1705 – 1780
William had wide interests, but his major achievement was to begin porcelain manufacturing in Britain. He was also a very active Quaker minister.
He was the eldest child of Quaker serge maker William Cookworthy of Kingsbridge Devon. His father died when he was thirteen leaving his mother in straitened circumstances.
He was apprenticed to Quaker apothecaries Timothy and Sylvanus Bevan in London at the age of 15. He walked over 200 miles to London, as he could not afford the coach fare. During his apprenticeship he learnt Latin, Greek and French as well as drug dispensing. On completion of his apprenticeship the Bevans, recognising his skills, took him into partnership. In 1726 the firm of Bevans and Cookworthy, wholesale chemists and druggists, was established in Plymouth under his management.
In 1736 he married Sarah Berry at Taunton Meeting House. After her death in 1745 with five daughters to bring up on his own he withdrew from the business and his brother Philip took over the day to day management. He then devoted his energies to religious work and china clay experiments.
At that time potteries only made earthenware and porcelain was imported from China. Cookworthy was the first to recognise that the twin ingredients of Chinese porcelain, (kaolin for the body and petuntse for the glaze) were to be found in Cornwall in the china clay and moorstone.
By 1758 his porcelain making experiments had resulted in successful firing of clay. Unfortunately the first clay he used contained black specks of mica, but soon after this, large deposits of china clay were found near St Austell. Thomas Pitt (later Lord Camelford), the owner of the land, helped Cookworthy to obtain a patent to manufacture porcelain using the Cornish ingredients and provided the necessary finance for his work.
A small porcelain factory was opened in Plymouth in 1768, financed by local men, including Cookworthy, and a group of Quakers from Bristol. Some of the blue and white china produced was exported to America. The factory closed in 1770 due to there being insufficient skilled people, but the work was transferred to Bristol. Cookworthy oversaw porcelain manufacture there until 1773 when he decided to sell his interest in the factory and his patent rights to his business partner and cousin, Richard Champion. Cookworthy continued to receive a royalty on every item made.
When Richard tried to renew Cookworthy’s patent in 1777, Josiah Wedgwood and other potters in Staffordshire raised objections and although the patent formula was upheld, the cost of the legal battle crippled the Company. Richard sold the formula in 1782 to the Staffordshire based New Hall Porcelain Company.
Cookworthy was also a Quaker minister and religious thinker. The death of his wife and his withdrawal from business strengthened his faith. He took an unpopular stance with his fellow Quakers in Plymouth when he urged them not to compromise their pacifist principles by dealing in “prize goods” which had been obtained from captured vessels. He travelled widely in the ministry in the south western counties of England and represented Devon Friends at yearly meeting in London in 1748. He believed in the importance of the power of the divine inner light within people. In 1751 he published a translation of Muralt’s ‘L’instict divin’ as the ‘The Divine Instinct Recommended to Men’. He also translated the writing of the Swedish visionary Emanuel Swedenborg.
He was a polymath, more inclined to scholarship than business. Amongst his friends were the doctor and botanist John Fothergill, scientist Joseph Banks and explorer Captain James Cook.
John Smeaton, builder of the Eddystone Lighthouse, near Plymouth, lodged with him for a time. Cookworthy assisted him with developing hydraulic lime, which was essential for the building of the lighthouse.
He advised naval officers that scurvy could be prevented and treated by supplying crews with fresh fruit and vegetables or with sauerkraut if fresh foods were not available.
He had a willingness to embrace unorthodox views and believed that divining rods could locate metallic lodes. He contributed an essay advocating their use to William Pryce’s ‘Mineralogia Cornubiensis’ in 1778.
He died in Plymouth in 1780 and is buried in the Quaker burial ground there.