Assessing the Long-term Success of Reigate Stone Conservation at Hampton Court Palace and the Tower of London

Reigate stone was extensively used in medieval London and is prone to rapid decay. A variety of different conservation treatments has been applied in the past; in many cases, these have not mitigated on-going decay. This paper presents an overview of wax, limewash, silane and ammonium tartrate treatment at the Tower of London and Hampton Court Palace. Documentary analysis and visual inspection indicate that whilst these methods have provided protection to some stones, no single method has resulted in the protection of all stones. Non-destructive and minimally-destructive testing is used to more closely assess the effects of ammonium tartrate treatment. The results imply that inherent stone mineralogy, past decay pathways and/or present environmental factors are a greater influence on on-going decay than treatment histories

Methodology for tensile testing historic tapestries

Historic tapestries are very important and complex artworks. Their heterogeneous structure composed with different materials is weaved in warp and weft threads with the objective of render an image to be displayed. Often on open display these objects are exposed to forces caused by their own weight as well as by the strain experience due to moisture adsorption and desorption cycles when temperature and relative humidity of the surrounding environment fluctuate. Since physical damage is usually supported by conservation stitching techniques there is a need to understand how certain decisions would influence future mechanical behaviour of a tapestry. This requires the need of establishing a methodology that helps to understand how different sections of these heterogeneous objects respond when forces are applied to them. Past research considered tensile testing of primarily new woven aged sections which are not representative of the historic tapestries [1]. Digital image correlation (DIC) was also successfully used in order to characterize the strain states of woven tapestries [2]. However, information on how wool and silk behaves as well as the influence of damage and stitching in some areas is still scarce and there is the lack of a methodology for a full strain analysis. In this research, tensile mechanical behaviour is being studied in order to inform on how different fragments of historic tapestries behave when a certain tensile force is applied on them. For this, a new methodology of analysis is proposed. Force strain curves collected from tensile tests are analysed together with complementary DIC data to understand the strain states that were present in different stages of the mechanical tests. Results proved that a holistic methodology, using both techniques required for successful interpretation of data. Furthermore, this experimental work demonstrated that tapestry areas behave differently when a tensile force is applied

The effect of changes in air humidity on historic tapestries

Historic tapestries are textile artworks usually found hanging inside historic buildings. They form part of the European heritage have been exposed for centuries to diverse environmental conditions some of which have permanently damaged them. To inform better appropriate conservation practices, their physical behavior when exposed to environmental changes must be understood. The research conducted aimed to assess how the internal environment conditions in a historic building affects the tapestries’ structures and produce change in their strain. For this a series of experiments on a historic 19th century tapestry inside an environmental chamber carried out and cycles of moisture adsorption and desorption tested. Digital Image Correlation (DIC) and magnetic sensors developed by were used to test successive stages of expansion and retraction of the tapestry given different levels of relative humidity (RH) in the environment

Diagrams of equal area coverage: a new method to assess dust deposition in indoor heritage environments

Particulate matter can cause a loss of value of in indoor heritage, and for this reason it is frequently monitored. The process of deposition is well-described by theoretical models that relate deposition rates with environmental variables. However, we find that the inputs and outputs of models are not directly relevant to preventive conservation. While heritage managers are concerned about area coverage by particulates, the existing models use deposition velocities as the main variable. We propose an improved graphical representation of predictions of deposition, that takes inputs that can be modified as part of preventive conservation plans (concentration and air movement) and an output that can be related to risk assessment and cleaning schedules (time to visible area coverage). By comparing the predictions with experimental data, we show that this approach is useful for small particles of outdoor origin. We also find that further research is needed to make numerical predictions relevant for cases where deposition involves coarse dust and is caused by visitor movement

FIB-FESEM and EMPA results on Antoninianus silver coins for manufacturing and corrosion processes

