Boole Reviews

Abstract

The roof of the Archaic Temple of Poseidon (early 7th century B.C.) at the Sanctuary of Poseidon on the Corinthian Isthmus in Greece was covered by unusually large terracotta tiles. The construction of a stone temple with a tile roof represented a major advance in building design. The tiles themselves are representative of the growth in technology at that time. Reproduction of the tiles was recently undertaken as a demonstration of the tools, skills, and manpower requirements of the new technology. It is shown here that a relatively small group of men using local materials could make all of the tiles and the kiln(s) to fire them in less than two years. The major innovation was the design of the mold.     

Neutron tomography for the assessment of consolidant impregnation efficiency in Portuguese glazed tiles (16th and 18th centuries)

Neutron tomography (NT) has been applied to visualize the inner structure of ancient Portuguese glazed tiles undergoing conservation treatments. Neutrons have the advantage of interacting strongly with hydrogen, so NT is able to map hydrogenous compounds with high sensitivity. The present study explores its potential for assessing the distribution of the consolidant Paraloid B-72 inside tiles, to evaluate the efficiency of two different methods of treatment: brushing and immersion in solution. Using a prototype NT setup at the Reactor Português de Investigação (Sacavém, Portugal), each two-dimensional image is obtained from a 90 s exposure, at a thermal neutron flux of 2 × 10⁵ n cm⁻² s⁻¹ at the irradiation site. The neutron beam has a diameter of 5 cm, so fragments with outer dimensions up to 4.8 cm can be inspected. Samples are automatically rotated by an angle of 0.9° between successive images. Images were obtained before and after the application of the consolidant. The results obtained show that: (i) NT is a useful tool for visualization of the inner structure of ancient glazed tiles, and to assess penetration depth of consolidant and its distribution inside the tile; and (ii) brushing with 10% Paraloid^® B-72 in acetone solution appears to be more efficient than immersion. Neutron tomography showed a greater and more uniform retention of resin inside the tile if the brush is used to apply the consolidant, to increase the cohesion of the object.     

Medieval Floor and Roof Tiles from Melrose Abbey,Scottish Borders,and the ‘Westminster Tilers’

Abstract

AN ASSEMBLAGE OF more than 2500 fragments of tile was recovered from within the precinct of Melrose Abbey during excavations in 2009. The collection includes a large group of decorated floor tiles, the designs of which have links with the ‘Westminster School’, and which are unlike any other previously excavated at the abbey. This paper places the group in context and considers the implications of the find.     

STUDIES OF CERAMIC TILES ATTRIBUTED TO GABRIEL DEL BARCO

This study reports the mineralogical and chemical characterization of the ceramic body of tiles created by Gabriel del Barco, an important tile painter in Lisbon from the 17th century. Six tile panels were studied: four are signed and two are attributed to the painter. The results obtained from the signed panels revealed that the samples have almost the same characteristics, with a magnesium‐rich phase, meaning that the artist, or the pottery where the tiles were made, kept to the same manufacturing procedure over some time. In contrast to this, the results of samples from the masterpiece Vista de Lisboa showed some heterogeneity, as two patterns were observed. However, one of these patterns matches with the one observed in the signed tile panels. Although a more detailed study still needs to be done, these findings, together with historical sources linked to painting characteristics, suggest that Gabriel del Barco was also the author of the non‐signed tiles.     

A Late 13th and Early 14th-Century Tile Factory at Danbury,Essex

THE EXCAVATION of a practically complete medieval tile factory, in operation between c. 1275/85 and 1325/35, is described. The establishment comprised three buildings, interpreted as workmen's accommodation (A), a workshop (B), and a drying shed (C), together with two kilns, within a ditched roadside enclosure. The kilns were of the normal type, with two parallel flues; one had a walled stokepit reached by a tile staircase. The methods of tile manufacture and firing are discussed, the conclusions being partially supported by experimental evidence. The patterns of the decorated tiles are seen as derivatives of the Chertsey-Westminster School, mostly via the 13th-century ‘Central Essex Group’; a relationship with Penn is also suggested. Distribution of Danbury products is largely confined to the Chelmer valley, but a waterborne distribution is suggested by a group of floor tiles from Virginia Water, Surrey.     

