Shoe with heel-calks for a front hoof.
A Shoe with Toe- and Heel-Calks.—Such a shoe should be of uniform thickness from end to end, and should have a toe-calk and two heel-calks that are somewhat stronger and longer than the heel-calks of a shoe which has no toe-calk. If to a shoe of uniform thickness, on which the heel-calks are somewhat higher than those already described, a piece of steel ([Fig. 116, b]) of the height of the heel-calks is welded at the toe, we have a shoe with toe- and heel-calks. The toe-calk should never he higher than the heel-calks. There are three principal kinds of toe-calks,—namely:
1. The Sharp Toe-Calk.—A bar of toe-steel of proper width and thickness for the toe-calk is thrust with the shoe into the fire. When the end of the bar is cherry-red in color it is withdrawn, laid across the straight hardy, and cut nearly through at a point a calk-length from the end. Bar and shoe are then brought to a welding heat, the calk quickly and securely welded across the toe of the shoe, the bar wrenched away, the calk gone over again with the hammer, when it is immediately beaten out to a sharp edge from the anterior face, either over the far edge of the anvil, or in a foot-vise. The posterior face of a sharp toe-calk should be perpendicular to the ground-surface of the shoe. Machine-made toe-calks, sharp, half-sharp and blunt, provided with a sharp spud at one or both ends, are in general use. Their use requires two heats, and the sharp calk is blunted in the welding.
Fig. 116.
Right hind shoe with toe- and heel-calks: a, heel-calks; b, toe-calk; c, greatest width of the base of support (i.e., contact with the ground) of this shoe when without toe- and heel-calks; d, the greatest, and e, the least width of the base of support of this shoe with calks.
2. The Blunt Toe-Calk.—It is a rather long rectangular piece of toe-steel, straight, or curved to conform to the toe of the shoe. The shoe-surface and the ground-surface of the calk are of equal dimensions. It should be welded on in one heat.
3. The Half-Sharp Toe-Calk (Coffin-Lid Toe-Calk).—It resembles the blunt calk, except that the surface of the calk that is applied to the shoe is somewhat broader and longer than the surface that comes in contact with the ground. It is welded on in one heat. The first and third kinds are most suitable for winter.
Since heel-and toe-calks raise the hoof far from the ground and prevent all pressure upon the frog, they diminish the elasticity of the hoof and injure it. They are injurious also to the joints, because they furnish a base of support which is essentially smaller than that afforded by a flat shoe ([Fig. 116]). However, they are indispensable for heavy draft purposes on slippery roads and in winter. Upon all other roads and in summer they are superfluous, at least upon front hoofs, especially as they do not wholly prevent slipping.
Special Properties.—The many different forms of hoofs require a great variety of shoes. Following are the special peculiarities of each of the chief classes of shoes.