478 CHAPTER 63. 



The thin part should begin where the nail quits the shoe to enter the 

 crust. 



976. Rose-headed Nails. 



Kose-headed nails eaimot cxaetly fit and fill the nail-holes. A portion 

 of the neek of the nail must be in the shoe, and at that point it will be 

 apt to break. Again, a portion of the head generally projects below the 

 shoe, and that portion must soon be lost by friction with the ground. 

 (Fig. 11.) 



977. Nail heads not to project below the shoe. 



The heads of the nails should be driven down very nearly but not 

 quite flush with the under surface of the shoe. A very little projection, 

 however, is necessary in order that the pincers may be held firm against 

 the heads of the nails, whilst the clenches are being turned down, other- 

 wise it is difficult to get a good firm clench. The needed accuracy in 

 punching the countersinks of the proper size, and selecting the nails to 

 fit them will give the farrier a little extra trouble. 



The objections to nails projecting below the shoe are that the exposed 

 portion of the head will be very soon worn off by friction with the 

 ground ; and, again, with the further wear of the shoe the remaining 

 portion of the head will be worn away. A nail without its head or 

 without its clench is useless. The shoe is held on by the head of the 

 nail and its clench. 



978. Clenching of Nails. 



Clenching is the technical term for turning down the end of the nail 

 after it has been driven through the crust. The nail should be broken 

 off as short as possible, and turned down and flattened by the hammer. 

 The rasp should not be applied to the clench. Any filing will weaken it 

 and may cause it to break off. Farriers often say that they cannot turn 

 down and flatten the clench properly with the hammer ; but they can do 

 so with safety if the crust be sound. 



But where the crust has been rasped, and thereby rendered thin and 

 brittle, it is probable enough that the hammering down of the clenches 

 may cause pain and pressure on the underlying sensitive layer of the 

 crust. In such cases it may be advisable slightly to file the under side 

 of the clench, so as to make it bend easier. There is no sense whatever 

 in filing the upper side of a clench after turning it down. 



979. Nail-bound. Tight Nailing. 



These arc terms applied to irritation of the feet, occasioning slight 

 lameness, from the nails having been driven too near the quick. The 

 injury is of the same nature, but less serious, than that known as " j rick- 

 ing." (See Chapter 05, Tar. 1006.) Tho remedy consists in carefully 

 drawing the nails and replacing them by others driven more fine. 



