the melancholy harvest which War is sweeping down with Dahlgren's mowing-machine and the patent reapers of Springfield and Hartford. The admirable contrivances of an American inventor, prized as they were in ordinary times, have risen into the character of great national blessings since the necessity for them has become so widely felt. While the weapons that have gone from Mr. Colt's armories have been carrying death to friend and foe, the beneficent and ingenious inventions of MR. PALMER have been repairing the losses inflicted by the implements of war.

The study of the artificial limbs which owe their perfection to his skill and long-continued labor has led us a little beyond its first object, and finds its natural prelude in some remarks on the natural limbs and their movements. Accident directed our attention, while engaged with this subject, to the efforts of another ingenious American to render the use of our lower extremities easier by shaping their artificial coverings more in accordance with their true form than is done by the empirical cordwainer, and thus Dr. Plumer must submit to the coupling of some mention of his praiseworthy efforts in the same pages with the striking achievements of his more aspiring compatriot.

We should not tell the whole truth, if we did not own that we have for a long time been lying in wait for a chance to say something about the mechanism of walking, because we thought we could add something to what is known about it from a new source, accessible only within the last few years, and never, so far as we know, employed for its elucidation, namely, the instantaneous photograph.

The two accomplishments common to all mankind are walking and talking. Simple as they seem, they are yet acquired with vast labor, and very rarely understood in any clear way by those who practise them with perfect ease and unconscious skill.

Talking seems the hardest to comprehend. Yet it has been clearly explained and successfully imitated by artificial contrivances. We know that the moist membranous edges of a narrow crevice (the glottis) vibrate as the reed of a clarionet vibrates, and thus produce the human bleat. We narrow or widen or check or stop the flow of this sound by the lips, the tongue, the teeth, and thus articulate, or break into joints, the even current of sound. The sound varies with the degree and kind of interruption, as the " babble" of the brook with the shape and size of its impediments,pebbles, or rocks, or dams. To whisper is to articulate without bleating, or vocalizing; to coo as babies do is to bleat or vocalize without articulating. Machines are easily made that bleat not unlike human beings. A bit of India-rubber tube tied round a piece of glass tube is one of the simplest voice- uttering contrivances. To make a machine that articu lates is not so easy; but we remember Maelzel's wooden children, which said, "Pa-pa" and "Ma-ma"; and more elaborate and successful speaking machines have, we believe, been since constructed.

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But no man has been able to make a figure that can walk. Of all the automata imitating men or animals moving, there is not one in which the legs are the true sources of motion. So said the Webers more than twenty years ago, and it is as true now as then. These authors, after a profound experimental and mathematical investigation of the mechanism of animal locomotion, recognize the fact that our knowledge is not yet advanced enough to hope to succeed in making real walking machines. But they conceive that the time may come hereafter when colossal figures will be constructed whose giant strides will not be arrested by the obstacles which are impassable to wheeled conveyances.

* Traité de la Méchanique des Organes de la Locomotion. Translated from the German in the Encyclopédie Anatomique. Paris, 1843.

We wish to give our readers as clear an idea as possible of that wonderful art of balanced vertical progression which they have practised, as M. Jourdain talked prose, for so many years, without knowing what a marvellous accomplishment they had mastered. We shall have to begin with a few simple anatomical data.

The foot is arched both longitudinally and transversely, so as to give it elasticity, and thus break the sudden shock when the weight of the body is thrown upon it. The ankle-joint is a loose hinge, and the great muscles of the calf can straighten the foot out so far that practised dancers walk on the tips of their toes. The knee is another hingejoint, which allows the leg to bend freely, but not to be carried beyond a straight line in the other direction. Its further forward movement is checked by two very powerful cords in the interior of the joint, which cross each other like the letter X, and are hence called the crucial ligaments. The upper ends of the thighbones are almost globes, which are received into the deep cup-like cavities of the haunch-bones. They are tied to these last so loosely, that, if their ligaments alone held them, they would be half out of their sockets in many positions of the lower limbs. But here comes in a simple and admirable contrivance. The smooth, rounded head of the thighbone, moist with glairy fluid, fits so perfectly into the smooth, rounded cavity which receives it, that it holds firmly by suction, or atmospheric pressure. takes a hard pull to draw it out after all the ligaments are cut, and then it comes with a smack like a tight cork from a bottle. Holding in this way by the close apposition of two polished surfaces, the lower extremity swings freely forward and backward like a pendulum, if we give it a chance, as is shown by standing on a chair upon the other limb, and moving the pendent one out of the vertical line. The force with which it swings depends upon its weight, and this is much greater than we might at first suppose; for our

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limbs not only carry themselves, but our bodies also, with a sense of lightness rather than of weight, when we are in good condition. Accident sometimes makes us aware how heavy our limbs are. An officer, whose arm was shattered by a ball in one of our late battles, told us that the dead weight of the helpless member seemed to drag him down to the earth; he could hardly carry it; it "weighed a ton," to his feeling, as he said.

In ordinary walking, a man's lower extremity swings essentially by its own weight, requiring little muscular effort to help it. So heavy a body easily overcomes all impediments from clothing, even in the sex least favored in its costume. But if a man's legs are pendulums, then a short man's legs will swing quicker than a tall man's, and he will take more steps to a minute, other things being equal. Thus there is a natural rhythm to a man's walk, depending on the length of his legs, which beat more or less rapidly as they are longer or shorter, like metronomes differently adjusted, or the pendulums of different time-keepers. Commodore Nutt is to M. Bihin in this respect as a little, fastticking mantel-clock is to an old-fashioned, solemn-clicking, upright time-piece.

The mathematical formulæ in which the Messrs. Weber embody their results would hardly be instructive to most of our readers. The figures of their Atlas would serve our purpose better, had we not the means of coming nearer to the truth than even their careful studies enabled them to do. We have selected a number of instantaneous stereoscopic views of the streets and public places of Paris and of New York, each of them showing numerous walking figures, among which some may be found in every stage of the complex act we are studying. Mr. Darley has had the kindness to leave his higher tasks to transfer several of these to our pages, so that the reader may be sure that he looks upon an exact copy of real human individuals in the act of walking.

bending at the knee, so as to lift the foot from the ground, in order that it may swing forward.

Fig. 1.

The first subject is caught with his legs stretched in a stride, the remarkable length of which arrests our attention. The sole of the right foot is almost vertical. By the action of the muscles of the calf it has rolled off from the ground like a portion of the tire of a wheel, the heel rising first, and thus the body, already advancing with all its acquired velocity, and inclined forward, has been pushed along, and, as it were, tipped over, so as to fall upon the other foot, now ready to receive its weight.

Fig. 3.

The next stage of movement is shown in the left leg of figure 3. This leg is seen suspended in air, a little beyond the middle of the arc through which it swings, and before it has straightened itself, which it will presently do, as shown in the next figure.

The foot has now swung forward, and, tending to swing back again, the limb