WHERE DID THE LUSTRE TILES OF THE SIDI OQBA MOSQUE (ad 836–63) IN KAIROUAN COME FROM?*

Metallic lustre decoration of glazed ceramics is a very special kind of ornament, because its colours change with the observational conditions. In diffused light, they can be green, brown or ochre–yellow. In specular reflection, they show an associated coloured metallic shine (blue, golden‐yellow or orange). The lustre tiles at the Sidi Oqba Mosque in Kairouan still have no defined origin (possibly Kairouan and/or Mesopotamia). Physicochemical analyses of eight Kairouan lustre tile samples and four Mesopotamian lustre pottery samples show that the Kairouan tiles probably came from Mesopotamia, from a major production centre, possibly Baghdad, Samarra or Basra.     

北京故宫和辽宁黄瓦窑清代建筑琉璃构件 的比较研究

为了更好地揭示清代不同地区建筑琉璃构件的原料、烧制工艺及其性能关系,本工作以北京故宫和辽宁黄瓦窑清代建筑琉璃构件为研究对象,利用WDXRF、EDXRF测定琉璃构件胎、釉的化学组成,利用热膨胀仪和理论计算方法测试计算胎、釉的热膨胀系数。在此基础上,研究了两地清代建筑琉璃构件胎釉的化学组成规律和胎釉热膨胀系数的匹配性关系。结果表明:两地琉璃构件釉料的化学组成基本一致,而琉璃构件胎体原料不同,北京故宫清代琉璃构件胎体化学组成属于硅-铝体系,辽宁黄瓦窑的琉璃构件则属于硅-铝-镁体系,因此两地胎釉热膨胀系数的匹配关系也不同。     

David Evans & Co. The Last of the Old London Textile Printers

Abstract

The Glasgow 'Tobacco Lords' were the subject of a classic study, but there has been no overall survey of their successors, the Scottish cotton masters. This article draws on a rich and surprisingly underused source, the wills and probate inventories of Scottish cotton merchants and manufacturers, to give a fuller picture of a group, which played a key role in Scotland's early industrialisation. It also casts light on the early decline of the cotton industry in Scotland by demonstrating how, as profits declined, the cotton masters, who had always had diverse business interests, began to move into more lucrative areas of investment, such as coal mining, iron manufacturing, railways, shipping and overseas trade.     

Paper 6: Grouting Mortars for Fragmented Bricks and Repair Mortars for Tiles in the Archaeological Site Coudenberg

Abstract

Different grouting and repair mortars were developed and evaluated for the conservation and restoration of fragmented bricks in the walls and floors of the remaining cellars underneath the Aula Magna, the palace’s main banqueting hall, and to fill the lacunae and perform edge repairs of red and blue-grey ceramic floor tiles in the remaining cellars underneath the chapel of the former Palace of Coudenberg in Brussels, Belgium.

To prevent the deposition of lime bloom at the surface of the masonry and to achieve an acceptable colour match of the grout in harmony with the bricks of the Aula Magna, the effect of brick powder added to natural hydraulic lime was studied. The pozzolanic properties and colour match of several historic and modern powdered bricks were investigated. Surprisingly, ancient bricks do not seem to possess higher pozzolanic properties than the more modern ones, although it is supposed that they were fired at lower temperatures. Additional evidence for the pozzolanic reaction of the different brick powder materials was obtained from a simple visual observation of stored samples. After eight weeks all of the samples containing brick powders, fired at low and high temperatures, added to putty lime had hardened under water and were transformed into a remarkably tough material. These results are important, as modern bricks are readily available in large quantities and different colours, which are hence in favour of being used instead of historical material from the site.

For the repair of the ceramic floor tiles different mortars were investigated with mixtures containing talcum, stone or brick powder, pigments, and chalk added to an epoxy binder. The mortars were tested in the laboratory and in situ for their workability and resemblance with the historic floor tiles. The finished mortars showed excellent aesthetic properties with the tiles in situ and good properties to prevent further loss due to human interaction.     

The Glaze Technology of Hispano‐Moresque Ceramic Tiles: A Comparison Between Portuguese and Spanish Collections

For the first time, Hispano‐Moresque glazed tiles from Portuguese and Spanish collections were studied together and compared. This work is included in a wider study tackling the technology of Hispano‐Moresque tile production from several collections in the Iberian Peninsula. While showing many similarities, differences were identified between collections, regarding both chemical and morphological characteristics. The collection from the Mosteiro de Santa Clara‐a‐Velha (Coimbra) stands out from the other collections, with higher SnO₂ content (up to 14 wt%), the highest Fe₂O₃ contents in amber glazes and a Ca‐rich interface layer (mostly comprised of wollastonite, CaSiO₃). Samples from Palácio Nacional de Sintra (near Lisbon) and Seville‐attributed samples (from the Instituto Valencia de Don Juan) are chemically similar, except that most Sintra's samples display a K‐rich glaze/ceramic interface, whereas the ones from Seville exhibit both K‐rich and Ca‐rich inclusions. The samples attributed to Toledo show glazes with many inclusions, contrasting with the homogeneous glazes in most Hispano‐Moresque tiles. From these results, we identify differences that can be used as markers in future studies on Hispano‐Moresque tiles.     

