I saw two episodes of ( Back To The Blue Print ). It's a show on the History Channel. They are restoring an eighteen hundred's era wind engine. This thing is an impressive four rotor 10,000 lb machine that sits on top of an old historic grain mill. The machine has two rotors that are 30 feet in diameter. They are set up parallel to each other like two sides of a fairis wheel. they are connected with spider gears. They spin opposite of each other. There must be about a thousand blades about two inches apart from each other. The other two rotors are ten foot in diameter that are perpendicular to the larger rotors. They sit in between at the outer diameter of the large rotors. They have a shaft that goes back to a worm gear that spins the main axle of the larger rotors. When the smaller rotors catch wind they make the whole machine turn into the wind with the worm gear. There has to be another episode because they still have to put it up on the mill yet. The name of the co. that made the wind mill was the (Challenge Wind Mill And Mill Co. of Batavia, Illinois.) Challengehistory2 I was searching for a goggle picture of it but all I could find was the history of the Co.