The so-called "chuan-lun-tsang", literally "revolving-wheel- sutras", refers to a mechanical device, which consists mainly of two parts: revolvable wheels and Buddhist sutras. The sutra is arranged layer upon layer. The volumes of Buddhist sutras are put on each layer. You turn the wheels and the wheels spin round. You will be charged for a certain amount of money for doing so. You will be, however, regarded as a good man or a believing woman who had just in a few minutes recited or copied all the scriptures on the book stack like wheels. An absolutely symbolical deed. Many a monastery in Sung times had such a device erected inside a splendid building built exclusively for this purpose. Questions arise. What for was such a pavilion built by a monastery? How was it constructed? When and Where did it first appear in Chinese history? How many monasteries possessed such pavilions? Where were they? Which sect(s) did these monasteries belong to? How economically and financially important was such a pavilion to a monastery? How did such an institution develop after Sung period? And so on.