THE
ART OF HORSE-SHOEING
A Manual for Farriers,

BY

WILLIAM HUNTING, F.R.C.V.S.

Editor of The Veterinary Record. Veterinary Inspector for Westminster and Chelsea. Consulting Veterinary Surgeon to the London Road-Car Company. Member of the Committee for National Registration of Farriers.

With nearly one hundred Illustrations.

London:

H. & W. Brown, 20 Fulham Road, S.W.

1895.

CONTENTS.

PREFACE.

This little book is written for three classes of readers—for horse-owners who may interest themselves in the subject, for farriers who are open to conviction, and for veterinary students who have to be examined.

The method pursued has been, to first describe the form and action of the foot, next the preparation of the foot for shoeing. Then the form of a shoe is treated of and the details to be observed in making it. The selection of shoes for varieties of feet or for special kinds of work follows, and afterwards the fitting and nailing-on are considered. Other chapters are devoted to "roughing," shoeing defective feet, accidents, the use of leathers and pads.

Throughout an endeavour has been made to be as simple and clear as possible in expression, to lay down correct general principles and to point out the technical details which are essential to good shoeing. On all these points authorities are not agreed, and I trust those who differ from me will pardon any too dogmatic expressions of opinion in these pages.

The illustrations will be of assistance in making clear the text. Some of these are copied from books, some are drawn from models or preparations, and some are diagramatic. The books I am indebted to are, "Anatomy of the Domestic Animals," by Gamgee and Laws; "On the Horse's Foot," by Bracy Clark; Bouley's "Atlas of the Foot," and Goyau's "Maréchalerie."

William Hunting.

16 Trafalgar Square,

London, S.W.

THE
ART OF HORSE-SHOEING
A MANUAL FOR FARRIERS.

[CHAPTER I.]

Farriery is the art of shoeing horses, and can only be properly learned by a long practical experience in the shoeing-forge. If the foot of the horse were not a living object perhaps the training obtained in the forge would be all that was necessary for efficient workmanship. As, however, the hoof is constantly growing it is constantly changing its form. The duty of a farrier therefore is not merely to fix a shoe upon the hoof but to reduce the hoof to proper proportions before doing so. Now as hoof is only the outer covering of a complex and sensitive foot, damage to the exterior surface may injure the structures within. Injury does frequently result, and not always from carelessness. Perhaps as much injury follows careful work, based upon wrong principles, as slovenly work carried out in perfect ignorance of any principle. The injury to feet resulting from shoeing may not be apparent at once. It may be, and often is, of a slow and gradual nature, and not credited to its true cause until the horse is rendered an incurable cripple.

It seems evident then that to do justice to a horse a farrier should not only possess manipulative skill, but should have a correct idea of the structures and functions of the foot, as well as a thorough knowledge of the form and variations of the hoof.

Few persons appreciate the importance of horse-shoeing, whilst a small number tell us it is unnecessary. Here and there an enthusiast has the courage of his convictions and is able, for a time, to exhibit animals doing work without shoes. In some countries horses are regularly ridden with no addition to their natural hoof, but in such places the surface over which the animals travel is grass land. In all civilised countries where good roads exist shoeing is practised. The gentleman with a fad who occasionally appears in England with unshod horses at work is an unconscious impostor. He sets his little experience against the common sense and universal practice of others. No man of business would pay for shoeing if he could do without it. The "shoeless" experiment has been tried over and over again, but always with the same result—a return to shoeing. In dry weather the hoof becomes hard, and it is wonderful how much wear it will then stand on the hardest of roads. In wet weather the hoof becomes soft, and then the friction on hard roads soon prohibits work without shoes. If work be persisted in, under such circumstances, the hoof rapidly wears away and lameness results. Persons trying to prove a pre-conceived theory meet this difficulty by resting the horse until the horn grows, but business men who keep horses for work in all weathers can afford no such luxury. Shoeing has been called "a necessary evil." The phrase is a misuse of words, for there is no necessary evil about it. Of course it is no more free from accident than other operations, but its evils are fairly described as accidents, whilst its benefits are fully apparent. Without shoes horses at work would be more often lame than with them; without shoes horses could not do half the work they do with them, and so we need not further discuss the necessity of shoeing.

The value of horse-shoeing depends upon the manner in which it is done. Very seldom does the owner of horses appreciate the quality of the work. As a rule the price charged, or the distance from the forge to the stable, regulates the choice of a farrier. Not having any pecuniary interest in the trade, I may say that such matters should not be allowed to decide between one farrier and another. A bad workman may do an injury at one shoeing which will cost the owner of the horse more than would pay ten times over the difference between his charges and the higher prices of a better man.

