DESCRIPTION OF APPARATUS. 



39 



Automatic stops, B and B', controlled the distance traveled by the 

 pulley. At each upward movement of the body the cord was lowered 

 and the counter pulled in one direction to the stop, the cord simply 

 slipping over the pulley if the movement continued. As the body 

 returned to its ordinary position, the weight drew the counter back to 

 the second stop. In this way each upward movement of the body was 

 accurately recorded. 



Records obtained with this counter of the number of steps taken by 

 one of our subjects in several walking experiments are given in table 2. 

 These are compared with the number of steps counted for the same 

 periods from kymograph records obtained by a method subsequently 

 described. 1 A large number of controls, which were made by counting 

 the movements of the body from the kymograph records and by obser- 

 vations of the counter, showed that this step-counter could be relied 

 upon. 



TABLE 2. Comparison of steps recorded by step-counter with those counted from 



kymograph records. 



METHOD OF MEASURING HEIGHT TO WHICH THE BODY IS RAISED. 



One factor of the mechanics of walking has hitherto been neglected 

 for the most part by writers, particularly when studies of the gaseous 

 metabolism have been made, that is, the height that the body is raised 

 during the process of walking. At each step the body is raised and 

 lowered a distance of approximately 25 to 50 mm., and even higher in 

 running. 2 In any careful research on the physiology of walking in 

 which the efficiency of the body for moving a certain weight a certain 

 distance forward is studied, it is necessary to note the height of this 

 upward movement. For this purpose Dr. Carl Tigerstedt used a device 



'See p. 40. 



2 See table 20, p. 98. 



