The Story of the Stones: A Look at the Millstones of the Mill at Anselma

Tucked along Pickering Creek in Chester Springs, Pennsylvania, the Mill at Anselma has stood for nearly 280 years as a testament to American ingenuity, agricultural tradition, and mechanical craftsmanship. Central to its enduring legacy are the millstones—massive circular stones used to grind grain into flour or meal. These stones are not merely tools; they are artifacts of transatlantic trade, early industrial precision, and centuries of rural life.

What Are Millstones? Millstones work in pairs—a bedstone that remains stationary and a runner stone that rotates above it. Grain is fed through the center (the “eye”) and ground between the grooved stone surfaces as the runner turns. The resulting flour or meal is then funneled out the sides.

The success of a mill depended heavily on the quality, maintenance, and type of millstones it used. Millers needed to select the right stone for the grain being ground and to regularly "dress" or resharpen the furrows etched into the stone surface.

European Origins: The French Buhr The most prized millstones in colonial America were French buhrstones—volcanic quartz stones quarried near Paris. They were renowned for their hardness, self-sharpening texture, and ability to produce fine flour. French buhrstones were not single solid pieces but mosaics of stone segments cemented together with plaster and bound by iron bands. Transporting them across the Atlantic and up inland creeks was expensive and labor-intensive, but millers who used them were considered elite craftsmen.

Millstones at the Mill at Anselma: The Mill at Anselma, built around 1747 by Samuel Lightfoot, originally used locally quarried sandstone millstones typical of the colonial era. These would have been effective for coarse grinding, such as producing animal feed or cornmeal. But as consumer demand shifted and wheat production increased in the 18th and 19th centuries, Anselma’s millers upgraded their equipment.

At the heart of the mill today is a French buhrstone set used for wheat flour grinding. This set dates to the late 18th or early 19th century and was used to produce fine white flour—a valuable commodity. These millstones are housed within a fully restored and functional colonial-era transmission system, driving the mill to operate exactly as it did two centuries ago.

In addition to the buhrstones, the mill also houses a gray granite set used for corn grinding. This type of stone, sourced more locally, is better suited for the oilier, coarser cornmeal traditionally used in American cooking.

A Rare Living Machine: What makes the Mill at Anselma especially unique is that these original or historically accurate stones are still in operation. Visitors can see the buhrstones in action during special demonstration days, where wheat is milled into flour much as it was in the 1700s. These grinding demonstrations offer a rare sensory glimpse into pre-industrial food production: the sound of the stones, the vibration of the gears, and the aroma of freshly ground flour.

Preservation of Craft and History: In April 2005, the Mill at Anselma was designated a National Historic Landmark, in part because of its remarkably preserved milling equipment and original stonework. The millstones are not just tools—they are cultural touchstones. They embody the transition from agrarian hand-milling to powered mechanization, from subsistence farming to commercial agriculture.

Every groove in the runner stone, every scratch on the bedstone, tells a story: of local farmers hauling in sacks of grain, of millers trained in the rare art of stone dressing, and of a rural economy centered on the rhythms of the wheel and stone.