Video: how glass has shaped Scottish architecture

Glass was first introduced to Scotland by the Romans although its use was limited to military buildings and even then was only limited to the offices and quarters belonging to senior ranking officers.

A few shards of glass have been recovered from post-Roman settlements in Scotland however it was not until the great Cathedral building phase of the twelfth century onwards that glass appears in any quantity.

Glass is made primarily from three basic raw materials. A source of silica is required, a fluxing alkali and a stabiliser.

Sourcing the raw materials was always straightforward as silica sand of suitable quantity, and lime for stabiliser, occur in plentiful quantities in Scotland.

The same is the case for the sources of alkali for fluxing.

Generally speaking, most glass made without a deliberate colourant will have a green tinge.

This is due to the presence of iron compounds in the raw materials or the pots in which the glass is made.

It was a long time before glassmakers understood that they key to making colourless glass was to adjust the chromatic balance rather than attempt to purify the raw materials.

• The above is an extract taken from Building Scotland: Celebrating Scotland’s Traditional Building Materials