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.     

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.     

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。     

Archaeomagnetic versus luminescence methods: the case of an Early Byzantine ceramic workshop in Thessaloniki,Greece

In this contribution, we present a combined archaeomagnetic and luminescence study of archaeologically dated structures. The investigated area is a ceramic workshop comprising several Early Byzantine kilns. Based on (a) the archaeological–anthropogenic stratigraphy of the site, (b) the structural characteristics of the kilns and (c) the few ceramic findings revealed within their context, the operation of this brick and tile factory is approximately dated between the middle of the fifth century until the first decades of the sixth century AD. Three of the well-preserved workshop kilns have been studied archaeomagnetically. The full vector of the geomagnetic field, accompanied by rock magnetic analyses of the studied material, has been defined. The archaeomagnetic study revealed similar directions among the three kilns indicating and confirming their contemporary use. Additionally, several luminescence measurements were obtained on material from the same kilns. The dating of the site was performed with both methods. The archaeomagnetic dating is convergent with the archaeological estimation only when its upper limit is considered. Concerning the luminescence dating, the calculated ages (corrected for anomalous fading and for the ⁴⁰K content) with their standard deviations are convergent with the archaeological estimations for the first kiln, while for the other two, the results seem to be incompatible. The possible factors that provoked this divergence are thoroughly discussed.     

Study on the source of raw material and firing technique of glazed tiles bodies in the Ming Imperial palace site,Nanjing, China

This article considered glazed tiles excavated from the Ming Imperial Palace site in Nanjing as the research object. Glazed tiles were selected and analyzed via vacuum porosimeter, thermal dilation (TD), X-ray diffraction (XRD), and energy dispersive X-ray fluorescence (EDXRF) to determine their physical property, firing temperature, phase composition, and chemical composition, respectively. Results show that the firing temperature of body belongs to the temperature range (of 950–1,100°C), whereas the water absorption and apparent porosity are large. The phase composition of glazed tile bodies is the same (predominantly quartz and mullite). However, some samples contain trace amounts of rutile, hematite, sodalite, and orthoclase. The firing temperature combined with the phase composition indicates that the raw material and firing process of glazed tile body samples have similarities, which embody of the strict and unified management system of the official kiln. The raw materials of glazed tile body in the Ming Imperial Palace site may come from Dangtu glazed kiln, whereas the rest of the samples remains to be explored. This study provides a scientific basis for understanding the evolution of glazed tile-making technology in ancient China, and is important for the protection and repair of glazed buildings in the Ming Dynasty.     

The Godwins of Lugwardine,and the Other Hereford Tile Makers

Abstract

Tiles were made in Hereford in Roman and in Medieval times, and the manufacture of plain quarry tiles from plastic clay maintained the tradition and technique of tile-making. During the nineteenth century the Gothic Revival stimulated the production of decorated tiles and Godwins began to make them. The firm is not as well known as some of its competitors such as Maw and Minton, but its tiles were much admired and widely used, and can still be seen in good condition in a surprisingly large number of churches. Standard reference books, give 1861 as the starting date for Godwin tiles, but the writer noticed that they had been used in 1857 in Giles Gilbert Scott's restoration of Hereford cathedral, and is attempting in this paper to give an outline of the rather complicated history of the Godwins and the other Hereford tile makers. The tile industry which began in 1850 has been an important source of employment in the Hereford area until the present day.     

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.     

湖北咸宁咸安辜家岭瓦窑发掘简报

辜家岭窑址群位于咸安区甘棠镇竹脑村四组,1999年考古工作对该窑址群中的一座“蚌壳形”窑进行了发掘,较完整揭示出窑址的结构特征,在窑内底部出土成品灰陶小板瓦,这为我们研究明代窑及建筑材料的烧制提供了有益资料。     

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.     

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.     

秦雍城豆腐村制陶作坊遗址发掘简报

秦雍城遗址位于陕西省凤翔县城以南,东距西安市170公里,西南距宝鸡市50公里。据文献记载,从春秋晚期的德公元年(前677年)至战国中期的献公二年(前383年)的294年间,雍城一直作为秦国都城,成为秦人由西向东逐渐迁徙     

ARCHAEOMETRIC INVESTIGATIONS OF SGRAFFITO CERAMIC TILES (FIFTEENTH‐SIXTEENTH CENTURIES) RECOVERED FROM EXCAVATIONS IN UDINE (NORTH‐EAST ITALY)*

Most of the Renaissance sgraffito tiles excavated in Udine (Italy) constitute a homogeous group, the tile body having a CaO/MgO molar ratio ?= 3:2. They were produced using a dolomite‐ and calcite‐containing clay fired at 900–950°C. A small group of samples, with a lower firing temperature and a CaO/MgO ratio ?= 2:3, was probably produced in a different factory. Slip and transparent glaze, characterized by optical microscopy and inductively coupled plasma atomic emission spectrometry, are an illite‐rich clay and a lead silicate, respectively.     

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.     

THE EFFECT OF PURIFICATION AND FIRING OF CLAYS ON TRACE ELEMENT PROVENANCE STUDIES

The effect of purifying, mixing and firing of clays on trace element concentration was systematically investigated using instrumental neutron activation analysis. Eight different clays from two sites in Crete were used together with sherds found around several kilns near the sites. Trace element analysis showed that the extent to which the concentration changes after purification and firing depends on the initial particle size and chemistry of the clay. The calcite concentration plays an essential role in this. An application is made using roof tiles found at the excavation of the ancient city of Pella in Macedonia.     

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.     

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.     

河南洛阳市隋唐东都外郭城五座窑址的发掘

2003年,洛阳市文物工作队在隋唐洛阳外郭城东北里坊区内发掘了5座烧窑遗址,出土有长方形砖、板瓦、筒瓦等建筑材料,以及瓷器、釉陶器及陶器等生活用具。根据烧窑的形制结构及出土遗物,再结合与临近地区窑址的比较,推断该窑址应属于隋唐时期的官营烧窑作坊遗址。     

辽宁省朝阳市文化路唐代窑址

2001年9月,朝阳博物馆在朝阳市文化路东段辽宁省微生物研究所院内发掘了5座唐代窑址,除1座烧陶器外,其余都是砖瓦窑,这几座窑址大小不一,形式各异,集中在一起,为研究唐代窑址及建筑材料提供了很重要的资料。     

Importing Clay for Local Pottery Production in the 4th Century b.c. at Tell el-Timai,Egypt

Archaeological evidence of ceramic production most commonly consists of locally procured raw materials. Excavations at Tell el-Timai in Lower Egypt recovered raw fine marl clay from two transport jars in the vicinity of pottery kilns dating to the 4th century b.c. Production wasters of small perfume bottles produced in the same fine marl clay were found inside the kilns. The marl clay inside the jars pointed to an origin outside of Lower Egypt. Samples of the clay and wasters, along with a confirmed locally sourced sample, were subjected to X-Ray Fluourescence (XRF) analysis, revealing significant differences in their chemical compositions. The results of the analysis are compared to published Egyptian data and an Upper Egyptian provenience is suggested because the raw clay is consistent with available comparative XRF data.     

洛阳龙门奉先寺遗址发掘简报

1997年至2000年,奉先寺遗址发掘工作队对奉先寺遗址进行了考古发掘,揭露面积1637平方米.发现的遗迹现象有殿址、水道等.出土遗物以砖、瓦等建筑构件为主.生活用品较少,多为瓷器.出土的十余件石刻造像弥足珍贵.奉先寺遗址的发掘为中国古代寺院建筑和佛教造像等方面的研究,提供了珍贵的实物资料.