Eighteenth-century glass and pottery manufacture at Morison’s Haven,Prestongrange, East Lothian

Abstract

This paper presents the results of archaeological investigations of the remains of an 18th-century glassworks at Prestongrange Museum, near Prestonpans, East Lothian. The site is part of an industrial complex previously known as Morison’s Haven, named after its associated tidal harbour. It has a long history of coal extraction that was established as early as the 13th century, and includes industries such as glassmaking, salt, pottery and brick and tile manufacture, and a colliery. The archaeological remains of the glassworks came to light during investigative works designed to locate Gordon’s Pottery, which was known to have manufactured fine tablewares in the 18th century.     

General Meeting,March 10th, 1848

Abstract

The tiled pavement in the nave of Haughmond Abbey, Shropshire, has been partly exposed twice in the last hundred years. Although no decoration appears to survive in situ, a few decorated tiles in the loose collection may derive from this floor. The most significant of these, a roundel fragment, carries the design of a tonsured monk with a crozier. Although this design and the whole mosaic arrangement of the in situ tiles are unique, a comparison can be drawn with the pavement donated by Abbot Nicholas at Halesowen. The arrangement of roundels and frame tiles and the subject matter of the decorated roundels are sufficiently similar to posit a direct connection. There are no close dates for the Haughmond floor, but it is suggested that the Halesowen pavement, dated 1290–98, was the prototype.     

EDWIN SANDYS,ARCHBISHOP OF YORK 1577–88, ‘STIFF-NECKED,WILFUL AND OBSTINATE’: CONFLICT IN THE ELIZABETHAN CHURCH

Abstract

This article examines the events that, as legend has it, resulted in the foundation of Balliol College (c. 1263) by John (I) Balliol (d. 1268). The Balliol family had long been at odds with successive bishops of Durham over certain lands in Sadberge, the homage of which the bishops believed they were owed. John (I) began his struggle just after his inheritance in 1229 and the dispute reached its height in 1255–60, at which time an intense argument broke out. Other factors, including his actions whilst serving as one of Henry III's English representatives in the Scottish government (1251–55), led to Balliol's ultimate submission to Bishop Kirkham (d. 1260) at Durham Cathedral in 1260 and the foundation of Balliol College at Kirkham's instance. The theory remains, as one historian argues, that Balliol's penance was to give the long delayed homage to the bishop for these lands and not to establish Balliol College. However, there are no surviving records of homage and other possibilities remain, including perhaps that the penance called for Balliol's youngest son, John (II), the future King of Scotland, to be educated at a Durham school.     

Application of veratraldehyde as a temporary consolidant for relics at underwater cultural heritage sites

Because it is often difficult to preserve fragile relics in situ at underwater cultural heritage sites, it is sometimes necessary for relics to be extracted and moved to a controlled environment on land for protection and study. This paper discusses the feasibility of using the volatile organic compound veratraldehyde as a temporary consolidant for underwater fragile relics extraction. The results show that different materials (iron, tile, sand, wood) under water can be bonded together and extracted when using veratraldehyde. The fact that veratraldehyde is difficult to spread on the surface of underwater objects is a problem that can be solved by adding a layer of strong hydrophobic polypropylene (PP) fibres onto the object, serving as a ‘package' for the relics. Under laboratory conditions, we used veratraldehyde and PP fibres to extract broken tiles from underwater sand onto an exhibition stand. The broken tiles, in both condition and distribution, were safely and completely retained as the veratraldehyde was slowly removed by the soaking process. This work fills a gap in knowledge about temporary consolidant materials in underwater archaeology, and provides a new method for extracting underwater fragile cultural relics without damaging them.     

Hellenistic Production of Terracotta Roof Tiles Among the Ceramic Industries at Gordion

Recent excavation at the ancient city of Gordion in central western Turkey has recovered part of the collapsed terracotta tile roof of a large Hellenistic building built in the third century BC. The roofing system consisted of large rectangular pan tiles and long half-round cover tiles. The evidence from ethnographic and historical accounts of tile production, forming and finishing methods, and chemical composition determined by neutron activation analysis has yielded insights into the organization of this coarse-ware ceramic industry, its use of local resources, and its relationship to the other ceramic industries serving the city and the local economy.     

