Glassworking at Glastonbury Abbey, a summary of the recent reanalysis, by Dr Hugh Willmott & Dr Kate Welham
University of Sheffield and Bournemouth University
Between 1955-57 the excavations at Glastonbury Abbey produced the first, and to date most comprehensive, assemblage of early medieval glassworking structures and debris to have been recorded in the UK. Since being excavated over 50 years ago, the assemblage has been subject to study by a number of scholars, the first descriptions of the furnaces and brief catalogues of artefacts undertaken by Donald Harden shortly after the excavations (Bayley 1990). The current project has brought together many additional finds and records, and is the first comprehensive study of every aspect of the glassworking archive. A short summary of the key work to date is presented here.
The Furnaces & Glassworking Practices
Analysis of the full archive including new work on the distribution of finds has allowed a reinterpretation of both the glass furnaces and glassworking practices at Glastonbury. The glass furnaces are similar in form to the Anglo-Saxon example excavated at Barking, and previous work had identified four furnaces, in three main areas. Area one contained furnaces 1 and 2, but stratigraphic analysis suggests that they were not contemporary; rather 1 appears to replace 2. Beneath both is a mortar working floor which, although not directly connected with the furnaces, can now be linked to them by a concentration of glassworking debris over them when compared with the surrounding area. Area two lies immediately to the west and contains the remains of the best-preserved furnace, previously numbered 3. This also has a similar associated working area, although one with a clay rather than a mortar floor. To the south-east in the east cloister walk the final area of glassmaking activity was recorded. Although previously described as furnace 4, no structural remains were found, and Harden originally suggested the furnace might actually lie to the east underneath the unexcavated portion of the eastern range. Reanalysis suggests that the furnace may well survive in-situ in the area of the former trench, underneath a layer of unexcavated clay.
The glassworking material indicates that there are clear differences in the types of glass recovered at Glastonbury. Almost all the blowing waste was naturally coloured (blue/green) glass; of the fifteen moils that still survive only one, which is amber, is not blue/green. This combined with the find of at least one coloured premade slab, leads to the suggestion that glass was primarily blown from reused Roman blue/green cullet and only decorated with coloured trailing and marvered decoration possibly using imported ingots. There is also a clear concentration of coloured glass in the cloister walk area, whilst the glass from the intercut furnaces (1 and 2) is almost exclusively naturally blue/green. This might suggest there is also a temporal differentiation between these two areas.
Of particular interest are a small number of crucibles that survive from the excavations and a firm provenance for their fabric needs to be established. Initial analysis has suggested non-local clay, possibly Poole Harbour, the Reading Beds, or a continental link. There have been hints at other comparative sites that French glassmakers may have been used at this time, and a wider comparison of similar material is required.
The project is coming to a close and work is now focused on finalising the archive and report. A range of samples have also been sent for analysis and the results will be incorporated into the final publication.