Note.—No person is expected to learn the structure of a foot entirely from this description. He must obtain two feet cut off at the fetlock joint. One he should soak in water till the hoof can be pulled off. The sensitive foot is then visible and the inside of the hoof; with these before him, the drawings and descriptions in this chapter will be of great assistance. The second foot he should have sawn vertically down the middle through the point of the toe, and again across the quarters, so as to show the inside of the foot from two different points of view; this will afford a view of the relation of parts.
The cheap wisdom of the amateur is often expressed in the remark "the shoe should be fitted to the foot, not the foot to the shoe." Like many other dogmatic statements this is only the unqualified assertion of half a truth. Foot and shoe have to be fitted to each other. There are very few horses whose feet do not require considerable alteration before a shoe can be properly fitted to them. As a rule, when a horse arrives at the forge, the feet are overgrown and quite out of proportion. In a few cases—as when a shoe has been lost on a journey—the foot is worn or broken and irregularly deficient in horn. In either instance the farrier has to make alterations in the hoof to obtain the best bearing surface before he fits a new shoe. The claim often made for some novel inventions in horse shoes, "that they may be fitted and applied in the stable by a groom or stableman" is evidence of a sad misunderstanding of the art of horse-shoeing. If shod feet always remained of the same shape replacement of shoes would be a very easy matter—but they never do. The living foot is constantly changing, and therefore the man entrusted with fitting shoes to it, must know what its proper form should be. When he finds it disproportionately overgrown he must know how much horn to remove—where to take away and where to leave alone. He must not carry in his head a theoretical standard of a perfect foot and attempt to reduce all feet to that shape. He must make allowance for varieties of feet, and for many little differences of form that present themselves in practice. He has, in fact, to prepare the foot for a shoe, and it is just as important to do this properly as it is to prepare a shoe for the foot. To fit a shoe to a foot which has not been properly prepared may be even more injurious to the horse than "to fit the foot to the shoe."
The general principle to be followed is—to remove superfluous horn, to obtain a good bearing surface for a shoe, to bring all parts of the hoof equally into proportion. A good foot so prepared, when the horse is standing on level ground should show, when looked at from the front, both sides of the wall of equal height; the transverse line of the coronet should be parallel with the line of the lower border of the hoof, and
the perpendicular line of the leg should cut those lines at right angles. (Fig. 17). When looked at from the side the height of the heels and the toe should be proportionate. When looked at from behind the frog should be seen touching the ground. On lifting the foot a level bearing surface wider than the wall should be presented, extending from heel to toe all round the circumference of the hoof; within this level border, the sole should be concave, strong, and rough.
Fig. 17.
In Fig. 17 is shown the foot on its ground surface and from the side. The parallel lines are quite arbitrary, but assist in explaining how the proportion of the foot is to be attained. Both sides of the foot are of the same height. The bearing surface just meets the middle line. All the lines at coronet, heel, and toe, are at right angles to the perpendicular line. The side view shows the proportionate height of heel and toe, and the slope of the wall in front. Compared with Figs. 22 and 23 deviations from proportion are seen.
These conditions are not attainable with all feet, but the prudent farrier does the best he can under the circumstances. It is easy to make the frog touch the ground by over-lowering the heels, but this is only introducing one evil in attempting to avoid another. Some feet have naturally a long toe with an excessive slope of the front part of the wall. To hide this defect a farrier may "stump up" the toe and leave the heels too high, but he does so at the expense of the horse's foot. Each foot requires treating with full knowledge of the form best adapted to its natural formation, and most capable of carrying a shoe.
The Instruments used to prepare a foot for shoeing are a rasp, a drawing knife, and a toeing knife.
The rasp is the most indispensable. It should be sixteen inches long, proportionately broad, and one part of it should be a file-surface. The shorter, narrow rasps do not afford all the advantages a farrier should possess to enable him to do the best work. To strike an even all-round level bearing surface on a hoof a farrier requires a large rasp, just as a joiner must have a large plane to produce a level surface on wood. Harm may be done by the careless use of a rasp, and a bearing-surface spoiled by the over-reduction of horn at one place. This fault may be aggravated by attempts to mend it, if such attempt take the form of further reduction of the whole hoof on a foot where horn is deficient.
