Nicholas Crisp's “Porcellien”: A petrological comparison of sherds from the Vauxhall (London; ca. 1751–1764) and Indeo Pottery (Bovey Tracey, Devonshire; ca. 1767–1774) factory sites
✍ Scribed by J. Victor Owen; Brian Adams; Roy Stephenson
- Book ID
- 102661158
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 595 KB
- Volume
- 15
- Category
- Article
- ISSN
- 0883-6353
No coin nor oath required. For personal study only.
✦ Synopsis
The character of porcelain wares made by Nicholas Crisp early and late in his career was assessed using microchemical and petrographic data for sherds excavated from the sites of the factories he operated at Vauxhall and Bovey Tracey. The results indicate that, over time, Crisp increasingly made use of diverse types of pastes as he struggled to produce a commercially viable line of porcelain. Based on the analysis of a limited number of samples, he appears to have largely restricted himself at Vauxhall to using soapstone (Mg-rich)-and flintglass (Pb-rich) frit-bearing pastes that varied in the amount of calcite they contained. He also experimented with MgϩPb-rich pastes at Bovey Tracey, but included a novel ingredient (barite) and varied the proportion of other minor constituents (e.g., bone ash), apparently in an effort to resolve some of the firing problems that plagued him at Vauxhall. In addition, Crisp appears to have produced bone ash (phosphatic) porcelain at Bovey Tracey, and, in collaboration with William Cookworthy, the proprietor of the Plymouth factory, fired a range of true porcelain (SiϩAl-rich) pastes. Bulk compositional data indicate that Crisp's diopsidebearing MgϩPb-rich wares were derived from pastes containing talc and calcite rather than dolomite. The mineralogy of these and some contemporary magnesian/plombian porcelains are interpreted using the SiO 2 -CaO-MgO phase diagram. This diagram shows that these wares can form and preserve diopside (Ca-Mg silicate) given suitable bulk CaO contents and kilnfiring temperatures. Phosphatic sherds from Bovey Tracey are compositionally distinct (lower SiO 2 and higher Al 2 O 3 and bone-ash components) from a single bone-ash sample from Vauxhall, indicating that Crisp experimented with novel bone-ash pastes, and was not positively influenced by the Vauxhall phosphatic recipe, if indeed one existed. True porcelains from Bovey Tracey have more extreme SiO 2 /Al 2 O 3 ratios (ϭ 2.0 [two sherds]; 4.5 [one sherd]) than their Plymouth/Bristol counterparts (SiO 2 /Al 2 O 3 ϭ 2.3-3.0). Collectively, the analytical data underscore the experimental-and ultimately unsuccessful-character of the diverse wares produced by Nicholas Crisp.