[Illustration: _The forge of Master Delafosse, royal farrier, in Paris in the mid-eighteenth century. From Diderot’s encyclopedia._] A smith who made, fitted, and applied shoes to horses, mules, and oxen was properly called a farrier. The trade demands knowledge and skill in handling iron, and also knowledge and skill in handling the animals being shod. Because of his close familiarity with these animals, his “horse sense,” so to speak, the farrier often served the function of veterinarian too. More often, however, it was the blacksmith who also served as farrier. Horseshoes were made from bar iron, and they were normally custom made to fit not just a particular horse, but a particular one of his feet. Each shoe of a set of four will differ in one or more respects—size, shape, or weight—from its fellows, and each set may differ from others depending on the type of horse involved—draft, riding, carriage, etc.—and the condition of surface on which the shoes are to be used—ice, mud, stone, etc. In addition, special shoes can correct defects in gait, guard against lameness, and the like. To describe how a smith made all of these possible variations is no part of this booklet. Suffice it to say that in the making of a horseshoe all of the blacksmith’s basic tools come into use: forge, anvil, tongs, and vise. Some attention to each of these in turn will help to round out an understanding of the workings of the smithy. _Forge._ The blacksmith’s forge, which he sometimes calls his fire, is the most important feature of his shop. It consists of a square hearth, usually raised about two and one-half feet and made of brick, with a bellows at the side or back to blow the fire, a hood or hovel above to carry smoke and fumes away, and a trough or tub of water close by in which to quench the iron or cool the tongs. The fire itself, of coal rather than charcoal, is always small and concentrated, a few inches across in the center of a hearth that may be four or five feet square. Around it lies unburnt fuel that the smith can handily bring closer when needed. With his slice—a long-handled, light-weight shovel—his fire-hook—a similarly long-handled rake—and his washer—a bunch of twigs to flick water around the fire—he carefully manages the size and depth of the fire. With the bellows he regulates its intensity. The blacksmith must be able to judge when his stock is hot enough, and he does it by eye, the right degree of heat for a particular operation being revealed by the color of the iron. Blood-red heat is called for when the iron is not to be reshaped but only the surface to be smoothed. Flame heat or white heat is necessary when the work is to be hammered to a different shape, drawn down, or upset. Sparkling heat or welding heat is used only for the delicate and highly skilled process of welding.