HUMAN MOVEMENTS 135 



and we gave as examples chronophotographic repre- 

 sentations of walking and running. Fig. 92 shows 

 how a long-jump is executed. The figures in the 

 photograph reveal attitudes which the eyes are not 

 accustomed to see ; they express better than language 

 the way in which the movement is executed, and allow 

 the different phases to be followed with ease. In 

 certain respects they correct ideas which existed on 

 the subject of the mechanism of jumping. Take, for 

 instance, the theory which led teachers of gymnastics 

 to recommend their pupils to land on the toes in order 

 to break the shock on coming in contact with the 

 ground. Our figures show, on the contrary, that in 

 long-jumping it is the heels which first reach the 

 ground, and that it is the flexion of the legs and 

 thighs that breaks the shock. To sum up, chrono- 

 photography affords the means of understanding the 

 real characters of a movement, and is therefore of 

 value in teaching athletic exercises. Guided by photo- 

 graphs of this sort, it is easy to imitate the style of 

 walking or running set by the person who serves as 

 a model, and to reproduce his method of extending 

 or flexing the limbs, of swinging the arms, and of 

 bringing the feet to the ground or removing them 

 from it. It would be much more difficult to imitate 

 these movements by merely watching the instructor, 

 because, especially in rapid movements, the motions 

 are so transitory as to escape observation. 



In Fig. 92 the number of images is only five to the 

 second ; this, however, is sufficient to show the series 

 of actions which must be accomplished in executing 

 a jump of this kind. By looking at these images in 

 the order of execution, it is seen that the jumper 

 acquires by a preliminary run sufficient impetus to 

 cover a considerable distance during the period of 

 suspension. 



