Porcelain
2 of the 7 encyclopedias on this shelf carry an entry for Porcelain. Both are reproduced below, so you can see where they agree and where they differ.
Collier's New Encyclopedia (1921)
a fictile material intermediate between glass and pottery, being formed of two substances, fusible and infusible, the latter enabling it to withstand the heat necessary to vitrify the former, thus producing its peculiar semitranslucency. The infusible material is alumina, called kaolin; the fusible substance is feldspar, and is called pe-tuntse, both Chinese terms. There are two kinds, hard and soft (pâte dure and pâte tendre); the hard body has more alumina and less silex and lime. Oriental porcelain is of two kinds, ancient and modern; the latter class includes imitations and reproductions. The manufacture began in China between 185 B. C. and A. D. 87, and reached its perfection during the Ming dynasty (1368- 1644). The rarest Chinese wares are of the Tsin dynasty (A. D. 265-419), the Soui (581-618), and the Thang (618- 907)-forms virtually extinct except as copies. The Tcheou porcelain (954-959) is so valued that fragments are worn as personal ornaments. Ware of the Song dynasty (960-1279) is also highly prized. Porcelain came by trade into Persia and Egypt, and was known in Syria in the 12th century. First imported into Europe by the Portuguese in 1520. In Japan the porcelain manufacture began before 27 B. c., with a whiter body and more brilliant glaze than that of the Chinese. It is doubtful if it was ever made in Persia. In Europe, Boettcher, a Saxon chemist, found kaolin while seeking the philosopher's stone; and Augustus II., Elector of Saxony and King of Poland, established and placed und under his control the famous Meissen factory at the castle of Albrechtsburg in 1710; 40 years later 700 men were emplo ployed. In Vienna, Stölzel, who esca escaped from Meissen in 1720, began the Austrian factory, which in 1785 employed 500 men; another was established in Berlin by Frederick the Great. During the 18th century, works were begun in Russia, Holland, Denmark, Spain, Portugal, Switzerland and Italy. In France, soft porcelain was made at St. Cloud in 1695. Comte de Brancas-Lauraguan, Alençon and porcelain was made at St. Yrieix, near in 1758, found kaolin near , Limoges. The Sèvres manufactory was first established at Vincennes in 1740, and moved to Sèvres in 1756. In France, the manufacture of soft porcelain extends from 1695 to 1770, after which 2 date the hard body of Sèvres takes its place. In England, William Cookwo worthy, a chemist of Plymouth, found kao kaolin at Tregonning, near Helstone, in Cornwall, and and his patent of 1768 was worked at Plymouth for two or three years, when the works were removed to Bristol. At Chelsea and Bow soft porcelain had been made. These two were transferred to Derby in 1770 and 1776. Bristol had a soft body works in 1753; its best period was from 1774 to 1778. Worcester porcelain dates from 1751; its best period ended witth 1783. Large quantities of porcelain are produced in the United States. Trenton, N. J., J., is a center for the manufacture. See Por-
Aiton's Encyclopedia (1910)
por'se-lin, a sort of pottery. It is the most delicate and expensive ware produced by the potter. When held up toward a window it allows more light to pass through than ordinary chinaware. It is less transparent than glass. The word is borrowed from the Italian name for the polished glassy Venus shell, so-called from its similarity in shape to the back of a little pig. Carried back to its origin, porcelain means little pig and has reference to shape rather than to the kind of ware. So far as known, this kind of ware originated in China. The body is formed of kaolin or fine pottery clay, combined with feldspar, white sand, chalk, ground flint, or some other glassy material. It is, in composition, therefore, somewhat between ordinary chinaware and glass. Articles are formed on the potter's wheel. They are burned at a low temperature to make them hard enough to handle. They are then dipped in a liquid glaze and are subjected to prolonged and hard firing. During this process they are inclosed in earthenware crucibles and protected carefully from smoke. When fired sufficiently they are allowed to cool very gradually. The porcelains of China and Japan are celebrated. The most noted European porcelains are those of Sevres, France, and of Meissen or Dresden, Saxony. The latter ware, or something very similar to it, is produced also at Berlin and in Grandenburg, whither the secret was carried by workers from Meissen. Factories of less note are found in England, the Netherlands, Italy, etc. A cheap porcelain is made near Brooklyn, Long Island . See Pottery ; Sevres