'A glaring ornament'

Forster No.133 Mus. No. 1886.1.1269

This breast ornament was collected on Tahuata in the Marquesas in April 1774.  Forster, in 'A Voyage Round the World' describes this 'glaring ornament', saying that 'their leaders wore a kind of gorget around the neck, or rather on the breast; it consisted of small portions of a light wood, like cork, glued together with gum, in a semicircular form; a quantity of scarlet beans (abrus precatorius, LInn.) are glued all round it with the same gum, forming a great number of rows, of the length of two or three inches.'

The gorget, known as a tahi poniu, is made up of seventeen sections of wood.  The red and black abrus seeds have been set in a thick layer of brittle brown resin, said to be gum from the breadfruit tree.

Microscope image of gum

As part of this project, samples of the gum were taken and will be analysed by scientists at the University of Bristol.

Sampling from 1886.1.1269

The gorget is missing quite a few seeds - even in 1884 when the collection was transferred from the Ashmolean Museum it was noted that 'many of the berries have come off this ornament and have been stuck from time to time with glue and many are wanting,particularly from the back edge.'  The back of the gorget has been extensively repaired, with new sections of plywood added to replace missing or damaged areas.  This was done before conservation records were kept.

The back of the gorget.  Replacement plywood rays can be seen near the top of the image.

Investigating objects

Last week, two of our project partners visited us in Oxford.  Professor Richard Evershed from the University of Bristol came with his postdoctoral student, Lucy Cramp, to take samples of resins from various objects in the Cook-voyage collections.  They will use powerful techniques such as gas chromatography, followed by mass spectroscopy to try and give more information about which plant resins were used.  These analytical techniques require very small samples, and, under the microscope, there are usually tiny loose pieces of resin which can be carefully removed using the end of a scalpel blade.

Removing a sample of resin from a chest ornament, Marquesas (1886.1.1269)

Andrew Charlton from the Food and Environment Research Agency (FERA) also came to the museum last week.  Andrew specialises in the effect of pesticides on wildlife, and the purpose of the visit was to work out a method of taking surface swabs from objects so that he can test them for pesticides residues.  We know that objects in the Pitt Rivers, as in all other museums, were routinely sprayed with pesticides, including arsenic, mercury and more recently developed chemicals such as DDT, to prevent insect attack.  We are interested in finding out if there are residues of these chemicals on the surface of museum objects.  The Cook-voyage collections have been in Oxford since the 1780s so we'd expect a wide range of pesticides to have been used on them.

Jeremy with Kloe Rumney, conservation intern from Cardiff University, taking samples from the surface of a Tongan mat (1886.1.1175)