The drawing knife is a comparatively modern instrument which replaced a tool called the buttress. A drawing knife is formed with great skill for the purpose of paring out the concave sole of the hoof, and has done infinite harm. In the days which have now almost passed away, when it was thought the proper thing to make the hoof look clean, smooth, and pretty, the drawing knife was the chief instrument in the preparation of the foot. Now, when nearly all men know that the stronger the sole and frog of the foot can be preserved the better for the horse, this knife is less used—and the less the better. The doorman, preparing a foot for the fireman to fit a shoe to, should not use a knife at all. The man who fits the shoe requires a knife to remove occasional little prominences of horn which are liable to cause uneven pressures or which are in the way of a properly fitted shoe—as, for instance, the edge of the wall to make way for a clip, or the angle of sole at the heel to prevent uneven pressure by the shoe.
The toeing knife usually consists of about a foot of an old sword-blade. This knife is held and guided by one hand of the farrier, whilst with the other it is driven through overgrown horn by the hammer. Skilfully used it is unobjectionable, and for the large strong hoof of heavy draught horses it saves a great deal of time and labour. For the lighter class of horses it is unnecessary, and for weak feet with a thin horn covering it is dangerous.
The toeing knife cannot leave a finished level bearing surface, and its work has to be completed by a few strokes of the rasp. A farrier should, therefore, never attempt to remove all the superfluous horn with the knife, he should leave some for the rasp so that in producing the final level surface no encroachment upon the necessary thickness of covering horn need be made.
Fig. 18.
The overgrown foot such as we find on a healthy horse that has retained a set of shoes for some weeks, or that has been without shoes on a surface not hard enough to cause sufficient wear, is quite unfitted to receive a shoe. It must be reduced to proportions. In Fig. 18, I have attempted to show diagrammatically a side view of an overgrown hoof. The dotted lines at the base show two effects of lowering one part more than another, although both attain a level surface. In Fig. 21 we see the result of over-lowering the heels, and in Fig. 20 of leaving them too high. It may also be noticed that these conditions affect other parts of the foot; in fact not only other parts but the whole foot, and even the relative position of the foot to the leg. If we compare the proportionate foot, Fig. 19, with the diagram Fig. 21, it will be seen that by over-lowering the heels the slope of the front of the foot is increased, that the bearing surface from heel to toe is slightly increased in length, and that if the dotted perpendicular line be accepted as showing the direction through which the weight of the body passes, lowering the heels tends to put an increased proportion of weight on the back parts of the foot. If we compare Fig. 19 with Fig. 20 we see the effect of leaving the heels too high. The bearing surface from heel to toe is shortened, the slope of the wall at the toe is made less, and more weight is thrown upon the front parts of the foot.
Fig. 19.—A proportionate hoof.
Fig. 20.—A disproportionate hoof—heels too high.
Fig. 21.—A disproportionate hoof—heels too low.
Now these alterations in both cases affect not only the form of the foot but its relative position to the leg, and as the bones of the limb above are a series of levers connected by muscles and ligaments so placed as to be most efficient for movement, it is evident that alterations of the foot must affect the action of the limb. (Compare Figs. 19, 20 and 21) In the unshod horse roaming about there is a natural automatic return to proper relative position whenever it has been temporarily upset. A long toe is worn down and high heels are reduced to their proper level by friction. Not so a foot protected by an iron shoe. Wear is stopped, and a disproportionate hoof becomes more and more disproportionate. Temporary alterations of the position of the foot do little harm because they are permitted, within a margin, by the movement of joints and by the elasticity of muscles. When, however, an alteration of position is continued for many weeks it tends to become permanently fixed and may thus do a great deal of harm, which is not traced to its real cause because the effect is slow and gradual. It is important, therefore, to remember that the proportion of the hoof is to be maintained not only because it is necessary to the well-being of the foot; but because it affects the action of the whole limb. Too long a toe may cause a horse to stumble, and it must always increase the strain on the back tendons during progression. Heels too high prevent the frog from taking its proper bearing on the ground, and thus cause a loss of function in the back parts of the foot. An excessively high heel has a tendency to throw the knee forward and to straighten the pastern.
Fig. 22.—Heels high—under surface and side view.
Fig. 23.—Heels low—toe long.