[EN] A set of ancient Antoninianus silver coins, dating back between 249 and 274¿A.D. and minted in Rome, Galliae, Orient and Ticinum, have been characterized. We use, for the first time, a combination of nano-invasive (focused ion beam-field emission scanning electron microscopy-X-ray microanalysis (FIB-FESEM-EDX), voltammetry of microparticles (VIMP)) and destructive techniques (scanning electron microscopy (SEM-EDX) and electron microprobe analysis (EMPA)) along with non-invasive, i.e., micro-Raman spectroscopy. The results revealed that, contrary to the extended belief, a complex Ag-Cu-Pb-Sn alloy was used. The use of alloys was common in the flourishing years of the Roman Empire. In the prosperous periods, Romans produced Ag-Cu alloys with relatively high silver content for the manufacture of both the external layers and inner nucleus of coins. This study also revealed that, although surface silvering processes were applied in different periods of crisis under the reign of Antoninii, even during crisis, Romans produced Antoninianus of high quality. Moreover, a first attempt to improve the silvering procedure using Hg-Ag amalgam has been identified.Financial support was provided by Sapienza University of Rome (Ateneo funding, 2014 15) and Spanish projects CTQ2014-53736-C3-1-P and CTQ2014-53736-C3-2-P, which are supported with Ministerio de Economía, Industria y Competitividad (MINECO) and Fondo Europeo de Desarrollo Regional (ERDF) funds, as well as project CTQ2017-85317-C2-1-P supported with funds from, MINECO, ERDF and Agencia Estatal de Investigación (AEI). PhD grants of the Department of Earth Sciences, Sapienza University of Rome, are gratefully acknowledgedDomenech Carbo, MT.; Di Turo, F.; Montoya, N.; Catalli, F.; Doménech Carbó, A.; De Vito, C. (2018). FIB-FESEM and EMPA results on Antoninianus silver coins for manufacturing and corrosion processes. Scientific Reports. 8. https://doi.org/10.1038/s41598-018-28990-xS8Doménech-Carbó, A., del Hoyo-Meléndez, J. M., Doménech-Carbó, M. T. & Piquero-Cilla, J. Electrochemical analysis of the first Polish coins using voltammetry of immobilized particles. Microchem. J. 130, 47–55 (2017).Di Turo, F. et al. Archaeometric analysis of Roman bronze coins from the Magna Mater temple using solid-state voltammetry and electrochemical impedance spectroscopy. Anal. Chim. Acta 955, 36–47 (2017).Doménech-Carbó, A., Doménech-Carbó, M. T. & Peiró-Ronda, M. A. Dating Archeological Lead Artifacts from Measurement of the Corrosion Content Using the Voltammetry of Microparticles. Anal. Chem. 83, 5639–5644 (2011).Giumlia-Mair, A. et al. Surface characterisation techniques in the study and conservation of art and archaeological artefacts: a review. Materials Technology 25(5), 245–261 (2010).Robbiola, L. & Portier, R. A global approach to the authentication of ancient bronzes based on the characterization of the alloy–patina–environment system. Journal of Cultural Heritage 7, 1–12 (2006).Campbell, W. Greek and Roman plated coins, Numismatics Notes and Monographs 57, American Numismatic Society, New York (1933).Kallithrakas-Kontos, N., Katsanos, A. A. & Touratsoglou, J. Trace element analysis of Alexander the Great’s silver tetradrachms minted in Macedonia, Nuclear Instruments and Methods in Physics. Research B 171, 342–349 (2000).Catalli, F. Numismatica greca e romana. (Libreria dello Stato, 2003).Cope, L. H. The Metallurgical development of the Roman Imperial Coinage during the first