost wax” process is mind blowing.  The planning of how air escapes by displacement by the molten metal amazed me as much as the chemistry and metallurgy.  The audio visual commentaries are self explanatory though the display screens may offer some extra detail for those with some vision. 

There are finished castings to touch and I found the examples of ravens’ wings fascinating.  On the wall is a huge spider by Louise Bourgeois which I could make out.   Bronze has several colour phases and can also be gilded.

It was now time to do the exhibition item by item.  I have listed some objects which we found interesting and have included the audio described objects. 

There are large print room guides and as the exhibition covers virtually all the world which had bronze cultures in the past- pre Columbian Latin America seems to be an exception- the background to objects from a diverse culture range can be challenging even to the expert.  In the object section, I encountered a Krodo from Goslar.  Stephen did not know what it was.  To me it seemed like a bronze laundry basket with ventilation holes (I also thought it was a bingo or lottery contraption piece of conceptual art, but did not voice that).  It turned out to be a bronze altar and is unique.  The audio told me what it was and this was a surprise to Stephen.  The object had caught my eye and I found the history of it to be fascinating. 

We had many enjoyable discussions round the many objects.  I have listed a few items with the catalogue number and some object label for further searches. 

There is a lot on the Royal Academy website, especially on African and Asian bronze technologies. (  http://www.royalacademy.org.uk/exhibitions/bronze/events-and-resources/further-reading,859,MA.html).  I found this pdf file (http://static.royalacademy.org.uk/files/bronze-ra-egvf1-1395.pdf) to be particularly informative.  It is quite a long read and my screenreader (JAWS 13) made a tolerable listen, as with some pdf files occasional words appear to have been joined together. 

Also, there is going to be a described session on Monday 12th November at 9 am. 


This exhibition has a lot to offer and I have scarcely scratched the patina so far.  (http://www.royalacademy.org.uk/exhibitions/bronze/)

Items we discussed:

70 Seated Figure
Nigeria, Tada
Late 13th century
Copper with traces of arsenic, lead and tin
National Museum Lagos

99-89 Compare and Contrast

89 Leonhard Magt
Cast by Stefan Godl, 1526
St John the Baptist Preaching to a Levite and a Pharisee
Opera di Santa Maria del Fiore, Florence, 1506-11
By Giovan Francesco Rustici

84 1-6, Six Weepers , 1475-76

82 Donatello
Putto with Tambourine, 1429

149 David Smith
Portrait of a Painter, 1954

18 Sardinia, Nuragic period
Capotibu (tribal chief)
8th-4th century BCE

(audio 51) Satyr
(audio 52)  Lost Wax casting
(audio 53)  23 Chimaera

111 Giambologna
Turkey, 1567-70

124 Francois Girardon Laocoon and his sons, c1690

93 + 94 Satyr and Satyress, 1532-43

63 Ottonian
Krodo Altar
Late 11th – early 12th century

(audio 54) 9 China, Shang dynasty
Vessel of the type Fang Yi, 12th century BCE

153 Jasper Johns
Painted Bronze (ale cans), 1960

1-5 Nahal Mishmar
Judean desert, Israel

Sceptre, crown, male head, cornet, vulture standard
500-3500 BCE

15 Luristan
Standard – Finial
9th century BCE

157 Anish Kapoor
Untitled, 2012

(audio 56) 48 India, Bihar
Buddha Shakyamuni in Abhaya – Mudra
Late 16 century


Postcards

Ritual Vessel of the type zun in the form of an Elephant,
Shang Dynasty, c 1100-1050 BCE
Bronze, 64 x 34 x 96 cm

Chimaera of Arezzo, Etruscan
Late sixth – early fifth centuries BCE
Bronze, 78.5 x 129 cm

Conclusion

An ingenius collection of many conversation pieces.  The well lit gallery and presentation allows those with partial sight a good grasp of the form, and the audio guide with the selected objects can lead you on to others.  The big names such as Benvenuto Cellini, Donatello, Rustici and the more contemporary works of Bourgeois, Hepworth and Jasper Johns are represented.  The unknown craftsman is pitched with some more “famous” names and in the relief section it would be hard to pick out a leopard cast by a European from an Ife casting. Even Stephen agreed with that.