 Constructed in c. 1747, the Mill at Anselma is considered the most intact, authentic example of a custom water-powered grist mill in the United States. While the Mill was updated several times over its three centuries of operation, the grist mill’s basic power train is laid out and functions just as it did when it was first built.
This remarkable artifact exhibits layers of technological advances, including the revolutionary improvements of American inventor Oliver Evans, and the increased efficiency provided by the Fitz Water Wheel Company. It also tells the story of the historic landscape prior to the Industrial Revolution. Custom grist mills were very much local operations, serving local farm families, rather than the larger international markets.
In its early days, the Mill provided its vital flour milling service to approximately 50 families living in the Pikeland area. Over time, the Mill was adapted to produce for a broader market, but none of the Mill’s original hurst frame was altered in the process.
In 2005, the US Department of the Interior recognized the Mill at Anselma as a National Historical Landmark for the remarkable integrity of the grist mill’s power train, and its value to all Americans as a rare, intact artifact of early industry in the United States.
Elements of a Custom Grist Mill
The essential elements of a grist mill like the Mill at Anselma are the mill power source, which is the water turning the water wheel, the mill machinery, which converts the power generated by the water wheel into a form suitable to drive the millstones, and the millstones themselves, which grind the grain into meal.
The water wheel is sixteen feet in diameter, and it is called an overshot water wheel because the water flows over the top of the wheel to fill the water wheel buckets which causes the wheel to turn. As the water wheel turns, the buckets are continuously filled at the top, and are continuously emptied when they reach the bottom. The water wheel is mounted on a shaft, and this shaft turns as the water wheel turns. This rotating shaft powers the mill machinery.
The mill machinery, or gear train, performs two functions. First, the gear train converts the rotational speed of the water wheel shaft, which turns at approximately eight revolutions per minute, to the speed necessary to drive the mill stones, which is approximately ninety revolutions per minute. Second, the gear train changes the direction of rotation from the vertical rotation of the water wheel to the horizontal rotation of the millstones.
 The Mill at Anselma has three pairs, or three stands of stones, each of which consists of a stationary bedstone and a rotating runner stone directly above the bedstone. The grain is loaded into a hopper, part of an assembly called the millstone furniture, which is placed directly over the hole, or eye, in the center of the runner stone. The grain flows down through the eye of the stone from the hopper, at a rate controlled by the miller, and it then enters the small space between the stones, where it is ground. The grain is ground and forced to the outer edge of the stones by grooves cut in the stones called furrows. The ground grain, or meal, is collected at the periphery of the stones within a large wooden hoop, and it is swept around to a chute, or meal spout, where it flows down to be collected. The spacing between the stones is controlled by the miller, and this spacing determines how coarse or fine the meal is ground.
Other machinery in the mill is also driven by the water power. In order to convert the meal into flour, the meal must be sifted, and one of these machines is a sifter, or bolter. The bolter separates out the coarse bran and middlings, and it separates the flour into three grades, the finest being the most desirable, called superfine flour. Another machine, called a smutter, or scourer, cleans the grain of all impurities before it is ground. Grain elevators were introduced approximately seventy-five years after the mill was built, and these, too, are driven by the water power.
The Technical Guide to the Mill at Anselma
This guide was developed by the Mill at Anselma’s current miller Dave Rollenhagen in 2004 to provide an introduction to the Mill’s equipment for the purposes of volunteer training in the operation and maintenance of the Mill’s sensitive equipment. The guide provides a wonderful overview for understanding various Mill machinery parts and how they function.
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