Western Cowman-January 2017

Page 40

Range Sentinals by Heather Snith-Thomas

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indmills have a long history. Ancient civilizations discovered that the power of the wind could be harnessed in many ways, such as pushing against a sail to move a boat, including large ships. Wind wheels could turn machinery just as readily as a water wheel. The earliest known wind-powered grain mills and water pumps were used by the Persians in A.D. 500-900 and by the Chinese in A.D. 1200. One historian claimed that the Babylonian emperor Hammurabi planned to use wind power for his ambitious irrigation project in seventeenth century BC. Wind wheels have been used to pump water since at least the 9th century in the Middle East, in the region that is now Afghanistan, Iran and Pakistan. The use of wind pumps spread from there to China and India. Windmills were later used extensively in Europe, particularly in the Netherlands and in certain area of Great Britain from the late Middle Ages onwards, to drain land for agricultural or building purposes. Early windmills had four paddle-like wooden blades on top of a tower. These were followed by mills with thin wooden slats nailed to wooden rims. Most windmills had tails on the wind wheel to orient them into the wind, but some were like weather vanes and operated downwind of the tower. Speed control of some models was provided by hinging sections of the blades, so they would fold back like an umbrella in high winds. The biggest improvement in the American fantype windmill was development of steel blades in the early 1870’s. Steel blades could be made lighter and could also be worked into more efficient shapes. These blades worked so well that their high speed required a reduction (slow-down) gear to turn the standard reciprocal pumps at the proper speed. For hundreds of years, the most important use of windmills has been mechanical water pumping using relatively small systems with rotor blade diameters (width of the wind wheel) of about 3 feet to several yards. These systems were perfected in the U.S. during the19th century, beginning with the Halladay wind40