The influence of temperature on rehydroxylation [RHX] kinetics in archaeological pottery

Almost all archaeological ceramics undergo slow, progressive rehydroxylation by chemical combination with environmental water. The reaction is accompanied by an expansion, and also by the small but measurable mass gain that provides the basis of the RHX dating method. The rate of the RHX reaction increases with increasing temperature. Here we describe comprehensively the effects of temperature on the RHX process in relation to the dating methodology. We deal in turn with the kinetic model of the RHX reaction, the temperature dependence of the RHX rate, and the influence of varying environmental temperature on the RHX mass gain. We define an effective lifetime temperature and show how this is calculated from an estimated lifetime temperature history. Historical meteorological temperature data are used to estimate the lifetime temperature history, and this can be adjusted for long-term climate variation. We show also how to allow for the effects of burial in archaeological sites on the temperature history. Finally we describe how the uncertainties in estimates of RHX age depend on the estimates of temperature history and effective lifetime temperature.     

Reviews

Sam Smiles, The Image of Antiquity: Ancient Britain and the Romantic Imagination, New Haven and London: Yale University Press, 1994. x + 252 pp., 128 b. & w. illus. ISBN 0–300–05814–4. £35.00.

Marcia Pointon (ed.), Art Apart: Art Institutions and Ideology Across England and North America, Manchester and New York: Manchester University Press, 1994. 292 pp., 39 b. & w. illus. ISBN 0–7190–3918–5. f 10.99.

Daniel J. Sherman and Irit Rogoff (eds.), Museum Culture: Histories, Discourses, Spectacles, London: Routledge and Minneapolis: the University of Minnesota Press, 1994. xx + 301 pp., 26 b. & w. illus. ISBN 0–415–09274–4. £14.99.

Sheena Mackellar Goulty, Heritage Gardens. Care, Conservation and Management, London and New York: Routledge, 1993. 176 pp., 82 b. & w. illus. ISBN 0–415–07474–6. £19.99.

Anne Fahy (ed.), Collections Management, London and New York: Rontledge, 1995. xii + 304 pp., 2 figs. ISBN 0–415–11283–4. £19.99.

Annie E. Coombes, Reinventing Africa: Museums, Material Culture and Popular Imagination, New Haven and London: Yale University Press, 1994. vii + 280 pp., 112 b. & w. illus. ISBN 0–300‐ 05972–8. £35.00.

Lesley Hoskins (ed.), The Papered Wall. The History, Patterns and Techniques of Wallpaper, London: Thames and Hudson, 1994. 256 pp., 185 col. and 157 b. & w. illus. ISBN 0–500–23695‐X. £32.00.     

Capturing Understanding of Women’s Embroidery Designs: A Methodology for Research and a Critique of Cataloguing Databases using the Example of Women’s Embroidery in Nineteenth-Century Britain

Daughter of a merchant, the amateur designer and embroiderer Sarah Bland came from an upper-middle-class family. She made an album of a collection of drawn and printed designs between 1835 and 1854 that includes her original designs, patterns traced from magazines, and commercial, printed designs for Berlin wool work. This case study explores her kinship networks, social context and environment as well as perceptions of a woman’s role. It concentrates on Bland’s designs, both made and collected, and compares these to her botanical illustrations, made while she was staying at St Leonards-on-Sea on the south-east coast of England from 1835 to 1843. These pieces are now held at the Victoria and Albert Museum, and the Museum’s database is discussed in relation to other systems to explore its potential for cataloguing such designs as well as its shortcomings. This article posits that art historical databases can be used to catalogue designs for embroidery with a method which is both sensitive to gender and socially contextual. This allows women’s history in relation to designs for embroidered textiles and dress to emerge.     

Māori Textiles from Puketoi Station,Otago, New Zealand

Abstract

A group of Māori textile artefacts were discovered in a rock shelter in the southern South Island of New Zealand in 1895. The assemblage comprised a significant number of textile and textile-related artefacts including large and small bags, footwear and prepared leaf and fibre for textile production. The artefacts were privately owned until the 1920s when they were acquired by the Otago Museum, remaining there until new techniques made further investigation possible. This paper presents information from an interdisciplinary investigation of the Puketoi Station assemblage of textile artefacts, which examined artefact structure, form and function, and materials of construction. Interpretation of these artefacts using contemporary textile analysis methods, traditional weaving knowledge, and recent archaeological research, turns them from static objects into dynamic components of culture. The Puketoi Station artefacts embody and illustrate a unique material culture associated with the late prehistoric southern New Zealand Māori lifestyle.