<P> Technical drawing of a 1793 Dutch tower mill for land drainage </P> <Li> <P> 1813 technical drawing </P> </Li> <P> 1813 technical drawing </P> <P> In the 14th century windmills became popular in Europe; the total number of wind - powered mills is estimated to have been around 200,000 at its peak in 1850, which is modest compared to some 500,000 waterwheels . Windmills were applied in regions where there was too little water, where rivers freeze in winter and in flat lands where the flow of the river was too slow to provide the required power . With the coming of the industrial revolution, the importance of wind and water as primary industrial energy sources declined and were eventually replaced by steam (in steam mills) and internal combustion engines, although windmills continued to be built in large numbers until late in the nineteenth century . More recently, windmills have been preserved for their historic value, in some cases as static exhibits when the antique machinery is too fragile to put in motion, and in other cases as fully working mills . </P>

Who invented the windmill in the middle ages