Statistical Analysis in Art Conservation Research

Evaluates all components of data analysis and shows that statistical methods in conservation are vastly underutilized. Also offers specific examples of possible improvements

Micro-Computed Tomography with 3D Image Analysis to Reveal Firing Temperature Effects on Pore Systems in Archaeological and Ethnographic Ceramics

Understanding the firing regimes of archaeological ceramics reveals clues about the history of technological developments, but current methods for determining firing history have limitations. We experimented with non-destructive micro-CT combined with 3D image analysis to collect data on 42 pore variables, hypothesizing that pore systems are affected by ceramic firing temperatures. Analysis of variance showed that 26 of the variables are significantly related to firing temperature. Total volume porosity (open and closed pores) goes down with increased firing temperature, as does the fraction of pores accessible to a surface. Maximum pore volume, maximum and standard deviation of pore surface area, and pore elongation measures all decrease with higher firing temperatures while shape factors indicating greater sphericity increase. Pore connectivity measures decrease with higher firing temperatures, and variation in pore and connection lengths increases. The highest fired ceramics have low connection tortuosity. Three-dimensional image analysis of micro-CT data can augment existing methods of archaeothermometry, and since many pore characteristics impact the functional properties of ceramics (density, durability, mechanical strength, thermal conductivity, permeability, and diffusion), firing temperature studies of pore systems can inform wider archaeological ceramics research

The Disappearing Technology and Products of Traditional Tibetan Village Blacksmiths

Tibetans have a long history of iron mining, smelting, and forging. For centuries, craftsmen in major cities and large iron production centers made high-quality swords and suits of armor, as well as decorative iron ritual objects for monasteries and the elites, but blacksmithing workshops in small villages have always produced and repaired everyday objects for agricultural and home use. Modern political changes, along with greater availability of industrial objects in local markets, have greatly reduced the rank of the village blacksmith. Ethnographic fieldwork reported here from two Tibetan Bön villages in the Aba Tibetan and Qiang Autonomous Prefecture, China (once part of traditional Amdo area of Tibet), highlights some of the threats to the continued existence of village blacksmiths. Both a part-time blacksmith in one village and a full-time blacksmith in another make only a marginal living from their work. Their descendants are unlikely to continue the business. Many of the village blacksmiths in the area have already stopped production and closed their workshops. It is likely that the village blacksmith tradition might soon disappear altogether in this region of the world without support. Preservation of this tradition could benefit both cultural and environmental sustainability goals

Bricks from Read House, New Castle, DE

Read House Brick 1: total optical porosity 14%; area percent sand 10% (??? 0.063 mm) Read House Brick 2: total optical porosity 14%; area percent sand 20% (??? 0.063 mm

White Clay, 25% Fine Sand: Scanned Thin Sections

White Clay, 25% Fine Sand (earthenware clay that fires to white), with added sand 25% by volume; sand with fine grain size of 70 mesh (0.210 mm screen opening)

Red Clay, 10% Coarse Sand: Tiled Image, Stitched From Multiple Fields of View Under Microscope, 50x, Plane Polarized Light

Earthenware clay that fires to red, with added sand 10% by volume; sand with coarse grain size of 16 mesh (1.190 mm screen opening)

White Clay, 40% Coarse Sand: 50x Microscope Field of View of Single Thin Section, Plane Polarized Light

Earthenware clay that fires to white, with added sand 40% by volume; sand with coarse grain size of 16 mesh (1.190 mm screen opening)

Red Clay, 10% Coarse Sand, 2x Stereomicroscope Image of Ceramic Surface

Earthenware clay that fires to red, with added sand 10% by volume; sand with coarse grain size of 16 mesh (1.190 mm screen opening)

Red Clay, 40% Medium Sand: 50x Microscope Field of View of Single Thin Section, Plane Polarized Light

Earthenware clay that fires to red, with added sand 40% by volume; sand with medium grain size of 30 mesh (0.595 screen opening)

Red Clay, 40% Medium Sand: Scanned Thin Sections

Earthenware clay that fires to red, with added sand 40% by volume; sand with medium grain size of 30 mesh (0.595 screen opening)