William Cookworthy (12 April 170517 October 1780) was an English Quaker minister, a successful pharmacist and an innovator in several fields of technology. He was the first person in Britain to discover how to make hard-paste porcelain, like that imported from China. He subsequently discovered china clay in Cornwall. In 1768 he founded a works at Plymouth for the production of Plymouth porcelain; in 1770 he moved the factory to Bristol, to become Bristol porcelain, before selling it to a partner in 1773. Parents, birth, siblings and early life He was born of Quaker parents in Kingsbridge, Devon on 12 April 1705. His father, also called William, was a weaver and his mother was Edith, the daughter of John and Margaret Debell of St Martin-by-Looe in east Cornwall: they had married in 1704. Their children were: William – 1705 Sarah – 1706 Jacob – 1709 Susannah – 1711 Mary – 1714 Philip – 1716 Benjamin – 1717 William was a bright child but his education was halted when his father died on 22 October 1718 and the family's investment in the South Sea Company failed in the autumn of 1720. William had been offered an apprenticeship, at no cost, by the Bevan Brothers, two Quaker apothecaries, with a successful business in London. As the family had no spare money, William walked to London to take up the offer and, eventually, completed the apprenticeship. He was taken into partnership. Plymouth He moved to Plymouth, where he set up a pharmacy as Bevan and Cookworthy. This flourished. He eventually brought his brothers Philip and Benjamin into the partnership and bought out the Bevans' interest in 1745. He became prominent among Devon Quakers, being appointed as an Elder. Among his concerns was that Quakers should not tolerate their members trading in prize goods (ships and their cargoes seized in war), as Quakers should not benefit from war. The manufacture of porcelain was at the time attracting great attention in England, and while the factories at Bow, Chelsea, Worcester and Derby were introducing the artificial glassy porcelain, Cookworthy, following the accounts from China of the Jesuit priest Père d'Entrecolles, spent many years in searching for English materials similar to those used in China. From 1745 onwards he seems to have travelled over the greater portion of Cornwall and Devon in search of these minerals, and he finally located them in the parish of St