It is possible, of course, that evidence may yet be forthcoming to carry back the use of glaze in China beyond the limits at present prescribed, but all we can state with certainty to-day is that the oldest known objects on which it appears are those which for full and sufficient reasons can be assigned to the Han period. To explain all these reasons would necessitate a long excursion into archæology which would be out of place here. Many of them can be found in Berthold Laufer's[18] excellent work on the subject, and others will in due course be set out in the catalogue of the British Museum collections. But it would be unfair to ask the reader to take these conclusions entirely on trust, and some idea of the evidence is certainly his due. There are a few specimens of Han pottery inscribed with dates, such as the vase (Plate 2, Fig. 1) from the Dana Collection, which is now in the Boston Museum; but in almost every case the inscriptions have proved to be posthumous and must be regarded at best as recording the pious opinion of a subsequent owner. It will be safer, then, to leave inscriptions out of consideration and to rely on the close analogies which exist between the pottery and the bronze vessels of the Han period and between the decorative designs on the pottery and the Han stone sculptures, and, where possible, on the circumstances in which the vessels have been found. Unfortunately, the bulk of the Han pottery which has reached Europe in recent years has passed through traders' hands, and no records have been kept of its discovery. But there are exceptional cases in which we have first-hand evidence of Han tombs explored by Europeans, and in two instances their contents have been brought direct to the British Museum. Both these hauls are from the rock-tombs in Szechuan, the one made by the ill-fated Lieutenant Brooke, who was murdered by the Lolos, the other by the Rev. Thomas Torrance, to whom I shall refer again. The evidence of both finds is mutually corroborative; it is supported by Han coins found in the tombs, by inscriptions carved on their doorways, and by the rare passages of decoration on the objects themselves, which correspond closely to designs on stone carvings published by Chavannes. In this way a whole chain of unassailable evidence has been welded together until, in spite of the remoteness of the period, we are able to speak with greater confidence about the Han pottery than about the productions of far more recent times.