. American engineer and railroad journal . e power. 8. With an ordinary wind mans strength is sufflcient towork elliciently an appropriate Hyina: apparatus. 4. With a wind of more than 23 miles per hour, man canperform soaring or sailing flight by means of adequate and ap-l)ropriato sustaining surfaces. 5. A Hying apparatus, in order to operate with the greatestpossible economy, must be based, botli in shape and propor-tion, U]>on the wings of the large, high-tlying birds. 6. The sustaining wing surface may be from !l to per pound of weight. 7. Sutlieiently strong apparatus c
. American engineer and railroad journal . e power. 8. With an ordinary wind mans strength is sufflcient towork elliciently an appropriate Hyina: apparatus. 4. With a wind of more than 23 miles per hour, man canperform soaring or sailing flight by means of adequate and ap-l)ropriato sustaining surfaces. 5. A Hying apparatus, in order to operate with the greatestpossible economy, must be based, botli in shape and propor-tion, U]>on the wings of the large, high-tlying birds. 6. The sustaining wing surface may be from !l to per pound of weight. 7. Sutlieiently strong apparatus can be built of willowframe and stretched fabric, so as to provide a sustaining sur-face of 107 sq. ft., with a weight of about 33 lbs. ^ 8. A man provided with such an ajiparatus would have anaggregate weightof li(8 lbs., and would then ).sq. ft, ofsustaining surface per pound, or about the proiiortionsof largebirds. i). E.\periment must determine wliether the most advan-tageous .shape be that of liirds of prey and of waders, with. Fig. broad wings and spread out primary feathers, or that of seabirds, with narrow wings tapering to a point. 10. If the broad wing be adopted, the wings of an apparatuswith 107 sq. ft. of sustaining surface would needs be of 2( spread, with a maxim\im width of ft. 11. If the narrow wing be adopted, a surface of 107 sq. need a spread of 31) ft. with a maximum width of ft. 12. The application of an additional bearing surface, as atail, is of minor importance. 13. The wings must be curved in transverse section so as tobe concave on the under side. 14. The depth of flexure should be one-twelfth of the width,ill (Uder to correspond with that of birds 15. Experiment must determine whether greater or lessertlexure will prove jireferaltle for larger wing surfaces. U). The framing and spars of the wings should be at thefront edge so far as 17. A sharp cutting edge should ternnnate this
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectrailroadengineering
