Hobbies And Interests
Purpose
Bread made with flour has been the staple of the human diet since the beginning of humankind, according to the book, “The History of Grinding.” To make flour, wheat grains are ground to separate endosperm, nutritive tissue, from bran, and the endosperm is ground to make flour. Grinding is also used for size reduction of other types of grain, such as the grinding of corn to produce meal.
Hand Stones
Stones used for grinding by hand included mortars and pestles or bowl-shaped containers and bat-shaped grinding tools, respectively, introduced by 6000 B.C. Later, saddlestone mills, first appearing in Chaldea, came into use. These mills consisted of small stones with smooth faces that were rubbed on larger, slightly hollowed fixed rock slabs. The constant contact of the stones allowed the production of very fine particles, according to “The History of Grinding.”
Development
The rotary quern, invented around 600 B.C., had a fixed lower stone and an upper stone that rotated on a pin, keeping the moving and fixed surfaces just clear of each other, and could be operated manually using a crank. Ever-larger machines with higher production rates were built over time. In the large commercial mills at Pompei, men turned the upper stone by pushing on spokes that were inserted in slots, and animals were later used as a source of power.
Millstones
“Quern stones” refer to the stones used in hand-powered quern mills, which were still in use by U.S. settlers throughout the 18th and 19th centuries. These quern mills used a cylindrical stone rolled along a slightly concave one. Querns also were used by Canadian settlers, and the tiring work of grinding grain by hand eased by the building of grist (grain) mills when enough people moved into an area. The huge, flat, round grinding stones used in a grist mill were referred to as millstones, which operated the same way as stones in a quern, according to the City of Waterloo Heritage Resources publication, "Grist for the Mill."
Characteristics
The fixed, bottom stone of a pair of millstones was called the “bedstone,” while the moving, top stone was called the “runner.” The distance between the two stones depended on the type of grain being ground, such as corn, rye or wheat, and the miller had to make certain that the stones did not touch or the flour would spoil or even catch fire. The grooves, called “furrows,” cut in the stones ripped off the grain&'s outer husk and permitted the escape of ground flour or meal and of air that carried off the heat generated by friction. Millstones, made of ordinary granite or sandstone, varied in size from 4 to 6 feet in diameter and weighed up to a ton, according to the Penn State College of Engineering article “The Grist Milling Process.”