YONGZHENG SIX-CHARACTER MARK IN UNDERGLAZE BLUE WITHIN A DOUBLE CIRCLE AND OF THE PERIOD (1723-1735)

Compare to two closely related examples: one from the British Museum collection, donated by Sir Augustus Wollaston Franks, accession number: Franks.32.+; the other illustrated by Regina Krahl, Chinese Ceramics from the Meiyintang Collection, vol. 2, London, 1994, no. 856.