On the flow characteristics of the conical Minoan pipes used in water supply systems,via computational fluid dynamics simulations

The Minoan Terracotta pipes with their conical shape were widely used in the water distribution system in the ancient Minoan civilization. They remain one of the brightest achievements of the Minoan tribe in water supply technology and raise admiration as well as many questions about the technological advancements of antiquity, that are yet to be understood. The present work aims at answering the following questions: a) what inspired the Minoans to manufacture pipes with such a peculiar shape, that differs greatly not only from later pipe designs of antiquity, but also from contemporary cylindrical pipes and b) why was the design of those pipes abandoned after the fall of the Minoan civilization? It tries to address these questions by investigating the flow physics and dynamics that take place in such pipes, adopting advanced numerical and computational methods. The time-averaged Navier–Stokes equations along with the k − ? turbulence model are solved for a variety of geometrical parameters, pipe orientations and flow rates, in order to produce a comparative picture of the hydraulic efficiency of the conical Minoan pipes. The flow field is visualized and critical flow parameters, such as the head loss, the velocity magnitude and turbulence intensity, are calculated. These calculations show clearly that the conical Minoan pipes exhibit significantly higher pressure drops along their length compared to an equivalent straight pipe. In their widest part an extended recirculation appears, which could wash out impurities that may be present in the water, which at the same time cannot be deposited on the pipe wall. This evidence proves that the Minoan pipes are energetically expensive to operate and consequently their replacing by cylindrical pipes was inevitable. Therefore, it seems that the main advantage and purpose of the particular geometry was that they could be easily connected on site, forming long straight or slowly bending lines without having to add straight or many different fittings in between.     

SCIENTIFIC INVESTIGATION OF FAIENCE FRAGMENTS ATTRIBUTED TO THE TOWN MOSAIC AT KNOSSOS*

We analysed a faience fragment from Bristol Museum and Art Gallery, to determine whether it belonged to the Town Mosaic, excavated at Knossos. Three Town Mosaic fragments from the Ashmolean Museum, Oxford were also examined. The objects were analysed using non‐destructive variable‐pressure scanning electron microscopy with energy‐dispersive X‐ray spectrometry. The Bristol object's composition and microstructures are similar to those of the Town Mosaic samples. Our results are also comparable to those from polished samples of Minoan faience (Tite et al. 2009 ), showing that VP SEM–EDX gives reliable results without invasive sampling. Silicaceous, copper‐rich microspheres were identified for the first time in two of the Ashmolean objects.     

PRELIMINARY TECHNICAL OBSERVATIONS ON KNOSSIAN FAIENCE

Summary This preliminary study of a large number of Knossian/Minoan faience objects in the Heraklion (HM) and the Ashmolean (AM) Museums presents observations about the technological development of Knossian faience throughout the life of the Palace. In earlier deposits, such as the Vat Room, simple inlays, beads, and a figure appear; faience became more complex in the succeeding period (Loomweight Basements) and reached its culmination in the Temple Repositories period, where complex inlays and vases and large-scale figures appear.     

NEUTRON ACTIVATION ANALYSIS OF SIXTEENTH- AND SEVENTEENTH-CENTURY EUROPEAN BLUE GLASS TRADE BEADS FROM THE EASTERN GREAT LAKES AREA OF NORTH AMERICA*

Sixteenth- and seventeenth-century European blue glass trade beads from aboriginal sites in the eastern Great Lakes area of North America have been analysed non-destructively using low neutron dose instrumental neutron activation analysis, so that the beads could be returned to their keepers. Dark blue (cobalt-coloured) beads are readily separable from turquoise (copper-coloured) beads. Differences in the chemistries of the turquoise blue beads appear to be useful in separating glass beads from the two centuries. Low calcium, sixteenth-century turquoise beads tend to distintegrate by a leaching of the alkali metals.     

