20 i ON PROGRESSION. 



can be so ungiacefiil in appearance, as the figure 



of a rider swinging his arms and legs backwards 



and forwards as if they did not belong to liis 



body. 



Fig. 1, plafe 14, represents the liorse in a 

 moderate trot, in v\ hich pace he covers no more 

 ground at each motion than extends from one 

 hind leg to the other. Vide letters D, C. 



But in fig. 2, where the trot is accelerated, 

 he not only covers more ground by the greater 

 extension of his legs, but gains also an additional 

 space by the momentum of his body during 

 the period when all his legs are in the air. 

 Thus the letter Q marks the spot which the near 

 hind foot occupied before it was raised in the 

 air, and the letters A, B, describe the spots of 

 ground to which the near fore foot and oiY 

 hind foot will reach when they alight on the 

 earth. This momentum is, in a great measure, 

 lost, when the horse goes in harness, as the vis 



inertias 



