The speed at which the air current moves, and the direction from which it moves determines what the wind is named and also determines weather the wind is harmful or beneficial. A wind of 19 to 24 mile an hour is classified as a fresh breeze, and is not harmful. When the wind reaches a speed of 47 miles an hour, it is called a strong gale, and may cause some damage to fruit crops. At 64-75 miles an hour, it is considered a wind storm and dangerous to both crops and properties. Above 75 miles an hour, when it is classified as a hurricane, wind is devastating among its damage to crops, properties, and man himself.
The most dangerous wind of all winds is the tornado, a swirling movement of the wind in a counterclockwise direction, sometimes at more than 300 miles per house. The speed of a tornado has never been measures accurately, but the destruction is almost incredible.
In describing the force of wind, mariners use a scale drawn up in 1805 by Rear Admiral Sir Francis Beaufort, a famous British hydrographer. He developed a historic table of the strengths of winds based on the effect of wind on sailing ships.
0-1 MPH - Calm, 1-2 MPH - Light Breeze, 4-7 MPH - Slight Breeze, 8-12 MPH - Gentle Breeze, 13-18 MPH - Moderate Breeze, 19-24 MPH - Fresh Breeze, 25-31 MPH - Strong Breeze, 32-38 MPH - Moderate Gale, 39-46 MPH - Fresh Gale, 47-54 MPH - Strong Gale, 55-63 MPH - Whole Gale, 64-75 MPH - Wind Storm, Above 75 MPH - Hurricane
