32 American Economic Association [830 



by the reported valuation of agricultural implements 

 and machines, which increased from $1.68 per acre of 

 improved land in 1880, to $4.49 per acre in iQoo. 1 



With respect to the work of cultivating and caring 

 for those nine crops in the production of which ma- 

 chinery appears to be most extensively used, we may 

 determine what absolute displacement, if any, has 

 taken place by finding in each case what amount of 

 labor was necessarily employed in the time of produc- 

 tion by hand methods and comparing that amount with 

 the amount of labor necessarily employed in the time 

 of production by machine methods. Data of crop pro- 

 duction for the exact years covered by the report of the 

 Department of Labor concerning production by hand 

 method cannot be secured for all of the crops, but tak- 

 ing the best available data and tabulating results we 

 have the following : 



DAYS- WORK OF MAN-I,ABOR REQUIRED FOR PRODUCING THE 



Crop of 2 By methods of Days-work 



Barley 1839 . . . 1829-30 . . . 882,007 



Corn 1855 . . . 1855 . . . 74,151,217 



Cotton 1841 . . . 1841 . . . 13,717,188 



Hay 1849 l8 5 29,176,470 



Oats 1839 . . . 1830 . . . 20,381,312 



Potato 1866 . . . 1866 . . . 5,307,260 



Rice 1871 . . . 1870-71 . . . 124,383 



Rye 1849 . . . 1847-48 . . . 3,574,396 



Wheat 1839 1829-30 . . . 25,905,766 " 



Total 173,219,999 



1 Twelfth Census : Agriculture I, page 698. 



2 The barley crop of 1839 was 4t I 6i,5O4 bushels Sixth Census, page 



408. 



The corn crop of 1855 is assumed to be 765,431,923 bushels. This 

 is midway between the amounts reported to the census office in 

 1850 and 1860. 



The cotton crop of 1841 was 1,634,945 bales. World Almanac for 

 1896, page 164. 



The hay crop of 1849 was 13,838,642 tons. Eleventh Census : Agri- 

 culture, page 90. 



