Wolff, Alfred R · New York, J. Wiley & sons · leaf 74
orm, increasing in width as they approachthe outer extremity of arm; that the innermost cross-baris placed at about one-sixth to one-seventh of the lengthof the arm from the middle of the shaft; and that itslength is about equal to this distance. So the canvaslattice-work covers only five-sixths or… … Fig. 5. 58 THE WINDMILL AS A PRIME MOVER. inches wide, and at the outer end about six inches thickand four and a half inches wide. As the direction of the wind is changing perpetually,some contrivance is necessary for bringing the shaft intothe direction of the wind, so that the sails will be…
Windmills
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