442 HORSE-SHOEING 



malleable iron. Steel is too hard, and favours slipping on stone pave- 

 ments. Cast-iron is brittle. 



Weight. — A shoe should be as light as possible, provided it aflbrds 

 four weeks' wear. 



Thickness. — No shoe should be much more than half an inch thick, 

 as the areater the thickness the more the fros; is raised from a bearing 

 on the ground. Very thick shoes render it difficult to make the nail-holes 

 of the best size and form. 



Width. — The older shoes were all made wide apparently with the 

 idea that the sole needed protection. A weak, thin sole, esj)ecially when 

 travelling over loose, sharp stones, may need some extra cover, but a 

 sound sole which has not been robbed of horn by the farrier needs no 

 protection from the shoe. The width of a shoe should depend simply 

 upon the amount of iron necessary to afford four weeks' wear. If a narrow 

 shoe wears out too soon it is better to distribute the additional amount 

 of iron required in width than in increased thickness. A shoe should 

 not be the same width throughout; it should be widest at the toe and 

 gradually decrease towards the heels, as this provides the extra amount 

 of iron wliere it is most wanted for wear. 



The Foot Surface of Shoes. — A shoe has two surfaces — one applied 

 to the hoof, the other for contact with the ground. Both may be quite 

 flat, but there are conditions which govern the choice of form and render 

 advisable some ^^ariations. The surface which is applied to the foot 

 must correspond with the bearing surface on the hoof. On all sound, 

 well-formed feet a shoe with a flat surface is the best. The foot surface 

 of hind shoes is always made flat, as is that of narrow shoes for either 

 hind or fore. So long as the'sole of a foot is concave no uneven pressure 

 can result from a flat-surfaced shoe, but when the sole is flat or convex 

 there is danger of uneven pressure. Some front feet present this defect, 

 and to provide a safe form of foot surface a shoe is "seated" (fig. 633). 

 This means that the inner half, or more, of the foot surface is levelled so 

 that bearing is confined to the flat outer portion of the shoe. This form 

 of shoe is very commonly used, especially when the shoe is a wide one. 

 Properly made, this foot surface is a safe and useful one. When the outer 

 level portion is made too narrow, useful bearing surface is lost; when it 

 is left a little wider than the wall it is unobjectionable. A very bad 

 foot surface is formed by bevelling the iron so that it slopes from the 

 outer to the inner circumference of the shoe (fig. 634). Such a surface 

 affords no level resting-place for the hoof, and when it is attached to a 

 foot may cause lameness by squeezing the wall inwards. At the heels the 

 foot surface should always be left flat, and the seating of a shoe should 



