. The conquest of nature. in a stationary mechanism is familiar to were constructed at a comparatively earlyperiod, and notwithstanding all the recent progress inthe development of steam and electrical power, thisrelatively primitive so-called prime mover still holdsits own in agricultural districts, particularly in its appH-cation to pumps. A windmill consists of a series of in-clined planes, each of which forms one of the radii of acircle, or spokes of a wheel, to the axle of which a gearingis adjusted by which the power generated is utilized. Thewheel is made to face the
. The conquest of nature. in a stationary mechanism is familiar to were constructed at a comparatively earlyperiod, and notwithstanding all the recent progress inthe development of steam and electrical power, thisrelatively primitive so-called prime mover still holdsits own in agricultural districts, particularly in its appH-cation to pumps. A windmill consists of a series of in-clined planes, each of which forms one of the radii of acircle, or spokes of a wheel, to the axle of which a gearingis adjusted by which the power generated is utilized. Thewheel is made to face the wind by the wind itself blowingagainst a sort of rudder which projects from the wind blowing against the inclined surfaces orvanes of the wheel causes each vane to move in accord-ance with the law of component forces, thus revolvingthe wheel as a whole. It has been affirmed that the Romans had windmills,but the silence of Vitruvius, Seneca, and Chrysostom,who have spoken of the advantages of the wind, makes [68]. WINDMILLS OF ANCIENT AND MODERN TYPES. The smaller figures show Dutch windmills of the present day, many of which areidentical in structure with the windmills of the middle ages. It will be seen that thesails can be furled when desired to put the mill out of operation. In the mill of moderntype (large figure) the same effect is produced by slanting the slats of the wheel. THE WORK OF AIR AND WATER this opinion questionable. It has been supposedby other writers that windmills were used in France inthe sixth century, while still others have maintainedthat this mechanism was unknown in Europe untilthe time of the Crusades. All that is tolerably certainis that in the twelfth century windmills were in use inFrance and England. It is recorded that when theybegan to be somewhat common Pope Celestine that the tithes of them belonged to the clergy. INHERENT DEFECTS OF THE WINDMILL The mediaeval European windmill was suppliedwith great sails of cloth, and
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Keywords: ., bookcentury1900, bookdecade1910, booksubjec, booksubjectmachinery
