Structure
Threshing floors are usually located near a farm or farmhouse, or in places easily accessible from growing areas. They are usually paved with material that may be of various kinds, for example round stone cobbles about the size of a fist; slate; tile; or sometimes the underlying bedrock itself is exposed. Unpaved earthen threshing floors are also sometimes found. The floors usually have a slight slope, to avoid water standing on them after rain; and the paving may be divided by rays traced from a central focus to facilitate the pavement.
To overcome possible unevenness, and isolate them from water running off after rain so helping to preserve them, threshing floors are often surrounded by a stout low wall. The construction was often in a high place, to take advantage of soft and steady winds to facilitate the work of winnowing, separating the grain from the chaff, once the threshing had been completed.
Use
Sheaves of grain would be opened up and the stalks spread across the threshing floor. Pairs of donkeys or oxen (or sometimes cattle) would then be walked round and round, often dragging a heavy threshing board behind them, to tear the ears of grain from the stalks, and loosen the grain itself from the husks. After this threshing process, the broken stalks and grain were collected and then thrown up into the air with a wooden fork-like tool called a winnowing fan. The chaff would be blown away by the wind; the short torn straw would fall some distance away; while the heavier grain would fall at the winnower's feet. The grain could then be further cleansed by sieving.
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