476 CHAPTER 63. 



shoe projects beyond the crust, or if the clenches are filed away after 

 turning down, or if the nails are bad, no number of nails will retain a 

 shoe under circumstances favorable for pulling it off. 



N.B. If the shoe be what is called " back punched," i. e. the upper 

 end of the nail holes opened out too much, the shoe may drop off, leaving 

 all the nails in the foot. 



971. Nails to be frequently examined. 



Where few nails are used, it is absolutely necessary that the farrier or 

 groom should frequently examine them and see that each nail and clench 

 is good. A broken nail, or one with its head or clench gone, is obviously 

 useless, and must be replaced. 



The necessity of replacing a damaged nail is often urged as a serious 

 objection to the use of few nails by persons whose horses are seldom 

 seen by the farrier, except at the end of the month. This objection 

 may, however, be easily obviated by making the groom responsible for 

 looking to the nails, and taking the horse to the forge whenever neces- 

 sary. , 



972. Form and material of nails. 



Nails must be made of the best and toughest iron, for none other can 

 stand the. strain and jar of fast work. The quality of a nail may be 

 easily tested by fastening it in a vice. It should not break before point- 

 ing under five bendings. The operation of " pointing " renders nails 

 more brittle, and they will then generally break at the third bending. A 

 great improvement has taken place of late years in the manufacture of 

 machine-made nails, and some competent judges think them as good as 

 the best hand-made nails. 



The size of the nail must be varied according to the size of the foot 

 and the weight of the shoe. The dimensions of the head must of course 

 be proportionate to the size of the nail. The point should be hammered 

 out fine and sharp. A nail larger than necessary is objectionable, be- 

 cause it needlessly damages the crust, and besides requires a larger hole, 

 which obviously must weaken the shoe. 



When a nail breaks in a shoe, the seat of fracture is generally at the 

 neck. The ordinary cause of its breaking at that point arises from the 

 neck having been made too thick for the upper part of the hole. When 

 this is the case, there is a difficulty in driving the nail home, and the 

 neck is frequently so injured in the operation that it breaks off when 

 subjected to the strain and jar of work. Whenever the head requires to 

 be much battered in the operation of driving the nail home, the farrier 

 may be pretty sure that it has become injured in the neck, and he should 

 draw it and substitute another. On the other hand, if a nail be too small 

 for the hole, it gets but little hold, becomes loose, and by working about 

 soon breaks. Wnen the neck is sound, the nail seldom breaks during a 

 month's wear. 



