PROGRESSION ON THE LAND. 



63 



a given time three times as fast as he can walk. In running, 

 the object is to acquire a greater velocity in progression than 

 can be attained in walking. In order to accomplish this, 

 instead of the body being supported on each leg alternately, 

 the action is divided into two periods, during one of which 

 the body is supported on one leg, and during the other it is 

 not supported at all. 



The velocity in running is usually at the rate of about ten 

 miles an hour, but there are many persons who, for a limited 

 period, can exceed this velocity." ^ 



^Cyc. of Anat. and Phy., article " Motion." 



