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. 
Drawbar rating 
of engine (horsepower). 
Cylinder-oil consumptit a 
per hour. 
12 
15 
20 
22 
25 
30 
40 
First year: 
Per engine 
gallons.. 
0.168 
0.267 
0. 291 
0.302 
0.325 
0.401 
0.424 
Per drawbar horsepower . . 
do.... 
.014 
.0178 
.0145 
.0137 
.013 
.0134 
.0106 
Second rear: 
Per engine 
do.... 
.280 
.282 
.276 
.408 
.302 
.338 
.477 
Per drawbar horsepower. . 
do.... 
.0233 
.0188 
.0138 
. 0185 
.012 
.0112 
.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 comparative^ 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 show^s the average number of acres plowed per hour 
by tractors of different ratings on farms in North Dakota. These 
