THE ECONOMY OF MOVEMENT. 9 



to the price paid for movement and work, that were not con- 

 cordantlv explainable as proportionate to differences in body- 

 weight. Therefore, when extending my list of subjects it was 

 extended as far as possible along the scale of available body- 

 weights, and not along the scale of habits. Now, it is not 

 orthodox to regard these other characteristics as producing 

 so little influence on the price of movement and work actually 

 accomplished. Nevertheless, this opinion is the definite result 

 of some experience leading to the different view that these 

 habits tend rather to operate upon the effective accomplishment 

 of movement than upon the expense of such movement when 

 definitely accomplished. Be this as it may be, the results 

 obtained are such as to confirm immediately the major impor- 

 tance of body- weight. 



This importance of body-weight can be shewn as con- 

 vincingly in reference to the maintenance of rhythmical 

 movement, as in reference to external work performed by 

 movement. It is curious, however, and not hitherto expected, 

 that the two processes are oppositely affected, movement being- 

 hampered and the performance of external work facilitated 

 by increasing body- weight. The fact was brought to my notice 

 in the following fashion. In a long series of experiments with 

 subjects cycling against the resistance of a variable " brake," 

 the rate of " cycling " was carefully maintained the same 

 throughout the series, all sorts of precautions being observed 

 to secure that end. Relieved then from the necessity for 

 considering any other than one particular rate of similar 

 movement, I was in a good position to observe the consequences 

 of altering the value of the " brake." It might be said, perhaps, 

 that when the " brake " was altered, so that a different amount 

 of external work was performed, it might be possible that the 

 character of the movement would also be to some degree 

 affected. This is probably true enough when extreme changes 

 are made, such as on the one hand complete removal of the 

 " brake," and on the other its insertion to such values as 