Many years ago I knew a firm who changed their farrier and system of shoeing for a cheaper plan. The cost for shoeing alone fell very considerably, but the cost of horse-flesh rose in one year more than £100. The old saw—"that for want of a nail the shoe was lost, for want of a shoe the horse was lost, and for want of a horse the man was lost," has been illustrated times without number. Few persons, however, are aware of the terrible consequences which have more than once attended neglect in the shoeing of horses. Napoleon's retreat from Moscow depended for most of its hardships and horrors upon the simple fact that his horses were not shod properly for travelling on snow and ice. The horses could not keep their feet, and were unable to drag the guns and waggons, which had to be abandoned. During the Franco-Prussian war, Bourbaki's retreat became a confused rout from a similar cause. In civil life no winter passes without injury and death to hundreds of horses from the same neglect. These are instances that anyone can see; but heavy losses due to bad shoeing are constant from other or less evident evils—from the adoption of wrong methods and the practice of erroneous theories.

The farrier has not been fairly treated by the public. His practical knowledge has been ignored, he has been instructed by amateurs in all sorts of theories, and coerced into carrying out practices for the untoward results of which he has been blamed. The natural consequence of all this has been that the art of farriery degenerated, and the farrier was forced into a position destructive to the self-respect of any craftsman. In no other trade do persons entirely ignorant of the business presume to direct and dictate as to how the work should be done. No one presumes to instruct the watch-maker or bell-hanger as to the details of his craft, but the farrier has been compelled to take his instructions from all sorts and conditions of men.

Only in recent years has the man who shoes horses been allowed to know something of his calling. Various causes have acted in putting an end to the state of discord, and the trade is now entering upon a brighter time. The Worshipful Company of Farriers—one of those ancient City Guilds which had survived their original vocation and usefulness—has wakened up, and is striving to resume its proper function as the head and director of the trade over which it ought to preside. Agricultural Societies have also taken the matter up, and fostered a healthy emulation amongst farriers by instituting practical competitions at their shows. Veterinary Surgeons have devoted considerable research to the elucidation of the anatomy and physiology of the foot, and many old errors have been corrected. School Boards have made the present generation of farriers able and willing to supplement their practice by a study of principles. We have, in fact, arrived at a time when everyone interested seems inclined to recognise the importance of the art and its technical difficulties, and when no one has a brand new infallible discovery which alone can save the horse and guide the farrier.

My object in writing is not to suggest anything new but to point out the general principles upon which the art is based, and to indicate those details which are essential to success, and those which are to be avoided if soundness and duration of service are recognised as true economy in a stud of horses.

[CHAPTER II.]
The Form and Action of the Foot.

The foot of a horse consists of a variety of living structures, differing in form and texture, and enclosed in a horny covering called the hoof. Although the farrier's work is applied only to the hoof it is necessary that he should know something of the whole foot, because it is but too easy to injure the structures within by alterations of the horny covering without.

The simplest way to understand the foot is to study separately the different parts, and to apply that knowledge in obtaining a general idea of the relations of all the parts to each other. There is not then much difficulty in appreciating the functions of each part, and the uses and action of the whole organ.

The Hoof.

Everyone is familiar with the general appearance of the hoof. It is not a regular geometrical figure. Each of the four feet of the horse shows some peculiarity in form, by which a farrier can at once identify a fore from a hind or a left from a right.

The fore feet should be similar in size and shape. Disease may be suspected when any marked difference exists. But a healthy hoof which has been broken, or much rasped, does not retain its proper form and may thus confuse a novice.

The hind feet should be proportionate in size to the fore, and then it is not of much practical consequence whether the whole are large or small.

The front feet are rounder and less pointed at the toe than the hind; they are also more sloping in front. The two fore feet and the two hind should be in pairs. The right and left feet are distinguished from each other by the inner side being more upright or, if examined on the under surface, by the outer border being more prominent.

Although to a casual observer the hoof appears as one continuous horny structure, it may easily be separated into three distinct parts by prolonged soaking in water. The division takes place so as to leave the sole, frog, and wall separate portions. These may now be considered.

Fig. 1.—A Fore Foot.

Fig. 2.—A Hind Foot.

The Wall is that portion of the hoof seen whilst the foot rests upon the ground. It covers the front and sides of the foot. It extends from the coronet downwards and slightly outwards so that its lower circumference is greater than its upper. The front portion shows its greatest height and obliquity, diminishing in these respects as it passes backwards. At the heels the wall is turned in upon itself, and passes forward towards the centre of the foot until it becomes lost in the structure of the sole. These turned-in portions of the wall are called the bars, and serve two purposes; they increase the bearing surface of the wall, and by embracing a part of the sole on each side, they afford an increased solidity to the union of the wall with the rest of the hoof.

If we detach the wall its inner surface is seen to consist of a number of thin horny projections running parallel to each other from above downwards and forwards. These are called the horny laminæ. They number from five to six hundred and correspond to similar processes on the sensitive foot. ([Fig. 3]).

