On the shaft that holds the sails, 2 large wooden wheels with theet are mounted. Only one is visible here, but the other one is a few meters further. The one you see here is closest to the sails and is also the brakewheel. You see the wooden teeth that will drive the horizontal gear below. This one has theet on both sides of the wheel because it is not only driving the millstones for the flour but one shaft with horizontal gear goes all the way down to the oil mill. It will be easier to understand with the next photos.