Notes on the Manufacture of Porcelain at Chelsea

A furnace built in 1618 by Abraham Bigo and Sir William Clavell for the manufacture of window glass was excavated at Kimmeridge, Purbeck, Dorset (SY 909788) in 1980–81. Local oil-shale was used as a fuel in the furnace, whose central fire was fed with air by means of two passages below ground level, as found at other seventeenth-century furnaces and indicated in contemporary sources. The above-ground structure comprised sieges and wings whose plan resembled those of sixteenth-century forest-glass furnaces. Vessel glass was produced at Kimmeridge in traditional forms for sale in the south-western counties, by agreement with Sir Robert Mansell, patentee of the monopoly for glass manufacture. Trade beyond the designated area led to legal action which resulted in the demolition of the furnace in 1623. The excavation showed that the product of the furnace was green vessel glass of good durability, melted in crucibles made from high-quality refractory clay derived from Purbeck sources.