THE NEW AGRICULTURE 3 



sown broadcast by hand, as in Bible days. Reaping was still 

 done with the sickle and the cradle, with little improvement since 

 early history (Figs, i a, i b, 2, and 3). Hay was mowed with a 

 scythe and collected with a hand rake, and a wooden stick 

 served as a fork for pitching it upon the stack. 



The first epoch-making scientific discovery relating to agri- 

 cultural practice was made by the German chemist Liebig 

 (Fig. 4) and was first announced in 1840. Liebig showed where 



FIG. 3. A modern wheat-heading-and-threshing machine 



The power is furnished in this case by thirty-three mules. The threshed wheat is left in 

 bags ready for market 



and how plants obtain their food and how wornout soil can be 

 restored to productiveness by the use of artificial fertilizers. 



In 1845 the people of the United States did not raise enough 

 wheat for their bread. At that time the production was only 

 4.33 bushels for each person. In 1859 the production had been 

 increased to 5.6 bushels for each person ; in 1869, to 7.5 bushels ; 

 and in 1879, to 9.2 bushels. In 1830 it required three hours of 

 man's labor to produce a bushel of wheat ; in 1896 it required 

 only ten minutes. In 1850 the labor represented in a bushel 

 of corn was four and a half hours ; by 1 894 this had been 



