Gravity, the legs move by the force of, [18]
Gravity, centre of, [18]
History of the figure-of-8 theory of walking, swimming, and flying, [15]
Joints, [23]
Kite-like action of the wings, [98]
Kite—how kite formed by wing differs from boy’s kite, [166]
Laws of natural and artificial progression the same, [4], [17]
Legs, moved by the force of gravity, [18]
Lever—the wing one of the third order, [103]
Levers, the three orders of, [19]