Fanning Mills: The Devil's Wind

Fanning mills changed grain threshing and winnowing


| September 2000



Cross section of a fanning mill showing the multiple screens, as well as the way different sized seeds were graded.

Cross section of a fanning mill showing the multiple screens, as well as the way different sized seeds were graded.

In a letter to the editor in the July issue of Farm Collector, Tom Moon stated that he had found a Gem fanning mill hiding in his barn, and he was wondering about the machine's use and value. I won't discuss value here, but I can furnish some other information about the machine. 

For centuries, grain threshing was done in several crude methods. Our ancestors beat the grain with flails, trampled it with horses or oxen, or pulled stone or wooden rollers and sledges over it. These endeavors succeeded, with varying degrees, in separating the grain kernels from the heads, but left them mixed up with the chaff, straw and a lot of dirt. The early threshing machines, known as groundhogs or chaff pilers, did nothing more than remove the grain from the head, leaving the task of separating the straw and chaff to a later operation called winnowing.

First, the larger hunks of straw and debris were raked aside and the remaining grain, dirt and chaff were swept into a pile. This mixture was shoveled into a large, shallow basket and tossed into the air. Hopefully, the dust and other undesirable pieces were blown to one side by the wind, and the heavier grain fell back into the basket. In Europe and America this was usually done on a barn floor in the current blowing through two open doors located opposite each other. When there was no wind, sheets or blankets were waved to create the air current. Obviously, winnowing was not only hard work, but was slow, tedious and inefficient as well.

There is evidence that winnowing machines, with rotary fans in boxes, were used in China as early as the Han Dynasty (206 BC - 221 AD). In the 1500s, Dutch East India merchants carried Chinese technology back from their trading expeditions in the Far East, and these machines were built and demonstrated in the Netherlands. A contemporary account of one such demonstration tells of a local dignitary who looked into the opening out of which the air was coming, and the force of the blast was enough to lift the wig off his head and carry it across the floor.

In 1710, James Meikle, a Scottish millwright, traveled to the Netherlands where he saw winnowing machines of the Chinese design in use. When Meikle returned to Scotland, he built a hand-operated winnower with four canvas sails to provide the air. Meikle's winnowing machine met with much prejudice, especially amongst the clergy, who labeled it the "Devil's Wind" and thundered from their pulpits that the machine "impiously thwarted the will of Divine Providence, by raising wind by human art, instead of soliciting it through prayer."

In spite of this opposition, winnowing machines caught on because of the big savings in time, labor and grain. James Meikle's sons, George and Andrew, began building fanning mills in about 1768, featuring what was called a "double blast." The uncleaned grain first passed through a dressing stage, where the larger bits were blown away, after which the grain went through a finishing stage, where a second fan blew away any remaining chaff and dirt. In England, in 1761, William Evers patented a winnowing machine that combined a rotary fan with sieves. Later improvements included scroll-shaped fan housings for a more efficient wind blast, as well as a series of shaking, or vibrating, sieves, one above the other.