Study and Conservation of the St. Nicola's Basilica Mosaics (Bari,Italy) by Photogrammetric Survey: Mapping of Polychrome Marbles,Decorative Patterns and Past Restorations

ABSTRACT

This present work focuses on the mapping of marbles, decorative patterns and area of the mosaics of the St. Nicola’s Basilica in Bari (Italy) by their photogrammetric survey. The extraordinary importance of these mosaics is due to the stylistic uniqueness and the undisputed workmanship and to the employed materials for tesserae. These mosaics include the white and polychrome marbles, used in the Roman age and reused in medieval artistic production, and imitation stones used as substitutes during the past restorations. The digital survey was realised by the photogrammetric reconstruction of mosaics collecting a photo dataset, after the mosaics redrawing by an image processing software and finally implemented it with lithological identification marbles. It allowed to obtain a punctual mapping of materials, through which to identify original areas and restoration areas, decorative patterns, recurring geometries. The research carried out, supported by the photogrammetric reconstruction as established method for high resolution digital reproduction and mapping, not only ensures the conservation and improvement of the enjoyment of the mosaic floors of the St. Nicola’s Basilica, but allows to conduct studies on materials, decorative patterns and restoration areas directly on the digitized product.     

Technique and treatment of the St Michael Weighing Souls in the Royal Convent of Santa Clara,Toledo, Spain

Abstract

The history, materials and technique of an early fifteenth-century wall painting, St Michael Weighing Souls, are described. The pigments are typical of mediaeval Spain but the methods by which they were applied show a sophisticated understanding of their optical properties. Complex mechanisms of deterioration in some areas of colour are discussed, together with the rationale, materials and methods used in the conservation treatment.     

A New Methodology for the Characterisation of Natural Dyes on Museum Objects Using Gas Chromatography–Mass Spectrometry

The derivatising agent m-(trifluoromethyl)phenyltrimethylammonium hydroxide (TMTFTH) has been employed for more than a decade at the Canadian Conservation Institute (CCI) to extract natural dyes from historical textiles and other dyed substrates. The alkaline reagent breaks the bonds between the colourants and the mordant ions or functional groups of the substrate, releasing the dye compounds into the extraction solution, and derivatises polar functionalities to produce compounds that are amenable to subsequent analysis by gas chromatography–mass spectrometry (GC–MS). This approach allows for the identification of the colourants, and is also useful in determining the presence of degradation products from the dyes and substrates, non-dye marker compounds, auxiliary compounds added to the dye bath, and substances present on the object through anthropogenic use, conservation treatments, or possible pesticide contamination. This paper discusses compounds formed through the reactions of TMTFTH with flavonoid dyes (dyer’s buckthorn, old fustic, weld, red sandalwood, and brazilwood), quinone dyes (madder, Relbunium, Galium, cochineal, lac, and walnut), indigoid dyes (indigo, Tyrian purple, and indigo carmine), turmeric, marigold, lupin and several lichen species. Results from a selection of historical dyed textiles and other decorative objects analysed at the CCI are provided to illustrate applications of the methodology.     

Oryza sativa L. (Rice) in the Ancient Earthen Plasters of Painted Fragments from Bezeklik,China

ABSTRACT

This research reports for the first time the inclusion of Oryza sativa straw, root, and husk as a vegetal additive in the fifth century CE decorative mud plaster of the Buddhist cave of Bezeklik. The investigation is based on the morphological, anatomical, and silica bodies study of the vegetal additives accomplished through a light microscope, stereomicroscope, Fourier-transform infrared spectrophotometer, and scanning electron microscope from the isolated fragments of the painted plaster, transported to India in the nineteenth century and presently housed in National Museum, New Delhi. Studies indicate that loamy sand soil sourced locally for the earthen plaster was mixed with paddy straw in the proportion of 25–30% by volume for cohesion and strength. The excess of sand and absence of clay-size particles in plaster is, however, causing disaggregation of the grains due to lack of cohesion. As locally available materials are preferably used for any plaster works, this study also raises the question – was ancient Bezeklik, now a desert of Northwest China, once a rice-growing area in addition to the crops of Triticum aestivum (wheat), Setaria italica (Foxtail millet), and Hordeum vulgare (barley) reported by many researchers, based on hypothetical environment recreation. This study will help prepare a compatible plaster for the restoration of fragile-painted plaster fragments.     

