200 



HORSESHOEING. 



of screws four- to five-sixteenths of an inch long. The plate is 

 heated, bent to conform to the cun'^ature of the wall and pressed 

 against tlie horn till it burns a bed for itself, when it is screwed 

 fast. It will not loosen (see Fig. 220, b). In every complete 

 crack of the wall the growing down of coherent horn is favored 

 by thinning the horn for an inch on both sides of the crack 

 directly over the coronary band (see Fig. 221, a), so that any 

 gliding movement between the sides of the crack below can 



Fig. 221. 



Fig. 220 



Hoof with coronary quarter-crack, shod with Hoof with complete quarter crack, shod with 

 a bar-shoe. The part of the quarter reheved of a bar-shoe : a, area thinned almost to the podo- 

 pressure a, is indicated by the dotted lines; b, derm; b, tg inch metal plate secured by screw 

 iron plate secured by small wood screws xVib is of an inch long; c, quarter relieved of pres- 

 of an inch in length, j sure from bottom of crack to a perpendicular 



dropped from top of crack. 



not be transmitted through the thinned area to the crack in the 

 velvety tissue of the coronary band. Cutting a " V " at the 

 coronet acts similarly, but is less efficient. 



Quarter-crack is usually associated mth contraction of the 

 heels. It occurs on the inner quarter of base-wide (toe-wide) 

 hoofs, and rarely in the outer quarter of base-narrow hoofs. 

 For quarter-cracks w^e use a bar-shoe and determine the extent 

 of the wall to be laid free in the following manner: We 

 imagine the crack to be prolonged in the direction of the horn 

 tubes to the plantar border, and drop a perpendicular line from 

 the upper end of the crack to the plantar border. That part 

 of the plantar border lying between these two points is then to 



