This is wind gauge, also known as an anemometer, it is an instrument used to measure wind speed, direction and pressure. It has cups mounted on the end of horizontal arms which are positioned at equal angles from one another. The cups turn as the wind flows past them and the speed of rotation is used to determine the speed of the wind. The faster the wind, the faster the cups spin.
Today we measured wind speed and direction. It was fun. We made our own anemometer using a sticks and ribbons.
