SKETCH OF MODERN AGRICULTURE 99 



Machinery. Among the more important inventions of agri- 

 cultiral machinery during this period the twine binder stands 

 preeminent. Except where the summers are dry, as in the semi- 

 arid plains of the West, and where, therefore, the harvesting 

 may be prolonged over a considerable period of time, and where 

 huge combination harvesters can be used, the harvesting of the 

 crop is a crucial point in {he economy of grain growing. The 

 farmer must ask himself, not how much wheat he can grow, 

 but how much he can harvest. The amount which he can prof- 

 itably grow is limited by the amount which it is physically pos- 

 sible for him to harvest. Before the invention of the twine binder 

 harvesting was a much greater problem than it has been since. 

 The amount which could profitably be grown was even more 

 strictly limited by the physical impossibility of harvesting it. 

 The invention of the twine binder, therefore, by increasing the 

 amount which a farmer could harvest, increased by that precise 

 amount the quantity which he could profitably grow. In other 

 words, it was the twine binder more than any other single machine 

 or implement that enabled the country to increase its production 

 of grain, especially wheat, during this period. The per capita 

 production of the country as a whole increased from about 

 5.6 bushels in 1860 to 9.2 bushels in 1880. There were also 

 numerous minor improvements, and the general substitution of 

 steam for horse power in the running of the threshing machines 

 during the period now under discussion. All these improve- 

 ments brought about a considerable increase in the efficiency of 

 the threshing machine. However, all these things put together 

 have not contributed so much toward the revolutionizing of the 

 grain-growing industry as did the twine binder. 



The roller process. Though not an agricultural process, the 

 roller process of manufacturing flour was also a great factor in the 

 agricultural expansion of this period. Flour made from spring 

 wheat by the old process was so inferior in quality that many of 



