approved their selection. We have thought it proper to show that Mr. Palmer's invention did not stand in need of our commendation. Its merits, as we have seen, are conceded by the tribunals best fitted to judge, and we are therefore justified in selecting it as an illustration of American mechanical skill. We give three views of the Palmer leg: an inside view when extended, a second when flexed, a third as it appears externally. [Illustration] [Illustration] [Illustration] The Committee on Science and the Arts of the Franklin Institute of Pennsylvania thus stated the peculiarities of Mr. Palmer's invention:-- "_First,_ An ingenious arrangement of springs and cords in the _inside_ of the limb, by which, when the wearer is in the erect position, the limb is extended, and the foot flexed so as to present a natural appearance. "_Second_. By a second arrangement of cords and springs in the inside of the limb, the foot and toes are gradually and easily extended, when the heel is placed in contact with the ground. In consequence of this arrangement, the limping gait, and the unpleasant noise made by the sudden stroke of the ball of the foot upon the ground in walking, which are so obvious in the ordinary leg, are avoided. "_Third_. By a peculiar arrangement of the knee-joint, it is rendered little liable to wear, and all lateral or rotary motion is avoided. It is hardly necessary to remark that any such motion is undesirable in an artificial leg, as it renders its support unstable." Before reporting some of the facts which we have seen, or learned by personal inquiry, we must be allowed, for the sake of convenience, to exercise the privilege granted to all philosophical students, of enlarging the nomenclature applicable to the subject of which we are treating. Man, according to the Sphinx, is successively a _quadruped_, a _biped_, and a _triped_. But circumstances may change his natural conditions. If he loses a leg, he becomes a _uniped_. If he loses both his legs, he becomes a _nulliped_. If art replaces the loss of one limb with a factitious substitute, he becomes a _ligniped_, or, if we wish to be very precise, a _uni-ligniped_; two wooden legs entitle him to be called a _biligniped_. Our terminology being accepted, we are ready to proceed.