It is impossible to lay down any hard and fast rule to guide a farrier in maintaining the proportions of heel and toe when reducing an overgrown hoof to proper form. Feet differ much in their natural formation, some are high-heeled and some low, some are straight in front some very much sloped, some are narrow and upright, others round and spreading. In Fig. 22 the heels are too high, and the bearing surface does not reach the transverse line at the heels. The side view shows the excessive height of heels and the slope of the wall in front too upright. Great assistance is afforded the farrier in judging whether he should remove more horn from heel or toe by the appearance of the under surface of the foot. When the heels are much above the level of the frog there is an indication for their lowering. When the wall and bars are about flush with the angle of sole between them, there is, as a rule, no more horn to spare at that part. The length of the toe may be usefully gauged by the condition of the junction between wall and sole. When the sole is sound and strong all the wall above its level—wall unsupported by sole and showing on its inner aspect marks of the horny laminæ—may be rasped down so that a firm bearing surface is obtained consisting of wall and sole.
In Fig. 23 the bearing surface at the heels is below the line marking a proportionate foot. The toe is too long and projects beyond the transverse toe line. The side view shows the low heel and the corresponding excess in the slope of the wall in front. The lower transverse line in each figure does not represent the ground, but is added to make clear the height of heels and length of toe.
Important as it is to maintain the relative proportions between the front and back parts of the foot, it is perhaps even more important to preserve the balance between the two sides of a foot. Both sides must be left of equal height. If one side be higher than the other a disproportionate amount of weight is thrown on the lower side, and more or less strain is put upon the ligaments of the joint above. In the Figs. 24 one limb is shown with both sides of the hoof even, and the straight line of the limb cuts squarely across the transverse line of the bearing surface of the foot. In the the other limb one side of the hoof is too high, and in the preparation for shoeing only that side will require attention.
Fig. 24.
Through constant neglect of this point some feet become more or less permanently twisted—and the twist occurs at the coronet. The ground surface of a foot or a shoe always tends to remain at right angles to the direction of the limb, and when the sides of a hoof are allowed to remain of unequal height, the higher side presses the soft tissues of the coronet upwards. As the hoof grows from the coronet the side thus increased in height is not so noticeably uneven at the lower border of the wall as at its upper, and it cannot be restored to its proper form, except by months of careful attention and slight over-lowering at each shoeing. The diagrams (Figs. 25 and 26) represent vertical sections through a foot from side to side. One shows the wall uneven at the base, the other shows it uneven at the coronet.
Fig. 25.—Uneven at ground surface.
Fig. 26.—Uneven at coronet.
Peculiarities in the formation of a limb sometimes cause an apparent error in the relative position of the foot. Thus we have horses that turn their toes in, and those that turn their toes out. The cause of this twist takes place at the upper part of the limb, and it will be found that when the toes turn out the elbow turns in and vice versâ. The farrier can do no good to this formation, and attempts to alter it or disguise it by devices in shoeing are only injurious to the foot,—little deceptions worthy of a horse-coper.
A good bearing surface is the primary object aimed at in preparing the foot for a shoe. The relative position of the limb to the foot and the proper proportions of every part of the foot are matters to be borne in mind whilst the farrier is directly forming the bearing surface for a shoe. A good bearing surface must be even, level, on sound horn, and as wide as can be obtained to give stability to the shoe. It should not be limited to the wall. If, without over-reduction, the use of the rasp leaves a firm portion of the sole as a level surface continuous with the lower edge of the wall, the best of bearing surfaces is obtained. (Fig. 27). The bearing surface should be level from heel to toe, and no part of it can be singled out either as unfit to bear weight or as specially capable of enduring undue pressure. No broken or diseased horn should be used as bearing surface for a shoe. The broken horn should be removed and the diseased horn must, if not entirely removed, have so much of its border cut or rasped off as will prevent contact with a shoe.
Fig. 27.
After forming a level bearing surface with the rasp the sharp outer border of the wall is lightly removed with the file, so as to prevent splitting of the horn. The outer surface of the wall should not be rasped for it affords protection to the deeper layer of horn. The harder the outer layer of horn is kept the tougher and firmer is the whole thickness.
