There is little doubt that T’ang Ying[430] was the most distinguished of all the men who held this post. He is, at any rate, the one whose achievements have been most fully recorded. He was himself a prolific writer, and a volume of his collected works has been published with a preface by Li Chü-lai. His autobiography is incorporated in the _Chiang hsi t’ung chih_; his twenty descriptions of the processes of porcelain manufacture are quoted in the _T’ao shuo_ and the _T’ao lu_, and in themselves form a valuable treatise on Chinese porcelain; and before taking up his post at Huai-an Fu in 1736 he collected together, for the benefit of his successors at Ching-tê Chên, the accumulated notes and memoranda of eight years. This last work is known as the _T’ao ch’êng shih yu kao_ (“Draughts of Instructions on the Manufacture of Porcelain”), and the preface[431] quoted in the Annals of Fou-liang furnishes some interesting details concerning Tang’s labours. We learn, for instance, that when he was appointed to the factory at Ching-tê Chên in 1728, he was “unacquainted with the finer details of the porcelain manufacture in the province of Kiangsi,” having never been there before. He worked with heart and strength, however, sleeping and eating with the workmen during a voluntary apprenticeship of three years, until in 1731 “he had conquered his ignorance of the materials and processes of firing, and although he could not claim familiarity with all the laws of transformation, his knowledge was much increased.” The commissionership of the customs was transferred in 1739 from Huai-an Fu to Kiu-kiang, which is close to the point of junction between the Po-yang Lake and the Yangtze, and considerably nearer to the Imperial factory at Ching-tê Chên, the control of which remained in T’ang’s hands until 1749.