38 43 FIG. 8. Two determinations of the speed of the muscular wave FIG. 10.-Determination of the speed of the nervous agent in man FIG. 12.-Measure of the time which elapses between the excitation of the electric nerve, and the discharge of the torpedo . 58 FIG. 82.-Determination of the direction of the movements in an insect's wing 195 FIG. 94.-Experiment to determine by the electric and myographic methods at the same time, the frequency of the movements of the bird's wing, and the relative duration of its elevation and depression 230 FIG. 26.-Determination of the rapidity of walking at various instants, by means of a chronographic tuning-fork 122 NOTATIONS. FIG. 34.-Notation of a tracing of man's mode of walking FIG. 36.-Notations of the gallop (man). FIG. 37.-(Upper line) notation of a series of jumps on two feet. (Lower line) notation of hops on right foot NOTATIONS OF THE PACES OF THE HORSE. FIG. 38.-Notation of a horse's amble FIG. 39. 133 134 135 142 143 Notation of the horse's walking pace FIG. 51.-Notation of the walking pace, with predominance of the lateral pressures. FIG. 45.-Graphic curves and notation of the horse's trot FIG. 41.-Synoptical notations of the paces of the horse, according to various writers. No. 1. Amble, according to all writers. Broken amble, according to Merche. No. 2. { High steps, according to Bouley. Ordinary step of a pacing horse, according to Magure. No. 3. Broken amble, according to Bouley. Traquenade, according to Lecoq. No. 4. Normal walking pace, according to Lecoq. No. 5. Normal walking pace (Bouley, Vincent and Goiffon No. 6. Normal walking pace, according to Raabe. No. 8. Ordinary trot. (In the figure, it is supposed that the animal trots without leaving the ground, which occurs but rarely. The notation only takes into account the rhythm of the impacts of the feet). No. 9. Norman pace, from Lecoq. No. 10. Traquenade, from Merche FIG. 56.-Gallop in three-time FIG. 62.-Notation of the gallop in four-time Notation of full gallop; re-actions of this pace FIG. 64. Transition from the walk to the trot FIG. 68. Notation rule, to represent the different paces PAGE 146 166 . 170 . 171. 174 174 . 174 174 . 175 176 PISTES OR FOOT TRACES OF THE HORSE'S FEET. FIG. 52.-Piste of the walking pace, after Vincent and Goiffon . 167 REPRESENTATION OF THE HORSE IN ITS VARIOUS PACES. FIG. 54.-Representation of the horse at a walking pace . 163 157 FIG. 49.-Horse at full trot. The dot placed in the notation corresponds with the attitude represented 158 FIG. 59.-Horse galloping in the first time (right foot advancing), the left foot only on the ground 168 FIG. 60.-Horse galloping in the second time (right foot forward). 169 FIG. 61.-Horse galloping in the third time (right foot forward) . 169 PAGE FIG. FIG. TRACINGS. TRACINGS OF THE MUSCLES. 4.-Character of the shock according to the degree of fatigue and on the left of the figure are shown the first effects FIG. 11.-Gradual coalescence of the shocks produced by electric 34 35 46 TRACINGS OF HUMAN LOCOMOTION. FIG. 20.-Tracings of the impact and the pressure of the two feet in our ordinary walk FIG. 22.-Tracings of the oscillations of the body during walking FIG. 25.-Tracing of the impact and rise of the right foot, furnished by a lever subjected at the same time to 10 vibrations per second 114 117 121 FIG. 29.-Tracing produced by walking upstairs 128 128 time of suspension remains evidently constant, even 132 FIG. 32.-Leap on two feet at once. 131 TRACINGS OF THE LOCOMOTION OF THE HORSE. FIG. 50.-Tracing and notation of the walking pace, with equal pressures of the feet, both diagonally and laterally FIG. 45.-Tracing and notation of the trot TRACINGS OF THE FLIGHT OF INSECTS. 160 . 153 . 165 FIG. 70. Showing the frequency of the strokes of the wing of a drone-fly and a bee 183 FIG. 72.-Graphic tracing of the middle portion of the course of a bee's wing 189 PAGE FIG. 73.-Tracing of the middle zone of a humming-bird moth FIG. 75.-Tracing of the course of a wasp's wing: lower loops FIG. 78 and 79.—Tracing of a wasp's wing, compared with a Wheat- 190 190 191 192 192, 193 FIG. 80.-Tracing of the wing of a humming-bird moth (lower border) 193 FIG. 81. Tracing of the wing of a tired humming-bird moth . . 194 TRACINGS OF THE FLIGHT OF BIRDS. FIG. 95.-Myographical tracing to determine the frequency of the strokes of the wing in different species FIG. 96.-Differences of frequency and of amplitude in the strokes of a pigeon's wing 232 234 253 FIG. 105.-Tracing of different movements of the pigeon's wing buzzard's wing . 262 FIG. 111.—Inclination of the plane of the wing, with reference to the axis of the body during flight FIG. 113.-Vertical oscillations of the bird during flight TRAJECTORIES. FIG. 23.-Attempt to illustrate, by means of a metallic wire, the sinuous trajectory passed through by the pubis FIG. 71.-Appearance of a wasp the tips of whose wings have been FIG. 100.-Elliptical course of the point of a bird's wing FIG. 101.-Ellipse traced by a Wheatstone's rod on a revolving cylinder 243 ANIMAL MECHANISM: TERRESTRIAL AND AERIAL LOCOMOTION. INTRODUCTION. LIVING beings have been frequently and in every age compared to machines, but it is only in the present day that the bearing and the justice of this comparison are fully comprehensible. No doubt, the physiologists of old discerned levers, pulleys, cordage, pumps, and valves in the animal organism, as in the machine. The working of all this machinery is called Animat Mechanics in a great number of standard treatises. But these passive organs have need of a motor; it is life, it was said, which set all these mechanisms going, and it was believed that thus there was authoritatively established an inviolable barrier between inanimate and animate machines. In our time it is at least necessary to seek another basis for such distinctions, because modern engineers have created machines which are much more legitimately to be compared to animated motors; which, in fact, by means of a little combustible matter which they consume, supply the force requisite to animate a series of organs, and to make them execute the most various operations. The comparison of animals with machines is not only legitimate, it is also extremely useful from different points of view. It furnishes a valuable means of making the mechanical phenomena which occur in living beings understood, by placing them beside the similar but less generally known phenomena, which are evident in the action of ordinary B |