In fact it is this that gives to Cookworthy so important a place in the history of porcelain. He was probably the first in Europe to attack practically, and finally to conquer, the problem of making a true porcelain strictly on the lines of the Chinese as interpreted by the Père D’Entrecolles. Böttger’s success, if one is to accept the official German account, was rather the result of some happy accident--an accident, it is true, of which only a man of genius knows how to avail himself. Cookworthy had his attention directed to the subject by an American quaker, of whom he writes, in May 1745: ‘I had lately with me the person who hath discovered the China-earth. He had several examples of the China ware of their making with him, which were, I think, equal to the Asiatic; ... having read Du Halde, he discovered both the China-stone and the Caulin.’[246] Both the petuntse and the ‘Caulin’ were first identified by Cookworthy at Tregonnin Hill (between Marazion and Helston)--this was about 1750. The nature and mode of occurrence of both the growan or moor-stone and of the growan clay, to use the local names, are admirably described by him. Soon after this he found the two materials at St. Stephen’s, between Truro and St. Austell, in the centre of what is now the great china-clay district of Cornwall. There must have been many experiments with the new materials, and many failures, before the year 1768, when Cookworthy took out his patent, and with the pecuniary assistance of Thomas Pitt of Boconnoc (later Lord Camelford) started his factory at Plymouth. It is doubtful whether this factory was in existence for more than two years. In any case there is evidence that already, by the year 1770, the ‘Plymouth New Invented Porcelain Manufactory’ was at work at Bristol. We have proof, too, that before this time Richard Champion and others had been working in the latter town with the new Cornish materials. Champion had been asked by Lord Hyndford to make a report upon some kaolin sent to him from South Carolina. In his reply he says: ‘I had it tried at a manufactory set up some time ago on the principle of the Chinese porcelain, but not being successful, is given up.... The proprietors of the works in Bristol imagined they had discovered in Cornwall all the materials similar to the Chinese; but though they burnt the body part tolerably well, yet there were impurities in the glaze or stone which were insurmountable even in the greatest fire they could give it, and which was equal to the Glasshouse heat.... I have sent some [_i.e_. of the Carolina clay] to Worcester, but this and all the English porcelains being composed of frits, there is no probability of success.’ This is written in February 1766, before the date of Cookworthy’s patent.[247]