How is the speed of wind measured?
The speed of wind can be measured by an Anemometer. The Beaufort system developed by Admiral Sir Francis Beaufort in 1805 judges the speed of wind. He made a scale, and at each point he gave the wind a number, a name, a speed and a description of its effects. It classified the force of wind from 1-12.
Force 0 shows that the speed of wind is less than 1 km/hr. and there is absolute clam. Force 1 has a speed of 15 km/hr. enough to drift a column of smoke or steam. Force 4 is a moderate breeze in which small trees are moving and the speed is between 20-28 km/hr. at force 7-9 strong wind having a speed of 50-71 km/hr. bows and it is hard to walk against the wind.
At force 10, the strangest gale having a speed of 89-102 km/hr uproots the trees.
Force 12 or a hurricane blows at a speed up to 120 km/hr. causing great damages to ships at sea and houses on land.