408 



ANIMAL MECHANICS. 



to the horizontal position, at a given rate, until fatigue sets in, 

 and then repeating the experiments with the same weight, at 

 a different rate. In every case, the time of raising the weight 

 is made equal to the interval of rest that elapses until the next 

 lift. 



The following observations were made by me on Dr. Alex- 

 ander Macalister. The weight used was 14 lbs., and the 

 height through which it was lifted was 30 inches. One arm 

 only (the right) was used in the experiments. 



In the following Table, I have compared the results, 

 observed with the results calculated from the Law of Fatigue, 

 and the agreement is highly satisfactory. 



n represents the number of lifts before fatigue; 

 t represents the time occupied by the lift, which is made 

 equal to the time of repose. 



Dr. Macalister (Raising Weights at varying rates), 

 w = 14 lbs. h = 30 inches. 





t. 



n (obser- 

 ved). 



n (calcu- 

 lated). 



Differ- 

 ence. 



I. 



0. 65 sees 



36. 0 



36. 1 



— 0.1 



2 . 



o.75 „ 



39-° 



39-7 



- 0.6 



3- 



1. 18 „ 



51.0 



49-5 



+ 1 .5 



4. 



I. . 40 



5i.7 



5i-4 



+ 0.3 



5- 



2.00 „ 



S3- 0 



50.6 



+ 2.4 



6. 



2.8zL „ 



44-5 



44-5 



0,0 



7. 



3.68 „ 



37-8 



38.1 



- o.3 



8. 



5-°9 » 



27-5 



29.8 



- 2.3 



The column of calculated values of n was found as fol- 

 lows ; — I n raising the arm and weight from the vertical to the 

 horizontal position in the time t, the muscles perform two 

 distinct kinds of work, dynamical and statical ; the dynamical 

 work being measured by weight multiplied by height lifted, 

 and the statical work being measured in a manner similar to 