Fig. 3.—Half of a Hoof, showing the inside.

Round the upper circumference on the inside of the wall is a depression or groove presenting innumerable small pits or openings. This corresponds to a part of the sensitive foot called the coronary band, which will be noticed again.

A section of wall enables us to see variations in its thickness. ([Fig. 4]). It is thickest at the toe, becoming gradually thinner towards the heels; thus affording strength and solidity to resist wear at one part, as well as pliancy at another to ward off concussion.

Fig. 4.—Transverse Section of Wall showing variation in thickness.

The structure of the wall is fibrous—the fibres running parallel to each other, and with the same obliquity as that presented by the front of the wall. Although the wall varies in thickness from before backwards, it does not from above downwards. It maintains the same thickness from the coronet to its lower circumference.

The layers of the wall are hardest externally, becoming softer as they approach the inner surface—a condition due to the outer layers being exposed to friction and evaporation. This is a simple and valuable provision of nature which should not be interfered with. The hard outer layer is best adapted to withstand wear, and its density protects the deeper layers from evaporation. This maintains the whole wall at the degree of softness and toughness which best preserves elasticity and strength of horn.

The Sole is that division of the hoof which forms the floor of the foot. It is situated within the lower border of the wall, and is slightly arched so that on a hard level surface its central part takes no bearing. ([Fig. 5]). Posteriorly the sole is divided by a triangular space into which the frog fits, and thus its continuation to the heels consists of two angular portions embraced between the bars and the wall. The unmutilated sole is throughout of nearly equal thickness, but a slight excess round the circumference gives firmer attachment to the wall.

Fig. 5.—The Sole with Frog removed.

The inner surface presents a finely pitted appearance which is most marked at the toe and round its border. The part immediately related to the frog shows few pits, and we shall find that the whole surface corresponds to the sensitive parts to which it is attached.

The structure of the sole is, like the wall, fibrous; but the fibres are smaller. They run downwards and forwards in the same direction as those of the wall. The outer layers are the hardest and protect the deeper from injury.

The Frog is the smallest division of the hoof, and is a triangular shaped body filling up the space left between the bars. ([Fig. 6]). Its broad base is rounded and prominent, and is continued laterally by a thin layer which binds together the heels and envelopes the back of the foot. This thin layer is continuous with a horny band extending round the upper part of the wall at its junction with the hair, and sometimes prolonged downwards on the surface of the wall. ([Fig. 7]). It appears to be a continuation of the outer layer of the skin, analogous to the free border of skin at the root of the human nail. ([Fig 8]). It serves the useful purpose of covering and protecting the young horn of the wall at its source of growth.

Fig. 6.—The Frog, detached from the Sole.

Fig. 7.—The Frog and frog-band.

Fig. 8.—The frog band detached from wall by a small wedge.

The point of the frog, much the harder part, extends forward to the centre of the sole. Though situated between the bars the frog is only attached to their upper border—the sides remaining free and separate. Thus on each side is formed a deep fissure which permits the frog to expand laterally when compressed, without such force being continued to the sides of the foot. The frog is elastic, and when pressed upon must expand slightly. If these spaces between frog and bars did not exist, the foot would be injured when the frog was compressed by the weight of the horse—either the sensitive parts within would be bruised or the heels would be forced apart.

The centre of the frog presents a depression or "cleft" caused by the doubling in of the horn. Few shod feet exhibit it of natural appearance, and the term cleft, by implying a narrow deep fissure, keeps up the false notion. The cleft should be shallow and rounded. It serves two purposes—it increases the mobility of the frog, and by breaking the regularity of surface affords a secure foot-hold on level ground.

The prominence of the frog might lead a superficial observer to consider it a thick solid mass; and I believe this mistake is the cause of its too frequent mutilation. It is merely a layer of horn following the outline of the structures within, which are similarly prominent and irregular in surface. ([Figs. 9] and [10]). The diagrams show a section through the point and through the cleft of the frog.

Fig. 9.—Section of Foot at cleft.

Fig. 10.—Section at point.

The frog is fibrous, though not to such a marked degree as the other portions of the hoof. Its chief qualities are elasticity and toughness.

The Secreting Structures.

If we macerate a dead foot in water for a week or two, the hoof may be removed entire without injuring the tissues within. In this way the sensitive foot or "quick" is exposed to view, and presents an exact counterpart of the inside of the hoof. The sensitive foot consists of a layer of fibrous tissue stretched over the bones and other structures which form the centre of the foot. It is plentifully supplied with blood-vessels and nerves necessary to its double function as the source of horn growth and as the tactile organ of the foot. Horn is, of course, not sensitive, although the slightest touch on a horse's hoof is recognised by the animal, and this feeling is due to the impression made upon the sensitive foot. In the living horse any injury to the "quick" causes the greatest pain, and although this sensitiveness is a serious disadvantage in disease it is a most valuable provision in health, enabling the horse, even through a thick layer of horn, to recognise the quality of the surface upon which he may be standing or moving. It is this sense of touch—this tactile function—which demands that the sensitive foot should be so bountifully supplied with nerves.

