A part of this project to conserve and investigate the
Cook-voyage collections at the Pitt Rivers Museum is to attempt to
identify the materials from which the objects are made. Knowing what artefacts are made from can help us find out where they were collected. Although
the Catalogue of Curiosities gives us fairly good information about
this, sometimes there is still confusion, as in entry No. 98. 'Nine
different kinds of necklaces; together with three mother of pearl shells
which hang on the breast.' Although
this entry appears in the section entitled 'The Friendly Isles' (Tonga)
not all of the necklaces come from there - some, in
fact, were thought to be from New Zealand.
Information
about materials comes from various sources - the Forsters sometimes
mention what the objects they collected were made from. Curators
and researchers have added information over the years - but sometimes
materials are very similar and only close observation under the
microscope can distinguish them. Plant fibres come into this category, which brings me back to the nine necklaces which are part of Forster No. 98.
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| Nine necklaces, part of Forster No. 98 |
The necklaces are all made from beads of various kinds, threaded on cords made from vegetable fibre. If the necklace is from New Zealand, the fibre will probably be from New Zealand flax (Phormium tenax - harakeke). This
plant did not grow on Tonga in the Eighteenth century - the Tongans
used a plant in the nettle family, Pipturus argenteus (olonga) to make a
fine cord, also used in the manufacture of fish hooks and nets.
Samples consisting of a single fragment of fibre were taken from the cords of all of the necklaces. The samples were dehydrated in ethanol, and then washed in toluene before being mounted on slides in Numount, a synthetic mounting medium intended as a replacement for Canada Balsam. The samples need to be washed in toluene, which is the solvent for Numount, because ethanol would make the Numount go cloudy.
Samples of loose fibres were taken from several Maori
objects in the Cook-voyage collections, as examples of aged New Zealand
flax fibres, and also from Tongan fishing hooks and a fishing net - likely to be samples of olonga.
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| New Zealand flax fibres, x100 |
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| New Zealand flax fibres, x400 |
Comparison
of the 'known' samples under the microscope, using crossed polars
showed the the two fibres are quite distinct - the
olonga fibre in
particular has characteristic diagonal lines on the surface which may be
a result of varying thicknesses within the cell wall.
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| Olonga fibres, x100 |
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| Olonga fibres, x400 |
The samples taken from the necklaces could then be compared with the 'known' fibres. The
cords of those considered stylistically to come from Tonga were all
made from olonga fibre, and those thought to come from New Zealand were
made from harakeke. One necklace was the subject of debate, but the fibre proved to be olonga, suggesting that it came from Tonga.
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| Fibres from necklace 1886.1.1575, x100 |
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| Fibres from 1886.1.1575, x400 |
