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. Do. Do. Do. 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, Marey, Chabrier, Straus-Durckheim, PAGE 13 92 209 115 199 8 14 219 226 233 233 Do. how to apply to the air, 245 Do. nature of forces required to propel, 246 Artificial wave wing of Pettigrew, 236 Do. how to construct on insect type, 240 Do. how to construct to evade the superimposed air during can be driven at any speed; can make new currents compound rotation of: the different parts of the wing travel at different speeds, 252 Do. necessity for supplying root of, with elastic structures, 247 Body and wing reciprocate in flight, and each describes a waved track, 12 21 Bones of the extremities twisted and spiral, 28, 29 Bones of wing of bat-spiral configuration of their articular surfaces, 176 178 220 CHABRIER'S artificial wings, 233 PAGE Flight the least fatiguing kind of motion, Flight-the regular and irregular, ELYTRA or wing cases and membranous wings, FEATHERS, primary, secondary, and tertiary, Fins, flippers, and wings form mobile helices or screws, Flight, weight necessary to, Flight the poetry of motion, Flight under water, Flight of the flying-fish, Flight, horizontal, in part due to weight of flying mass, Flight-how to ascend, descend, and turn, Flight of birds referrible to muscular exertion and weight, Fluids, mechanical effects of, on animals immersed in them, 170 180 14 3, 4, 110, 111, 112, 113 6 13 90 98 110 201 201 204 18 18 Forces which propel the wings of insects, bats, and birds, GRAVITY, the legs move by the force of, 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, 2, 3 186, 189 8, 104, 165 18 18 15 23 98 166 4, 17 18 Ligaments, elastic, position and action of, in wing of pheasant, snipe, 191 Ligaments, elastic, more highly differentiated in wings which vibrate Motion associated with the life and well-being of animals, Motion not confined to the animal kingdom, Motion, natural and artificial, 2 PAGE Motion, of uniform, Motion uniformly varied, Muscles, their properties, mode of action, etc., Muscles arranged in longitudinal, transverse, and oblique spiral lines, Muscular cycles, Muscular waves, PENDULUMS, the extremities of animals act as, in walking, 17 17 24 28 26 211 Pettigrew's method of constructing and applying artificial wings as QUADRUPEDS walk, fishes swim, and insects, bats, and birds fly, by SCREWS the wing of the bird and the extremity of the biped and 235 236 242 37 64 103 Screws-difference between those formed by the wings and those em- 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 variously modified and adapted to WALKING, Swimming, and flying correlated, 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, PAGE 242 Weight necessary to flight, 110 Weight contributes to flight, 112 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 Weight, momentum, and power to a certain extent synonymous in 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, 147 Wing and body reciprocate in flight, and each describes a wave track, Wing vibrates unequally with reference to a given line, 150, 231 Wing, compound rotation of, 149 Wing a lever of the third order, 103 creases, Wing acts on yielding fulcra, Wings, their form, etc., all wings screws, structurally and functionally, Wing-area decreases as the size and weight of the volant animal in-` Wing, natural, when elevated and depressed must move forwards, Wing acts as true kite both during down and up strokes, Wing, traces of design in, Wing of bird not always opened up to same extent in up stroke, Wing flexed and partly elevated by action of elastic ligaments, 191 Wing, power of, to what owing, 194 Wing, effective stroke of, why delivered downwards and forwards, 195 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 at all times thoroughly under control, 154 Wings of insects, consideration of forces which propel, 186 Wings of bats and birds, consideration of forces which propel, 189 PRINTED BY T. AND A. CONSTABLE, PRINTERS TO HER MAJESTY, AT THE EDINBURGH UNIVERSITY PRESS. |