The windmill was almost certainly developed from the geared watermill.
Wind was the source of power, instead of water, to turn the millstones, to grind grain into flour.
The average strength of a windmill was the same as that of a watermill - 5 to 10 horsepower.
The Normans knew of the windmills in Europe.
How was the wind harnessed to work the mill shown in the picture?
Click the picture for an answer.
A windmill was first recorded in England in 1180.