Date: 1886
For instance, throughout New England, generally, where various kinds of grain are raised in close proximity, oats, peas, barley, wheat, etc., frequently become mixed, and a machine called a separator is used, by means of which the several grains may be rapidly obtained free from others.  In the Western States such a machine is rarely needed, for wheat is there generally free from other grains.  In such case the ordinary cleaning apparatus is commonly used ; it consists of a cylindrical sieve of wire cloth fixed in a sloping position, and having internal partitions causing it to resemble an Archimedean screw.