Miller (Robertson's Windmill)
Robertson's Windmill is not currently open to the public.
Giant structure with simple purpose
A colonial windmill was a large and complicated machine built for the simple purpose of grinding small grains.
William Robertson's windmill closely resembled the one located in Colonial Williamsburg's Historic Area today – a narrow, two-story house balanced on an oak post and fitted with four 26-foot frames rigged with linen sails. When the wind rose – a 20- to 30-mile-per-hour breeze was best – the miller pivoted the house to harness the power of the wind.
System of gears drove mill to grind grain
The sails spun a shaft mated to a geared wheel of 51 teeth called a "rack." The rack drove a perpendicular wooden cage gear called a pinion. The pinion turned a shaft that spun a running millstone against a fixed bed stone below. Wheat and corn fed through a hopper between the stones emerged as flour and meal.
Keeping everything running smoothly – the running stone had to turn from 105 to 110 times a minute – was tricky and dangerous. For his skill and trouble, the miller received one sixth of the grain he ground.
The windmill sits idle in this autumn view, but the miller worked when the wind was blowing – often at night or during a storm.