Every farrier knows how profusely blood flows from any wound of the "quick"—evidence that the part is well supplied with blood-vessels. This full supply of blood is not merely for the ordinary waste and repair which takes place in every tissue; it is to meet a special demand—to supply the material for the production of horn. The sensitive foot is the secreting structure of the hoof, and the source of the constant growth and reproduction of horn. It corresponds with great exactness to the inside of the hoof, and as we have described the hoof in sections it may be convenient to follow that course with this structure, and to describe the sensitive frog, the sensitive sole, and the sensitive laminæ. We shall begin with the last.

The Sensitive Laminæ. Corresponding to the horny leaves on the inside of the wall, the sensitive foot presents an arrangement of minute parallel folds which are called the sensitive laminæ. ([Fig. 11]). Between these the horny laminæ rest, so that there is a kind of interleaved attachment which affords the very firmest connection between the wall and the sensitive foot. If the laminæ be laid bare in a living horse by removal of the wall, it is found that they have the power to secrete a kind of horn, not a hard fibrous horn like that of the wall, but a softer variety. This function is not very active in health or we should find that the lower edge of the wall was thicker than the upper; but it exists, and is very evident in some cases of disease.

Fig. 11.—Foot with hoof removed showing at the upper part the Coronary band, and below the Sensitive Laminæ.

In laminitis the wall at the toe is often pushed forward out of position by a horny mass formed by the laminæ, and so we have the deformity of an excessive length of toe. In some cases of long continued sandcrack the irritation of the laminæ causes excessive secretion, and a horn tumour results. The sensitive laminæ, then, fulfil two functions; they offer a firm connecting medium for the wall, and they secrete horn. By the cruel experiment of removing the horny sole and frog of a living horse and then forcing him to stand on the maimed foot on a level surface, it has been shown that the laminæ are capable of alone supporting the weight of the animal. It has been argued from this that the laminæ always support the weight, and that the horse's foot may be described as being slung by the connecting laminæ. This is not true. The frog and sole help to support weight, and the hoof acts as one continuous whole, each part taking its direct and proportionate share of the weight placed upon the foot. The sensitive laminæ are not elastic, they are unyielding, and, therefore, allow no downward yielding which would impose excessive pressure on the sole.

The Coronary Band. (See [Fig. 11]). The sensitive laminæ do not cover the whole of the upright portions of the sensitive foot. There is between their upper extremity and the line which separates the skin from the sensitive foot, a convex band which runs round the upper border of the foot, and is turned downwards and inwards at the heels. This is called the coronary band, and corresponds to the groove which we noticed on the inner side of the upper border of the wall. On its surface are innumerable small projections or papillæ which, in the living animal, fit into the openings on the groove of the wall. From each of these papillæ grows a horn fibre, and from the surface between them is formed a softer horny matter—the two products forming together the substance of the wall. The coronary band is, then, an important structure, being the source from whence the wall is produced. Upon the healthy condition of this band depends the soundness of the wall, and any interference with its integrity must lead to defects or deformities in the wall.

The Sensitive Sole ([Fig. 12]) is that portion of the "quick" to which the sole is attached. Its surface is covered with papillæ, like those on the coronary band but much smaller, giving an appearance somewhat like the pile of velvet. From these the horn fibres of the sole are formed, and a firm means of connection is afforded for the floor of the hoof.

Fig. 12.—Under Surface of Foot showing Sensitive Frog and Sole.

The Sensitive Frog in structure resembles the sensitive sole, but its papillæ are very much smaller, and the surface therefore is smoother. The irregular prominent surface of the frog, with its cleft and the space at each side of it, is exactly reproduced on the sensitive frog, as might be expected, for the one is moulded on the other. There is one difference between the sensitive frog and the other portions of the sensitive foot which I may here mention. It is not attached to the bones of the foot except by its point, but is situated behind the bone, and has as a basis a mass of soft tissue which forms an important cushion or pad, to be referred to later.

Growth of Hoof.

Like every other part of an animal body, the hoof is constantly changing. Wear and tear cause waste of the horn, which is replenished by growth. When wear exceeds growth the foot becomes denuded of horn, and lameness results. When growth exceeds wear the hoof becomes disproportionately long, and some parts suffer by the overgrowth of others—for instance, whenever the heels are unduly high the frog becomes small and weak. In a state of nature the horse's foot keeps itself of proportionate form. On hard ground the hoof is worn away as quickly as it grows. On soft ground it may, for a time, become overgrown, but this is rectified by the soft horn becoming fractured and broken off. In enclosed cultivated grounds the movements of the horse, even on grass land, are too limited to ensure a proportionate form of hoof. When horses are turned out without shoes the feet should not be left to take care of themselves, unless the pasture is of large area and the time at grass extends for several months.

