COMPARING GLASS COMPOSITIONAL ANALYSES*

In a recently published study of Romano‐British colourless glass compositions, using inductively coupled plasma spectroscopy, 28 glasses from Colchester sampled in a previous study were resampled. This was done deliberately, with a view to examining the repeatability of results from sampling on different occasions. We report on our results here, developing in the process some simple statistical methodology that could be applied in similar situations. The potential for combining analyses undertaken at different times is discussed and illustrated.     

AN ASSESSMENT OF COMPOSITIONAL AND MORPHOLOGICAL CHANGES IN MODEL ARCHAEOLOGICAL GLASSES IN AN ACID BURIAL MATRIX

The degradation mechanisms of glass in a buried context result in surfaces that have been depleted in various elements. The stability of the glass is primarily affected by the burial environment and the glass composition. However, in all archaeological glasses, the corroded layer that is formed on the surface tends to be low in alkalis, high in silica and lacking in cohesion. The extent to which the material has degraded, along with the physical nature of the corrosion, has a profound effect upon a wide range of factors affecting the stability of artefacts, as well as the choice of conservation techniques to be employed. This study has a number of objectives: determination of the morphology of the surface of the leached layer in glasses of two different compositions with different surface finishes; examination of the transition between the corroded material and the unaffected substrate; and investigation of concentration profile of different elements within the surface layers, as a function of depth. The study uses two glasses, fabricated under laboratory conditions, to replicate two common glass types found in the historical environment; a soda–lime–silica glass typical of those found in the Roman period throughout the Mediterranean and northwestern Europe, and high‐lime–potash glasses typical of those of Western Europe in the late medieval period. Three different surfaces have been prepared to mimic alternative manufacturing techniques such as blown, cast and ground surfaces for each composition. The glasses have been corroded under controlled laboratory conditions to replicate the buried environment. Imaging and chemical information is obtained using SEM–EDX and morphological information using IFM to produce 3‐D mapping from topographical surfaces.     

Missions on the Frontiers of Spanish America

This article examines missions as a colonial institution on the fringes of Spanish America. The Spanish Crown employed the mission as a cost-effective form of converting to Catholicism native peoples living on the frontiers of Spanish America, and incorporating them into the new colonial social and economic order. The article compares missions in northern Mexico, the Río de la Plata region, and eastern Bolivia.     

MAKING COLOURLESS GLASS IN THE ROMAN PERIOD*

This paper discusses the compositional analysis of Roman colourless glass from three sites in Britain. The findings suggest that two broad compositional groups can be identified on the basis of the choice of the initial raw materials selected for glass production, in particular the sand. The largest of these groups is inherently different from the naturally coloured, blue–green glasses of the same period, while the other group is compositionally similar. Further subgroups are apparent on the basis of the decolorizers used. These glass groups are explored in the light of the current theories concerning the organization of glass production in the Roman world.     

GLASS BY DESIGN? RAW MATERIALS,RECIPES AND COMPOSITIONAL DATA*

Compositional analyses of ancient and historic glasses have often been interpreted in terms of the use of specific raw materials in glass manufacture. However, the known inhomogeneity of many glass‐making raw materials and the insolubilities of some compounds make any explanation of compositional data problematic. This paper looks at three glass‐making alkalis with a view to understanding how the compositions of these raw materials are carried through to the final glass. The chemistry and variability of the raw materials are discussed, as is their contribution to the final glass composition. In addition, the choices and decisions made by glassmakers are acknowledged in the final glass compositions. This combination of factors addresses the complexity of predicting the use of specific raw materials from the finished glass composition.     

From colonialism to theology: encounters with Martin Wight's international thought

Martin Wight's writings range far more widely than those of most leading historians and theorists of International Relations. His thought escapes from the parochialism of particular academic disciplines and departments. It also escapes from the provincialism of the present, our preoccupation with immediate issues of foreign policy, which is a preoccupation with ourselves and our society. He grappled with some of the great questions of his era, from colonialism to nuclear war. But in doing that he tried to get beyond his time, by recalling other times when similar questions were current. The mark of a leading thinker and writer is the heavy weight of his thought on his readers. Martin Wight's writings left me with a number of ideas and suggestions the accumulative effect of which is the view I hold of International Relations.     

The case of the World Trade Organization

This article explores the relationship between power and rules within the context of international relations, utilizing as a case‐study what is arguably the most powerful international juridical institution in the world today, the World Trade Organization (WTO). The author draws upon a number of his previous works on the subject of the WTO and its predecessor, the GATT, wending through such topics as: the way that political and diplomatic leaders improvized and filled in the gaps of international institutions when the original idea for an International Trade Organization (ITO) failed; the remarkably elaborate development of the particularly deep and rich WTO Dispute Settlement (DS) jurisprudence (over 60,000 pages); and the constant tension between the role of nation‐state power and the power allocated to international institutions, apparently necessitated by the huge impact of ‘globalization’ and interdependency in world affairs (especially economic) today. Various specific issues and cases illustrate these tensions and allocations, including treaty interpretation techniques, the degree of deference towards the members’ government actions, the arguments about the appropriate role of the ‘adjudicators’, and the delicately sensitive approach of the DS system towards clashes of policy necessitating ‘balance’. Throughout, particular emphasis is laid upon the ‘rule oriented’ (‘more legalization’) approach of the WTO DS jurisprudence, both in reflection on the historical and current developments of that juridical system—from ‘power oriented’ to ‘rule oriented’—and also in the important roles regarding tensions between ‘sovereignty’ concepts and international rule needs.