Something of thispassed through my brain as I watched the circling hawk. Once, with a flash of his strong wings, he made a downward turn and, swift and still, he dropped earthwardThen, as if frustrated in whatever had been his design, he wheeled again and climbed as swiftly up the air
I like that phrase as describing the flight of a bird. It is so literally what the creature does. A bird is not superior to gravitation. But for that force he would be the helpless victim of every little breeze, like a balloon, which is unable to shape a course or do anything but float helplessly before the wind. The balloon floats because it is lighter than the air, but the air which the bird displaces is lighter than he, and he only moves in it by virtue of his ability to extract from it, by the motion of his wings, sufficient recoil to propel himself forward. He rises, as do we humans, by means of that which resists him
I love to watch the seagulls. They do this so perfectly, and seem to delight to give us lessons in ærial navigation as they dip and whirl and call about the steamers, on the Bay. Their wings are so easy to study while in action.The first joint, to where the wing bends back and outward, is strong and compact, cup shaped underneath. The second joint tapers. The feathers are long and do not overlap so closely as do those of the first joint, and at the free end they spread out and turn upward. The upper surface of the wing is convex, the lower surface concave. In flying the wings are thrown forward and downward. Flying is not a flapping of the wings up and down, and if a bird were to strike its wings backward and downward, as its manner of flight is so often pictured, it would turn a forward somersault in the air.