112 



Gait of the American Trotter and Pacer 



calks behind have done no end of harm ; but to-day there is evidently 

 a tendency for simplicity in shape and lightness in weight, and this is 

 a move toward a better and less forced gait. 



The rolling motion shoe appears to-day, if not in its pure form, at 

 least as the fundamental idea of construction, for we cannot disregard 

 its great advantages when modified so as to prevent slipping or undue 

 high action. 



F/Cr 



In the Figs. 84-87 I have endeavored to show the relative effect 

 of the plain shoe and calked plain shoe, as compared with its corre- 

 sponding rolling motion form. The curve M N is in each case an arc 

 of a circle and this arc, by its longer or shorter radius, is meant to in- 



dicate the longer or the shorter contact of foot with ground. A B is a 

 lever whose real fulcrum will be at B, when on ground. The ground 

 surface of this lever is straight, and the longer A B the slower will 

 be the motion of the points A and B, and hence the longer the contact 



