CHARACTERS OF SHOE — SURFACES AND BORDERS. 135 



works, and may vary from ^ up to ^ of an inch or even more. 

 As a rule, shoes should be of such thickness that on a horse 

 with sound limbs and doing ordinary work they wear for four 

 weeks. Generally, the shoe is made of an even thickness 

 throughout, though this is subject to exceptions, — fiat shoes 

 being sometimes thicker at the toe, sometimes at the heels. 

 The necessity for such special shoes must be judged of by the 

 w^ear of the old shoes. 



Before thickening any portion of a shoe it is well to recall 

 that, cceteris paribus, undue thickness at any point means un- 

 equal tread, that thickening one side of the shoe only transfers 

 the wear to the other, that if one side has to be raised it is 

 usually advisable to narrow it from side to side so as to 

 preserve an equal balance of weight between the two sides, 

 and lastly, that the upper surface of the shoe must always 

 be flat, i.e., the projection must appear on the ground and not 

 on the foot surface of the shoe. As a rule, it is inadvisable to 

 attempt correcting excessive local wear by thickening the shoe 

 at the point worn ; by far the better course is to weld in a 

 piece of steel, or to give more cover, which increases the dura- 

 bility of the part without disturbing the correct relative heights 

 of the two sides of the foot. 



(3) Surfaces and Borders. — The upper or hoof surface of 

 the shoe may be divided into a bearing surface and a seated 

 surface. The bearing surface (fig. 88, a), or that part of the 

 shoe which comes in direct contact with 

 the wall, must be absolutely horizontal and 

 broad enough to cover the bearing^ surface 

 of the wall, including the white line, and a 

 narrow rin<>- of the outer circumference of i^^ig. ss -Transverse section 



c" of a fore shoe through cue 



the horny sole. In makino- shoes it is cer- o; the naii holes ; natural 



•^ " size, a, bearing surface ; 



tainlv not always possible to know how ^ seated surface ; e.fuUei. 



<j r ^ ijig ; f^ iiaii hole. 



broad the bearing surface of the wall may 

 be, but this is not so very important, because the bearing surface 

 of the shoe can very easily be made a little broader or narrower 

 when fitting. Shoes for heavy horses are always made with 

 a rather broader bearing surface than those for light horses. 

 The seated part of the surface (fig. 88, h), which is opposed to 

 the horny sole, without, however, touching it, is more or less 

 hollowed out accordincr to the condition of the sole, but must 



