212 ELEMENTARY BIOLOGY 



The mechanical problem is to find out the fewest movements 

 that are necessary for performing the work. The biological 

 problem is (i) to arrange the material and the machinery 

 and tools in such relations to the body of the worker as to 

 put the least strain on the muscles, the attention, the sense 

 organs, etc., and (2) to establish a pace that will result in 

 a maximum of output with a minimum of fatigue. 



In other words, the efficiency of the day's work will depend 

 not only on the nutrition and respiration and training of the 

 worker but also to a very large extent upon the prompt 

 elimination of wastes from the working cells. 



