10 



THE ART OF HORSE-SHOEING. 



border of the wall, and is slightly arched, so that on a 

 hard, level surface its central part takes no bearing. 

 (Fig. 5.) Posteriorly the sole is divided by a triangular 

 space into Avhich the frog fits, and thus its continuation 

 to the heels consists of two angular portions embraced 

 between the bars and the wall. The unmutilated sole is 

 throughout of nearly equal thickness, but a slight excess 

 round the circumference gives firmer atta,chmout to tlio 

 wall. 



The inner surface jiresents a finely pitted appearance, 

 which is most marked at the tea and round its border. 

 The part immediately related to the frog shows few pits, 

 and we shall find that the whole surface corresponds to 

 the sensitive parts to which it is attached. 



The structure of the sole is, like the wall, fibrous: 

 but the fibres are smaller. They run dov,'nwards and 

 forwards in the same direction a:> thc^se of the wall. The 

 outer layers are the hardest arid protect the deeper from 

 injury. 



Fig. 6,— The Frog, detached from the Sole. 



The Frog is the smallest division of the hoof, and. 

 is a triangiilar shaped body filling up the space left be- 

 tween the bars. (Fig. G.) Its broad base is rounded and 

 prominent, and is coutinued laterally by a thin laytn- 

 "which binds together "^he heels and envelopes the back of 



