HORSESHOEING. 



149 



special security to prevent their becoming loose. Experimenta- 

 tion with the screw toe-calks, though not yet entirely satisfactory, 

 cannot be said to have ended. 



The advantages of shoes provided with good screw heel- 

 calks are so manifold that they deserve marked preference 

 over shoes sharpened by the ordinary methods. 

 The common objections urged against screw- 

 calks, — namely, that they loosen and are lost, 

 or break off, are not worthy of serious con- 

 sideration, since these evils are merely the re- 

 sult of unskilful workmanship and poor ma- 



FiG. 1G3. 



Fig. 164. 



IS 



Sharp screw-calks with Whitworth thread 

 (half-inch, natural size). 



Whitworth tap (half-inch, 

 half natural size). 



terial. Shoes with screw heel-calks are the best shoes for winter, 

 especially for horses that have to worJc hard and continuously. 

 Balling with snow is prevented by using shoes narrow in 

 the web and concave upon the ground-surface (convex iron), 

 and thoroughly oiling the sole^ and frog. Sole-pads of felt, 

 leather, or straw serve the same purpose. Balling with snow 

 is best prevented by a rubl^er sol&-and-frog pad, or by a " stop- 

 ping " of a patent hoof cement known in Germany as "huf- 

 lederkitt." 