five centuries. (Liverpool, 1974).Scriptores Historiae Augustae. Historia Augusta. (The Perfect Library, 2014).Vlachou-Mogire, C., Stern, B. & McDonnell, J. G. The application of LA-ICP-MS in the examination of the thin plating layers found in late Roman coins. Nucl. Instruments Methods Phys. Res. Sect. B Beam Interact. with Mater. Atoms 265, 558–568 (2007).Keturakis, C. J. et al. Analysis of corrosion layers in ancient Roman silver coins with high resolution surface spectroscopic techniques. Appl. Surf. Sci. 376, 241–251 (2016).Ingo, G. M. et al. Roman sophisticated surface modification methods to manufacture silver counterfeited coins. Appl. Surf. Sci. 1–11, https://doi.org/10.1016/j.apsusc.2017.01.101 (2017).La Niece, S. In: La Niece S. & Craddock, P. (Eds), Metal, Plating and Platination, Butterworth–Heinemann, London, 1993, p. 201.Anheuser, K. & France, P. Silver plating technology of the late 3rd century Roman coinage. Historical Metallurgy 36(1), 17–23 (2002).Anheuser, K. & Northover, P. Silver plating on Roman and Celtic coins from Britain– A technical study. The British Numismatic Journal 64, 22–32 (1994).Anheuser, K. Where is all the amalgam silvering? Materials Issues1996 in Art and Archaeology - V proceedings, Boston.Beck, L. et al. In NIM 269, 2011 and in Counterfeit coinage of the Holy Roman Empire in the 16th century: silvering process and archaeometallurgical replications, Archaeometallurgy in Europe III.Deraisme, A., Beck, L., Pilon, F. & Barrandon, J. N. A study of the silvering process of the Gallo-Roman coins forged during the third century AD. Archaeometry 48, 469–480 (2006).Giumlia-Mair, A. On surface analysis and archaeometallurgy. Nucl. Instruments Methods Phys. Res. Sect. B Beam Interact. with Mater. Atoms 239, 35–43 (2005).Tate, J. Some problems in analysing museum material by nondestructive surface sensitive techniques. Nuclear Inst. and Methods in Physics Research, B, 14 (1), pp. 20–23 (1986).Beck, L., Bosonnet, S., Réveillon, S., Eliot, D. & Pilon, F. Silver surface enrichment of silver-copper alloys: A limitation for the analysis of ancient silver coins by surface techniques. Nucl. Instruments Methods Phys. Res. Sect. B Beam Interact. with Mater. Atoms 226, 153–162 (2004).Pardini, L. et al. X-ray fluorescence and laser-induced breakdown spectroscopy analysis of Roman silver denarii. Spectrochim. Acta - Part B At. Spectrosc. 74–75, 156–161 (2012).Klockenkämper, R., Bubert, H. & Hasler, K. Detection of near-surface silver enrichment on Roman imperial silver coins by x-ray spectral analysis. Archaeometry 41, 311–320 (1999).Ponting, M., Evans, J. A. & Pashley, V. Fingerprinting of roman mints using laser-amblation MC-ICP-MS lead isotope analysis.Del Hoyo-Meléndez, J. M. et al. Micro-XRF analysis of silver coins from medieval Poland. Nucl. Instruments Methods Phys. Res. Sect. B Beam Interact. with Mater. Atoms 349, 6–16 (2015).Cesare Brandi. Il restauro. Teoria e pratica (1939–1986). (Editori Riuniti, 2009).Barberio, M., Veltri, S., Scisciò, M. & Antici, P. Laser-Accelerated Proton Beams as Diagnostics for Cultural Heritage. Sci. Rep. 7, 40415 (2017).Linke, R., Sehreiner, M., Demortier, G., Alram, M. & Winter, H. Non-Destructive Microanalysis of Cultural Heritage Materials. Comprehensive Analytical Chemistry 42, (Elsevier, 2004).