HAND AND MACHINE LABOR. 



145 



489. How many times as much human labor were re- 

 quired in 1830 as 1906 ? 



490. In 1866. to produce an acre of potatoes, yield- 

 ing 110 bushels, 55 hours of human labor were required; 

 in 1906 the human labor requirement for producing an 

 acre yielding 220 bushels was but 38 hours. What is the 

 percentage of decrease from 1866 to 1906? 



491. What was the human labor requirement per 

 bushel in 1866 ? In 1906 ? 



492. In 1860 the amount of human labor expended on 



Various Types of Sickles. 



an acre of cotton was 115.9 hours; in 1911 it was 111.9. 

 The production in both cases was 350 pounds of lint cot- 

 ton an acre. How many minutes of human labor were 

 required to produce one pound of lint cotton in 1860? 

 In 1906? 



493. In 1855 the amount of human labor expended on 

 an acre of sugar cane was 351.3 hours; in 1906 it was 

 161.5 hours. The production in both cases was 20 tons 

 an acre. What was the human labor requirement per 

 ton in 1855 ? In 1906 ? 



494. In 1855 the cost of human labor was $14.30 and 

 of animal labor $2.03 for the production of an acre of 

 corn. In 1906 the cost of human labor was $4.23 and 

 animal labor $2.39. The production in both cases was 40 



