The first point to notice in this catalogue is that more than half of the objects described are attributed to the Sung period (960-1279 A.D.), that is to say, they were at least three hundred years old at the time when Tzu-ching wrote. The Sung dynasty, we must bear in mind, was above all remembered as a period of great wealth and material prosperity. Less warlike than the Tang which preceded it, the arts were cultivated at the court of the pleasure-loving emperors who had their capital during the earlier time at Kai-feng Fu (in the north of Honan, near to the great bend of the Hoang-ho). When driven south by the advance of the more warlike Mongols they retired to Hangchow, the Kinsay of which Marco Polo has such wonderful tales to relate. In these early days there was no great centre for the manufacture of porcelain; it was made in many widely separated districts, so that the classification of these early wares is, in a measure, a geographical one. At King-te-chen, at least in the later Sung period, they were already making porcelain, but for court use only, it would appear, for at that time the factory was a strict imperial preserve, and its wares did not come into the market. As to the still older wares, those of Ch’ai and of Ju, which generally hold the place of honour in Chinese lists, it was of the first that the emperor spoke when he commanded that pieces intended for his own use should be clear as the sky after rain; but no specimen of this porcelain was extant even in Ming times. Its place, it would seem, was taken by the JU YAO (the word _yao_ is about equivalent to our term ‘ware’), which, like the Ch’ai, came from the province of Honan. This ware also is now practically extinct; Tzu-ching, however, claims to have possessed some specimens, and of these he gives more than one illustration. The glaze was thick and like melted lard (a comparison often made by the Chinese), and varied in colour from a _clair-de-lune_ to a brighter tint of blue. The name Ju, we may add, is often applied to more modern glazes which resemble the old ones in colour and thickness. The name KUAN YAO, which means ‘official’ or ‘imperial’ porcelain, has been the cause of much confusion; the term has been applied to any ware made for imperial use. That of the Sung dynasty was made in the immediate neighbourhood of the imperial court, first at Kai-feng Fu and later at Hangchow. In its more strict use the term Kuan yao is applied to pieces generally of archaic form, to censers ornamented with grotesque heads of monstrous animals, and to wares of other shapes copied from old ritual bronzes. The glaze varies in colour from emerald green to greyish green and _clair-de-lune_, it is generally crackled, the cracks forming large ‘crab-claw’ divisions. Other kinds are described as white and very thin, but of these, perhaps for one of the reasons given above, no examples have survived to our day.