TIME 



sheet of indiarubber, provided with a hollow chamber. 

 This latter cavity communicates through a long 

 flexible tube with the recording tambour. Each time 

 the foot touches the ground the air within the cavity 

 of the sole is compressed, and passing along the con- 

 necting tube raises the corresponding recording needle. 

 The pedestrian furnished with a pair of these shoes 

 (Fig. 4), carries in his 

 right hand the record- 

 ing apparatus with its 

 registering needles. 

 When he wishes the 

 tracing to commence 

 he squeezes an india- 

 rubber ball which he 

 holds in his left hand ; 

 if, a moment later, he 

 releases the pressure, 

 the needles cease trac- 

 ing. Records are thus 

 obtained which vary 

 according to the pace, 

 the weight carried, and 

 the incline. 



Changes in the se- 

 quence and duration of 

 the footfalls are shown 

 by the four figures in 

 the diagram (Fig. 5). In this the contact of the 

 right foot is represented by a white, and that of the 

 left by a diagonally shaded line. The first of 

 the series represents walking on level ground. The 

 steps of the two feet are alternate and regular. 

 The second tracing is obtained by walking upstairs; 

 in this, one foot does not leave the ground until the 

 other one has been down some time. This represents 



Fig 4. — Pedestrian furnished with special shoe?, 

 and carrying a chronographic apparatus. 