Observations on the Ancient City Walls of Rochester

Abstract

A recent survey of the floor-tiles of Cleeve Abbey has revealed a much larger range of designs and fabric groups than had previously been assumed. The style of the earliest pavements derive from those laid at Clarendon Palace in the first half of the 13th century, and may have been made on site. In the late 13th century tiles of high quality were imported from the Gloucester region to pave the frater. The next group of tiles came from a Somerset tilery operating at the same time or just after the Gloucestershire tilery. By c. 1330 the entire church was paved along with the sacristy and chapterhouse, using tiles made by a local industry. There was no revival of tile-making after the mid-14th century.     

‘The Bay and the Ocean’: A History of the ANC in Swaziland, 1960–1979

Abstract

South African political refugees first began arriving in Swaziland in significant numbers in the late 1950s. In the mid-1960s the ANC tried to recruit these refugees to engage in operational activities but with little success. After Swazi independence in 1968 the kingdom's rulers were too scared of South African retaliation to provide active support for the ANC's armed struggle. Meanwhile ANC members in Swaziland were cut off from ANC structures in central Africa because the kingdom was landlocked between white-ruled South Africa and Mozambique. This changed following the army coup in Lisbon in 1974 which led to Mozambican independence. Mozambique's provisional government allowed the ANC access to Swaziland. The ANC sent Thabo Mbeki to try and establish links with activists in South Africa, but whilst he made some progress, this was reversed by police countermeasures early in 1976. A rump of activists left behind after Mbeki's expulsion led ANC efforts to handle the exodus of youths into Swaziland after the June 1976 Soweto uprising. In the late 1970s Swaziland formed part of what the ANC referred to as the ‘Eastern Front’ of its liberation struggle. In trying to stop ANC infiltrations South Africa made use of an extensive network of highly-placed agents in the Swazi establishment. However this collaboration proved ineffective in stopping the ANC because, even if it wished to, Swaziland lacked the resources to prevent its territory being used, whilst there were also many prominent Swazis, including King Sobhuza II, whose sympathies lay with the ANC. By the end of the 1970s ANC activity in Swaziland had grown to such a scale that it began to unnerve the Swazi authorities. This set the stage for the closing of the ‘Eastern Front’ in the early 1980s.     

Early Railways 6: Papers from the Sixth Annual Early Railways Conference

Abstract

Mass production of decorative tiles enabled nineteenth and twentieth century builders and architects to 'beautify' the 'halls of the noble and the churches of the peasant'. Tiles were also used for public houses, fire stations, inebriates' homes and turkish baths, etc. Maw of Jackfield in the Ironbridge Gorge and Craven Dunnill and Company of the same place, were two of the most important manufacturers of decorative tiles, and their products, a triumph of Victorian mass production, can still be seen in many places.     

The Idea of a Category Mistake: From Ryle to Habermas,and Beyond

Summary

The term ‘category mistake’ began to turn up regularly in public discourse in the 1990s as a general term to describe a confusion between different fields of thought with serious practical consequences. But it began its career in philosophy, introduced by Gilbert Ryle in The Concept of Mind in 1949 to attack Cartesian dualism and assert a monistic solution to the so-called mind-body problem. This paper traces the stages by which it came into general usage, arguing that while by the later 1960s it had generally been rejected by philosophers, it was saved from disappearance by its migration into fields such as psychology and theology. From there, it moved into critical theory and then into international relations. Its entry into these latter areas first made plain its potential in political argument. Eventually, multiple meanings of the term came to coexist with one another, with the practical and rhetorical usage supplementing rather than replacing its original philosophical sense.     

Site preservation at Gordian,an Iron Age city in Anatolia

Abstract

Since excavations began at the Citadel Mound of Gordion in the 1950s, the site has been exposed to the extreme weather conditions of Central Anatolia. The architectural remains, including a unique palace quarter and citadel, are deteriorating to the extent that the legibility of the site is threatened.

The excavated area within the mound, comprising more than two hectares, is too vast to be covered by protective sheltering given the current budget. Conventional backfilling is also precluded, as this would obscure key topographical elements of the site and distort the stratigraphical context of the city within its surrounding citadel.

To preserve the site under these conditions, a technique of sandbag buttressing and clay capping has been implemented at Gordion. Using locally available materials, this system of interpretive stabilization not only preserves the architecture of the ancient city within its stratigraphical context, but improves the legibility of the site as a whole.