Representations of birds in Minoan art

During the second millennium BC , the Minoan civilization was established in the southern Aegean Sea. In Minoan art, especially on Crete, birds occupied a prominent place, and were often represented in wall-paintings and craft objects. Species still occurring on the island, such as cormorants, mallards, cuckoos, owls, hoopoes, and swallows, as well as exotic taxa such as partridges and possible domestic forms such as pigeons, were the subject of artistic inspiration, and they were depicted not only in purely cult contexts, but also in the backgrounds of naturalistic landscapes. The aim of this paper is to reconsider the identification of some of the birds depicted and to discuss them in the context of the environmental conditions and osteological finds from the southern Aegean islands in Minoan times. © 1997 John Wiley & Sons, Ltd.     

A technological study of ancient faience from Egypt

The chemical compositions and microstructures of some 35 faience objects from Egypt spanning the period from the Middle Kingdom through to the 22nd dynasty are determined using analytical scanning electron microscopy. Replicate faience beads glazed in the laboratory using the efflorescence and cementation methods are similarly investigated. In efflorescence glazing, there appears to be preferential efflorescence of soda over potash, and in cementation glazing, preferential take up of potash over soda into the glaze. These data are then used to try to infer the raw materials and methods of glazing employed in the production of the ancient faience. The glaze/glass phases present in the faience differ significantly in composition from that of New Kingdom glass. This could be due either to the use of different plant ashes or to changes in the composition of the plant ashes during the production of faience and/or glass. Although it is only rarely possible to determine with certainty whether ancient faience was glazed by efflorescence, cementation or application, the observed microstructures provide an indication of the approach adopted to achieve desired performance characteristics such as strength.     

湖北宜昌万福垴遗址出土费昂斯珠科技分析与研究

湖北宜昌万福垴遗址是西周中晚期至春秋时期的以楚文化为主的遗存,以该遗址M8出土的费昂斯(faience)珠为研究对象,以期通过分析其成分和结构特征并讨论其工艺特征,丰富对长江中下游地区该时期费昂斯的相关认识。本研究使用扫描电子显微镜,分析结果显示费昂斯制品以富钾费昂斯及混合碱费昂斯为主。再依据以往发表的西周时期费昂斯制品的科技研究,结合考古发掘相关材料,试图从费昂斯器物使用方式的角度,窥视其在古人精神文明进程中的角色,反观费昂斯在中原地区的发展脉络。     

Geoarchaeological tsunami deposits at Palaikastro (Crete) and the Late Minoan IA eruption of Santorini

The explosive eruption at Santorini in the Aegean Sea during the second millennium BCE was the largest Holocene volcanic upheaval in the Eastern Mediterranean region. The eruption was disastrous for the Minoan settlements at Santorini, but the effect on human society in the neighbouring islands and regions is still clouded in uncertainty. Tsunami generation was suggested, but comparatively little evidence was found. The lack of firm tsunami traces is particularly puzzling in Crete with its coastal settlements of the Late Minoan IA period, during which the Santorini eruption occurred. Here, we report the discovery of extensive geoarchaeological tsunami deposits at Palaikastro in north-eastern Crete. These deposits are characterized by a mixture of geological materials, including volcanic Santorini ash, and archaeological settlement debris. Various tsunami signatures were identified: (1) erosional contact with the underlying strata, (2) volcanic ash intraclasts in the lower part of the deposit, (3) reworked building stone material in the lower part of the deposit, (4) individual marine shells, (5) marine micro-fauna, (6) imbrication of rounded beach pebbles, settlement debris, ceramic sherds and even bones, (7) multi-modal chaotic composition. Late Minoan human settlement activities at Palaikastro provided architectural and stratigraphic frameworks in space and time that recorded and preserved tsunami evidence as geoarchaeological deposits. Such stratigraphic resolution and preservation may not occur in the natural landscape. Volcanic ash transported by wind from Santorini south-east to Crete preceded the tsunami. Geological, archaeological and radiocarbon dating criteria all converge, indicating that the tsunami deposits are coeval with the Minoan Santorini eruption. Field evidence suggests that tsunami waves at Palaikastro were at least 9 m high. Inverse tsunami modeling was attempted, based on these newly discovered tsunamigenic deposits. The initial wave in the generation region at Santorini that best fits the stratigraphic data is a wave with +35 to −15 m initial amplitude and a crest length of about 15 km.     

