A similar ball-form watch is illustrated in Timepieces, The Forbidden City Publishing House, pp.294. The tome comprises a selection of timepieces in Beijing's Palace Museum which owns one of the largest collections of mechanical timepieces of the 18th, 19th and early 20th centuries in the world, comprising over 1,000 pieces. The collection contains both Chinese and foreign-made watches, clocks and automatons. Chinese exhibits came from the Palace's own workshops, Guangzhou (Canton) and Suzhou (Suchow). Watches made abroad include manufacturers from Britain, France, Switzerland, the United States and Japan.