. Animal locomotion, or Walking, swimming, and flying, with a dissertation on aëronautics. Animal locomotion; Aeronautics. Fig. 59.—The Red-legged Partridge (Perdix rubra) with wings fully extended as in rapid flight, shows deeply coneave form of the wings, how the primary and secondary feathers overlap and support each other during extension, and how the anterior or thick margins of the wings are dii'ected upwards and forwards, and the posterior or thin ones downwards and backwards. The wings in the partri<tge are wielded with iiijiiiense velocity and power. This is necessary because of th
. Animal locomotion, or Walking, swimming, and flying, with a dissertation on aëronautics. Animal locomotion; Aeronautics. Fig. 59.—The Red-legged Partridge (Perdix rubra) with wings fully extended as in rapid flight, shows deeply coneave form of the wings, how the primary and secondary feathers overlap and support each other during extension, and how the anterior or thick margins of the wings are dii'ected upwards and forwards, and the posterior or thin ones downwards and backwards. The wings in the partri<tge are wielded with iiijiiiense velocity and power. This is necessary because of their small size as compared with the great dimensions and weight of the body. If a horizontal line be drawn across the feet {a, e) to represent the horizon, and another from the tip of the tail («) to the root of the wing (d), the angle at which the wing strikes the air is given. The body and wings Avhen taken together form a kite. The wings in the partridge are rounded and broad. Compare with heron, fig. 60.—Original. than the air. It must tread and rise upon the air as a swim- mer upon the water, or as a kite upon the wind. It must act against gravity, and elevate and carry itself forward at the expense of the air, and by virtue of the force which. Fig. 60 —The Grey Heron (Ardea cinerea) in full flight. In the heron the wings are deeply concave, and unusually large as compared with the size of the bird. The result is that the wings are moved very leisurely, with a slow, heavy, and almost solemn beat. The heron figured weighed under 3 lbs. : and the expanse of wing was considerably greater than that of a wild goose which weighed over 9 lbs. Flight is consequently more a question of power and weight than of buoyancy and surface, d, e, f Anterior thick strong margin of right wing, c, a, b Posterior thin flexible margin, composed of primary (b), secondary (a), and tertiary (c) feathers. Compare with part- ridge, fig. 59. —Original. resides in it. If it were rescued from
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectaeronau, bookyear1874
