12 
BULLETIN" 174, U. S. DEPARTMENT OF AGRICULTURE. 
considered as evidence that the estimated life of the tractor, as fur- 
nished hy the tractor owners reporting, is too high. 
Table IV. — Service rendered annually by tractors on farms in North Dakota and other 
States ivest of the Mississippi River, showing the length of life as estimated by the 
owners. 
[Arranged according to the opinions of owners as to the tractor's desirability as an investment.] 
ts the State of North Dakota. 
Result of investment as reported 
by owners. 
Men having one season's experi- 
ence: 
Profitable 
Unprofitable 
Men having two seasons' experi- 
ence: 
Profitable 
Unprofitable 
Men having three seasons' expe- 
rience: 
Profitable 
Unprofitable 
Men having four seasons' expe- 
rience: 
Profitable 
Unprofitable 
Average 
annual 
use. 
Days. 
87.1 
69.2 
97.3 
76.6 
85.2 
75.6 
92.5 
73.4 
Hours in field per 
dav. 
Spent. 
12.5 
12.4 
13.1 
12.9 
12.6 
12.0 
Lost. 
1.2 
2.1 
1.4 
2.7 
1.5 
2.7 
1.6 
2.8 
Esti- 
mated 
average 
life of 
tractor. 
Years. 
8.5 
5.0 
8.8 
4.9 
8.8 
5.4 
8.7 
5.9 
Number 
averaged 
108 
106 
73 
L54 
25 
Farms where night 
work was reported. 
Percent- 
age of all 
tractors. 
14.6 
13.7 
23.1 
10.7 
30.0 
12.9 
10.0 
8.0 
Average 
number 
of nights 
operated 
per year. 
31.8 
12.9 
26.9 
16.0 
17.3 
11.7 
60.0 
22.5 
In All States West of the Mississippi River except North Dakota. 
one season's experi- 
Men havinj 
ence: 
Profitable 
Unprofitable 
Men having two seasons' expe- 
rience: 
Profitable 
Unprofitable 
Men having three seasons' expe- 
rience: 
Profitable 
Unprofitable 
Men having four seasons' expe- 
rience: 
Profitable 
Unprofitable 
105.8 
77.9 
11.4 
11.5 
1.3 
2.2 
10.2 
6.4 
356 
178 
21.3 
16.5 
102.1 
73.9 
11.7 
11.8 
1.4 
2.2 
9.7 
J.0 
177 
183 
28.6 
16.0 
98.9 
73.0 
11.6 
11.6 
1.4 
2.5 
9.9 
5.7 
80 
69 
16.9 
5.2 
93.5 
65.2 
11.6 
11.4 
1.6 
2.6 
9.3 
5.9 
35 
48 
10.7 
7=1 
26.5 
13.7 
.34.7 
22,2 
38.9 
18.3 
22.0 
38.3 
To judge hy the estimates, the average life of a tractor in North 
Dakota is approximately only 6 years, while the average estimated 
life in other States is about 8 years. It is believed, however, that in 
the case of estimates on the life of tractors for States other than 
North Dakota, some allowance must be made for the fact, already 
mentioned, that most of these estimates are based entirely on the 
owner's personal experience, which the figures show has been a 
short one for 80 per cent of the men reporting, whereas for North 
Dakota the figures are to a great extent based on observation of 
neighboring tractors as well. 
