192 HORSE-SHOEING. 



prolonged application of the hot shoe to affect the shoe to any 

 considerable depth. Three minutes' burning of the lower face 

 of the sole has been found necessary to produce any indication of 

 increase of temperature by the thermometer on its upper surface. 

 It is never required that the shoe should be applied longer than 

 a few seconds. 



The hot shoe, in fusing the horn with which it comes in con- 

 tact, imprints itself like a seal in melted sealing-wax, and in this 

 way the two surfaces of foot and shoe exactly coincide ; while no 

 matter how expert the workman may be in using his tools to level 

 the horn in a cold state, he can never do it so quickly or so com- 

 pletely as may be done by making an impression with the heated 

 shoe, and consequently establishing between the lower margin of 

 the hoof and the shoe an exact coaptation. 



It may be added that, when the surface of the horn has been 

 softened by the action of caloric, the nails enter it more readily, 

 the clips and inequalities are more easily embedded, and when it 

 recovers its habitual consistency after cooling, the union between 

 it and the metallic parts which are in contact becomes all the 

 more intimate because of the slight contraction that follows the 

 expansion produced by the heat. Under these conditions, the 

 horn contracts on the shanks of the nails, and retains them most 

 securely. 



All the highest veterinary authorities who have studied the 

 subject are unanimous in recommending hot fitting in preference 

 to cold ; the latter is only j ustifiable when it is impossible to 

 adopt the former. The red-hot shoe at once disposes of those 

 inequalities which cannot be discovered, or removed by tools ; 

 and it shows the workman at a glance the bearing of the shoe on 

 the hoof, as well as the imprint on the nail-holes. Without being 

 reheated, any alteration can be readily and at once effected in 

 moulding the shoe to the shape of the two. 



