Monday, 25 February 2013

Cook and La Perouse

While working on a very large barkcloth this week (1886.21.29, a barkcloth from Tahiti collected on the first voyage by Joseph Banks) I was listening to a biography of Marie Antoinette.  In her final prison of the Conciergerie the ci-devant French Queen apparently liked to read tales of foreign adventures, her favourite being the Travels of Captain Cook.  This was translated into French for Louis XVI - a special edition was made for the edification of the Dauphin.

Posthumous portrait of Marie Antoinette, the Widow Capet, in her cell at the Conciergerie

Louise XVI and Marie Antoinette had admired Cook and followed his voyages - the Queen is said to have wept at the news of Cook's death.

In 1785, Jean Francois de Galaup, Comte de La Perouse was made Minister of the Marine in France, and charged with leading an expedition around the world to complete Cook's Pacific discoveries.

Louis XVI and La Perouse (1785, Edouard Nuel)

La Perouse left Brest on the 1st August 1785, and visited Chile, Easter Island and Hawaii before sailing to Alaska, California, East Asia, Japan, Russia and the Pacific.

Map of La Perouse's voyage

After visiting Australia, the expedition was lost, and its fate not confirmed until 1964.  Both of La Perouse's ships, L'Astrolabe and La Boussole, were wrecked on the reefs around Vanikoro, in the Santa Cruz islands.  However, documents were regularly sent back to France and an account of the voyage was published in 1787 by the French Government as Voyage de La Perouse autour du monde (La Perouse's Voyage Around the World).

Friday, 15 February 2013

Every Conservators' Nemesis...

Pesticides are now no longer routinely used on our collections.  My colleague Kate Jackson, conservator at the Pitt Rivers Museum, has written a post about our current pest management systems:

1923.85.293 Textile from Nagaland, N. India, with active moth infestation

In the past, museum collections were routinely treated with pesticides in an attempt to stop the damage caused by moth, beetle and wood boring insects.  The Museum's Annual report dated 1906 boasts – ‘the addition of a fuming-room, in which specimens infected with moth and beetle may be cured, will be of great convenience, and will greatly lessen the trouble caused by insect depredations’.

Unfortunately there was no 'miracle cure’ and as it transpired the commonly-used pesticides have over time proved to be highly hazardous not only to insect pests but also to us humans and in some cases to the objects themselves. Due to the health and safety issues surrounding the use of pesticides in museums they are no longer widely used, and we must instead find alternative methods of warding off unwanted insect pests.

Up to eighty percent of the Pitt Rivers ethnography collection is made up of objects composed of organic materials such as textile, feather, fur, hair, wool, felt and skin. It is these organic materials that attract every conservator’s nemesis - the common clothes moth (Tineola bisselliella). Due to warmer winters and the decline in pesticide use over past decades the cloths moth has enjoyed a population boom within UK museums. In order to tackle the issues of moth in museums it is vital that we understand what we are dealing with.

Adult common clothes moth

The adult moth, which prefers dry, warm, dark areas, lives for between 70-80 days. The female lays her eggs within undisturbed, organic materials.  As the larvae hatch they feed for between 2-30 months (depending on environment) on any organic material close by. It is this larval stage that can cause devastation to museum objects if left undiscovered. The larvae will eventually cocoon before the adult moth emerges after 8-10 days.

There are 35 pheromone moth traps within the museum, the majority within high-risk cases, with others placed in open areas. The pheromone used on the traps attracts the male moth and the sticky surface holds the moth in the trap. Every week a conservator checks the traps and counts the number of moths caught. The number will indicate if there is a gradual or sudden rise in moth in the area, this will lead us to do a thorough search of the surrounding cases. If an outbreak is found the objects infested are sealed in bags and placed in one of our chest freezers at -30 for three days. This temperature will kill every stage of the moth whether adult, egg, larvae or cocoon. The conservator will then assess the objects, any pest debris will be removed and any damage recorded.

