Page:Dictionary of National Biography volume 12.djvu/113

 a scientific person, they used to sit up most of the night engaged in their favourite subjects.’

In a letter written on 5 May 1745 Cookworthy says: ‘I have lately had with me the person who has discovered the china earth. … It was found in the back of Virginia, where he was in quest of mines, and having read Du Halde, he discovered both the petunze and kaolin.’ The first true porcelain manufactured in Europe was made by Böttcher in 1709 at Dresden, and in 1710 he was appointed director of the Meissen factory, and after five years of experiment he succeeded in making the fine porcelain known as ‘Dresden china.’

Cookworthy having seen the kaolin from Virginia (china clay), and the petunze (china stone, or growan stone), he discovered on Tregonning Hill the Cornish china clay, and soon after he noticed that a portion of the granite, or moorstone, of the same district resembled in some respects the petunze, and on exposing it to a white heat in a crucible he obtained ‘a beautiful semi-diaphanous white substance.’ This was the Breage china stone, but, containing black particles which burnt red, it was not fitted for a porcelain glaze. At Carlegges, in St. Stephen's parish, near St. Austell, he found subsequently both the clay and the stone of the desired purity. This appears to have been between 1755 and 1758. The clay and stone found in St. Stephen's was on the property of Lord Camelford, who assisted Cookworthy in his first efforts to make porcelain in Plymouth, the works being established at Coxside. His progress was slow, and it was not until 1768 that he obtained a patent for the exclusive use of Cornish clay and Cornish stone in the manufacture of porcelain. In the Plymouth works from fifty to sixty persons were employed. The company—Lord Camelford being one of the firm—obtained a high-class porcelain painter and enameller from Sèvres. Henry Bone [q. v.] was educated in this pottery

Cookworthy afterwards sold the patent right to Mr. R. Champion of Bristol, who founded a pottery in that city. Neither the porcelain works in Plymouth nor those in Bristol were profitable, and in 1777 the patent right was sold to a company in Staffordshire. Cookworthy brought his chemical knowledge to bear on the porcelain manufacture, and he appears to have been the first chemist who in this country obtained cobalt-blue direct from the ores. A well-known Staffordshire potter writes of Cookworthy's discovery: ‘The greatest service ever conferred by one person on the pottery manufacture is that of making them acquainted with the nature and properties of the materials, and his introduction of “growan stone” for either body or glaze, or both when requisite.’ Cookworthy is said to have been a believer in the dowsing, or divining rod, for discovering mineral veins, and we learn that he became a disciple of Swedenborg. As a Friend he was universally esteemed by the Society; as a minister he was zealous, engaging, and persuasive; as a lover of science he was much appreciated, as is proved by the fact that Sir Joseph Banks, Dr. Solander, and Captain Cook dined with him at Plymouth before their voyage round the world. Cookworthy died on 16 Oct. 1780, aged 76.



COOLEY, THOMAS (1740–1784), architect, was born in 1740 in England, and originally apprenticed to a carpenter. He obtained a premium at the Society of Arts in 1753, and in 1769 was the successful competitor for building the Royal Exchange in Dublin, which he completed in 1779, and continued to reside in Dublin. He also erected a tower to Armagh Cathedral, and the Newgate prison in Dublin; neither of these was a successful work. He was employed on several other public buildings in Dublin, but died in 1784 while engaged on the Four Courts, having only completed the western wing. From 1765 to 1768 he contributed architectural designs to the exhibitions of the Free Society of Artists.



COOLEY, WILLIAM DESBOROUGH (d. 1883), geographer, was elected a fellow of the Royal Geographical Society of London in 1830, and was made an honorary free member in 1864 (Proceedings of Royal Geogr. Soc. for 1883, p. 233). He wrote for Lardner's ‘Cabinet Cyclopædia,’ ‘The History of Maritime and Inland Discovery,’ 3 vols. 1830–1, a work of considerable merit which was translated into French. On the publication of M. Douville's ‘Voyage au Congo’ in 1832 Cooley wrote a criticism in the ‘Foreign Quarterly Review,’ in which the fraud practised by that pretended explorer was exposed. After that time his name was chiefly associated with African subjects. In 1852 he