Maya blue: its presence in cuban colonial wall paintings

Abstract

A blue pigment frequently found in Cuban colonial decorative wall paintings from about 1750 to 1860 has been identified with the aid of thin-layer chromatography, IR spectrometry, X-ray diffraction, thermal analysis, scanning electron microscopy and X-ray microanalysis as ‘Maya blue’. This is the first reported occurrence of Maya blue from a period after the conquest and in a non-Mayan cultural area.     

Chuc Nichim,the washing of the flowers — a look at traditional preservation practices

Abstract

The ceremonies ofthe Maya people of Chiapas, Mexico, combine Catholic symbolism and ancient ritual. The clothes belonging to the effigies of saints, as well as other textiles, are taken out of storage, washed, dried and incensed in preparation for the saint's feast day. One such feast, Chuc Nichim, is described in detail, and the conservation implications of the rituals are discussed.     

Evaluation of the relief line and the contour line on Greek red-figure vases using reflectance transformation imaging and three-dimensional laser scanning confocal microscopy

Abstract

The relief and contour lines on a group of ancient Greek red-figure vases and vase fragments in the collection of the Harvard Art Museums and the Worcester Art Museum were examined using two surface examination methods – reflectance transformation imaging and three-dimensional laser scanning confocal microscopy. These methods helped characterize the lines and answer questions regarding tools, techniques, and production sequence used by Greek vase painters. This research also incorporated fabricated mock-ups to gain a better understanding of the ancient technology and in so doing confirmed that the relief lines were not produced by an extruded method, but with a brush made with only a few hairs, termed linierhaar as first proposed by Gérard Seiterle in 1976. Furthermore, it was discovered that not one but two distinct types of relief lines exist on these ancient vases: the laid line (proposed by Seiterle) which has a characteristic ridged profile, and the pulled line (proposed in a previous publication by the authors) which has a furrowed profile. It was also determined that the relief line used to outline figures was applied prior to the contour line in Attic vase decoration, although variations in this sequence occur in vases from South Italy. Based on observations made during this research, the authors propose a likely evolution for the techniques used to produce decorative features throughout the period of red-figure vase production.     

Technical analysis of a Central Asian wall painting detached from a Buddhist cave temple on the northern Silk Road

A great number of Central Asian wall paintings, archeological materials, architectural fragments, and textiles, as well as painting fragments on silk and paper, make up the so called Turfan Collection at the Asian Art Museum in Berlin. The largest part of the collection comes from the Kucha region, a very important cultural center in the third to ninth centuries. Between 1902 and 1914, four German expeditions traveled along the northern Silk Road. During these expeditions, wall paintings were detached from their original settings in Buddhist cave complexes. This paper reports a technical study of a wall painting, existing in eight fragments, from the Buddhist cave no. 40 (Ritterhöhle). Its original painted surface is soot blackened and largely illegible. Grünwedel, leader of the first and third expeditions, described the almost complete destruction of the rediscovered temple complex and evidence of fire damage. The aim of this case study is to identify the materials used for the wall paintings. Furthermore, soot deposits as well as materials from conservation interventions were of interest. Non-invasive analyses were preferred but a limited number of samples were taken to provide more precise information on the painting technique. By employing optical and scanning electron microscopy, energy dispersive X-ray spectroscopy, micro X-ray fluorescence spectroscopy, X-ray diffraction analysis, and Raman spectroscopy, a layer sequence of earthen render, a ground layer made of gypsum, and a paint layer containing a variety of inorganic pigments were identified.     

BOOK AND CD-ROM REVIEWS

Abstract

SORKINS DIRECTORY OF BUSINESS & GOVERNMENT-1996 CHICAGO EDITION. St. Louis, MO: Sorkins Directories, 1996, 18 volumes, $1,450., Reviewed by Tim Dixon.

SORKINS ELECTRONIC BOOK-CHICAGO. St. Louis, MO: Sorkins Directories, 1996, 1-disc, DOS version only, $1,895., Reviewed by Tim Dixon.     

