For many years after its publication in 1912 Berthold Laufer's book Jade: a study in Chinese archaeologh and religion remained a standard reference work for Western scholars. In his third chapter Laufer discusses certain three-lobed jade discs (pl. I); he is in general agreement with the theories of the late-nineteenth-century Chinese scholar Wu Ta-ch'eng , who named the discs hsüan chi and suggested that they were originally intended to be used for astronomical purposes. After Laufer the discussion was taken up by other writers on jade, and was carried a stage further in a series of papers by Henri Michel, beginning in 1947, in which he presented a considerable amount of literary and scientific evidence in support of his interpretation of the astronomical purpose of the discs. Michel's theories were lent additional weight and given a wide circulation by their inclusion in Joseph Needham's survey of Chinese astronomy. Since Michel, those writers who have doubted the astronomical connexions of the discs have nevertheless tended to retain the name huüan chi, which now seems to have become established as the standard term for this particular jade form on museum labels and in archaeological reports in China as well as in the West.