Studying the process of enamel powder preparation for émail champlevé by colour measurements and μ‐X‐ray mappings

Colour measurements and non‐destructive μ‐X‐ray mappings have been used for the first time in a comprehensive study of medieval émail champlevé works from different production areas in France and Germany. This approach has given a new insight into the enamel powder preparation process of the glass material used for enamelling. Colour measurements demonstrated that all production centres used glass of very similar hues, but with large differences in colour saturation. The μ‐X‐ray mapping results of blue enamels are described by a semi‐qualitative approach. Significant variations in oxide contents of lead, cobalt, manganese and antimony oxides were found. The variations suggest that more than one glass material was used to prepare the powder for enamelling. The variations in antimony and cobalt show that glass had different degrees of opacity and colour depth. The manganese and lead contents, which do not correlate with the cobalt or antimony contents, indicate that probably glass of different base compositions was used to prepare the enamel powder for one champlevé field.     

清代皇家雅曼达噶神坛丛考

“雅曼达噶”即大威德金刚,是藏传佛教重要的护法神。本文考证了乾隆时期所建的七处皇家“雅曼达噶坛”,分析了神坛的建筑特点与文物陈设状况,理清了这种重要的佛堂模式的特点。同时探讨了清富神坛与西藏寺庙的渊源及乾隆与藏传佛教的关系。藏传佛教中神灵众多。有一个庞大的神系。乾隆皇帝建七处雅曼达噶坛。说明了清宫廷对保护神大威德的特别崇拜,这种做法来自藏传佛教格鲁派的直接影响。由此种神坛之模式可见藏传佛教曾对清代宫廷的文化环境产生过深刻的影响。     

Degradation processes in colourless Roman glass: cases from the Bocholtz burial

A group of Roman glass objects from the Bocholtz burial in the SW of Limburg (The Netherlands) was found to have been subject to varying degrees of degradation. Many of the 25 colourless glass objects were fragmented to pieces <0.1 cm (“sugared”), whereas the three transparent blue-green glass objects were in near-pristine state. Analyses using SEM, XRF and EDS revealed that the fragmentation was the direct result of the intense leaching of Na₂O from the glass structure and its replacement with water. The resulting gel layers with low-Na₂O contents and large amounts of water are sensitive to cracking when they dry out. Thin-walled glass appears to be less sensitive to cracking from the resulting stress than thick-walled glass. Local differences in the moisture regime during burial also influence the severity of the glass degradation. Glass with low concentrations of CaO seems to be the most sensitive to this form of degradation. The typical blue-green Roman glass is less sensitive as it generally has considerably higher concentrations of CaO.     

美术学水彩画专业方向教与学解析

从分析水彩画教学的教育理念和影响水彩画教与学的二个方面,来培养学生的创新精神与绘画能力为重点来全面实施水彩画教与学。     

康熙朝雕漆初探

康熙朝有无雕漆,一直悬而未决。本文通过对故宫博物院所藏7件雕漆作品的造型、漆色、雕工、装饰纹样、款识等多方面的分析,认为康熙朝有雕漆,并推断为苏州制造。     

Mapping race and gender in the academy: the experiences of women of colour faculty and graduate students in Britain,the US and Canada

This paper examines the experiences of women of colour in geography. An analysis of qualitative, open‐ended questionnaires with women of colour geography faculty and graduate students in North America and Britain suggests that policies and practices within geography departments continue to reflect a pervasive persistence of racialized and gendered inequities in the workplace. There has been relatively little application of theoretical work on race and gender to the minority experience within geography. Some strategies suggested to challenge racialized and gendered barriers that limit women of colour's full participation in geography include a proactive recruitment programme, diversification of the curriculum and development of mentoring.     

Optical spectroscopy as a rapid and low-cost tool for the first-line analysis of glass artefacts: a step-by-step plan for Roman green glass

Archaeometric research on glass artefacts is continuously evolving and is converging towards a multidisciplinary research domain where different types of techniques are applied depending on the questions asked and the circumstances involved. The technique described in this work is optical spectroscopy. The benefit of this technique being the possibility of building up a knowledge database for a large amount of material in a relatively short period of time and with a relatively limited budget. This is of particular interest for the investigation of extensive and/or unexplored glass collections where a first-line analysis of artefacts could facilitate the selection of material needing further and more detailed examination.     

New books received for review

Abstract

Geological information was first printed in colour on a map in 1820 but serious efforts to print geological maps in multiple colours began in Europe only in the 1840s. Increased geological mapping activity created the need to print more maps by cheaper methods, while general advances in lithographic colour printing provided the means. Better colour registration, transparency, range, permanence and distinctiveness were attained in the 1840s and 1850s by technical innovations and also by new design strategies. Consequently, as printed colour replaced hand colour as the norm, it also influenced the look of the geological map.     

Experimental Heating of Moravian Cherts and its Implication for Palaeolithic Chipped Stone Assemblages

The applicability of colour, magnetic susceptibility and remanent magnetization measurements for the identification of heated or accidentally burned Palaeolithic cherts from Moravia (Czech Republic) is tested in this study. We conclude that all these methods are usable. Colour changes are best detectable in materials heated at between 250–350°C, while magnetic susceptibility and remanent magnetization change at higher temperatures, closer to 600°C. This latter temperature, however, is usually destructive for cherts and is probably evidenced by accidentally burned artefacts. With the use of the three methods, we managed to identify three probably heated chert artefacts from two early Upper Palaeolithic assemblages from Moravia.     

Skin, hair and cloth remains from the ancient kerma civilization of Northern Sudan

Animal skins from human burials, dated 2nd and 3rd millenium BC, including haired skin bags lined with cloth, provided evidence of ox, goat and sheep, the cloth being made of plant fibre, possibly flax. Two thirds of the skin samples had evidence of vegetable tanning. Of 18 samples of livestock hair or skin 61% were from cattle with the remainder being about equally shared between goats and sheep. The hair diameter distributions indicated that all had been killed in late summer. Only two colours, black and white, were presented in each livestock species. That the sheep were of hair type accords with the use of plant fibre in the cloth, and is in keeping with the later appearance of fleeced sheep in the Egyptian New Kingdom.