252 THE PORT AND COVERING FOR MOUTH-PIECES. 



THE JOINTED MOUTH-PIECE consists of two sec- 

 tions in the form of segments, the inner ends of 

 which terminate in rings and are linked together; 

 this is the most effective mouth-piece for a single 

 bit, as almost all the pressure acts on the bars. 



THE GRIDIRON is an attachment rather than a 

 distinct form of bit and is used on the stiff types 

 of mouth-pieces for the purpose of preventing the 

 horse from getting his tongue over the mouth- 

 piece. It revolves on both sides of the port and 

 FIG. 116. is blocked so as to prevent it from turning for- 

 ward. (See Fig. 116.) 



THE PORT. 



The port is for either of one of two purposes. First, to 

 take the pressure off of the horse's tongue, in which case 

 the curve is made slight, about three eighths of an inch at the 

 deepest point, and about one and a half inches wide at 

 the bottom. Care must be taken to prevent the corners of 

 the port bearing on the bars of the mouth ; the canons 

 should be long enough to cover this part. Second, in driv- 

 ing bits the port is often made very high in order to get a 

 bearing against the roof of the mouth and it is used with a 

 tight nose-band. This exaggerated form of mouth-piece is 

 brutal, there is no other word to describe it, and any horse 

 that cannot be held by a less severe form is unfit for the use 

 of the private horse owner. 



COVERING FOR MOUTH-PIECES. 



Soft leather and rubber are employed as coverings to the 

 mouth-piece to temper its action. When either material is 



