English: Charles F. Brush's 60 foot, 80,000 pound turbine that supplied 12kW of power to 350 incandescent lights, 2 arc lights, and a number of motors at his home for 20 years. It today is believed to be the first automatically operating wind turbine for electricity generation and was built in the winter of 1887 - 1888 in his back yard. Its rotor was 17 meters in diameter. The large rectangular shape to the left of the rotor is the vane, used to move the blades into the wind. The dynamo turned 50 times for every revolution of the blades and charged a dozen batteries each with 34 cells. For scale, note the men standing on the platform behind the rotor in the right image pane.