Technological Study of the Decoration on an Erard Harp from 1818

ABSTRACT

Historical pedal harps from the early nineteenth century are highly adorned objects, decorated with various techniques such as polychromy, gilding, decoupage, and gilt composition ornaments. Even though a large number of such instruments are kept in private and public collections, until now their decorative features have not been examined systematically. Moreover, little has been written about the motives behind the choice of various decorative techniques by harp makers. This article presents results from the investigation of a double-action harp made in 1818 by Erard, the leading manufacturer of harps in Regency London, focusing on the technological aspects of its decorative features. Various analytical methods, such as visual examination, microscopy, SEM-EDX, FTIR, and Py-GC-MS, were used to identify the inorganic and organic components in the coating of the harp and to analyse its stratigraphy. Inspection with ultraviolet light revealed details of the original layers and of later additions, while radiography made the internal structure as well as damaged areas and repairs visible. The outcome of this object-based examination was complemented by archival research on the Erard firm, providing new insight into Erard’s production and marketing strategies.     

A case study of the conservation of the polychromed wooden choirloft of the seventeenth-century church at Carabuco,Bolivia

Abstract

The restoration of the seventeenth-century adobe church at Carabuco, Bolivia, offers a model of how to conduct the preservation of the Latin American cultural heritage at remote sites. This paper details the conservation of the church's polychromed wooden choirloft, which had previously been restored in 1765-66 after this and other portions of the church collapsed. The choirloft is made oflocally grown eucalyptus wood painted all over with a tempera-based medium. It was executed by a local artist whose style draws on local folk-art traditions while reinterpreting European Renaissance decorative schemes. The choirloft conservation project had two goals: to guarantee its structural integrity and to stabilize the decorative paint layers. These goals were accomplished in a four-month conservation project which formed part of a larger effort to restore the church.     

Sanguine Paint: Production,Characterization, and Adhesion to the Glass Substrate

ABSTRACT

For centuries, the only painting materials used in stained-glass production were grisaille and yellow (silver) stain. At the end of the fifteenth century, stained-glass painters began to use a new material, sanguine. This paint is mainly produced with iron oxide particles, usually haematite, and allowed to obtain a colour that can vary from yellowish to brownish-red due to the nature and particle size of the iron oxide. A translucent sanguine was mostly applied as flesh and hair colour, with an opaque sanguine used for drapery, architectural motifs, and heraldry. The main goal of this study is to investigate the relationship between historic sources on the preparation and use of sanguine from the fifteenth to the nineteenth centuries and the evolution evidenced in the recipes regarding the production method. Representative recipes from several centuries (sixteenth to nineteenth centuries) were selected and reproduced for this study. These reconstructions were thoroughly characterized using X-ray powder diffraction, optical microscopy (OM), and fibre optic reflectance spectroscopy (FORS). The OM and FORS data were correlated with historic sanguine paints applied on historic stained-glass. The similarities and differences between historic and reconstructed paints are presented. The study of reconstructed sanguine’s adhesion to glass using cross-cut testing was also performed, revealing that the adhesion is strongly influenced, not only by the binder, but also by the composition and morphology of the sanguine paint.     

Changes in confidence during a period of speech training: Transfer of training and comparison of improved and non‐improved groups on the bell adjustment inventory

The Examiner papers, the Conduct of the Allies, the History of the Four Last Years of the Queen, and the other productions which Jonathan Swift composed during his years as chief publicist for the Tory administration of Harley and St. John (1710–1714) are among the most effective examples of persuasive discourse in the history of British political pamphleteering. Much of this effectiveness is attributable to the skill with which Swift‐steadily aware of the prejudices and demands of his predominantly rural and conservative audience—manipulated such specific rhetorical devices as imagery, anecdote, analogy, historical example, allegory, insinuation, and other such items from the vast catalogue available to the polemicist.     

Scientific evidence by fluorescence spectrometry for safflower red on ancient Japanese textiles stored in the Shosoin Treasure House repository

Shosoin textiles, handed down from the eighth century in Nara, Japan, have entranced many people with their beautiful colors made from natural dyes. Dye analysis of the Shosoin textiles, including the red carpet laid inside the workshop hall at the Todaiji Temple in Nara, used for the inauguration of the statue of the Great Buddha in the temple in 752 AD; a red undergarment and a gown with a tie-dyed design worn by craftsmen in the Todaiji Temple; and embroidered shoes belonging to Empress Komyo (701–760 AD), were conducted by excitation–emission matrix fluorescence spectrometry equipped with a fiber optics probe. Comparison of the spectra to references identified safflower red (Carthamus tinctorius L.) in the red or orange areas on these original textiles. The spectrometry of the gown and the shoes offered the identification not only of safflower red but also of amur cork tree. This study finds these examples to be the oldest scientifically confirmed presence of safflower red on historic textiles at present.     

