482 



ANIMAL MECHANICS. 



If we assume the weight of the arm to be 10 lbs., and its 

 length 2 feet, we have 



w = 10 lbs. 

 a = io lbs. 

 x= 1.5 ft.; 

 and equation (144) gives us 



Total work = 30 (t + 1). 

 Substituting for its value 10.85 = ft we have 



Total work = 30 x 11.85 ft. lbs. 

 To find the Coefficient of Refreshment, we must divide this 

 work by the number of ounces in the muscles in action, and 

 by the whole time of the cycle of rest and work. 



The muscles more or less engaged in lifting and holding 

 the loaded arm horizontally are 



1. Upper half of Trapezius, 



2. Cleido-mastoid, 



3. Levator anguli scapulae, 



4. Deltoid, 



5. Supraspinatus, 



6. Biceps humeri, 



7. Brachiaeus, 



8. Supinator radii longus, 



9. The flexors of the wrist 



and fingers, 



Holding up scapular arch. 

 Holding up arm. 



Guarding the forearm 

 from forcible extension. 



Guarding the hand from 

 forcible extension. 



From the Tables (pp. 406, 408), we may calculate the 

 total weight of these muscles at 35.41 oz. Hence as the time 

 of the cycle of rest and work is 



we have 



Coefficient of Refreshment 



60 + 10.85 = 70.85 ; 



30 x 1 1.85 



35.41 x 70.85 



0.1417- 



