14 AGRICULTURAL ENGINEERING 



and animals of the farm is essential to those who would make 

 good farming the aim of their life's work, and these subjects 

 should be carefully studied by the agricultural student. 

 But the study of agricultural engineering is quite as impor- 

 tant in assuring that efficiency in farm management which 

 results in the greatest and most permanent benefits. 



The truth of the foregoing statement is better understood 

 when one learns that the producing capacity or earning ability 

 of the farm worker is in direct proportion to the amount of 

 power one is able to control. There was a time when man 

 tilled the soil by his own individual efforts, depending upon 

 no other source of power than the strength of his own body. 

 Later, one beast per worker was pressed into service to draw 

 suitable implements. Still later, two animals were used, and 

 development has continued, until at the present time we have 

 reached the "age of four-horse farming." In other words, 

 the four-horse team is now recognized as the most efficient 

 one for field work. 



Man as a motor or producer of power is able to develop 

 about one-eighth of one horsepower. When use was made 

 of one good horse per worker, man's labor capacity was 

 increased eightfold. When four horses became the unit, 

 his efficiency was multiplied about 32 times. Just now there 

 is a desire to increase still further the amount of power for 

 each farm worker, by the use of powerful tractors or engines 

 arranged for drawing and operating farm implements. 



The application of power to farm operations, which must 

 come mainly through the use of machinery, is only one branch 

 of agricultural engineering. Some element of agricultural 

 engineering is concerned in nearly every department of 

 agricultural endeavor. It serves man in one or both of 

 two ways : (1) By making it possible to increase the capacity 

 of the worker, as just explained; and (2) by making condi- 



