Laura Ware Adlington

The life histories of medieval stained glass windows: An archaeometric approach using handheld pXRF

A stained glass window represents a complex chaîne opératoire and has the potential to deepen our understanding of medieval craft workshops. This work aims to investigate the life history of medieval stained glass windows through a materials science approach.

Unfortunately, analysis is made difficult by the architectural context of the glass, so often we must rely on in situ methods such as pXRF, which is problematic due to deterioration. Therefore, the development of a methodology using pXRF for the study of medieval stained glass has been a core part of this work. The two major contributions of this research are (1) the development of a methodology using heavy trace elements, which are well analysed despite poor surface conditions (presence of corrosion, grisaille paint and yellow silver stain) and (2) the design and production of a custom attachment for the pXRF for window analysis, intended to reduce the obstacle of the lead cames which hold the glass pieces together.

The primary case study is the Great East Window of York Minster, constructed between 1405 and 1408 by master glass-painter John Thornton of Coventry and his workshop. This window has been the focus of an extensive conservation project called York Minster Revealed, which has enabled in-depth examination and study of the window. The glass was analysed by pXRF, EPMA-WDS, LA-ICP-MS and TIMS, and the exciting results of this study include (1) the identification of a glass-making workshop in Staffordshire that supplied the window; (2) the identification of the work of different painters, which allowed the study of skill, learning and the role of apprentices; and (3) study of changing workshop organisation over the course of the three year project glazing the window.

A secondary case study focused on the Ancestors of Christ series, glazed between 1178 and 1220 for the clerestory of Canterbury Cathedral. As sampling the glass was not possible for these panels, this case study provided an opportunity to test the newly developed pXRF methodology in isolation of other techniques. The results of this study include (1) the identification of a change in glass source, which is then related to the changing circumstances in production, and (2) the confirmation of an earlier hypothesis (Caviness 1987) that one of the figures dates to the early 1100s and was then re-used in this series almost a century later.

Both case studies provide an opportunity to study the weathering of the glass, a significant topic given the susceptibility of medieval glass to deterioration, as well as the conservation interventions that have been undertaken in the several centuries since their original glazing. 

Funding organisation

  • UCL Graduate Research Scholarship
  • UCL Overseas Research Scholarship

Supervisors

 Educational background

  • BA (Honours), Classical Studies, Wake Forest University, 2010
  • MSc (Distinction), Technology and Analysis of Archaeological Materials, UCL, 2013

 Adlington, L.W. and Freestone, I.C. (2017). Using handheld pXRF to study medieval stained glass: A methodology using trace elements. MRS Advances, 2(33-34): 1785-1800. doi: 10.1557/adv.2017.233, open access version available at discovery.ucl.ac.uk/1541186

Adlington, L.W. (2017). The Corning Archaeological Reference Glasses: New Values for "Old" Compositions. Papers from the Institute of Archaeology, 27(1): 1-8. doi: 10.5334/pia-515

Adlington, L.W. (2016). The Hand of the Painter? Understanding Medieval Glass-painting Workshop Organisation through Scientific Analysis. Vidimus 101: Feature. vidimus.org/issues/issue-101/feature/

Bruschetti, P., Gialluca, B., Giulierini, P., Reynolds, S. and Swaddling, J. (eds.) (2014). Seduzione Etrusca. Dai segreti di Holkham Hall alle Meraviglie del British Museum. Milan: Skira. [Contributor]

Selected Conference Presentations

Adlington, L.W. (2017, November) "3D printing for the study of medieval stained glass", Invited paper presented at the Institute of Making, London, UK.

Adlington, L.W. (2017, September) "Glass recycling in the early medieval period", Paper presented at Material (Im?)mobility in Past Societies, London, UK.

Adlington, L.W., Freestone, I.C. and Seliger, L. (2017, May) "The Ancestors of Christ from Canterbury Cathedral: An investigation of medieval stained glass window production by handheld pXRF". Paper presented at UK Archaeological Science conference (UKAS), London, UK.

Adlington, L.W., Freestone, I.C. and Teed, N. (2016, November) "The Organisation of Production in the Medieval Glass-Painting Workshop of John Thornton - An Archaeometric Investigation Using Handheld pXRF". Paper presented at the Materials Research Society Fall Meeting, Boston, Massachusetts, USA.

Adlington, L.W. Freestone, I.C. and Teed, N. (2016, May) "Elemental Composition and Craft Practice in a Medieval Window Glass Workshop". Paper presented at the 41st International Symposium on Archaeometry (ISA), Kalamata, Greece.

Adlington, L.W., Freestone, I.C., and Teed, N. (2015, September) "The hand of the painter? Understanding medieval glass-painting workshop organisation through scientific analysis". Paper presented at the 20th Congress of the International Association for the History of Glass (AIHV), Fribourg-Romont, Switzerland.

  • Illustration of the depth of analysis of potassium and calcium by pXRF, imposed on a back-scattered electron image of a glass piece from the Great East Window of York Minster that shows a leached layer extending to about 50μm. A key contribution of this research is the development of a methodology using heavy trace elements, which are analysed from deeper within the glass and are less affected by surface conditions. Figure 8 from Adlington & Freestone 2017.
  • Four glass pieces from the Great East Window of York Minster, representing the four most commonly used colours surviving amongst the original glass. The various colours, with their different chemical compositions, have variable deterioration. Scale is in centimeters. Figure 2 from Adlington & Freestone 2017.
  • Analysis by pXRF of a figure from the Ancestors of Christ series from Canterbury Cathedral. While the pXRF methodology developed and used in this research will always be best when used together with other analytical techniques, this is not always possible. This case study was a successful test of the methodology used in "in situ" conditions, in isolation of other techniques.

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