In a hoof which is overgrown—and all shod feet become overgrown in four or five weeks—there is apparently a greater excess of horn at the toe than elsewhere. This is due to the oblique direction of the wall at the toe, and to the fact that the horn fibres of the hoof do not grow down vertically, but obliquely forward. When the natural wear of the hoof is prevented, the effect of growth is to lengthen the toe and carry forward the bearing surface of the foot. Now this bearing surface has a proper relative position to the limb above it. Therefore a disproportionate foot must injuriously affect both the action and position of the whole limb.

The rate at which the wall grows varies greatly in different horses, and is affected by external conditions. The good average wall grows nearly one inch in three months, and the whole hoof is replaced in from ten to fifteen months. The hoof grows more rapidly when a horse is actively exercised than when he is confined in a box. Febrile diseases check growth, and irregularities of the system cause the formation of ridges in the horn, each one commencing at the coronet and being carried down with the growing horn until the hoof is marked by a series of rings running transversely and parallel to each other. These rings are of themselves no detriment to a horse, but they mark irregularities of growth which may have been due to illness or lameness.

The growth of horn on a shod foot is affected by the bearing it takes. When a part of the wall takes no bearing on the shoe it grows quicker than that which does. We see this when a shoe is so fitted that the heels take no direct pressure on the shoe, also when a portion of wall is broken at the quarters, and again when, for any reason, a portion of the edge of the wall has been rasped away to prevent bearing upon some special spot. In all these cases, after the shoe has been worn a month, it will be found that the horn has grown more rapidly at the part where bearing did not take place, and, when the shoe is removed, the horn which was relieved of pressure is found to have been in apposition with the shoe.

The growth of horn cannot be accelerated by any application to its surface. If we desire to hasten growth of the wall we can do so by stimulating the part from which it is produced, i.e., the coronary band. A mild blister to the coronet causes considerable increase in the rapidity of growth, but no ointments applied to the surface of the wall affect its production in the least, though they may modify its condition and prevent dryness and brittleness.

The sole grows in much the same way as the wall, but it wears quite differently. It never becomes overgrown to the extent seen in some instances of the wall. The hard firm structure of the wall, if not worn down by friction on roads or dry hard surfaces, may grow to a great length. As a rule, when much overgrown, it splits in the direction of its fibres and becomes detached in broken fragments. The sole, when overgrown, has a tendency to become detached in flakes, and never very much exceeds its normal thickness without becoming dry and brittle, when the movements of the horse cause it to break up and fall off.

The frog when it takes a bearing on the ground wears off in shreds. A frog which takes no bearing dries up, and sometimes a large superficial layer is cast off. Though the softest of the horny divisions of the hoof, the frog is able to withstand wear and tear as well as any of the others. Being elastic and resting upon soft tissues, it is able to yield to any undue pressure and leave the firmer horn of the wall and bars to sustain the greater strain. The growth of the frog depends a great deal upon the form of the back parts of the wall. If the heels become overgrown, the frog is removed from bearing and consequently wastes. High heels have always between them a small frog. On the other hand low weak heels have always a large frog, and the explanation is that the increased bearing thrown on the frog causes greater development.

Properties of Horn. Horn is light, hard, tough, and elastic, properties most essential to its usefulness as a protector of the foot. Horn is porous, and absorbs moisture. Too much moisture in horn weakens it, and therefore it must be remembered that the natural protection against this is the hard outer layer of the hoof. When this layer is rasped off moisture is more easily absorbed until the dry, hard surface is restored by exposure and friction.

Horn is a bad conductor of heat, and thus an equally good protective against the effects of snow in some countries, and of hot dry sands in others. With a sound thick hoof the application of a red-hot shoe produces very little effect on the internal structures, provided, of course, it remain in contact only a reasonable time. With a foot protected by a thin layer of horn, fitting a red-hot shoe must be done quickly or it may damage the soft tissues.

Dissection of the Foot.

So far we have only described the outer covering of the foot and the structure from which it grows and by which it is connected to the parts within. A little deeper examination is necessary to understand the mechanism of the whole organ.

Fig. 11.—Section of Foot.

If we divide into two lateral halves a foot cut off at the fetlock joint, we have a section which should show the whole of the deeper structures. In the centre we see the three lower bones of the limb—the pastern, coronet, and pedal. ([Fig. 11]). On the front surface of these bones we notice a tendon or sinew which comes from above the knee and is fixed to the upper part of the pedal bone. At the back of the bones two very large tendons run down and are fixed on the last two bones. These tendons are the structures through which the movements of the foot are made. They have in themselves no power of contraction but they are connected above the knee, and in the hind leg above the hock, to powerful muscles which possess the power of contraction. When these muscles contract the tendons are drawn up towards knee or hock, and so move the foot backwards or forwards.

