172 BITS AND BITTING. 



dimension, we have 3^ inches for the former one, both 

 measured from the line of bearing (see Fig. 11), and 

 5 inches for the entire length of the bit measured from 

 the point at which the curb-hook acts above to that 

 where the lower ring acts below (see Fig. 13). This will 

 be the maximum required, and will be found to suffice 

 in all cases ; with very small horses or large ponies the 

 upper cheek will have to be reduced to 1| inch, the 

 lower one to 3 inches, leaving the total equal 4|- inches, 

 which will be about the minimum. 



Some authorities, amongst these Von Weyrother, 

 recommended the measured width of the mouth to be 

 taken as a rule for the length of the lower cheek : this 

 varies, as we have already shown, from 3 T 8 Q, 4|- to 5^ 

 inches, and would be, therefore, somewhat more than 

 the rule given above ; but Von Oeynhausen adheres to 

 this latter, and we are convinced that he is perfectly 

 justified in so doing, because we have it in our power, by 

 means of the mouth-piece, to effect the nicest adjust- 

 ment that can be desired, and there is a much better 

 chance of having the proper proportions adhered to by 

 the bit-makers if we give them one or two fixed quantities, 

 instead of a number of variable ones. 



Next to the dimensions of the cheeks of the bit, the 

 most important point to be considered is the curb ; or 

 rather, the position of the bit in the horse's mouth, 

 taken in conjunction with the line of the curb, is what 

 determines in the first instance the height of the upper 

 cheek, and consequently that of the lower one. The 

 curb must lie in the curb-groove, without any tendency 

 to mount up out of it on to the sharp bones of the 

 lower jaw, otherwise, as we have seen, it ceases to be 

 a painless fulcrum, and renders the best-constructed 



