Wind winnowing

Wind winnowing is a method developed by ancient cultures for agricultural purposes.(also called threshing) It involves taking a basket of mixed grain and chaff, or using a winnowing fork on a pile of harvested grain and tossing the contents into the air, thus causing the chaff to blow away while the heavier grains would fall back into the basket or onto the ground or threshing floor.

External Links
* Antique Farm Tools