HUMAN MOVEMENTS 139 



described by climbing up the pole at the moment it 

 passes the vertical, and then by inclining the body 

 until it becomes almost horizontal, that is to say, at 

 right angles to the radius of the circle described, the 

 jumper falls naturally on his feet at a much greater 

 distance from the starting-point. 



In pole-jumping, the initial impetus is not, as in 

 the case of long-jumping, the only force upon which 

 the extent of the jump depends ; but this distance 

 can be augmented by manoeuvres of the jumper, who 

 can make use of his arms by employing the pole as 

 a fixed point of support while he is still in the air. 



For a more detailed study of movements in physical 

 exercises, recourse must be had to those outline or 

 geometrical photographs of which we have already 

 given an example in the case of a man walking. A 

 man dressed in black velvet with bright lines down 

 his arms and legs produces Fig. 94 as the result of 

 a long-jump preceded by a preliminary run. 



Here all the phases of the movement are arranged 

 in close series with no sudden transitions, because of 

 the great number of images (twenty-rive to the second) 

 taken during the jump. 



In order to render chronophotographs of movements 

 more instructive, these images should be taken from 

 very strong and competent athletes ; for example, 

 from the prize-winners at athletic sports. These 

 champions will thus betray the secret of their success, 

 perhaps unconsciously acquired, and which they would 

 doubtless be incapable of defining themselves. 



The same method could equally well be applied to 

 the teaching of movements necessary for the execu- 

 tion of various skilled industries. It would show how 

 the stroke of a skilful blacksmith differed from that of 

 a novice. It would be the same in all manual per- 

 formances, and in all kinds of sport. 