DARK AND SHINY: THE DISCOVERY OF CHROMITE IN BRONZE AGE FAIENCE*

The Late Bronze Age (1550–1200 bc ) in the Near East was a period of cultural development, international trade and technological innovation, notably in metallurgy and silicate technology. As a spin‐off of the new glass technology, new colorants were also applied to faience glazes presumably to increase their aesthetic value. Here, we report on the presence of chromite minerals in the glaze of a faience vessel from Deir ‘Alla, Jordan, 1200 years earlier than reported so far. Importantly, chromite was not only used as a greyish pigment, but also as a nucleating agent for spherulitic crystallization of augite in the amorphous glaze. These synthetic augite formations give a unique, sparkly appearance to the faience vessel, apparently imitating a metallic look. The making of such an intricate glaze and its contemporary significance reflect not only the high level but also the appreciation of innovation in that region at that time.     

NEUTRON ACTIVATION ANALYSIS OF FAIENCE BEADS

A selection of faience beads has been examined using neutron activation analysis, with a view to distinguishing the provenance of individual specimens. Evidence is presented that the tin content in beads from British sites is significantly higher than in those from other areas. Characteristic features of beads from other sources are also discussed.     

“Mycenaean” political domination of Knossos following the Late Minoan IB destructions on Crete: negative evidence from strontium isotope ratio analysis (Sr/Sr)

Strontium isotope ratio analysis of human dental enamel and bone is applied to investigate a highly debated question of population movement and cultural discontinuity in Prehistoric Aegean Archaeology. The Late Minoan IB (ca. 1490/1470 BC) destructions on Crete are succeeded by cultural upheaval. The novel cultural features that appear at Knossos (Crete) in this period have forerunners in the Mainland. In Cretan context, the Linear B writing system, the funerary architecture and burial practices of the Mainland style are interpreted as evidence of an actual “Mycenaean” long-term settlement and political domination of Knossos. Human skeletal material from tombs that are associated with non-locals from the Mainland based upon the material culture is analysed to measure ⁸⁷Sr/⁸⁶Sr. The results of the analysis show that all the examined individuals from the Knossos tombs were born locally.     

NEW DATA ON THE TECHNOLOGY OF FAIENCE PRODUCTION IN CENTRAL EUROPE IN THE EARLY BRONZE AGE

New data on faience production technologies in central Europe come from an analysis of 12 faience beads from an Early Bronze Age cemetery in Poland. The beads were tested with the EPMA method. Altogether 65 measurements were made. In terms of morphology, the artifacts are all the same, but they differ in microstructure and chemical composition. For some a mixed alkali flux was used, for others soda-rich plant ashes. Even so, all of the beads seem to have been made from local raw materials in central Europe (soda-rich plant ashes could have come from plants growing near one of the mainland salt sources, which are frequent, for example, in south-eastern Poland).     

The production technology of Egyptian blue and green frits from second millennium BC Egypt and Mesopotamia

The microstructures and chemical compositions of some 55 Egyptian blue and green frit samples from New Kingdom Egypt and 15th century BC Mesopotamia are determined using analytical scanning electron microscopy, the main focus being on frit cakes, powder residues, and frit vessel and bead fragments from one of the “factory areas” at Amarna in Middle Egypt. Replicate Egyptian blue frits produced in the laboratory are similarly investigated. Comparison of the microstructures of the ancient and replicate samples suggest that frit cakes are the primary product, and that these were ground to produce the powder, and then moulded to shape and refired to produce the vessels and beads. Egyptian blue and green frits are shown to be distinct pigments, the pigment produced depending on the relative proportions of copper oxide and lime in the mixtures. The bulk and glass phase compositions are used to try to infer the different sources of the quartz, lime, copper and alkali flux used in the production of frits from Egypt and Mesopotamia. An estimate is made of the scale of production of Egyptian blue frit in New Kingdom Egypt.     

