and other countries, there is reason to believe that our knowledge of this most difficult department of science will go on increasing until the knotty problem is finally solved. If this day should ever come, it will not be too much to affirm, that it will inaugurate a new era in the history of mankind; and that great as the destiny of our race has been hitherto, it will be quite out-lustred by the grandeur and magnitude of coming events. INDEX. AERIAL creatures not stronger than terrestrial ones, Air cells in insects and birds not necessary to flight, Albatross, flight of, compared to compass set upon gimbals, Amphibia have larger travelling surfaces than land animals, but less than aërial ones, Artificial fins, flippers, and wings, how constructed, Artificial wings, Borelli, RAGE 13 92 209 115 199 8 14 219 Do. Marey, 226 Do. Chabrier, 233 233 can be driven at any speed; can make new currents compound rotation of: the different parts of the wing travel at different speeds, Do. necessity for supplying root of, with elastic structures, Artificial compound wave wing of Pettigrew, Atmospheric pressure, effects of, on limbs, Axioms, fundamental, BALANCING, how effected in flight, Bats and birds, lax condition of shoulder-joint in, Birds, lifting capacity of, Body and wing reciprocate in flight, and each describes a waved track, Bones of the extremities twisted and spiral, Bones of wing of bat-spiral configuration of their articular surfaces, CHABRIER'S artificial wings, 252 247 242 24 17 118 210 ELYTRA or wing cases and membranous wings, FEATHERS, primary, secondary, and tertiary, Fins, flippers, and wings form mobile helices or screws, Flight the poetry of motion, Flight the least fatiguing kind of motion, Flight under water, Flight of the flying-fish, Flight, horizontal, in part due to weight of flying mass, Flight-the regular and irregular, Flight-how to ascend, descend, and turn, Flight of birds referrible to muscular exertion and weight, PAGE 170 180 14 3, 4, 110, 111, 112, 113 Fluids, mechanical effects of, ou animals immersed in them, Flying machine, Henson, Do. Stringfellow, A flying machine possible, Forces which propel the wings of insects, bats, and birds, HISTORY of the figure-of-8 theory of walking, swimming, and flying, . JOINTS, KITE-LIKE action of the wings, Kite-how kite formed by wing differs from boy's kite, LAWS of natural and artificial progression the same, Legs, moved by the force of gravity, Lever the wing one of the third order, Levers, the three orders of, Life linked to motion, Lifting capacity of birds, Ligaments, Ligaments, elastic, position and action of, in wing of pheasant, snipe, Ligaments, elastic, more highly differentiated in wings which vibrate Membranous wings, Motion associated with the life and well-being of animals, Motion not confined to the animal kingdom, Motion, natural and artificial, 15 166 4, 17 233 170 Motion, of uniform, Motion uniformly varied, Muscles, their properties, mode of action, etc., Muscles arranged in longitudinal, transverse, and oblique spiral lines, Muscles, oblique spiral, necessary for spiral bones and joints, Muscular cycles, Muscular waves, PENDULUMS, the extremities of animals act as, in walking, PAGE 17 17 24 28 26 9, 18, 56, 57 211 Pettigrew's method of constructing and applying artificial wings as Pettigrew's wave wing, Pettigrew's compound wave wing, Progression on the land, Do. on or in the water, Do. in or through the air, 235 236 242 37 64 103 QUADRUPEDS walk, fishes swim, and insects, bats, and birds fly, by SCREWS the wing of the bird and the extremity of the biped and Screws-difference between those formed by the wings and those eni Speed of wing movements partly accounted for, Spine, spiral movements of, transferred to the extremities, Swimming of the turtle, triton, crocodile, etc., TERRESTRIAL animals have smaller travelling surfaces than amphibia, The travelling surfaces of animals increase as the density of the media The travelling surfaces of animals variously modified and adapted to 7,8 31 how to construct to evade the superimposed air during the forces required to apply to the air, necessity for supplying root of, with elastic structures, 245, 246 247 Wave wing, compound, Weight necessary to flight, Weight contributes to flight, Weight, momentum, and power to a certain extent synonymous in The wing of the bird and the extremity of the biped and quadruped are Wing in flight describes figure-of-8 curves, Wing during its action reverses its planes and describes a figure-of-8 PAGE 242 110 112 114 12, 136 12 track in space, 140 Wing when advancing with the body describes looped and waved tracks, 143 146 Wing, tip of, describes an ellipse, Wing and body reciprocate in flight, and each describes a wave track, 147 12 168 Wing ascends when body descends, and vice versa, 159 Wing during its vibrations produces a cross pulsation, 148 Wing vibrates unequally with reference to a given line, 150, 231 Wing, compound rotation of, 149 Wing a lever of the third order, 103 Wing acts on yielding fulcra, 8, 104, 165 Wings, their form, etc., all wings screws, structurally and functionally, 136 147 Wing-area variable and in excess, 124 creases, Wing acts as true kite both during down and up strokes, Wing-area decreases as the size and weight of the volant animal in- Wing, natural, when elevated and depressed must move forwards, Wing, traces of design in, Wing of bird not always opened up to same extent in up stroke, 132 156 167 165 180 182 183 Wing flexed and partly elevated by action of elastic ligaments, 191 194 Wing, effective stroke of, why delivered downwards and forwards, Wing acts as an elevator, propeller, and sustainer both during exten- 197 Wings, points wherein the screws formed by, differ from those in ordi- nary use, 151 Wings of insects, consideration of forces which propel, Wings at all times thoroughly under control, Wings of bats and birds, consideration of forces which propel, 154 186 189 |