New trials in the consolidation of waterlogged archaeological wood with different acetone-carried products

Some acetone-carried consolidants for waterlogged archaeological wood were tested in order to evaluate treatments able to save time and energy. In details, colophony (rosin), two esterified colophonies (Rosin 100^® and Rosin 459^®), a mixture of colophony with PEG 3400 and a vinyl acetate - vinyl versate copolymer (Vinavil 8020S^®) were tested. The treatments were carried out at temperatures of 20 and 35 °C on waterlogged maritime pine, elm, oak and beech. The materials came from the archaeological site of the ancient ships of Pisa (Tuscany, Italy) and were dated back to VII cent. BC – II cent. AD. To evaluate the processes, equilibrium moisture content and dimensional stability of treated wood samples at different relative humidity, and retention of impregnating products were measured; moreover macroscopic and microscopic examination were also run to respectively assess the shape and appearance of treated wood and the way of deposition of consolidants. The results highlighted that natural and modified colophony treatments gave the most satisfactory results both in the maintenance of shape and dimensions of samples and in the stabilization with respect to RH variations. Moreover, the equilibrium moisture contents of samples treated with R100 and R459 were much reduced in comparison to the other consolidants and to untreated archaeological wood. This fact was related to the high retention values of those products that occluded most of the porosity including the microporosity of cell walls. Therefore, in terms of higroscopicity treated wood was more similar to impregnating substances rather than to decayed wood. This fact was considered helpful in contrasting the moisture-related negative effects in cases of eventual faults in the climate control during e.g. exhibition and in protecting treated wood from the risks of new fungal attacks.     

Geographies of exploration and improvement: William Scoresby and Arctic whaling, 1782–1822

Although historians of the long eighteenth century have broadened our understanding of the concept of improvement beyond the agrarian reforms of a landed elite, to other social groups and geographical settings, the private ownership and access to the resources of the oceans and seas are phenomena that have until recently been largely neglected. This paper examines the concept of improvement in the maritime context by exploring a range of tensions between whaling as a form of economic private self-interest on the one hand and as a source of disinterested, virtuous knowledge about the oceans and the animal kingdom on the other hand. William Scoresby, a leading whaling captain and improver, embodied the spirit of those northern European nations which competed to improve the maritime sphere of the northern ocean by implementing different social and technical schemes of enlightenment. He went further than developing new and more efficient and profitable whaling technologies by cultivating disinterested virtue through providing privately obtained natural history specimens from the Greenland Seas for gentleman of science. This in turn gave him entry to participate in the civic circles of polite science and imperial networks of natural history. Although the ascent from industrial whaling in pursuit of profit to disinterested whaling in pursuit of science and exploration made perfect sense to Scoresby, his implicit social improvement laid him open to criticism from those who for different reasons disapproved of the marriage of industrial artisanship and polite natural history. The complexity of Scoresby's identity as an improver is revealed through Robert Jameson, the Professor of Natural History at Edinburgh University, who jealously controlled access to Scoresby's specimens, research, and publications from the Greenland Seas, while simultaneously promoting Scoresby as an intrepid, disinterested captain capable of representing the nation as an Arctic explorer. Through Jameson's Wernerian Natural History Society, they called on government to finance Arctic exploration to reach the North Pole, benefit science, and subsidise the costs through whaling. Their plans were consistent with a long tradition of commercial improvement serving state interests. The Royal Navy's response, to wrest control of Arctic exploration, was by contrast, not a rejection of improvement per se, but rather a determination to place itself at the centre of improvement, by renewing the Board of Longitude with elite, improvement-minded, gentlemen of science, while damning Scoresby with faint praise as an accomplished artisan.     

How an integrated diagnostic approach can help in a correct evaluation of the state of preservation of waterlogged archaeological wooden artefacts

Artefacts made of wood coming from archaeological excavations provide insights into human cultural behaviour of the past. They show how man utilised natural resources and how the development of woodworking techniques and artistic endeavour were developed. Within archaeological contexts, waterlogged anaerobic conditions generally preserve the appearance of artefacts, although wood is subject to severe decay processes. The said conditions can transform the original material into a new one, thus demonstrating specific differences from those of the “fresh” wood of the same species. In order to assess these new properties correctly, an integrated diagnostic approach is needed, one which includes a multidisciplinary (micromorphological, physical and chemical) evaluation of the state of preservation.     

Characterization of Materials and Artistic Techniques on Two 17th‐Century Neapolitan Wood Sculptures

Two sculptures of Gaetano Patalano, one of the most important Italian sculptors of the late 17th century, were analysed to study the stratigraphy, the organic and inorganic materials, and to distinguish the original layers from the repaintings. Samples taken from the Immacolata Concezione and from San Gaetano da Thiene (Santa Chiara church, Lecce, Italy) were studied by optical microscopy, μ‐Raman spectroscopy and Py‐GC–MS. Different binders and pigments were used for the preparatory layers on the different parts of the statues: the results demonstrate that Patalano mastered the various materials and techniques, and that his choices have allowed his carving ability to be emphasized.     

3D modelling of magnetic data from an archaeological site in north-western Tlaxcala state,Mexico

In Archaeology, geophysical methods had been applied usually in a qualitative form, limited only to the use of filters that enhance the data display. The main objective in this work is the implementation of a modelling technique that allows us to reconstruct the geometry of buried bodies and the determination of their depths. This is done by means of the estimation of the magnetic moments of archaeological objects using a three-dimensional mesh of individual magnetic dipoles using the least squares method and the singular value decomposition of a weighted matrix to solve the linear problem. The distribution and shape of the underlying archaeological remains can be inferred. This methodology was applied to an archaeological site called Los Teteles de Ocotitla, in the state of Tlaxcala, Mexico. A high-resolution magnetic prospection was carried out in three selected areas (terraces). The most important total field anomalies found on each area were inverted, obtaining results that were corroborated by archaeological excavations. This investigation demonstrates the potential of quantitative geophysical methods for the characterization of archaeological structures, in extension and in depth.     

Electoral rule and public sector efficiency: Some evidence from Italian municipalities

We study the effect of Law 81/1993, which introduced a different rule for the election of mayors, on the technical efficiency of Italian cities over the period 1998–2006. Since 1993, municipalities below 15,000 inhabitants vote with a single-ballot system, whereas cities above 15,000 inhabitants are subject to a double ballot. We first estimate the output-oriented technical efficiency of municipalities through data envelopment analysis, and then we perform a regression discontinuity design analysis by exploiting the exogenous change in the electoral scheme at the 15,000 inhabitants cut-off. We find evidence that municipalities voting under a double-ballot rule show lower levels of efficiency—in terms of provision of public goods—compared with cities voting under a single-ballot scheme, by about 6.5%. This effect is driven by inefficiencies registered in specific sectors, that is, police, education, and maintenance of roads. Furthermore, the overall lower efficiency of municipalities voting under runoff is related to the different level of educational attainment of elected mayors, whereas it is not driven by the features of Law 81/1993 relating to the number of lists forming a coalition in support of mayoral candidates and to disjoint votes.