To permit movement of one bone upon another the ends of the bones are suitably shaped, and covered with a layer of gristle or cartilage. To limit the movement and to hold the bones together the ends of each bone are surrounded by ligaments, and thus we have joints formed.

Fig. 12.—Side view of Pedal Bone.

The pastern bone is altogether above the level of the foot, the coronet bone is partially within the hoof, and the joint between it and the pedal bone is quite within. The pedal, often called the coffin bone, ([Fig. 12]) is entirely within the hoof and fills the front part of the horny envelope completely. It is a peculiarly shaped bone, being continued backwards by two projections which follow the course of the wall to a little beyond the quarters of the foot. ([Fig. 13]). From this point to the extremity of the heels the wall is not supported by bone but by strong plates of gristle, which are called the lateral cartilages.

Fig. 13.—Under surface of Pedal Bone.

Fig. 14.—The Lateral Cartilage.

The Lateral Cartilages are situated one on either side of the foot partly within and partly without the hoof. They form the basis upon which the back part of the wall is moulded, and being elastic permit a certain amount of movement in the posterior parts of the foot. ([Fig. 14]). If the coffin bone filled the whole hoof, the foot would be too rigid. With bone at the front portion we have a firm surface for attachment, and with cartilage at the back we have an equally firm attachment, but one that will yield to blows or pressure and thus better protect the internal parts. These cartilages extend above the level of the hoof, and may be easily felt in the living horse at the back part of the coronet. ([Fig. 15]). Between them, and behind the body of the coffin bone is a large space which is filled up by a mass of soft tissue to which various names have been given, such as plantar-cushion, frog-pad, etc.

Fig. 15.—Coffin Bone and Lateral Cartilages seen from above.

The Frog-Pad is the name under which we shall notice it. It forms the bulbs of the heels and is the soft basis upon which is spread the sensitive frog. It extends from side to side of the foot between the two lateral cartilages, and fills up all the space within the hoof behind the body of the coffin bone. The structure of this pad may be described roughly as consisting of a network of fibrous bands, having the interstices filled up with elastic tissue. ([Fig. 16]). Down the centre of the pad runs a vertical partition of inelastic fibres; from this strong fibrous bands pass to each cartilage, and so the whole of the back part of the foot is tied together. The heels and quarters may be pressed together to some extent, but they are prevented from being forced asunder by the fibrous connections of the frog-pad. During progression the downward movement of the coronet bone is provided for by this soft pad, and so is an upward movement of the frog when excessive bearing is placed upon it.

Fig. 16.—Section of foot showing the frog-pad and at each side the cut edge of the lateral cartilage.

The frog-pad serves other purposes besides those we have just referred to. It is essentially a cushion or pad to prevent jar or concussion, but it also plays an important part in the action of the foot, as we shall see later on.

The Coronary Cushion or Pad is another mass of tissue of a similar nature to the frog-pad. It is situated just above the upper border of the hoof, and gives to the coronet its prominence and elasticity. At this part of the foot there is an enormous number of small blood-vessels and nerves, and the coronary pad forms not only a base for these to rest on but a necessary protection for them. If instead of this elastic bed they were placed merely between the skin and the hard bones and tendons of the part, they would be injured by every slight bruise. Even with this cushion, we have in practice very many serious conditions following bruise of the coronet.

Blood-vessels of the Foot. It is not necessary to describe the course of these vessels. All we need remember is that every part of the tissues within the hoof is very plentifully supplied with blood, and that the flow of blood is most rapid when the foot is in action. In a dead foot from which the blood has escaped a certain amount of movement of the bones within the hoof is easily effected. In the living foot when every vessel is filled with blood no such movement takes place. The blood in the vessels forms a sort of waterbed which assists in preventing concussion and which distributes evenly over the whole organ the pressure applied when weight is thrown on the foot. In studying the dead foot with a view to understand its mechanism we must not lose sight of the difference which results from having in one case the blood-vessels empty, and in the other—the living animal—the blood-vessels full.

The Foot as a whole.

The details I have given of the structure and uses of each separate part of the foot will, I hope, be sufficient to enable us to understand the form and action of the organ as a whole.

No one part of the foot is of greater importance than another, each is dependent for its highest development and soundest condition upon the integrity of neighbouring parts.

A weak wall allows of the flattening and spreading of the sole, whilst a weak sole permits contraction of the wall. Overgrown heels cause wasting of the frog, but low weak heels are usually accompanied by excessive development of frog.

