Re-creation of the 1744 Heylyn and Frye ceramic patent wares using Cherokee clay: Implications for raw materials, kiln conditions, and the earliest English porcelain production
✍ Scribed by W.R.H. Ramsay; G.R. Hill; E.G. Ramsay
- Publisher
- John Wiley and Sons
- Year
- 2004
- Tongue
- English
- Weight
- 378 KB
- Volume
- 19
- Category
- Article
- ISSN
- 0883-6353
No coin nor oath required. For personal study only.
✦ Synopsis
Porcelain wares have been produced following the directions contained in the Heylyn and Frye patent of 1744, using Cherokee clay and a lime-alkali glass frit. The wares were fired to the bisque (~ 950°C), glazed using a clay-glass mixture, and then fired to a "heat-work" level of Orton cone 9-90°deflection at 150°C per hour (1279°C). Modal mineralogy comprises Caplagioclase and two glass phases, one relict frit and the other a melt phase. The bulk chemistry of the body comprises 64.3 wt % SiO 2 , 21.7 wt % Al 2 O 3 , and 5.6 wt % CaO. Molecular ratios are SiO 2 :Al 2 O 3 5.0 and SiO 2 :CaO 10.7. It is concluded that the patent, whose significance has been questioned over many years, was a practical working recipe, that close comparison may be made with porcelains of the "A"-marked group, and that the patent represents a remarkable landmark in English ceramic history.