154 WINTER SHOEING. 



(4) Durability. — The ' rough ' must neither wear away fast 



nor become loose, otherwise it may lead to dangerous 

 cutting or to severe falls. At the same time, as 

 increase of weight is a disadvantage, durability must 

 be sought by the use of the best material. The 

 method of fastening must also be such that the ' rough ^ 

 can be affixed even when the shoe is considerably 

 worn. 



(5) Ada'ptability. — A proper system should be adaptable to 



all horses, all kinds of work, and to all shoes. 



(6) Efficiency is more or less represented by the sum of the 



above, but also depends on the depth to which the 

 ' roughs ' enter the ground, and on their number. It 

 becomes less, of course, as wear advances. 



1. EouGH Nailing. 



Ivough nailing consists in removing an inner and an outer 

 nail, and replacing them by others with pointed or chisel-shaped 

 heads. This method does very well for saddle horses and 

 animals used only occasionally and for light work. 



In the German army lOugh nails are employed in addition 

 to screws of three sizes. In Denmark and other northern 

 countries large, strong nails, with heads case-hardened by means 

 of ferrocyanide of potassium, are a common means of roughing, 

 a specially large hole being punched in the toe of the shoe. 

 Such nails are termed ' broddar,' and replace the ordinary 

 toe-grip. They can, of course, be changed from time to time, 

 and appear to suit the local requirements excellently. Eough 

 nails, the shanks of which do not pass through the horny wall, 

 but are driven through special holes in the shoe, and turned 

 down on its upper and outer border, are technically known as 

 ' stubs,' and are largely used in England, France, Denmark, 

 Sweden, Finland, and North America. They can be inserted 

 at any point in the shoe, though the heels and inner and 

 outer parts of the toe are the best places. 



Of those shown here the wedge-headed are the best, and 

 wear longest. Owing to their small mass the diamond-headed 

 soon lose their efficiency, in addition to which they are more 

 likely to inflict injury on the coronet of the opposite foot. 



