234 POWER AND THE PLOW 



numbers, and in warm countries where the animal motor is 

 very inefficient, only one course is possible the utilization 

 of the mechanical motor for propulsion as well as for the opera- 

 tion of machines. In temperate regions, however, especially 

 where fields are small, and where moderate work the year round 

 is actually essential to the health of animals, the advisability 

 of mechanical traction in small units is more open to question. 



The soil is the workshop of the plow or the cultivator. The 

 arable earth forms the raw material to be worked, but, contrary 

 to what happens in the factory, the machine must go to the 

 material and work it up in its original place. If the latter work 

 can be so regulated as to require a constant amount of power, 

 a mechanical motor must, by its nature, be wonderfully efficient. 



Distinction must be made between the effective work of the 

 farm machine and its propulsion over the ground. As the 

 movement of the machine is only an accessory operation and 

 not productive, it is one on which the least possible effort 

 should be expanded. The productive force is that which cuts 

 and turns the earth. With the animal motor this distinction 

 is unnecessary, since the only movement of which the horse 

 is capable i. e. 9 forward or linear motion has had to suffice 

 for both the propelling and operation of the machine. Advo- 

 cates of the fourth system insist that non-recognition of this 

 distinction, and the consequent efforts merely to substitute 

 a mechanical tractor for an animate motor, have delayed the 

 solution of the problem of "moto-culture" ten or fifteen years. 



To fit the foregoing analysis, a cultivator is being equipped 

 with rotary working parts operated by a mechanical motor, 

 animals being used to draw it. The force required to move 

 it over the ground should not be great, as Yankee ingenuity 

 has demonstrated in adapting mechanical power to harvesting 

 in small units. The harvester, or binder, for instance, weighs 

 only 1500 to 1800 Ibs., which is not an excessive load for one 

 large horse, and a very light load for two. A gasoline motor, 

 either mounted on the frame or carried on a separate truck and 



