. Animal locomotion, or Walking, swimming, and flying, with a dissertation on aëronautics. Animal locomotion; Aeronautics. 136 ANIMAL LOCOMOTION. tion of power, speed, and small surfaces versus weight. Elaborate measurements of wing, area, and minute calculations of speed, can consequently only determine the minimum of wing for elevating the maximum of weight—flight being attainable within a comparatively wide range. Wings, their Form, etc.: all Wings Screws, structurally and functionally.—Wings vary considerably as to their general contour; some being falcated or scythe-like, some oblong, som
. Animal locomotion, or Walking, swimming, and flying, with a dissertation on aëronautics. Animal locomotion; Aeronautics. 136 ANIMAL LOCOMOTION. tion of power, speed, and small surfaces versus weight. Elaborate measurements of wing, area, and minute calculations of speed, can consequently only determine the minimum of wing for elevating the maximum of weight—flight being attainable within a comparatively wide range. Wings, their Form, etc.: all Wings Screws, structurally and functionally.—Wings vary considerably as to their general contour; some being falcated or scythe-like, some oblong, some rounded or circular, some lanceolate, and some linear.^ All wings are constructed upon a common type. They are in every instance carefully graduated, the wing tapering Pig, 61.—Right wing of the Kestrel, drawn from the specimen, while being held against the light Shows how the primary (h), secondary (a), and ter- tiary (c) feathers overlap and buttress or support each other in every direc- tion. Each set of feathers has its coverts and subcoverts, the wing being conical from within outwards, and from before backwards, d, e, / Anterior or thick margin of wing. a, c Posterior or thin margin. The wing of the kestrel is intermediate as regards form, it being neither rounded as in the partridge (ftg. 96, p. 176), nor ribbon-siiaf)ed as in the albatross (fig, 62), nor pointed as in the swallow. The feathers of the kestrel's wing are unusually symmetrical and strong. Compare with figs. 92, 94, and 96, i)X). 174, 175, and 176.—Original. from the root towards the tip, and from the anterior margin in the direction of the posterior margin. They are of a generally triangular form, and twisted upon themselves in the direction of their length, to form a helix or screw. They are convex above and concave below, and more or less flexible and elastic throughout, the elasticity being greatest at the tip and along the posterior margin. They are also moveable in all their parts. Figs. 61
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectaeronau, bookyear1874
