Porcelain having been invented in the province of Ho-nan, during the Han Dynasty, between the years B.C. 185 and A.D. 88, was manufactured for upward of fifteen hundred years before it was generally known in Europe. For about five or six hundred years the industry made comparatively little progress, but after A.D. 583 it advanced with great rapidity. In that year the imperial patronage was bestowed upon King-teh-chin, a city in the district of Fauling, and province of Kiang-si. There were here at one time, in 1717, three thousand furnaces. It is said by some recent authorities that all the kilns and potteries were destroyed by the Taepings, and that the entire city was reduced to ruins. According to the official catalogue of the Chinese department at the Centennial Exhibition, the city must have been rebuilt. Both the largest quantity and finest quality of porcelain are said still to be made at the imperial potteries at King-teh-chin, and out of upward of seventeen hundred and fifty pieces exhibited, all were from that city, with the exception of ten from Ningpo, Nankin, and Pekin. Some of the others, although painted at and sent from Canton, were manufactured at King-teh-chin. All Chinese porcelain has been classed as hard. The only kind about which any doubt has been entertained is the white, variously ornamented in relief. To this ought, however, to be added certain rare but superb specimens which come from China as well as from Persia. The process by which they were manufactured is not known, but it seems clear that they belong to the same family as the _pate tendre_ of France, that is to say, that their vitrification is due to an alkaline frit, and that the glaze is also alkaline. Of the dynastic colors the azure-blue adopted by the Tcheou, in 945, is the most celebrated. It was very highly valued, and after the secret of making it passed out of sight, which it did at a very early date, it was never rediscovered. It is known as Tch’aï porcelain, and in color resembled the “blue of the sky after rain.” Under the Song Dynasty four very valuable kinds of porcelain were made. The first of these was the Jou-yao, a very fine blue, produced at Jou-tcheon, where crackle porcelain was also made in great perfection; the second (1107-1117) was the famous Kouan-yao, or porcelain for magistrates, of two shades of blue, with a slightly reddish tint; the third takes its name from the Tchang family of potters, and was pale blue and rice-colored crackle; the fourth, the Ting-yao, was of different colors--red, white, brown, and black, and was of great value. These, with the Tcheou blue, are the five ancient qualities held in highest estimation.