The Sole and Frog require very little attention. No sensible farrier now puts himself to the unnecessary trouble of cutting away horn that is wanted for protection. It was not the practical farrier that introduced the stupid "paring and cutting" that ruined horses' feet for nearly a century. It was the theorists, who taught expansion of the wall and descent of the sole as primary necessities in the function of a foot, who must be credited with all the evils resulting from robbing the sole and frog of horn. When a horse is shod with an iron shoe the wall cannot wear, and therefore it has to be artificially reduced at each shoeing. But the shoe does not interfere with the wear of a frog, and the farrier may safely leave that organ entirely to take care of itself. To some extent the shoe does interfere with the natural wear of the sole, and, therefore, any flakes of horn which have been prevented by the shoe from detaching themselves from the sole may be removed. The best way to remove these is with the buffer. The sole should not be pared out. I mean not only that the horn should be left strong, it should not be pared with a drawing knife, even if only a harmless surface layer be removed. The effect of leaving the sole of a shod foot with a smooth, level, pared surface is to stop its natural method of throwing off more or less broken flakes, and to cause it to retain that which is half loose until it is removed in one great cake.
A portion of the sole that requires a little special care in preparing for shoeing is the angle between the wall and the bars—the well-known seat of "corn." This must not be left so as to come in contact with the shoe. It is not to be "scooped" out, but it should be reduced distinctly below the level of the wall so that when the shoe has been in position for a week or two there is still no contact between the horn of the soles and the iron at that point.
Level or adjusted surface? The bearing surface of a hoof must, of course, be exactly adapted to the surface of shoe intended to be applied. Presuming that the best surface for a shoe is one level from toe to heel, I have insisted upon the necessity of a level bearing surface on the foot. There are, however, exceptional cases in which a level shoe is not used, and then we must alter the foot accordingly. Horses that wear the toe of a shoe out of all proportion to the rest of the iron may be beneficially shod with a shoe turned up at the toe. To fit such a shoe the hoof surface must not be made level, it must be rasped away at the toe and rounded off to follow the line of the shoe. In the three diagrams (Fig. 28) is shown—(a) side view of a foot prepared to suit the turned-up shoe at the toe, (b) a level line to fit a level shoe and, (c) a form often adopted on the Continent to suit a shoe fitted with a slight curve throughout. This adjusted shoe is designed to imitate the shape of the worn surface of an old shoe or to some extent the worn surface of an unshod foot. Every farrier knows how many horses go better after a level shoe has been worn a few days than when first applied, and it is argued, with reason, that the greater ease is due to the shoe being worn to the form offering least resistance to the movement of the foot in locomotion. I have nothing to say against this form of shoe and the necessary form of foot surface for it, except that it is more difficult to make than the ordinary level one. When adopted the curve of the foot should not be obtained by over-lowering the toe and heels but by leaving the quarters higher.
Fig. 28.—Three forms of bearing-surface.
Fig. 29 shows a hoof in which shortening of the toe has been effected not by reducing the ground surface of the wall, but by rasping away the wall in front of the toe. This should not be done with any good foot, but it may be adopted with feet having an unnaturally long toe and no superfluous horn on the under surface. A "stumped-up" toe is very ugly and it weakens the hoof in front.
Fig. 29.—A "stumped-up" toe.
Uneven bearing surfaces are easily produced by a careless use of the rasp. One side of the wall may be made lower than the other, one heel may be reduced more than the rest of the foot, or one side of the toe may be unevenly reduced. In Fig. 30 the foot presents an uneven surface which not uncommonly results from careless work. The parts over-reduced are those most easily reached with a rasp. The near foot suffers at the outside heel and inside toe. The off foot at the inside heel and outside toe. A left handed farrier would injure the feet in just the opposite positions.
Fig. 30.—Uneven surface.
Another fault results from holding the rasp untruly. If we suppose the inside heel of the near foot to be under preparation and the farrier inclines his rasp too much inwards, he leaves the wall at the heel lower than the sole within it. On such a foot a level shoe rests upon the sole instead of upon the wall, and a bruised heel soon follows.
Paring away the sole to produce a deep concave appearance has another evil effect in addition to that before pointed out. It removes the horn just within the border of the wall, taking away the natural support, and leaving as bearing surface for a shoe a narrow ridge instead of a strong flat surface. Fig. 31 shows this fault, and it must be remembered that this ridge may be left as thin as a knife edge. Such a ridge cannot sustain the weight of the horse, and when it yields the shoe also yields, the clenches are raised and the shoe becomes loose.
