FARM EXPERIENCE WITH THE TRACTOR. 



23 



LUBRICATING OIL. 



The quantity of lubricating oil required is another question of con- 

 siderable importance in connection with the operation of a tractor. 

 The average consumption per hour for tractors of different ratings is 

 shown in Table XIII. The increase in the amount of oil consumed 

 shows closer relation to the increase in the horsepower of the tractor 

 than did the fuel, although there are some irregularities, most of 

 which are explained by the remarks in connection with Table XI. 

 The price per gallon for lubricating oil not only varies in different 

 sections, but varies according to quality. The prices paid per gallon 

 range from 25 to 60 cents, the average price being about 40 cents. 



Table XIII. — Average consumption of cylinder oil per hour for different sizes of farm 

 engines and per drawbar horsepower hour. 



Cylinder-oil consumption per hour. 



Drawbar rating of engine (horsepower). 



12 15 



20 22 



First year: 



Per engine gallons. . 



Per drawbar horsepower do 



Second year: 



Per engine do 



Per drawbar horsepower do 



0.168 

 .014 



.280 

 . 0233 



0.267 

 .0178 J 



.282 

 .0188 



0.291 

 .0145 



.276 

 .0138 



0. 302 

 .0137 



.408 

 . 01S5 



0.325 

 .013 



.302 

 .012 



0.401 

 .0134 



.338 

 .0112 



0.424 

 .0106 



.477- 

 .0119 



The figures shown include all lubricating oil used, whether for cylin- 

 ders or other purposes, but do not include the cost of greases. This is 

 a comparatively small item, and it is difficult to obtain figures for it. 



CROSS SECTION OF PLOWS DRAWN AND AREA PLOWED BY TRACTORS. 



The cross section of plows drawn by tractors of different ratings is 

 given in Table XIV, showing that the area of the cross section of 

 plows drawn by the different sizes of tractors bears a close relation to 

 the quantity of fuel used. In this table it will also be seen that the 

 20 and 25 horsepower outfits do not pull plows commensurate with 

 their ratings, to judge by the loads drawn by the other tractors. 

 Attention is invited to the remarks made in connection with Table XI 

 regarding the rating of tractors in the 20 and 25 horsepower classes 

 and the percentage of gasoline and kerosene tractors in the remainder 

 (p. 22). The area of the cross section of plows drawn by the tractors 

 which have been used two seasons is generally less than the area the 

 first season. There are several possible explanations of this, but the 

 most probable one is believed to be that before the end of the second 

 season many owners have learned that it does not pay to overload a 

 tractor. 



Table XIV also shows the average number of acres plowed per hour 

 by tractors of different ratings on farms in North Dakota. These 



