Nails and nail holes. It is necessary to consider these together as they are dependent on each other. Shoes were first nailed to the feet by flat-headed nails, and probably it was a long time before the wedge-headed nail was thought of. When the nail head fits into the nail hole it may retain the shoe till it is worn as thin as a penny, but if only the shank of the nail enters the shoe, the head is soon worn off and the shoe becomes loose. Within the last 20 years the horse-shoe nail trade has been revolutionised by the introduction of machinery. Machine-made nails are now almost entirely used, and the three or four leading brands are as near perfection as were the very best hand-made. Practically there is no fault to find with them, and as they are ready-pointed for driving they save time and labour in the forge. They are made in various sizes, and numbered from 2 up to 16. Only the very best iron can be used to produce good nails. Nothing is dearer than bad nails which cause injury to the foot and loss of shoes.
Fig. 41.
A good nail should present certain forms of head, neck and shank. The head should not be too broad at the top or it may become fixed in the nail-hole only by its upper edge, as shown in the middle diagram [Fig. 41], and when the shoe has had a few days wear the nail loses its hold, and the shoe is loose. The neck should not be too thick, as it is then liable to press on the sensitive foot and to break the wall. The shank should not be too wide or too thick. The point should not be too long or too tapered as this leaves insufficient metal to form a good clinch.
There are two methods of putting nail-holes into shoes—by "fullering" and by "stamping." A stamped shoe is one in which the nail holes are merely punched at certain distances, so as to leave four-sided tapered holes of the exact shape of a nail-head. A fullered shoe is one having a groove round the circumference through which the nail-holes are punched. Both processes, when well-done, admit of nails being driven into the hoof with equal safety and ease.
Whether stamped or fullered, there are a few more important points to remember about the nail-holes. The wall is not of the same thickness throughout, but becomes thinner towards the heels. The inner side of the foot is also somewhat thinner and more upright than the outer. The safest position, then, for the nails is in the front half of the foot, but should this position not present sound horn they may be placed further back. The danger of placing nails near the heels is due entirely to the greater risk in driving them through the thin horn. There need be no fear of interfering with expansion.
The distance of the nail-holes from the outer edge of the shoe should depend upon the thickness of the horn of the wall, and therefore be greater in large shoes than in smaller, and greater at the toe than at the heels of the same shoe. When the nail-holes are all near to the circumference of the shoe ([Fig. 42] B.) they are described as "fine"; when they are all placed far from the edge ([Fig. 42] A.) they are called "coarse." When the nail-holes are too "fine" a nail has to be driven high up in the wall to obtain a firm hold, and this is liable to split the horn. When nail-holes are too "coarse" the nail in driving goes dangerously near the sensitive foot. The evils of coarse and fine nailing depend a great deal upon the method of fitting the shoes. When shoes are fitted full to the foot (when the outer circumference of the shoe is greater than the circumference of the wall) "coarse" nail-holes are brought to about their best position. When shoes are fitted close (i.e., when their outer edge is brought within the border of the wall) "fine" nail-holes are brought to their best position in relation to the foot. It need hardly be added that the fit of a shoe ought not to be subject to the position of the nail-holes, but that these should be properly placed so that fitting be guided only by the requirements of the foot.