Łojewska, J. et al. Recognizing ancient papyri by a combination of spectroscopic, diffractional and chromatographic analytical tools. Sci. Rep. 7, 46236 (2017).Meulebroeck, W., Wouters, H., Nys, K. & Thienpont, H. Authenticity screening of stained glass windows using optical spectroscopy. Nat. Sci. Reports 6 37726, 1–10 (2016).Martina, I., Wiesinger, R. & Schreiner, M. Micro-Raman Characterisation of Silver Corrosion Products: Instrumental Set Up and Reference. e-Preservation. Sci. Rep 9, 1–8 (2012).Rizzo, F. et al. Non-destructive determination of the silver content in Roman coins (nummi), dated to 308–311 A. D., by the combined use of PIXE-alpha, XRF and DPAA techniques. Microchem. J. 97, 286–290 (2011).Carl, M. & Young, M. L. Complementary analytical methods for analysis of Ag-plated cultural heritage objects. Microchem. J. 126, 307–315 (2016).Cepriá, G., Abadías, O., Pérez-Arantegui, J. & Castillo, J. R. Electrochemical Behavior of Silver-Copper Alloys in Voltammetry of Microparticles: A Simple Method for Screening Purposes. Electroanalysis 13, 477–483 (2001).Capelo, S., Homem, P. M., Cavalheiro, J. & Fonseca, I. T. E. Linear sweep voltammetry: a cheap and powerful technique for the identification of the silver tarnish layer constituents. J. Solid State Electrochem. 17, 223–234 (2013).Doménech-Carbó, A. et al. Detection of archaeological forgeries of Iberian lead plates using nanoelectrochemical techniques. The lot of fake plates from Bugarra (Spain). Forensic Sci. Int. 247, 79–88 (2015).Doménech-Carbó, A., Doménech-Carbó, M. T. & Peiró-Ronda, M. A. ‘One-Touch’ Voltammetry of Microparticles for the Identification of Corrosion Products in Archaeological Lead. Electroanalysis 23, 1391–1400 (2011).Doménech-Carbó, A., Doménech-Carbó, M. T., Montagna, E., Álvarez-Romero, C. & Lee, Y. Electrochemical discrimination of mints: The last Chinese emperors Kuang Hsü and Hsüan T’ung monetary unification. Talanta1 69, 50–56 (2017).Ager, F. J. et al. Combining XRF and GRT for the analysis of ancient silver coins. Microchem. J. 126, 149–154 (2016).Fawcett, T., Blanton, J., Blanton, T., Arias, L. & Suscavage, T. Non-destructive evaluation of Roman coin patinas from the 3rd and 4th century. Powder Diffraction, 1–10.Salvemini, F. et al. Neutron tomographic analysis: Material characterization of silver and electrum coins from the 6th and 5th centuries B.C. Mater. Charact. 118, 175–185 (2016).Ashkenazi, D., Gitler, H., Stern, A. & Tal, O. Metallurgical investigation on fourth century BCE silver jewellery of two hoards from Samaria. Sci. Rep. 7, 40659 (2017).Romano, F. P., Garraffo, S., Pappalardo, L. & Rizzo, F. In situ investigation of the surface silvering of late Roman coins by combined use of high energy broad-beam and low energy micro-beam X-ray fluorescence techniques. Spectrochim. Acta - Part B At. Spectrosc. 73, 13–19 (2012).Ingo, G. M. et al. Ancient Mercury-Based Plating Methods: Combined Use of Surface Analytical Techniques for the Study of Manufacturing Process and Degradation Phenomena. Accounts of Chemical Research 46(11), 2365–2375.Pouchou, J. L. & Pichoir, F.¨PAP¨ (ϕ–ρ–Z) procedure for improved quantitative microanalysis, in: Armstrong, J. T. (Ed.), Microbeam Analysis, San Francisco Press, San Francisco, pp. 104–106 (1985)

Tennis player J. Willard after hitting a forehand shot, New South Wales, ca. 1930 [picture].

Title devised from accompanying information where available.; Part of the: Fairfax archive of glass plate negatives.; Fairfax number: 4918.; Condition: silvering.; Also available online at: http://nla.gov.au/nla.pic-vn6251103; Acquired from Fairfax Media, 2012