Rise of the American Windmill

Tracking the technological advances that made way for the American windmill in the 19th century.

A later model Improved Standard Halladay mill. The mill’s rudder vane keeps it facing into the wind. As the wind increases, the sails (or blades) are gradually turned edgewise to the wind by the combined action of centrifugal governors, weights and wind pressure, thus presenting less and less surface to the wind. When the wind drops, the weights pull the blades back into position.
Photo by Sam Moore