Numerous recent excavations in the UK have uncovered furnaces and other structures used for the manufacture of glass. The scale of these sites (especially the later brick-built cone structures that housed furnaces) provides numerous challenges that are best tackled with the provision of expert advice on the most effective approaches.Understanding the ways in which glass was produced allows the selection of the best contexts for sampling and the identification of the most rewarding materials.
The visual examination of glass-working waste is crucial as a high proportion of the vitreous waste from later (especially coal-fired) glasshouses has been contaminated by reactions with coal ash or other materials. Some of the most useful materials are small threads which are often best recovered from soil samples.
The scientific investigation of the glass-working residues from these sites has provided insights into the English glass industry. The scientific examination of early glass (in particular its chemical analysis) provides a basis for understanding how it was made and can underpin conservation treatments. This can include well established techniques but has made use of innovative technologies such as scanning micro-XRF to image decoration on poorly preserved medieval glass.