Their stone-ware, covered with porcelain, presents us with some of their most wonderful works. This ware is made into jars, seats, cisterns, and many other utensils and objects. It is said to have been in attempting to make plaques of this kind that Pousa or Pou-tai met with his tragic end as before told. The plaques, Licou-li, or glazed tiles, are devoted to the embellishment of imperial and religious edifices, and by the brilliancy of their many colors, yellow, blue, green, red, and violet, produce a dazzling and gorgeous effect. The famous porcelain tower of Nankin (Fig. 71), or, as it is alternatively called by the Chinese, Tower of the Licou-li, or Poa-en-ssi, the Convent of Gratitude, was covered with tiles of the above description. This building has been repeatedly destroyed and rebuilt. The original consisted of three stories, and was erected B.C. 833. Having been demolished, it was rebuilt A.D. 371-373. It was again destroyed, and again rebuilt by one of the Ming emperors, who, after nineteen years’ work, finished it in 1431. Once more it was demolished during the insurrection of the Taepings; and although travellers--including some Americans--have within the past twenty years been fortunate enough to secure a few fragments as relics (Fig. 72), nothing now remains to mark its site. It was this last tower which was known as the Convent of Gratitude. It consisted of nine stories, and was three hundred and fifty-three feet in height. It was covered with enamelled bricks of red, white, blue, brown, and green colors; but whether the previous towers were so decorated is not known, so that the Tower of Nankin cannot be brought forward as proving the architectural use of enamelled stone-ware at a very remote age. [Illustration: Fig. 71.--Tower of Nankin.] A material which is neither stone-ware nor porcelain, but resembles very fine pipe-clay, is used in making opium pipes. The bowl is enamelled, and decorated with flowers or other forms, and is not unfrequently almost perfect as a work of art. The Chinese _boccaro_ remains one of the finest specimens of a _grès_ known to ceramists, and far above any of the stone-wares of Europe. Some specimens are as perfect in their beauty as jewels. The paste is sometimes brown of a reddish tinge, sometimes a gray faintly colored with yellow. It is made into single pieces and services, occasionally of fantastic design. When covered with colored enamels, the _boccaro_ is at once so delicate and brilliant as to be likened to nothing but a gem. [Illustration: Fig. 72.--Enamelled Bricks from the Tower of Nankin. (N. Y. Metropolitan Museum.)]