LEAPING. 271 



which he sat when his horse rose at it ? The fact 

 is, his body so far partakes of the speed of his 

 horse, and increases in common with it, that, with 

 very little assistance from his bridle-reins, he keeps 

 himself in his proper place. If it were not so, what 

 w^ould become of the rider in the circus, who leaps 

 directly upward, through a hoop perhaps, or over 

 his whip, whilst his horse is going at considerable 

 speed I He would, of course, alight upon the 

 ground, perpendicularly, under the point at which 

 he sprang from his saddle. It is evident, however, 

 that on leaving the saddle, the body of the rider 

 has equal velocity with that of the horse ; and the 

 spring, which he takes perpendicularly upward, in 

 no degree diminishes this velocity ; so that, while 

 he is ascending from the saddle, he is still advanc- 

 ing with the same speed as his horse, and continues 

 so advancing until his return to the saddle. In this 

 case, the body of the rider describes the diagonal 

 of a parallelogram ; one side of which is in the di- 

 rection of the horse's motion, and the other perpen- 

 dicularly upward, in the direction in which he makes 

 the leap. From these facts, these striking instances 

 of the composition of motion, then, may the advan- 

 tages of good, and the disadvantages of bad, horse- 

 manship be appreciated ; and as it appears that 

 the motions of the rider and his horse are so inti- 

 mately connected and in unison with each other 

 (for were the circus rider to project his body for- 

 ward, in his leap through the hoop, as he would do 

 if it were on the ground, he would alight on his 

 horse's head or neck, or perhaps before his head, 