Fig. 31.—A Pared-out Sole.
Excessive rasping of Wall. The best farriers—those most proud of their work—have a great temptation to use a rasp too freely to the outer surface of the wall. The hoof gets rough, or it may be ridged, its appearance is improved by being made smooth, and it is only human to turn out work which is clean and neat. Owners and grooms are rather inclined to forget the claims of the horse when judging shoeing, and the result is that some harm is done by excessive rasping. A strong foot does not suffer much, but its strength is preserved by leaving the hard outer surface intact. Rasping off an outer layer of horn favours evaporation and hardening of the underneath layer, and the toughness so desirable is to some degree replaced by hardness and brittleness. Excessive rasping below the clenches is even more injurious than rasping above them. The wall, between its bearing surface and the clenches, has to withstand the contact of the shoe, and the perforation by nails. It should be the toughest and strongest part, and, therefore, should not be rasped more than is necessary to lay down the clenches and finish the fitting. Unfortunately the neatest work is done by fitting a shoe "close" and then rasping off any protruding horn. This is bad for the foot, as it weakens the wall and spoils the bearing surface at each shoeing. The worst offenders in this direction are dealers, who sacrifice everything to appearances and insist upon shoeing being neat at all hazards.
Opening the Heels is one of the gravest faults a farrier can be guilty of. It consists in cutting away the extremity of the wall at the heel and generally a slice off the side of the frog at the same time. The effect is to produce an appearance of width at the back of the foot—to make what is called "a fine open foot." Fig. 31 shows a foot which has been injured in this way. The wedge shaped opening which results has many objections. It breaks the continuity of structures at the heels, it removes horn unnecessarily, it weakens the foot and, when the wall is interfered with, it shortens the bearing surface for a shoe. The bearing surface at the back of the foot is perhaps the most important of any afforded by the wall. The longer the bearing surface is at the heels the more the base for sustaining weight is brought under the leg, and the better the position for supporting the body. All removal of horn that shortens this surface is injurious.
Over-reduction of hoof is always a fault. It is true a carefully fitted shoe on a foot so treated may do no harm for a time. Too much horn should be left rather than too little. A strong covering of horn is a protection against many mistakes in the fitting or form of a shoe applied to a foot. So long as a hoof is everywhere strong enough to sustain pressure and afford bearing, weight is evenly distributed throughout the whole foot. When the horn is thin it yields to any uneven pressure and damage is done to the foot, even if immediate lameness is not induced.
Horse-shoes are made either by hand or machinery. In this country most are hand-made—the front shoes from new bar-iron, and the hind from old shoes welded together and drawn out under heavy hammers. Probably no method of working iron gives such good results as this in producing a hard, tough shoe that will withstand wear. The custom of the trade is to keep a stock of shoes suitable for all the regular customers. From this stock are selected sizes and forms, which are then specially fitted for each foot.
Various materials have been tried in the production of horse-shoes. Leather, compressed and hardened, has been tried, and failed. Vulcanite was experimented with unsuccessfully. Paper, or more correctly, a compressed papier maché, has also been tested but proved unsatisfactory. Steel has been pretty largely tried in many different forms, but it is difficult to temper. As nearly all shoes are applied immediately after being fitted they have to be rapidly cooled in water, and steel treated in this way is made so hard that, if the shoes do not break, they are dangerously slippery on most paved streets. As a material for shoes good malleable iron has no equal. It can be obtained in bars of various sizes to suit any form and weight of shoe, and the old shoes made from it may be worked up over and over again.
The chief objects to be attained in any particular pattern or form of shoe are—that it be light, easily and safely retained by few nails, capable of wearing three weeks or a month, and that it afford good foot-hold to the horse. All shoes should be soundly worked and free from flaws.
The first shoes were doubtless applied solely to protect the foot from wear. The simplest arrangement would then be either a thin plate of iron covering the ground surface of the foot, or a narrow rim fixed merely round the lower border of the wall. Experience teaches that these primitive forms can be modified with advantage, and that certain patterns are specially adapted to our artificial conditions. A good workman requires no directions as to how he should work, and it is doubtful if a bad one would be benefitted by any written rules, but it should be noted that a well-made shoe may be bad for a horse's foot, whilst a very rough, badly-made one may, when properly fitted, be a useful article. To make and apply horse-shoes a man must be more than a clever worker in iron—he must be a farrier, and that necessitates a knowledge of the horse's foot and the form of shoe best adapted to its wants.