The special function of the foot is to sustain the weight of the animal whilst standing or moving. The horse standing squarely on all four feet rests his weight chiefly on the lower circumference of the wall. On level ground the sole, on account of its arched form, takes no direct bearing, but if sole and wall be sound a proportion of all pressure applied to the wall is transmitted to the sole. So also must all weight imposed on the arch of the sole be transmitted, through its abutments or union with the wall, to the wall. If the sole be so thin that it yields to pressure then its proper action is destroyed, and instead of acting like an arch and supporting weight imposed on it, it yields and injury results. The arched form of the sole indicates that it was not intended to take a direct bearing on hard ground. On a soft surface the edge of the wall sinks and the whole under surface of the foot takes a direct bearing. Pressure of the sole on the soft surface does no harm because it is diffused evenly over the whole of the sole. We take advantage of this when the wall is diseased or injured, and we desire to throw on the sole a larger share of weight. We turn such animals out into a soft field or stable them on sand or saw-dust. Any system of shoeing founded upon the true form and action of the foot must recognise the arch, and not endeavour to force the sole to take a bearing for which it is not adapted. There is only one part of the sole which should act as a bearing surface, viz., that outer border which is firmly joined to the wall. This part—the abutment of the arch—is destined by nature to take a bearing and through it the whole of the sole supports its share of weight.

The frog takes a bearing on the ground but it has a weight sustaining function quite secondary to the harder and firmer parts of the hoof. It is formed of a softer horn, and it has above it only soft tissues which permit yielding. The frog then, when weight is placed upon it by the standing horse, recedes from pressure, and leaves the heels (wall and bars) to sustain the primary weight. Wall, sole, and frog, each take their share in supporting weight, but this function is distributed over them in different degrees, and it is fulfilled by each in a varying manner. During progression the foot is repeatedly raised from and replaced on the ground. It has not only to support weight but to sustain the effects of contact with the ground at each step, and the effects of being the point of resistance when the body is carried forward and the foot is again raised from the ground.

What part of the foot comes first to the ground? Many different answers have been given to this question. It has been said by some that the toe first touches the ground, by others that the foot is laid flat down, and by a few that the heel is the first part to come in contact with the ground. Fortunately it is not now necessary to argue this question on a purely theoretical basis. Instantaneous photography has shown that on level ground, at all paces, the horse touches the ground first with the heel. This fact gives significance to the structural differences we find between the front and back portions of the foot. At the back part of the foot we have the wall thinner than elsewhere, we have the moveable and elastic frog, the lateral cartilages, and the frog-pad. We have in fact a whole series of soft and elastic structures so arranged as to provide a mechanism best adapted to meet shock and to avoid concussion. Whilst drawing heavy loads, or ascending or descending hills, the horse may vary his action to suit the circumstances, and then we have the exception which proves the rule—then we have sometimes the heel, sometimes the toe brought first to the ground.

At the time when the foot first touches the ground, the leg is extended forward and the pastern is in the same oblique position to the shank as when a horse is standing. This obliquity of the pastern is another safeguard against concussion, and it renders impossible the first contact with the ground at any point other than at the heel. As the leg becomes straightened, the weight of the body is imposed upon the foot, but the greatest strain arrives just before the toe leaves the ground, for then there is not only weight to sustain, but the friction to be borne which results from the toe being the fulcrum upon which falls the whole effect of the muscular effort necessary to raise and carry forward the body of the animal. The front part of the foot is structurally well adapted for its use. It presents the thickest and strongest part of the horny covering, and, as an inside basis, it has the unyielding coffin bone. Thus we have at the toe strength and rigidity—at the heels strength and elasticity.

Another important point in the action of the foot is implied by the question—does it expand when weight is thrown on it? The principles of horse-shoeing require that this question should be answered. There are those who say that the foot does not alternately expand and retract as weight is placed upon or removed from it. There are others who assert that the expansion of the foot is an important natural function that must be provided for in any system of shoeing. It is agreed by most observers that at the upper border of the hoof, more particularly at the heels, expansion does occur. It is when we come to the lower border of the foot that the statements are most conflicting. Ordinary measurements taken at this part with calipers or by tracings on paper of the foot when raised from the ground and when resting upon it, show no variations in the width of the foot. These methods of measurement are not sufficiently delicate to be trustworthy. Experimentalists in Germany and in this country have recently used an apparatus by which the slightest variations are detected by electrical contact, and the results are very interesting. These experiments show that in a well-formed, healthy foot the hoof throughout its posterior two-thirds does expand to pressure, and perhaps that the arch of the sole is slightly flattened. This expansion is, however, comparatively slight—about equal to the thickness of a sheet of writing paper—and may practically be disregarded in considering the best methods of shoeing sound feet.

