Compare the censer and cover of this type, with different foot but similar cutouts, dated to the Northern Song dynasty, 10th or 11th century, Hebei area, illustrated by R. Krahl, Chinese Ceramics from the Meiyintang Collection, vol. 1, London, 1994, p. 197, no. 345. See, also, another example of this type illustrated in the Catalogue of the Memorial Exhibition of The Charles B. Hoyt Collection, Museum of Fine Arts, Boston, 1952, p. 95, no. 378, where it is described as being of ying ch'ing type.