5. WATER MILL
An Important Cultural Property of Kawasaki City
Original site: 451, Kanizawa, Ōaza-Kamigaya, Nagano City, Nagano Prefecture
Type of building: Water Mill
Built: Mid 19th century
Form: Hipped roof of thatch
Length (parallel to ridge): 4.5 m
Width: 4.2 m
Water mills can be classified into two groups: those used for raising water for irrigation, and those used as a power source of grinding and flour milling.
This water mill is of the latter type. The rotary motion of the wheel turned by the flow of water provides the power source, and is transmitted by a sophisticated system of cog wheels to drive usu for pounding rice, and a mill for grinding grain, buckwheat, the ingredients for making incense sticks etc.
Water wheels used as a power source in Japan can be divided into 3 types according to the height of the water intake, namely high intake types (uekakeshiki) where the water intake is at the top of the wheel, breast intake types (munekakeshiki) and low intake types (shitakakeshiki). Both high and breast intake types need a channel to bring the water in at high level, but with the low intake type, the lower part of the wheel is often set directly in the water of the stream. This mill is an example of a pitch back undershot high intake type, with a large waterwheel 3.6 m in diameter. The waterwheel is detachable from the main shaft, an arrangement devised so that the easily damaged moving parts can be taken off without difficulty for repair or replacement.