Though little is heard of the coloured Ting wares after the Sung period,[203] the manufacture of white Ting and the commoner _t´u ting_ continued at Ching-tê Chên and elsewhere. In fact, it cannot be said to have suffered intermission up to the present day. A few of these imitative wares of later date were of such excellence as to merit historical notice. In the Yüan dynasty, for instance, P´êng Chün-pao, a goldsmith of Ho Chou, in Shansi,[204] was celebrated for his imitations of old Ting wares, and the _Ko ku yao lun_, an almost contemporary work, describes his productions as exactly like Ting ware when of fine body,[205] but as being "short" and "brittle," and consequently not really worth much. "But dealers in curiosities give them the name of _hsin ting_ or New Ting, and amateurs collect it at great cost, which is most ridiculous." Again, the _Po wu yao lan_ describes another wonderful imitation of Ting ware made in the sixteenth century[206] by Chou Tan-ch´üan, a native of Wu-mên, who settled at Ching-tê Chên, and was reputed the best potter of his time. Though, generally speaking, his material was not as fine as the original, still his copies of _Wên wang_ censers[207] and sacrificial vessels with "monster heads and halberd ears" so closely resembled the originals that it was only necessary to "rub away the kiln-gloss all over the surface" to make the illusion complete. Among the literary references to pottery and porcelain collected in books viii. and ix. of the _T´ao lu_ is a story narrated in the _Yün shih chai pi t´an_, illustrating the cleverness of Chou Tan-ch´üan. Julien[208] has translated it as follows: "One day he (Chou) embarked on a merchant boat from Kin-tchong and landed on the right bank of the Kiang. Passing P´i-ling, he called on T´ang, the President of the Sacrifices (_T´ai ch´ang_), and asked permission to examine at leisure an ancient tripod of Ting porcelain[209] which was one of the gems of his collection. With his hand he took the exact measurements of the vessel; then he made an impression of the patterns on the tripod with some paper which he had hidden in his sleeve, and returned at once to Ching-tê Chên. Six months after he returned and paid a second visit to Mr. T´ang. Taking from his sleeve a tripod, he said to him, 'Your Excellency owns a tripod censer of white Ting porcelain. Here is its fellow, which belongs to me.' T´ang was astounded. He compared it with the old tripod, which he kept most carefully preserved, and could find no difference. He tried its feet against those of his own vessel and exchanged the covers, and found that it matched with perfect precision. T´ang thereupon asked whence came this wonderful specimen. 'Some time ago,' answered Chou, 'I asked your leave to examine your tripod at leisure. I then took all its measurements with my hand. I assure you that this is a copy of yours, and that I would not deceive you in the matter.' The _T´ai ch´ang_, realising the truth of this