You can tell wind direction by looking at a wind vane. This device has a(n) pointer that blows around in the wind. It’s mounted so it can indicate the four different compass markings. When the wind blows, it exerts more pressure on the tail than the tip. A device called a(n) anemometer measures wind speed. This is a series of cups mounted on a(n) shaft that spins. When the cups whirl, they resemble a(n) pinwheel. A(n) speedometer is calibrated to measure wind speed.