Animal locomotion : or, walking, swimming, and flying, with a dissertation on aëronautics (1873)
Pettigrew, James Bell, 1834-1908 · London : Henry S. King · leaf 162
e degrees of obliquity. All wings obtain their leverage by presenting oblique surfaces to the air, the degree of obliquity gradually increasing in a direction from behind forwards and downwards during extension and the down stroke, and gradually decreasing in an opposite direction during flexion… … Fig. 63.— The Lapwing, or Green Plover ( Vandlus cristatus, Meyer), with one wing (c b, d' e' f) fully extended, and forming a long lever ; the other (<Z e /, c b) being in a flexed condition and forming a short lever. In the extended wing the anterior or thick margin ( d ' e’ f) is directed up…
Aeronautics
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