Optical Coherence Tomography for the non-invasive investigation of the microstructure of ancient Egyptian faience

Optical Coherence Tomography (OCT) is a non-invasive subsurface 3D imaging technique based on the Michelson interferometer. The non-invasive nature of OCT and its speed of acquisition makes it possible to image large volumes of intact objects to yield a complete overview of the microstructure. The production methods for ancient Egyptian faience were first investigated using scanning electron microscopy (SEM) imaging of the microstructure in polished sections and microprobe analysis of the composition of the glass phases. These studies were based on original Egyptian faience objects and laboratory reproductions of faience beads made using three different production methods. The microstructure of the same laboratory samples and the Egyptian faience objects from the British Museum Research Laboratory Collection are re-examined using OCT. It is found that OCT virtual cross-section images can be used to group ancient faience objects into three categories on the basis of the morphology of the surface glaze layer and the glaze/core interaction layer. The OCT images correspond well with SEM images of polished sections of ancient faience objects and laboratory reproductions. The virtual cross-sections produced by OCT are somewhat limited by the penetration depth, which is affected by the high absorption coefficient of the material and, therefore, cannot always provide information on the presence or absence of interparticle glass that binds together the quartz particles in the core. Nevertheless, the top two layers are well imaged and since OCT images can be obtained rapidly and without the necessity of removing a sample, the method can be applied to a very much wider range of ancient faience objects than is possible by SEM examination of polished cross-sections. In summary, this paper examines to what extent OCT can assist the investigation of the production techniques of ancient Egyptian faience.     

New light on old pumice: the origins of Mediterranean volcanic material from ancient Egypt

This paper presents and discusses the Neutron Activation Analysis (NAA) results newly obtained from pumice pieces found decades ago at the Egyptian sites of Maiyana, Sedment, Kahun, and Amarna – now in the collections of the Ashmolean Museum, Oxford, and the Petrie Museum of Egyptian Archaeology, London – which could be successfully related to several volcanic eruptions in the Mediterranean. The work contributes to the constant accumulation of knowledge concerning the first appearance of pumice from the so-called Minoan eruption of the Santorini volcano. In addition, it unexpectedly sheds more light on the long-distance trade of Mediterranean volcanic material in the Bronze Age world by disclosing another connection between Lipari and the Eastern Mediterranean.     

甘肃张家川马家塬战国墓地M4出土料珠研究

甘肃马家塬墓地是战国晚期至秦初的西戎墓地,本研究以该墓地M4出土的料珠为研究对象,以期通过分析其成分和结构特征,讨论其工艺特征,以丰富对战国时期费昂斯的相关认识。研究使用扫描电子显微镜-能谱和激光拉曼光谱仪,分析结果显示料珠为费昂斯制品,其釉层玻璃化程度很高,经历腐蚀后熔剂流失严重,明显区别于西周时期的费昂斯制品。同时确定釉层中的一些高锡颗粒物为SnO_2,表明当时在釉层制作中加入锡石或锡粉末。该费昂斯制品应采取了直接施釉或包埋施釉工艺。研究结果可为我国费昂斯发展历程演变提供信息。     

河南三门峡虢国墓出土西周——春秋时期费昂斯珠的分析研究

河南三门峡虢国墓是西周晚期至春秋初期的大型邦国墓地,其中M2009的六璜组玉佩上使用了费昂斯珠,作为人工制品的费昂斯珠,其材料组成和工艺特点显示了古代科技水平,利用科学分析揭示其科学价值很有意义。本研究运用扫描电子显微镜(SEM-EDX)、激光拉曼光谱(Raman)分析了四件三门峡虢国墓M2009出土的费昂斯珠的微观结构和成分。研究发现,四件费昂斯珠采用直接施釉法,釉层使用了铜离子着色,可能使用了含氯和铜的矿物。费昂斯珠的内外表层还发现了羟基磷灰石和朱砂,来自于墓主遗骸和墓葬环境。     

Vergemeinschaftung and Vergesellschaftung in Max Weber: A reconstruction of his linguistic usage

When Max Weber made use of the terms “Vergemeinschaftung” and “Vergesellschaftung” in the first chapter of “Economy and Society”, he was among other things alluding to Ferdinand Tönnies’ well-known usage of “Gemeinschaft” and “Gesellschaft”, as well as to related conceptions in the work of Georg Simmel. However, Weber's usage not only differed from the senses in which Tönnies and Simmel used these terms; he had himself altered his own usage since the early draft of this chapter, published in 1913 as “On some Categories of Interpretive Sociology”. The tangled resonances that result from this are carefully identified and separated, and in so doing light is shed upon the nature and status of Weber's intentions in writing his important chapter on “Basic Sociological Categories”.     

