Millstones or mill stones are stones used in gristmills , used for triturating , crushing or, more specifically, grinding wheat or other grains. They are sometimes referred to as grindstones or grinding stones. Millstones come in pairs: a stationary base with a convex rim known as the bedstone [ 1 ] or nether millstone [ 2 ] and a concave -rimmed runner stone [ 3 ] that rotates.
The movement of the runner on top of the bedstone creates a "scissoring" action that grinds grain trapped between the stones. Millstones are constructed so that their shape and configuration help to channel ground flour to the outer edges of the mechanism for collection. The runner stone is supported by a cross-shaped metal piece millrind or rynd fixed to a "mace head" topping the main shaft or spindle leading to the driving mechanism of the mill wind , water including tide , or other means.
Often referred to as the "oldest industry", the use of the millstone is inextricably linked to human history. Integrated into food processes since the Upper Palaeolithic , its use remained constant until the end of the 19th century, when it was gradually replaced by a new type of metal tool. However, it can still be seen in rural domestic installations, such as in India , where million women used hand mills daily to produce flour in The earliest evidence for stones used to grind food is found in northern Australia, at the Madjedbebe rock shelter in Arnhem Land , dating back around 60, years.
Grinding stones or grindstones, as they were called, were used by the Aboriginal peoples across the continent and islands, and they were traded in areas where suitable sandstone was not available in abundance. Different stones were adapted for grinding different things and varied according to location.
One important use was for foods, in particular to grind seeds to make bread, but stones were also adapted for grinding specific types of starchy nuts, ochres for artwork, plant fibres for string, or plants for use in bush medicine , and are still used today.
