"This movement is complicated by several other factors that means wind does not always flow from the equator in the direction of either pole. The rotation of the earth creates a force known as the Coriolis force and this factor along with the temperature differences create winds at high altitudes above the earth on a large scale. These Geostrophic winds play a part in the wind's that affect us in everyday life, but local winds are largely affected by the surface of the earth - which is neither uniform or smooth. The earth has large flat plains (desert regions), areas covered with plant life (rainforests), very uneven regions (mountain ranges) and very smooth regions (seas and oceans), all of which affect the wind near the surface of the earth to varying degrees. These areas of the earth all have different values of roughness, which can impeded the flow of air. Obviously the lower the value of roughness the less the air is impeded."

"China has also laid claims to having invented windmills around 2,000 years ago, but the first documented claims appear in the 1200's. Around 250 A.D. the Romans introduced windmills into their culture and in the 700's so did Afghanistan. The Afghanistan windmills were also of the vertical axis style and cloth sails or reed matting was developed to catch the air. These windmills were used to grind corn and sugarcane plus draw water. In the 13th century Holland started developing large horizontal axis windmills. These four-blade windmills were larger, carried more torque and wind speed and could do more work than other windmills previously designed. The Holland windmills were also being used to grind grains and to drain part of the Rhine River. In the 19th century Denmark had an estimated 2,500 windmills and in the U. S. windmills were starting to be used to pump water. The Halladay windmill of 1854 is one such example of this. The first windmill in the world built for electrical production was in 1887 in Scotland built by Professor James Blyth. A year later in 1888 in the U. S. Charles Brush of Cleveland, Ohio built a large wind turbine used to generate electricity."