Newton gained thorough knowledge of the windmill by frequently visiting the windmill near his grandma’s house. He spent many hours examining its parts, studied its internal machines, when the windmill was not working. When the sails were moving by the wind, he observed the process by which the mill-stones were made to revolve and crush the grains that was put into the hopper.
Newton gained a thorough knowledge of the windmill to construct a similar model of the windmill on his own.