We also have a number of ‘blunder’ traps. These are also sticky, and would hold a blundering beetle if it wandered across the trap. Thankfully we have not had major problems with beetles or wood boring insects for a number of years. If we were to find an outbreak we would use the same freezing method, which would kill the beetle at all stages of its life-cycle.

An unaccessioned Biddenden Biscuit, with biscuit beetle damage.

Friday, 8 February 2013

More about Pesticides

In a previous blog post, I wrote about pesticide residues on museum objects, and the work being done as part of this project to attempt to identify pesticide residues on objects from the Cook-voyage collections at the Pitt Rivers Museum.  

Detail of barkcloth 1886.1.1240, showing staining and associated damage

This week, I've been taking more samples to send off for analysis.  It has been noticeable that many of the barkcloths I've conserved so far have had areas of staining on them, often associated with damage to the structure and weakening in the stained area.  We're starting to suspect that this damage might be the result of the application of pesticides in the past.  

One of the problems when thinking about pesticides and their effects is that the chemicals were available in many different formulations, with lots of ways of applying them.  These methods include dissolving pesticides in water or other solvents and spraying or misting objects, or the objects could just have been dusted with a powder. The same pesticide could have been applied in different ways at different times.

Whilst we understand that the past use of pesticides on museum collections has saved them from the devastating effects of insect damage, and, we suspect, in many cases, continues to do so, the effects of these pesticides both on objects and on those who work with the collections are not yet properly understood.

A 30x30cm area of barkcloth framed within a temporary border

Here, I am taking samples of surface residues from a large barkcloth collected in Tahiti on Cook's second voyage.  The barkcloth is about seven meters long, and there are areas of staining in several places.  I've made a frame so that I can take surface swabs from an 30cm by 30cm section - this may help us to make a rough estimate of how much pesticide remains on the surface of the entire barkcloth.

Using swabs barely dampened with distilled water to remove residues from the surface of the barkcloth

Friday, 1 February 2013

'Two fanns from the Marquesas'

1886.1.1412 (left) and 1886.1.1411 - Two fans from the Marquesas

There are two fans from the Marquesas Islands in the Forster Collection.  Listed in the appendix of the 'Catalogue of Curiosities', they are Nos. 169 and 170 'Two fanns from the Marquesas'.  They were collected on the island of Tahuata (Sta. Christina) between the 8th and the 11th April 1774.

Detail of 1886.1.1412 showing the woven fan blade, central top section

The fans (tah'i) are woven around a wooden handle, or ke'e.  Usually, grass, pandanus leaf or the leaves and midribs of the coconut palm were used to made the blades, and they were whitened with crushed coral or lime, as reported by George Forster in 'A Voyage Round the World'.

'The weather was exceedingly hot his day, for which reason many of the inhabitants made use of large fans to cool themselves.  These fans, of which they sold us a great number, were formed of a kind of tough bark or grass, very firmly and curiously plaited, and frequently whitened with shell-lime,'

Microscopic examination of the larger fan, 1886.1.1412, showed that there were white deposits in the crevices of the basketwork.   

White deposits x20

A small sample of the deposit was taken, and tested with a drop of a dilute solution of hydrochloric acid.  Bubbles were evolved, which were probably carbon dioxide.  Whilst not conclusive proof, this strongly suggests that the deposit is a carbonate, for example calcium carbonate, from which shells are made.  

A sample of the deposit reacting with hydrochloric acid (x200)

Fans were symbols of status on the Marquesas, carried by high ranking men and women, as well as warriors (toa) and ritual specialists (tau'a).  Carol s. Ivory, in 'Adorning the World - Art of the Marquesas Islands (Metropolitan Museum of Art, 2005) writes about fans, saying that that 'displayed on important occasions, especially feasts, their visual impact was enhanced by the elegant manner with which they were carried, particularly by women.'

Patini, a high-ranking female chief, drawn on Nuku Hiva by artists from the expedition of 1838 led by Dumont d'Urville.  She holds a fan in her left hand.