A view on the 2 big wooden wheels on the shaft of the sails that are driving the horizontal wooden gears. The one on the right drives the first set of millstones. The horizontal wheel between the 2 big vertical wheels is the shaft that goes down to the oil mill. Behind the left vertical wheel(Brake wheel) is another small horizontal wheel to drive the second set of millstones. These small horizontal wheels can be taken away from the vertical wheels if the stones do not have to work. More explanation with the next photo.