Wednesday, 18 September 2013

A Story of Reuse and Fermentation

This is another post written by Emma Schmitt, the Conserving 'Curiosities' project summer intern.

1886.1.1367 Paddle, Tonga

This carved wooden paddle from Tonga was listed by George Forster in 'The Catalogue of Curisoities Given to Oxford' as No 81 “A spatula of wood to mix up their paste of breadfruit with”.   

The form and shape of this object suggests that the object may have had a prior role as a dance paddle, used by men of high rank in a dance called me’etu’upaki (Kaeppler 1978). This term means ‘dance’ (me’e) ‘standing’ (tu’u) ‘with paddles’ (paki). The Forsters did not see this dance being preformed and thus probably had no knowledge of it. Cook, however, saw and described the dance during his third voyage:

‘It was a kind of dance, performed by men and youths of the first rank; ... Any number may perform it, there were in this one hundred and five, each having in his hand an Instrument shaped something like a paddle of 2.5 feet in length, with a small handle and thin blade so that they were very light and the most of them neatly made. With these Instruments, they made many and various flourishes each of which was attended with a different attitude of the body and some different movement or another They at first ranged themselves in three lines, and by different movements and motions each man changed his station in such a manner that those who were in the rear came in front. Nor did they remain long in the same form, but these changes were made by pretty quick movements; they at one time extended themselves in one line then formed into a semicircle and lastly into two square Columns, while this last was performing, one of them came and danced a harlequin dance before me with which the whole ended.’

Broken handle of paddle lashed together with plaited coconut fibre

The Pitt Rivers’ paddle has been carved from native hardwood, and it is deceptively lightweight.  It was damaged at some point, the handle breaking away from the blade completely.  It was mended using braided coconut fiber to secularly wrap the break and hold the two pieces in place.  Chips to the wooden blade are on the edge of the blade, possibly indicating a long period of use.

Tip of paddle, showing damage

This pattern of damage indicates that the paddle may not have ended its time on Tonga as the prestige item it was first meant to be.  How can an object move from a prestige object used by elite men to a utensil of daily use? In simplest terms, the very fact that this was a prestige object is what saved it for repurposing.  The time, energy and material that went into creating such and object meant that, if it could be repaired it should not be thrown away.  It was probably no longer appropriate to be used during dances, but it could be used for another task, in this case the preparation of breadfruit paste.  The spatula’s role in the preparation of breadfruit paste is difficult to discern.  Methods of paste production have been documented, though not thoroughly, and tend to vary between the islands.  

The breadfruit tree grows throughout the south pacific and was a main source of food for the population of the islands Cook visited; it was also one of the products he traded for to keep the crew of the ships provisioned.  The fruit was out of season for some portion of the year making preservation of this staple imperative for the island communities. And earlier post here provides Joseph Banks’ description of the process as well as his opinions on taste: 

Banks’ opinion aside, the description he provides is helpful, but does not give any indication as to what a spatula may have been used for.  More modern discussions of the fermentation of breadfruit provide a fuller description of the later stages of the process.  

After the breadfruit has been buried, the period of time the fruit remains in the pits is variable, from a few months to years.  In fact in the 1980’s a pit was uncovered that was believed to be over 300 years old and the paste inside was deemed “still in edible condition” (Pollan, 2013).  It must be said that this was a rare find and the definition of  “edible condition” may very between people, however, the general thought is that breadfruit paste gets better with age.  

Overall, the management of these pits differs. In some cases fresh fruit may be added to the pits, or old paste mixed with new.  In other places, paste from year to year was kept completely separate (Pollock 1984). 

The paste, when eaten, goes through a preparatory process that involves mixing it with water, kneading, and baking.  Descriptions of the fermented paste indicate that is dry and possibly hard in its fermented form.
No direct reference is made to where in the process a spatula may be used, however, there are many times with both the fermentation process and the food preparation that such a utensil may have been put to use.  These include, but are not limited to, removing the paste from the pits if old and new paste were to be layered together or if paste was needed for food.  A spatula may have also been useful while mixing the paste with water before the kneading process.  

Objects like this are incredibly important because it makes us think differently in terms of use and reuse.  Had the Forsters not recorded what they saw as the use of the paddle we would be seeing it as a completely different object, not related to food preparation at all, but to the male members of society and the role of dance on the island; completely different cultural practices that wind up coming together in this simple object.  

Beaglehole, John Cawte, The Journals of Captain James Cook on his Voyages of Discovery The Voyage of the Resolution and Discovery 1776-1780, Hakluyt Society, Extra Series, 36, 1 u. 2. vol. 3, Cambridge University Press, Cambridge, 1955

Kaeppler, Adrienne L, ‘Artificial Curiosities’ Being An Exposition of Native Manufactures Collected on the Three Pacific Voyages of Captain James Cook RN [Exhibition catalogue], Bishop Museum Press, Honolulu, 1978

Pollan, Michael  Cooked: A Natural History of Transformation.  New York, The Penguin Press 2013

Pollock, Nancy J. Breadfruit Fermentation Practices in Oceania.  Journal de la Société des Océanistes, Vol 40 Issue 79, 151-164.  1984.  