Examination and treatment of a seventeenth-century Spanish polychrome sculpture by Jose Caro

Abstract

The sculpture of St Gines de la Jara in the collection of the J. Paul Getty Museum, dated 1692, is an outstanding example of the estofado technique of imitating brocade in gold leaf and paint. The life-size figure retains most of its original polychromy. In previous restoration treatments, there had been an unsuccessful attempt to simulate the estofado. The present treatment included a comprehensive technical examination, using X-radiography to identify construction techniques and cross-sectional analysis for the layer structure and materials. The decoration of the sculpture was carefully studied with the goal of understanding more clearly the technique of the estofador. A cleaning strategy was then devised. Where there were losses in the estofado, it was decided to aim for a chromatic compensation using watercolours, rather than attempting to duplicate the original process.     

Seeking Nettle Textiles – Utilizing a Combination of Microscopic Methods for Fibre Identification

Bast fibres have been commonly used as a textile material in Northern Europe since Neolithic times. However, the process of identifying the different species has been problematic, and many important questions related to their cultural history are still unanswered. For example, a modified Herzog test and the presence of calcium oxalate crystals have both been used in identification. In order to generate more reliable results, further research and advancement in multi-methodological methods is required. This paper introduces a combination of methods which can be used to identify and distinguish flax (Linum usitatissimum), hemp (Cannabis sativa), and stinging nettle (Urtica dioica). The research material consisted of reference fibres and 25 fibre samples obtained from 12 textiles assumed to be made of nettle. The textiles were from the Finno-Ugric and Historical Collections of The National Museum of Finland. The fibre samples were studied by observing the surface characteristics and cross sections with transmitted light microscopy, and by using a modified Herzog test with polarized light, in order to identify the distinguishable features in their morphological structures. The study showed that five out of 25 samples were cotton, 16 nettle, one flax, and one hemp. Findings from two samples were inconsistent. The results show that it is possible to distinguish common north European bast fibres from each other by using a combination of microscopic methods. Furthermore, by utilizing these combined methods, new and more reliable information could be obtained from historical ethnographic textiles, which creates new vistas for the interpretation of their cultural history.     

The use of Loansome Doc to meet the needs of unaffiliated health professionals

Objective: This study was undertaken in order to determine how health sciences libraries in a ten-state region are using Loansome Doc, with an emphasis on whether this tool continues to be used to serve unaffiliated health professionals. Methods: Usage data were examined and health sciences libraries were administered a survey to determine how they are using this tool. Results: Loansome Doc usage across libraries is low and declining, and a number of libraries do not serve unaffiliated health professionals with this tool. Conclusions: Use of Loansome Doc is low and declining, in part, due to license restrictions, declining interlibrary loan, and the prevalence of alternatives, such as OCLC's ILLiad, for document delivery to affiliated users.     

A METALLURGICAL EXAMINATION OF TWO EARLY IRON SWORDS FROM LURISTAN

Abstract

Two iron swords from Luristan were examined by X-rays and using metallographic sections. The first sword was shown to have a hilt made of five pieces of metal joined by four rivets, while the pommel was secured by a dowel on the end of the tang. Hilt and blade were sectioned for metallographic study. This showed that while the core of each part was pearlite, decarburization had taken place at the surfaces to give ferritic structures. The second sword was shown to have been made of seven pieces. The pommel was secured as in the first sword, but all other pieces were joined by fitting into prepared slots, the edges of which were burred. A section was cut from the hilt at a point where a decorative band had been applied. This showed large-grained ferrite at the surface and fine-grained ferrite with cementite at the boundaries in the core. It is argued that work previously carried out by other metallographers was inconsistent due to inadequate sampling, and that swords of this type were essentially of wrought iron, the presence of pearlite being accidental rather than intentional.     

A New Hot Table for Relining

Abstract

Two red dyes from 21st dynasty Egypt and one from the 12th dynasty were analyzed. The first two were essentially madder, in one case mixed with small amounts of tannins. The third contained pure haematite (red ochre), thus representing one of the earliest known uses of this pigment for the dyeing of linen.