Something I find curious. How does it catch the wind anyway? It has so many holes in it...
As the wind rushes through the slits in the sails (the parts looking like a wooden fence), just like an airplane, there is a form of lift created. The sails are angled slightly so that from the top and the bottom their direction is reversed. So the same wind that pushes on the top, pulls on the bottom. Imagine a mag-lift train, how each ring is compressed magnetically, squeazing the cars forward one at a time, faster and faster. The wind is squeezing on the sails due the their slight angle. The imbalance in forces between the top and bottom causes the arms to rotate clockwise, which drives the threshing wheel below in a counterclockwise motion. That's the wheel you can see on the inside set in the groove. It is made of stone and is used to crush wheat or corn toward making homemade flour or cornmeal. So over a few hours the windmill (wind meal) does all the dirty work of grinding your food for you, or at least your main staples: flour and cornmeal. Then you don't need a horse to do it, which would eat up in the value of hay what it could produce in ground flour, rendering any potential savings (excess, which you could then sell to neighbors) moot.
The Mistake:
It's an easy fix, and it should be mentioned to Bethesda. And you, the one who got wound up over people mentioning a simple error ... when someone makes a terrible error on their business card, you
definitely want to tell them ... or else who would hire them, seeing that error? You're their friend, making them look better to a professional world.... so don't get so bent out of shape for people clarifying errors.