The Beaufort scale is an empirical measure that relates wind speed to observed conditions at sea or on land. It was devised in 1805 by Sir Francis Beaufort, then a Royal Navy captain, as an aid to navigation. The scale is based on the observed effects of the wind on the sea or land, and ranges from 0 (calm) to 12 (hurricane-force winds).
The Beaufort scale is used to determine the strength of winds. The scale is divided into 13 categories, each with a corresponding wind speed and description of the observed effects. The scale is used by sailors, fishermen, and other people who need to be aware of the wind conditions.
The Beaufort scale is not used to determine the direction of winds. The direction of winds is determined by a compass.
The Beaufort scale is not used to determine the height of aircraft. The height of aircraft is determined by an altimeter.