Once the grain and the chaff were swept up from the thrashing floor the farmer was left with the job of separating the wheat or whatever else he was growing. All grains unfortunately have chaff that must be removed before it can be further processed. For thousands of years the only way this could be accomplished was tossing the grain and chaff up into the air on a windy day. The wind blew the chaff away while letting the grains fall into a container that was resting on the ground. This was as good of a way as any to get rid of chaff. It is still practiced in some parts of the world today.
Sometime during the 19th Century; some genius decided that there had to be a better way to deal with this onerous task. His solution was to invent a device called a winnowing machine. My own mother had a great love affair with the family winnowing machine, she always spoke ill of it. One time we went to the Pennsylvania Dutch Festival in Kutztown, PA. They had one on display along with a collection of other antique farm equipment. She didn't want to say in English what she thought about seeing a prime example right before her, so she gave me her thoughts in German. They were none too good.
What she didn't know was that the Pennsylvania Dutch were actually Germans, and they all could speak German. Since many of their ancestors came from Franconia Germany as her parents had, they all understood her. Naturally there was a big crowd standing around, and they all burst into loud laughter at her description of the winnowing machine. Some of the guys were actually doubled over with laughter. The only thing missing was a German marching band.
A winnowing machine was invented like many other inventions to make the farmer's work a little easy. Notice, I said the farmer had it easy this did not extend to the farmer's kids. All the farmer had to do was too keep feeding wheat and chaff into the top of the machine. Through a set of wheels and pulleys that operated a big blower inside of the machine, and a set of shakers that the grain passed down through. The chaff came out of the end of the machine, and the grains fell down through the shakers to fall out of an outlet at the bottom of the machine. The grain was caught in a pan under the machine ready to be ground into flour by the miller.