This calking has a double object. In the common system of shoeing, to avoid slipping in winter upon the ice, and in the cities upon the wet, slimy surface of pavement, or to assist draft, it is customary to weld a calk upon the toe of a shoe, and to turn up the heels to correspond. In this motion the horse is placed upon a tripod, his weight being entirely upon three points of his foot, and those not the parts intended to bear the shock of travel or to sustain his weight. The position of the frog is of course one of hopeless inaction, and the motion of the unsupported bones within the hoof produce inflammation at the points of extreme pressure, so that, in case of all old horses accustomed to go upon calks, there is ulceration of the heels, in the form of "corns," which the smith informs the owner is the effect of _hard roads_ bruising the heel from the outside; he usually "cuts out the corn," and puts on more iron in the form of a "bar shoe." Or the same action which produces corns, acting upon the dead, dry, unsupported frog and sole, breaks the arch of the foot so that a "drop sole" is manifest, or "pumiced foot," for both of which a "bar shoe" is the unvarying, pernicious prescription. In the Goodenough shoe, the calks are supplied, and the weight so distributed that the objection to the old method does not exist. COUNTERSINKING THE NAILS. This is a point to which we call attention as of great importance. In shoeing a horse for light or rapid work with a common flat shoe, seven or eight nail-heads protrude, and take the force of his blow on the ground. The foot has just been pared, and those nails, driven into the wall and pressing against the soft inside horn and sensitive laminae, vibrate to the quick, and often cause the newly-shod horse to shrink, and show soreness in traveling for a day or two. No matter how skillfully shod, the horse will be all the better in escaping this unnecessary infliction. THE BEVEL OF THE FOOT SURFACE Is to keep the shoe a continuation of the crust or wall of the hoof, and to avoid percussion upon the sole. THE BEVEL ON THE GROUND SURFACE Is to follow the natural concavity of the foot and to give it the form which will have no suction on wet ground, will not pick up mud, or retain snow-balls. THE CALKS Have a use fully explained. When the shoe thus described is set so as to secure _frog-pressure_, as hereinafter directed, a horse may be shod without violation of nature's laws; foot disease, under fair conditions, will become almost impossible, and the useless refuse-stock, broken down by the old method, may be restored to usefulness. [Illustration: GOODENOUGH SHOE--BACK.] CHAPTER IV. HOW TO SHOE SOUND FEET.