Compare the pair of small vases of this shape, but imitating realgar, from the collection of James Biddle, included in the exhibition of Later Chinese Glass, Clear as Crystal, Red as Flame, China Institute, April 21-June 16, 1990, Catalogue no. 29, and a yellow glass example from the collection of the Asian Art Museum of San Francisco, no. 39. As well as these Qianlong marked examples, compare a Daoguang marked vase illustrated in the Robert H. Clague Collection Catalogue, Chinese Glass of the Qing Dynasty, no. 53. In this catalogue, Brown and Rabiner illustrate a Yongzheng marked example of transparent blue in the collection of the Palace Museum, Beijing, p.79, fig. 2