Although the mark on the base of this vessel is largely obscured by glaze which pooled during the firing process, it is likely that the mark is an incised Yongzheng seal mark.
This censer belongs to the group of Yongzheng flambe-glazed wares of surprisingly bright tone. Compare with the Imperial flambe-glazed vase, sold in these Rooms, 2 November 1999, lot 512; or to the pear-shaped vase sold in these Rooms, 1 November 2004, lot 1143. This distinctive glaze seeks to imitate the famous classical Jun wares of the Song period. The splashes and streaks characteristic of this glaze are described as Yao bian, or 'transmutation glaze' and have been the subject of much research. See R. Kerr, Chinese Ceramics: Porcelain of the Qing Dynasty 1644-1911, p. 75, and N. Wood, The Evolution of the Chinese Copper Red, Chinese Copper Red Wares, University of London, pp. 29-30 for a discussion on this topic.