POWER ON THE FARM 



393 



of tractor work: fuel, oil, grease repairs depreciation, man 

 labor, and interest on money invested. 



In some investigations it has been found that two and 

 one-half to three and one-half gallons of fuel is an average 

 amount consumed in plowing one acre. This amount varies 

 with the operator, kind of fuel (gasoline or kerosene) depth of 

 plowing, kind and condition of soil, sharpness and adjustment 

 of plows, and underloading or overloading of the tractor. 

 -,The quantity of lubricating oil per acre may be figured 



FIG. 24$. A caterpillar tracti 



drawing a wagon and hay loader. (Cleveland 

 Tractor Co.) 



at three-fifths of a quart, and the cup grease at about one 

 pound per day or about one cent per acre. 



Ten to twenty cents per acre should be allowed for re- 

 pairs. Depreciation should be calculated at from thirty to 

 forty cents per acre. At four dollars per day for an operator 

 the cost per acre for the two-plow to four-plow outfits is about 

 sixty-five cents down to thirty -seven cents. 



The interest ^on the investment cannot be calculated on 

 the acre basis unless it is kno\An how many acres will be 

 plowed each year. It should be counted at about seventy- 

 five cents to one dollar per acre if the tractor is used for plow- 

 ing say forty-five to sixty days in each year, with no other 

 work to its credit. 



