The Lever ^ the Bit and Curh^ etc. 150 



lever into two arms, a longer and a shorter one. The 

 mechanical advantage obtained is proportionate to the 

 relative length of these two arms. Thus, \i P F., fig. 8 

 («), be equal twice W F^ a power equal i applied at 

 P will counterbalance a weight equal 2 applied at W\ 

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

 sary to observe that the power and the weight move in 



\ St order ^ Ol Z jW 



2d order t ^ y^ F 



opposite directions, or rotate round the fulcrum or prop, 

 as is shown by the direction of the arrows. Applying 

 this to a bit, the bars of which represent the lever, there 

 can be no question as to where the power is applied, 

 being the lower ring to wliich the rein is attached, noi 

 as to the direction in which it is intended to act, being 

 toward 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 mouth- 

 piece acts, and the pressure of the curb on the chin 

 \vould necessarily represent the weight to be raised. 

 But it has been shown tliat, in levers of the first order, 

 the power and weight move in opposite directions in 

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

 the horse's chin, in consequence of the pressure exer- 

 cised 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 the rein, 

 so much the more would the horse be induced to stick 

 out his nose — an occurrence that is by no meatis infre- 

 quent, and at which some riders and drivers are very 

 much astonished. 



Now, in fact, there is no weight to be raised in the 



