Among the inventions attributed to him is an air conditioning system based on evaporative cooling.
The lower part of the canopy was in the form of a cylinder and had translucent panes with paintings of animals or men.
[1][3] The only such invention Needham attributes to Ding Huan is "a 'nine-storied hill-censer' ... on which many strange birds and mysterious animals were attached.
"[2] Needham claims these devices "certainly embodied the principle of a rapid succession of images",[2] but it is not apparent from any of the descriptions provided that there was anything other than a procession of painted figures or carvings or cast shadows seen actually moving through space.
[3] By contrast, the invention for which the name "zoetrope" was coined in the 19th century is, like the flip book, an animation device that creates an illusion of motion from a series of images showing successive phases of that motion, by rapidly presenting them to the viewer one after another in such a way that each abruptly replaces (or seems to abruptly replace) the previous one.