One result of these experiments is to show what an important part the frog plays in the foot, and also how the action of one part depends upon the conditions of others. When the frog rests firmly on the ground and weight is placed upon the foot expansion occurs, especially at the upper or coronary border of the hoof. When the frog does not touch the ground and weight is imposed upon the foot, contraction occurs. The explanation of this difference seems to be as follows. When weight is placed upon a foot, the coronet bone is depressed upon the soft mass of the frog-pad. With a sound frog taking a bearing upon the ground, the frog-pad cannot descend, and the compression to which it is therefore submitted causes it to bulge laterally and so expand the back of the foot. When the frog does not reach the ground and weight is placed upon the frog-pad, there is nothing to prevent it yielding downwards, and in so doing the fibrous bands connecting together the two lateral cartilages of the foot are depressed and the cartilages drawn together—hence the contraction of the foot. No better illustration could be given of the unity of all parts of the foot, and how one or many parts may suffer if the structure or function of one be defective.

There is one more movement of the hoof which is possible and which must be referred to, as it has been made the basis of a grave error in shoeing. I have said the back part of the foot is elastic and yielding. If you examine a shoe, so applied to a foot that an inch or more of its extremity has no contact with the hoof, you will find that when weight is rested on that foot the horn yields downwards and comes in contact with the shoe. This simply demonstrates that when there is nothing to support it the horn at the heels may be forced downwards. It is not a normal action, and in an unshod foot cannot occur on a level surface. The effect of this downward movement of the heels is to put a strain on the horn of the quarters. A shoe so fitted as to permit this evil is in common use, and no fault is more serious than thus forcing an unnatural action upon the hoof at every step. With unintentional irony this piece of bad work has been called "easing the heels."

In concluding this chapter, I would just repeat that the natural bearing surface of the horse's foot is the lower edge of the wall and that portion of the sole immediately in union with it; that the arch of the sole should not be in contact with the ground; that the frog ought to have a bearing on the ground, but ought not to be so prominent as to unduly share in sustaining weight. This natural bearing surface is what we want to utilize in shoeing. We put on a shoe merely to prevent excessive wear of the hoof. If we can protect the wall the frog can take care of itself, and we have only so to apply our shoe that we do not damage any useful structure or interfere with any natural function.

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.

[CHAPTER III.]
Preparation of the Foot.

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.

Faults to be avoided.

[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.

[CHAPTER IV.]
The Form and Manufacture of Shoes.

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:

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.

Fig. 37.—Concave ground-surface.

The concave shoe, often described as a hunting-shoe, presents a very different ground-surface from that just referred to. It rests upon two ridges with the fullering between, and on the inner side of these the iron is suddenly sloped off. This shoe is narrow and flat on the foot-surface, and is specially formed to give a good foot-hold and to be secure on the hoof.

Fig. 38.—Double-grooved ground-surface.

A Rodway shoe has two longitudinal grooves and three ridges on its ground-surface. The outer groove carries the nails, and the inner groove lightens the shoe and increases the foot-hold. It is not the number of grooves or ridges that prevents slipping; it is the absence of a continuous flat surface of iron, and the existence of irregularities which become filled up with sand and grit. A four-grooved shoe has no more anti-slipping properties than a three-grooved, and a one-grooved shoe is as good as either, although it cannot stand the same amount of wear.

Transverse ridges and notches have also been tried as ground-surfaces for shoes, but offer very little, if any, better grip than the longitudinal grooves. Their great disadvantage is that they cannot be made deep enough without weakening the shoe, whilst if shallow they are worn out before the shoe has been long in wear.

Fig. 38.—Ground-surfaces, notches, projections, ridges.

A Calkin is the name given to the extremity of a shoe when turned down at the heels. Calkins are used on most hind shoes and, in some parts of the country, on fore shoes. They are supposed to be the most convenient and effective means of giving good foot-hold. This supposition is correct when a horse travels on soft ground or on streets so paved that a space is left between each course of stones. They are of very little use on asphalte or wood pavement, and not much more use on roller-made macadam. With light modern carriages and level modern roads calkins are quite unnecessary, and better means of giving foot-hold may be substituted. It is a fact that horses when shoes are new and calkins prominent do their work without slipping, and that when the calkins are worn down the horse moves with less confidence and security. This does not prove that calkins are necessary. It must be remembered that horses possess a power of adapting themselves to circumstances, but having learned to rely upon any artificial assistance they are the more helpless, for a time, on its withdrawal. Calkins assist the horse for a time, but after the calkin is worn down the horse is in a worse position than if he had never become accustomed to its assistance. Of course on soft ground, especially grass, calkins afford a firmer grip than any other contrivance. On the other hand, their constant use lifts the frog out of bearing and causes it to waste, thus spoiling the action of the natural provision against slipping. Level shoes on the hind feet promote sound, prominent frogs, and give firm foot-hold for all light horses. Even omnibus horses, now that the vehicles are supplied with effective foot-brakes, may advantageously be worked without calkins. On country roads, especially when the district is hilly or the load is heavy, calkins may be requisite, and must then be made to do as little harm as possible.