Glassworks and Pottery
We know from both historical documents and map evidence that a pottery (Gordon's Pottery) was located at the eastern side of the site and that it was supposedly constructed on the site of an earlier glassworks. Nothing can be seen of the glassworks and pottery site today as the ground has been levelled and planted with trees.
From literary sources we know that the glassworks had two main phases of activity. During the early part of the 17th century Italian glassmakers were employed to produce fine Venetian. In the later part of the 17th century local glassworkers were employed to produce window glass, moulded glass and mirror glass.
A large area was opened up in the area of the pottery site and after months of painstaking work a substantial, partly-roofed building was identified. The building was represented by two substantial parallel stone-built walls bonded with lime-mortar. Excavation between the walls led to the recovery of a large quantity of pottery sherds dating to the mid-18th century, overlying a flagstone floor. The waste pottery included broken saggers (large pots in which ceramics were fired) and kiln fabric.
Interestingly, rather than being associated with the pottery, the building itself appears to be the surviving underground air flue that would have provided air to the 17th century glassworks furnace. Once it had fallen out of use it was then filled with pottery waste from the later pottery which occupied the site. Corraborating evidence that the building was associated with the glassworks rather than a pottery was found when tiny shards of glass were identified within the cracks of the paving slabs.
The remnants of other buildings, one of which appears to be earlier than the 17th century glassworks flue and had a beaten earth floor, lay close by the flue indicating that the archaeological team may also have found other glassworks and pottery buildings sealed below the ground.
George Haggarty, the project pottery expert, is very excited by the ceramic assemblage that we have recovered. According to George, we may have the largest late 18th century assemblage ever to have been found in Scotland. During a recent visit George confirmed that we have a large collection of forms that are new and, therefore, this is a very important group.
Biddy Simpson, East Lothian Council’s Heritage Officer, said: “Although these finds are relatively recent in date they are very important and exciting. It’s very rare to find an example of a 17th century glassworks and very few have been excavated and recorded. Additionally the types of pottery, which survive within the flue itself, are incredibly rare. Most of the pots that were produced at Prestongrange were exported so there are few surviving examples present in Scotland.”
Bisecting the glassworks flue is the full standing remains of a WW2 air raid shelter. The shelter is in fabulous condition and interestingly it actually re-uses the roofed portion of the flue as part of its underground passage/chamber (see the photograph below). The shelter was recorded as part of the project. 