The palaeo-Christian glass mosaic of St. Prosdocimus (Padova,Italy): archaeometric characterisation of tesserae with antimony- or phosphorus-based opacifiers

The present paper reports the results of archaeometric characterisation of the opaque tesserae, intentionally coloured with antimony- or phosphorus-based opacifiers, coming from one of the two only palaeo-Christian glass mosaics known in the Veneto region (Italy), i.e., the mosaic which decorated the votive chapel of St. Prosdocimus in Padova. In particular, 55 tesserae belonging to glass types “White”, “Blue”, “Yellow”, “Green” and “Brown” are examined here. The multi-methodological approach (SEM-EDS, EMPA, XRPD, imaging spectroscopy coupled, in some cases, with XAS) gave valuable insights into the complexities of palaeo-Christian glass mosaic production technologies. Two main groups are identified, one characterised by glassy matrixes and opacifiers (calcium or lead antimonate) typical of the Roman period and comprising all “White”, “Blue”, and “Yellow” tesserae and some “Green” ones, and the other characterised by glassy matrixes and an opacifier (calcium phosphate) typical of the 6th century AD, composed of “Green” and “Brown” tesserae. This suggests that, during that century there was a gradual change from older to “new” production technologies: although new opacifiers such as calcium phosphate started to be used, the frequent use of antimony-based ones (43/55 samples) supports the hypothesis that their systematic use was extended until the 6th century, although re-using old tesserae cannot be completely excluded. In addition, comparisons with compositional groups already identified in the “gold” tesserae of the same mosaic and tesserae from Ravenna demonstrate that both the same “base compositions” of the glass were used to produce transparent and opaque glass. This evidence, coupled with the results of the historical-artistic study, suggests technological connections between Padova and Ravenna, the capital of Byzantine mosaics in Italy. Micro-structural observations and chemical analyses of the Paduan antimony-based opacified glass demonstrate that different processes and raw materials were used in their production. Both in situ and ex situ crystallisation can be identified for calcium and lead antimonate in Paduan tesserae, whereas the production of tesserae opacified with calcium phosphate generally appears to be highly standardised. Although the opacifiers used in the Paduan tesserae support technological transitions, the colouring elements identified here, i.e., iron and manganese for white, yellow, brown and some green tesserae, cobalt for blue, and copper for blue and green, suggest continuity, because their use is widely testified in the production of both transparent and opaque glass artefacts dating from the Bronze Age until Medieval times, from whichever archaeological site the samples come. Peculiar relationships among the oxidation states of colouring elements, their contents in the glassy matrix, the types of opacifiers used, and the final colour of tesserae were identified. In addition, the correlations of cobalt and/or copper with other elements, together with identification of relics of colouring and “metallic” droplets, allow us to speculate on possible sources and production technologies. Lastly, identification of newly formed crystalline inclusions in tesserae also yields information on kiln temperatures, which ranged between 900 and 1150 °C, a range easily reached in the furnaces of the 6th century AD.     

Chemical and Mineralogical Alteration of Ceramics from A Late Bronze Age Kiln At Kommos,Crete: the Effect On the Formation of A Reference Group

The formation of reference groups comprises an important procedure in chemical provenance studies of archaeological pottery. Material from ancient kilns is thought to be especially suitable for reference groups, as it comprises a definite unit of past production. Pottery from the Late Minoan IA kiln excavated at Kommos, Crete was analysed in order to produce a reference group in this important area of Minoan ceramic production. The samples were characterized by a combination of techniques providing information on the chemistry, mineralogy and microstructure of the ceramic body. Initially, the study was unable to establish, in a straightforward manner, a chemical reference group. Different ceramic pastes and a range of selective alterations and contaminations, affected by variable firing temperatures and burial environment, were shown to be responsible for the compositional variability. Procedures are described to compensate for such alterations and the perturbations in the data that they produce.