The Lever^ the Bit and Curh^ etc. 165 



scarcely any value as a prop. The lever action, how- 

 ever, will be very great, the lower branch,yc/, being to 

 the upper one, d c, in the proportion of 4 to i. In fact, 

 it will be too great, and, therefore reduces the prop to a 

 nullity. 



The intermediate upper bar, d 3, equal d e^ will 

 assume the position b' df^ ; it will neither be stiff nor 

 fall through : the curb will remain in the chin-groove, 

 acting obliquely forward in the line e b\ and will afford 

 a sufficient prop or support ; and the lower branch of 

 the lever, y of, being in the proportion of 2 to i to the 

 upper one, d 3, there will be sufficient lever action. 



It will be now easy to understand how it comes that 

 people, in order to prevent a bit with a very short 

 upper bar falling through, are driven to using a very 

 tight curb, the result of which is, that the whole action 

 is transplanted from the interior of the mouth to the 

 chin ; as also that, in order to prevent one with a 

 very long upper bar standing stiff, they use a very 

 loose curb, which has the effect of making the bit f\ill 

 through ; and this — what is very common, nay, almost 

 invariable, in this country — an immensely long bit — is 

 pulled up as high as it will go into the horse's mouth, 

 and then a loose curb attached, and this great piece of 

 ironmongery of course not only falls through, but acts 

 nearly altogether on the exterior of the horse's jaw ; 

 whereas a much smaller and lighter bit, if adapted to 

 the mouth, would be much more efficient. 



Some portion of the objection to the long upper bar 

 referred to above — namely, its affording no lever action 

 — may be remedied by making the lower bar propor- 

 tionably longer ; and this is precisely what the iron- 

 mongers do, and, moreover, are encouraged to do by 

 ignorant buyers. As has been already shown above 

 with reference to fig. 9, we are thereby driven to use 

 much severer, that is, more painful, bits than are really 



