164 BITS AND BITTIXG. 



meclianical advantage obtained is proportionate to the 

 relative length of these two arms. Thus if FF, fig. 9 

 (a), be equal twice ^Y F, a power equal 1 applied at P 

 will counterbalance a weight equal 2 applied at W ; 

 but, as regards our purpose, it more especially neces- 

 sary to observe that the power and the weight move in 



7? order P a F j\y 



V 



2^ order P U "^ ,F 



Fig. 9. 

 opposite directions, or rotate round the fulcrum or prop, 

 as is shown by the direction of the arrows. Applying 

 this to a bit, the cheeks of which represent the lever? 

 there can be no question as to where the power is ap- 

 plied, being the lower ring to which the rein is attached, 

 nor as to the direction in which it is intended to act, 

 being towards the rider's hand ; and if a bit act as a 

 lever of the first order, the fulcrum or prop must be 

 represented by the bars of the horse's mouth on which 

 the mouthpiece acts, and the pressure of the curb* on 

 the chin would necessarily represent the weight to be 

 raised. But it has been shown that, in levers of the 

 first order, the power and weight move in opposite di- 

 rections in their rotation about the prop ; in this case, 

 therefore, the horse's chin, in consequence of the pres- 

 sure exercised by the curb, should move forward — that 

 is to say, away from the rider's hand ; and the greater 

 the lever power of the bit, and the stronger the pull on 



* We use the word curb for ciirb-cliain, aad bit or curbed-bit 

 for what is sometimes called curb. 