Thursday, 5 September 2013

'A Black Piece' revisited

This post was written by Emma Schmitt from the Textile Conservation MPhil at the University of Glasgow, who is the summer conservation intern on the Conserving 'Curiosities' project.

Barkcloth 1886.1.1256

'Upon arriving at the Pitt Rivers Museum I was shown the bark cloth object on which it was assumed I would spend most of my time.  The “black piece", as it was listed in Forsters Catalogue, is an interesting and singular object in many ways.  The cloth itself is constructed of three layers, two of plain white bark cloth and one of a decorated black cloth.  The decoration, similar to that seen on the headdress of the Pitt River's second Tahitian mourner’s costume, is itself, rare in form.

1886.1.1637 .9 Headdress, Tahitian mourner's costume

Detail of barkcloth on headdress

At first glace this object is a bit scary, as you can see there are many areas of loss, but on top of that the black cloth appears to be flaking apart in some areas and powdering in others.  The painted areas easily lift up from the surface of the black bark cloth taking both the paint as well as bark fiber with it.  Every time the piece moves other small fragments are lost.

Detail of 1886.1.1256 showing surface damage

The construction of the object has had an effect on some of the damage.  The layers of this cloth have been lightly pasted together.  The black bark cloth has been pasted down in a rather haphazard manner causing creases and folds to form.  These folds can be seen in the photo and, in some places, correspond to the areas where the piece has been damaged. 

Black dyed fibers overall are susceptible to damage for one main reason.  Black dyes tend to be very high in tannin and iron and thus very acidic.  In an acidic environment the fibers can break down at the molecular level eventually leading to visible damage, like we see on this object.  For the most part black dyes in the South Pacific were made using extracts of bark, high in tannin, followed by immersion in mud that would have been high in iron.  Earlier research on this cloth shows that the black portion of the cloth is high in iron, explaining why the barkcloth was breaking down. 

1886.1.1256 - detail of surface under microscope x24

On initial examination of the painted decoration it looked as if white paint had been applied to the black cloth. However, under magnification, the paint appears to have originally been black and, for an unknown reason, appears to have bloomed with a whitish powdery substance.  The question was raised as to whether or not the paint might be a Western paint, brought on Captain Cook’s earlier voyage.  Without chemical analysis of this paint this question is difficult to answer.  The fact that the paint may be black, instead of white, means that it could easily be a local resin.  This still leaves the possibility of it being a Western paint open to speculation. 

While the investigation into the piece leaves numerous questions unanswered it posed a number of conservation issues which led to some interesting experimentation. 

As mentioned, this bark cloth is in poor condition, however it is a rare piece and thus incredibly important to the Pitt Rivers collection.  When we started to discuss possible treatments consolidation of the surface was discussed, to prevent the continuing loss of the back fiber.  Consolidation is the process by which an adhesive is applied to a surface to bind a material together to prevent further loss.  In many cases this is something down to more rigid objects like flaking or powdery painted surfaces.  In dealing with bark cloth the flexibility of the cloth is important and maintaining that flexibility is key to the treatment. 

Research into different methods of consolidation led to the work of Rangi Te Kanawa, a Maori Conservator based at The Museum of New Zealand Te Papa Tongarewa.   Ms. Te Kanawa’s work focuses on the conservation of Mari Cloaks.  Her recent research has lead to the use of sodium alginate, a seaweed based gel, as a consolidate for black dyed New Zealand flax.  Her research showed that, not only did the sodium alginate bind the deteriorating fibers together, but it also had the added benefit of neutralizing some of the acids that are the result of the mud-based dye process. 

Sodium alginate has not been applied to bark cloth by Ms. Te Kanawa so it was unknown how it would affect a very different material.  We set up an experiment to see whether or not the treatment would have a beneficial effect.  Solutions of sodium alginate were made up in various concentrations.  Using fragments of bark cloth from a store of unaccessioned samples we applied the solutions to a dry bark cloth fragment with a brush and allowed them to dry.  The result of the treatment was a metallic sheen on the surface of the bark cloth samples, reminiscent of mica, and a slight stiffening of the material.  Checking of the pH of the samples before and after treatment showed that there had been no change in the acidity of the cloth. 

Unaccessioned fragments of deteriorated barkcloth consolidated with sodium alginate solutions of varying concentrations

A second test was run to see if wetting the cloth through humidification could reduce the metallic sheen.  It was hoped that by wetting the cloth first, the sodium alginate would be drawn into the bark cloth, thus leaving less on the surface.  This treatment was successful in reducing the sheen, however, a test of the pH showed that there was still no change in the acid levels and the fabric still retained the slight stiffening see in the original tests.

Overall the experiment showed that this type of treatment may not be appropriate for bark cloth.  This may be because of the structure of the fabric as the beaten fibers lack the directionality seen in woven fabrics and thus move differently.  The lack of affect it had on the acidic pH as well as the metallic sheen and change in handle made the treatment less than ideal for “the black piece” collected by the Forsters.  An object of such importance and rarity should be treated in a way that is safe and will not visually change the object.   In the end, ‘the black piece’ had a custom-padded board and box constructed for it that will allow it to lay flat and be stored safely, in hope that in the future a treatment may be able to stabilize it and preserve it for future generations.'