Weight of Shoes. The lighter a shoe can be made the better. Weight is a disadvantage we are obliged to put up with to obtain wear, for the frequent removal of shoes is only a little less injurious to the hoof than working with none at all. It is not to be understood that the heaviest shoe gives the most wear; on the contrary, a heavy shoe may have the iron so distributed as to increase the rapidity of wear, and a shoe of half the weight properly formed may last longer. It is no uncommon thing to find worn-out shoes still weighing more than a new shoe which will, on the same horse, give a longer period of wear. When a horse wears his shoes out very rapidly, the indication to the farrier is not simply to increase the weight, but to see if he can obtain more wear by altering the form and distributing the iron in a different way. A tired horse wears his shoes much more rapidly than a fresh and active one. Continued slipping wears away a shoe out of all proportion to the work done by a horse having a firm foot-hold. These two different conditions may be partially due to the shoes, for a heavy shoe tires the leg, and broad flat shoes favour slipping. Some horses wear one special part of the shoe excessively—as a rule, either at the toe or the heel—and this is better met by turning up the worn part out of the line of wear than by thickening it and so increasing weight. Besides, a heavy shoe requires a greater number or a larger size of nails to retain it securely in position, and this is a disadvantage. It has often been asserted that a horse "goes better" in a heavy shoe than a light one, and that this is due to the heavier shoe acting as a protection to the foot and warding off concussion. If the term "goes better" merely means that he lifts his foot higher and consequently bends his knee more, I do not deny the assertion. The reason of this is not that the horse feels less concussion and therefore goes freer. It is an exaggeration of the natural movements, due simply to the horse with weight imposed on his feet having to use the muscles of his arms more to lift that weight. The same thing can be brought about by tying bags of shot on to the hoof, which is done to cultivate "action." The healthy foot requires no artificial aids against concussion, but when a foot becomes tender from bad shoeing it may sometimes be relieved by adding to the substance and weight of a shoe.
The following are about the average weights, per shoe, of horses standing 16 hands high:
| Race Horses | 2 | to | 4 | ounces. |
| Hacks and Hunters | 15 | to | 18 | " |
| Carriage Horses | 20 | to | 30 | " |
| Omnibus " | 3 | to | 3-1/2 | lbs. |
| Dray " | 4 | to | 4 | " |
Thickness and Width of Shoes. To obtain the necessary amount of wear from shoes they must be increased either in thickness or width, and it will assist us in estimating the relative value of these conditions if we shortly consider their advantages and disadvantages. I may say at once that no sound foot requires a wide shoe merely as "cover" or protection for the sole. Defective soles may sometimes require protection, but sound ones never, and we may therefore put aside entirely all claims made for width of shoe under pretence that it gives a valuable protection to the foot. A shoe should be as wide as the natural bearing surface of the foot, so that it may occupy the whole of the space offered by nature as useful for bearing. Even when it is wider no harm is done until the width is such as to afford a lodgement for stones, etc., between the concave sole and the web of the shoe.
A thick shoe raises the foot from the ground and thus removes the frog from bearing—a very decided disadvantage. It also requires the larger sizes of nails to fill up the deep nail holes, and very often renders the direction of the nail holes a matter of some difficulty.
The width of a shoe may beneficially vary. It should be widest at the toe to afford increased surface of iron where wear is greatest. It should be narrowest at the heels so as not to infringe upon the frog, nor yet to protrude greatly beyond the level of the wall. The thickness of a shoe should not vary unless, perhaps, it be reduced in the quarters. Heel and toe should be of the same thickness so as to preserve a level bearing. Excess of thickness at the toe puts a strain on the back tendons, whilst excess at the heels tends to straighten the pastern.
The surfaces of Shoes. There are two surfaces of the shoe which claim attention, one which is applied to the foot, and another which rests on the ground. The form of these surfaces may be varied greatly, but of course the foot-surface presents much less necessity and less opportunity for alterations than the ground-surface. The foot-surface of a shoe must be formed in accordance with the requirements of the horse's foot, and no other consideration should be allowed to materially modify it. The ground-surface may be altered to suit the tastes and prejudices of the owner as well as the requirements of the horse and the peculiarity of roadways.
