ANIMAL MECHANICS. 



473 



Fig. i io. — Dr. Macalister {Raising Arm from vertical to hori- 

 zontal position, at varying rate). 



f At A = 6 45 1 



1" '*(?)' 



The foregoing observations and theory establish the im- 

 portant fact, that there exists a certain rate of lifting the 

 loaded arm to the horizontal position, which will give a 

 maximum amount of work. This rate is 



t = — = 1.607c. 



The observations also give us the value of the important 

 constant w, used in pp. 24-44 5 substituting for 77-, we find 



to = 0.9772. 



Having obtained the preceding results, I next made a series 

 of observations on my son, Mr. J. Gilbert Haughton (aet. 21), 

 who is accustomed to the vse of 10 lb. dumb-bells. Taking a 

 10 lb. dumb-bell in each hand, he raised both arms to the 

 horizontal position, with palms upward ; the time of rais- 

 ing (t) being constant for each experiment, but varied from 

 one experiment to another ; the interval between each effort 

 of raising was also made equal to the time t. The following 

 results were obtained : — 



