This picture was taken around 1890 and shows a farmer harvesting hay. What the farmers would do with the hay was to bundle it and leave it in the field to dry. Later on, the farmer would hook a team of horses up to the hay wagon and pick up the bundles. The farmer would haul them back to the barn and put them in the loft.
The threshing machine was used by attaching two horses to it. The horses would run on the treadmill, and the threshing machine would thresh the grain. It would probably take a long time. Today, we probably wouldn't use two horses to do that. We would use a machine without the horses.