Fig. 32.—A level, flat bearing-surface.
The Foot-Surface. It is quite obvious that the surface of the shoe upon which the hoof has to rest should be regular and even; that it should not consist of hills and holes or grooves and ridges. I should not have mentioned such a very evident matter but that in large towns, the cheaper and poorer classes of shoeing commonly possess this very fault. When shoes are made from thin, wide, old iron tyres they are "buckled" on one surface, and to hide this the farrier puts that side to the foot so that it is not noticed until it causes damage. There are three or four forms of foot-surface adopted by farriers, all of which have distinctive features, and some of which have very grave evils. There is the plain flat surface which is given to all narrow shoes, to hunting shoes, and to some heavier and wider shoes. So long as the sole is healthy and arched this is a very good form. All hind shoes have a flat foot-surface, and most fore shoes might have it with advantage. It utilises the whole of the natural bearing surface, and must of necessity afford a firmer basis for the foot to rest upon than a more limited surface. The fore feet are not so constantly arched in the sole as the hind. Sometimes they are flat and occasionally convex. If a shoe be intended for use on all feet—on feet with convex and flat soles as well as those properly formed—a wide flat foot surface would often cause injury by pressing unevenly upon the sole. To avoid this injury in less than five per cent of feet, and to save the trouble of keeping in stock shoes of different forms, the flat foot-surface of front shoes has been replaced by a bevelled or "seated" surface. (Fig. 33).
Fig. 33.—A "seated" bearing surface.
This form is very widely used. It consists of a narrow flat surface next the outer circumference of the shoe, about equal in width to the border of the wall, and within that, of a bevelled surface, sloped off so as to avoid any pressure on a flat sole. This "seated" surface is not positively injurious but it limits the bearing to the wall, and neglects to utilise the additional bearing surface offered by the border of the sole. If shoes were to be made all alike no shoe is so generally useful and safe as one with a foot-surface of this form, but it is evident that when the sole of the foot is concave there is nothing gained by making half the foot-surface of the shoe also concave.
There are two other forms of foot-surface on shoes. In one the surface slopes gradually from the outer to the inner edge of the shoe, like the side of a saucer. In the other the incline is reversed and runs from the inner edge downwards to the outer. This last form is not often used, and was invented with the object of spreading or widening the foot to which it was attached. The inventor seemed to think that contraction of a foot was an active condition to be overcome by force, and that expansion might be properly effected by a plan of constantly forcing apart the two sides of the foot. The usual result of wearing such a shoe is lameness, and it achieves no good which cannot be as well reached by simply letting the foot alone.
Fig. 34.—Foot-surface sloped outwards.
Fig. 35.—Foot-surface sloped inwards.
The foot-surface which inclines downwards and inwards like a saucer acts in an exactly opposite way to the other. The wall cannot rest on the outer edge of the shoe, and consequently falls within it, the effect being that at every step the horse's foot is compressed by the saucer-shaped bearing. This form of surface (Fig. 35) is frequently seen, and is at all times bad and unnecessary. Even when making a shoe for the most convex sole it is possible to leave an outer bearing surface, narrow but level, which will sustain weight without squeezing the foot.
Fig. 36.—Foot-surface level at Heels.
At the heels the foot-surface of all shoes should be flat—not seated—so that a firm bearing may be obtained on the wall and the extremity of the bar. No foot is convex at the heels, therefore there is no excuse for losing any bearing surface by seating the heels of a shoe to avoid uneven pressure. Fig. 36 rather exaggerates the "unseated" portion of shoe.
The Ground-Surface. As I have said, this may vary indefinitely. Sometimes it is a plain flat surface, broken only by the holes made for nails or by the "fullering" which affords not only space for the nails but some grip on the ground. When a shoe is "fullered" the groove made should be deep, so as to let the nail-head well down, and wide so as to afford room for giving the nail a proper direction. If the fullering be continued round the toe of a shoe by a good workman neatness is given, but when a clip is drawn the iron is so reduced that some wear is sacrificed. If only an inch at the toe be unfullered, the solid iron affords more wear just where it is wanted.